Viiiini<-iu> Unnl« NoicCo.NtnvAorU-
A
History of the Jetties
AT THE
MOUTH OF THE MISSISSIPPI RIVER.
BY
E. L. COETHELL, C. E.,
CHIEr A8SI?TA2TT AND RESIDENT ENGINEER DURING TBEIR CONSTRUCTION.
NEW YORK ;
JOHN WILEY & SONS,
15 Astok Place.
18S0
COPTRIGIIT,
1880,
ßy E. L. COETHELL.
fRÊSS CF J. J. LITTLE ico.,
NÛ3. 0 TO 30 ASTOS PLACE, NEW TOR*.
DEDICATION.
To Ulysses S. Grant and Eutherford B. Hayes, Presidents
of the United States ; to the Heads of Departments, and to
the Senators and Eepresentatives of our National Congress,
through whose wise statesmanship, sound judgment and
equal justice, those laws were enacted and executed under
which the jetties at the mouth of the Mississippi Eiver
have achieved beneficial results of svch vast importance to
the welfare of our whole country, this volume is respectfully
dedicated by
The Author.
Office of JAS. B. EADS, Civil Engineer,
Boom 302, Chamber of Commerce Building, Third and Chestnut Sts.,
St. Louis, September 15,1880.
To Mr. E. L. Corthell, Civil Engiiwer. '
My Dear Sir :—I have read the manuscript of your history
of the jetties as carefully as my numerous and pressing en¬
gagements will permit, and I believe that it gives a correct,
careful, and complete account of the various matters con¬
nected with the enterprise, from its inception to its comple¬
tion, including full détails of the construction of the work.
The very important position which you held during the
entire construction of the jetties, and the valuable services
rendered by you in securing their success, inspire the hope
that your literary labors in connection with them will be
fully appreciated and rewarded.
PREFACE.
Hating been connected with the jetties at the mouth of
the Mississippi River for five years, as chief assistant and
resident engineer, I place the history of the enterprise on
record, being led to do so not only by a conviction of duty,
but by an affection for the great work on which I have been
engaged.
I do it not only for those who have been personally and
professionally interested in the jetties, but also for the in¬
habitants of the great valley, whose agricultural and com¬
mercial interests have been so largely benefited by their
construction, and still further, for every human being on this
continent and in the old world, to whom directly or indi¬
rectly may come the beneficent influences of the Mississippi
jetties.
E. L. coethell.
COÎiTENTS.
CHAPTER I.
PAGE
Introduction—The Hiver—Its Tributaries—Necessity for a Commercial
Outlet 1
CHAPTER IL
The Delta—History—Growth—Regimen 8
CHAPTER III.
Attempts to Improve Navigation at the Mouth of the Mississippi River—
Port St. Philip Canal Project—Biographical 17
CHAPTER IV.
Civil versus Military Engineers—Canal and Jetties—Discussions before
Congress—Appointment of Commission 35
CHAPTER V.
European Jetties 50
CHAPTER VI.
Report of the Board—Passage of the Act Authorizing the Construction of
Jetties at South Pass 60
ix
X
CONTEXTS.
CHAPTER VIL
PAGE
South Pass—Location of Jetties—Construction 69
CHAPTER VIH.
Construction—Description and Progress of Works at the Mouth of South
Pass, from June, 1875, to June, 1876 81
CHAPTER IX.
Advisory Board—rResults of Works—Financial Embarrassments—Govern¬
ment Engineers 92
CHAPTER X.
Head of the Passes—General Conditions Described 110
CHAPTER XI.
Details and Results of Works at the Head of the South Pass, 1876-1877.. 123
CHAPTER XII.
Development of Jetty Channel—Twenty Feet Channel Obtained—Effects
of Wing Dams 142
CHAPTER XIII.
Financial Embarrassments—Description of the Dredge-Boat O. W. R.
Bayley—Twenty-two Feet Channel Secured—Report of Commission
—Congressional Action 155
CHAPTER XIV.
Head of the Passes—Works Described—Final Results Given, 1877-1879 .. 175
CHAPTER XV.
Work Delayed by Yellow Fever—Consolidation of Sea Ends of Jetties by
Concrete and Crib Work—Report of Commission and Passage of
Amendatory Act 186
CONTENTS. si
CHAPTEE XVI.
PAGE
Final Results 210
CHAPTER XVII.
Permanency oí Works and Results 224
CHAPTER XVIII.
Conclusion 230
APPENDIX.
Pace nî®®
No. ^ Paçe
I. Extracts from Report upon Fort St. Philip Canal and Jet¬
ties by Board of Engineers, January 13, 1874 243 21
II. Report of Board of Engineers, advocating Construction
of Jetties, January 13, 1875 251 60
III. The Grant from the United States, authorizing the Con¬
struction of Jetties at South Pass 231 65
IV. Proceedings of the Advisory Board of Engineers 266 92
V. Estimate of the Detailed Cost of One Cord of Mattress-
work 275 91
VI. Table of Depths in line of deepest Water in the Channel
at the Mouth of South Pass 276 94, 212
VII. Table of Interruptions to Contour Lines in Channel.... 277 94, 212
VIII. Letter of Mr. Eads to the Secretary of War, calling at¬
tention to Offlcial Interference with his work. May
23, 1876 278 103
IX. Estimate of the Detailed Cost of Construction of Dam
No. I., at Head of South Pass 296 127
X. Report upon Jetties and Questions relating to the Head
of the Passes, by Board of Engineers, Nov. 19, 1876. 297 142
XL Letter of Mr. Eads to the Secretary of War, asking to be
furnished promptly with facts relating to his work,
April 19, 1877 304 107
XII. Letter of the Secretary of War to Congress, submitting
a Statement of Mr. Eads relative to Work and Pay¬
ments, May 14, 1878 309 168
XIH. Letter of Gon. A. A. Humphreys, Chief of Engineers,
•U.S.A., to Hon. E. W. Robertson, to show that
Jetties were unsuccessful. May 1, 1878 320 171
XIV. Review by Mr. Eads of the Letter of Gen. Humphreys,
June 1,1878 325 172
XV. Estimate of Detailed Cost of the Construction of the
Sill across Pass à Loutre 331 177
XVI. Final Estimate of Materials in all Works 332 183,209
XVII. Table of Navigable Depths that can be carried through
each 2,000 feet in Jetty Channel 333 192, 212
XVIII. Report of a Board of Engineers, January 23, 1879 335 191
xiii
xiv CONTENTS.
XIX. Review by Mr. Eads of the Report of the Board, of Jan¬
uary 23, 1879 857 194
XX. Amendatory Act, March 3, 1879 368 202
XXI. Table showing Scour and Deposit seaward of Jetties on
Area of 178 Acres, 1875-1879 370 220
XXII. Table showing Changes in Gulf Bottom, on Fan-shaped
Area 372 221
XXIII. Table showing Rate of subsidence of Concrete Blocks... 374 228
XXIV. Record of Navigation of South Pass 375 235
XXV. Employés deserving honorable mention 376 240
XXVI. Geographical, Hydrometrieal, Meteorological 377
INDEX OF ILLUSTRATIONS.
FULL-PAGE PLATES.
DESCRIPTION.
See
Facing Text
No. Page Page
1. Basin of the Mississippi River 4 4
2. Ancient Map of the Delta of the Mississippi River 8 8
3. Cross-Sections of the River and Passes 14 14
4. Map of the Delta of the Mississippi River from the U. S. Coast
Survey 16 16
5. Map of the Deita of the Danube and the Sulina Mouth, and
Cross-Sections of the Jetties 52 52
6. Mattress Ways, in Plan and Elevation 78 78
7. Mattress, in Plan and Section 80 80
8. Sheet Piling and Driver ; Two Elevations 84 84
9. East Jetty, Cross-Section 86 86
10. Jetty Channel, Comparative Cross-Sections, 1875-1876 94 94
11. Proflie of Bar, Comparative, 1875-1876 94 94
12. East, Dyke, Head of the Passes, Cross-Section 114 114
12. Dam No. 1. " " " 114 124
12. Lighthouse Dyke, " " " 114 178
13. Island Dyke, " " " 136 181
13. Island Dam, " " " 136 135
13. Upper Dam, " " " 136 182
14. Dam at Grand Bayou, Cross-Section 140 140
15. Chart of Entrance Channel, Head of South Pass, April 25,1880. 184 184
16. Concrete Mixer, Plan 190 189
17. East Jetty, Two Cross-Sections 202 202
18. Pier Head, East Jetty, Cross-Section 208 208
19. Bird's-Eye View of Port Eads and Jetties 210 210
20. Jetty Channel, Comparative Cross-Sections, 1875-1879 212 212
21. Profile of Bar, Comparative, 1875-1879 212 212
22. Graphical Exhibition of Work Done and Works Obtained at Jet¬
ties 214 213
XV
XVI LIST OF ILLUSTRATIONS.
See
Pacing Text
No. Page Page
33. Comparative Chart of an Area of 178 Acres Seaward of Jetties,
1875-1879 220 220
34. Comparative Chart of Fan-Shaped Area Seaward of Jetties,
1876-1879 220 220
FOLDED PLATES.
DESCRIPTION.
No. See Text Page
A. Map of the Mouth of South Pass, U. S. Coast Survey, 1875 71
B. Map of the Head of the Passes, U. S. Coast Survey, 1875 112
C. Concrete Mixer, End Elevation 189
D. Concrete Mixer, Side Elevation 189
E. Concrete Mould (Plan and Sections) and Palmetto Crib (Plan and
Sections) 190 and 207
F. Map of the Mouth of South Pass, U. S. Engineers, 1879 311
G-. Map of the Mouth of South Pass, Comparative, 1875-1879 213
H. Map of the Head of the Passes, U. S. Engineers, 1879 132
J. Map of the Head of the Passes, Comparative, 1875-1879 183
K. Plot of Curves showing Changes in Seaward Face of the Bar—Gauge
of the Mississippi River at Carrollton—Currents—Sediments and
Tides at Port Eads, and Prism of Material Removed in Jetty
Channel 217
The Mississippi Jetties.
CHAPTER L
esteoduction—the ritee—its teibutaeies—necessity foe a
commercial outlet.
There is scarcely a civilized nation in tlie world whose in¬
terests are not more or less deeply affected by the Missis¬
sippi Jetties.
They have created, and will forever maintain, a deep and
safe outlet for the most important river system on the face of
the globe.
Some idea of the grandeur and magnitude of the valley,
whose commerce has been released by the completion of the
Jetties, may be formed from the following brief extracts from
an address delivered by their projector, thirteen years ago,
at the request of the Merchants' Exchange of St. Louis, to
the River and Harbor Convention :
" The improvement of the Mississippi River involves the
contemplation of one of the sublimest physical wonders of
a beneficent Creator. The boundless reservoirs which supply
its channels through such long periods of the year, and make
it so valuable to man, and which, if opened simultaneously,
would overwhelm the valley and mar its usefulness, are, with
that thoughtful care, which orders all things wisely, unlocked
in beautiful succession, month after month, by the touch of
Spring, as she leaves her home in the tropics to bless the
colder regions of the North.
" This giant stream, with its head shrouded in Arctic snows,
1
2
THE MISSISSIPPI JETTIES.
and embracing half a continent in tbe hundred thonsand
miles of its curious net-work, and coursing its majestic way
to tbe Southern gulf, through lands so fertile that human
ingenuity is overtaxed to harvest their productiveness, has
been given by its Immortal Architect into the jealous keeping
of this Republic.
"The garden, which it beautifies and enriches, contains
seven hundred and sixty-eight million acres of the finest lands
on the face of the globe ; enough to make more than one hun¬
dred and fifty States as large as Massachusetts ; acres of the
choicest soil in profusion, sufficient to duplicate England
twenty-four times over ; more territory than the areas of
Great Britain, France, Spain, Austria, Prussia, European
Turkey and the Italian Peninsula combined.
" If peopled as Belgium and the Netherlands are, and with
not half the danger of famine, it would contain four hundred
millions of souls—nearly one third of the entire popula¬
tion of the world. Human comprehension cannot grasp the
grandeur of such an empire. Human wisdom cannot estimate
the wonderful value of such an inheritance.
" This great valley lies between those parallels of latitude
that are known to be most conducive to health and to the de¬
velopment of the mental and physical energies of man. In
its capacity to produce the cereals, grasses, cotton, sugar, to¬
bacco, hemp, vegetables and fruits of every kind ; in the
richness and variety of its mineral wealth, the grandeur and
value of its forests, its inexhaustible quarries ; in a word, in
all the natural resources which conspire to increase the wealth
and power of a people, the bounty of Providence has been
most wonderfully manifested.
" The stream which in every direction penetrates this fa¬
vored region, and is the grandest natural feature of North
America, holds in its embrace the destinies of the American
people. Sooner or later it must give to the dwellers within
INTBODUCTION.
this valley, power and dominion over this whole immense
continent.
" It is the great arterial system of this Eepuhlic. Its vital
branches and wonderful reticulations permeate and envelop
the great body of our country, giving unity to amplitude,
value to productiveness, and to the State, resistless power and
an existence as enduring as human liberty and intelligence.
Through its copious channels, for all time to come, are des¬
tined to circulate the sustenance and abundance of its
people."
The commerce of this great empire will, in time, certainly
exceed that of any other in Christendom ; and the mouth of
the great river constitutes the only natural gateway through
which the immense products of that region will henceforth
find their way to the various nations of the earth.
These facts are quite sufficieùt to clothe with deep interest
everything relating to the removal of the natural obstructions
which have hitherto imprisoned the vast and increasing com¬
merce of the Mississippi Valley.
The motives, however, which have prompted the publica¬
tion of this history of the Jetties, are—their novelty as an
engineering work ; the peculiar circumstances surrounding
their inception ; the interesting scientific controversy which
attended every step of their progress, and the highly instruc¬
tive results which they have furnished to the science of Civil
Engineering.
A brief description of the chief drainage basins of the
Mississippi Valley will enable the reader to form a better
idea of the immense volume of water and earthy matters dis¬
charged at the mouth of the river, which had to be placed
under complete control by the works of improvement to
insure the effectiveness of the Jetties and the permanency of
the new channel.
Each principal tributary of the Mississippi River has its
4
THE MISSISSIPPI JETTIES.
distinctive characteristics, in reference to extent of territory
drained, rainfall, velocity and volume of its water, and its al¬
luvions.
■ The Missouri rises on the eastern slope of the Eocky
Mountains. It drains hy its upper branches the distant Ter¬
ritories of Wyoming and Montana and a portion of the Brit¬
ish Possessions. Its tributaries water a fertile country,
which for ages has been the home of the Indian and the
buffalo, but is now fast filling up with a hardy and industri¬
ous population, and promises to become the future granary of
the continent. It is rich, not only in agricultural products,
but in timber, coal, iron, and precious metals. Navigable for
more than two thousand miles, the Missouri fiows through a
country of magnificent mountain scenery, "America's Won¬
derland." After its confluence with the Yellowstone it be¬
comes a deep stream. It flows through Dakota, Nebraska,
Kansas and Missouri, and throws its turbid Avaters into the
Mississippi above St. Louis. Its basin is the greatest in ex¬
tent of all the tributaries, and its length is nearly three
thousand miles, exceeding the entire length of the Missis¬
sippi, from Lake Itasca to the Gulf of Mexico.
The Ohio, though its length is less than that of the Mis¬
souri and its drainage area much smaller, discharges a larger
volume, on account of the greater rainfall of its basin. It
fiows through one of the most fertile and populous regions in
America. From its sources in the Appalachians to its con¬
fluence with the Mississippi at Cairo, its banks are covered
with thriving cities, numerous factories and productive farms.
It floAYS through a rich soil, underlaid with limestone and
abounding in extensive mines of coal and iron, the products
of which form a large part of its commerce.
The Arkansas takes its rise in the mountains of Colorado,
among whose melting snows it finds its source. For the first
one hundred and fifty miles it is a rushing torrent, leaping in
PLATE I.
INTEODUCTION.
5
great falls down the mountain slopes, wearing into the quartz,
and carrying in its waters the golden grains that have drawn
representatives of all nations to the placer mines along its
banks and tributary gulches. At Cañón City, Colorado, it
is two hundred feet wide and fifty feet deep, and breaks
through a range of mountains, forming the walls of the
" Grand Canon," over two thousand feet in height. After
entering the State of Kansas, it passes through what was
known in the old geographies as the " Great American Des¬
ert," a vast plain, whose rich soil a rapidly increasing and
industrious population are converting into great fields of
grain. Thence it flows down through the fertile Indian Ter¬
ritory and the State of Arkansas, and unites with the Missis¬
sippi about seven hundred miles above its mouth.
The Bed Hiver has its source in a series of springs on the
east side of the " Llano Estacado "—the Staked Plain—in
Western Texas. This table-land is two thousand five hun¬
dred feet above sea level, and is mentioned by geographers
and explorers as a sterile desert, but it promises to become
the great cattle raising district of the country. This river
flows through the rich cotton and grain lands of Western
Texas, forming the boundary line between that State and the
Indian Territory. It drains one of the most fertile tracts in
America, the climate of which is salubrious, being tempered
by the constant breezes from the prairies ; the rainfall is suffi¬
cient for all agricultural products ; the soil is rich, and the
timber abundant.
Two other tributaries, though of less importance, are wor¬
thy of mention—the St. Francis and the Yazoo ; the former west
and the latter east of the main river. Both rivers flow for
nearly their entire length through a rich alluvion, formed by
the deposits from successive overflows of the Mississippi
Eiver. Each basin abounds in timber, and its soil is ex¬
tremely fertile.
6
THE MISSISSIPPI JETTIES.
The Mississippi, rising in Northern Minnesota, flows
through a rich grain and lumber country, and furnishes an
abundant water power to the milling towns of that State.
Passing these, and carrying with it their products of grain
and lumber, it is joined above St. Louis by the muddy flood
of the Missouri, bearing forward the grain and provisions of
the great Northwest : thence it flows past rich cities and
thriving towns, until the Ohio adds its volume of water and
its fleet of steamers loaded with provisions, iron, coal, and
other products, and soon the heavily loaded cotton carriers
become a feature of the stream. The Arkansas, the Red, and
many smaller branches swell the volume of discharge to
more than one million cubic feet every second, and the great
river rolls, a turbid flood, down through the sugar estates,
the orange groves and the rice fields of Southern Louisiana.
There was a limit, scarcely reaching the center of the Val¬
ley, beyond which, for the want of a deep channel at the mouth
of the river, it was unprofitable to raise cereals. All the in¬
land wealth of agriculture and minerals was land-locked by
an obstruction that had baffled every effort for its removal.
This natural blockade of commerce had forced the construc¬
tion of many expensive lines of railroad over the Alleghany
Mountains, from the West, Northwest, and even the South¬
west, to the Atlantic seaboard.
Among the many reasons for a constantly increasing de¬
mand for a better outlet were. First—The rapid development
of the Valley, and the impossibility of carrying its products
by artificial lines of transportation.
Second—The improvements that had been made in the in¬
land navigation of the river and its tributaries, on which for
many years large sums of money had been expended by the
Government ; and.
Third—The increase in the size and draft of ocean vessels
and the radical change which has taken place in ocean trans-
rSTKODUCTION.
7
portation witliin tlie last few years, by which sailing vessels
of small tonnage have been largely superseded by steamships
of great capacity and speed.
The following facts are given simply as illustrations of the
necessity for improving the outlet of the river.
In February, 1859, a committee from the New Orleans
Chamber of Commerce visited the mouth of the river and
reported, that the value of merchandise delayed at the bar
was — for exportation, $5,367,339 ; and for importation,
$2,000,000.
In this estimate no account was taken of the value of the
vessels, nor of any but the leading articles of produce, nor of
the cargoes of ships which had cleared and were ready for
sea, but whose commanders deemed it prudent to remain at
the wharves at New Orleans, until there was a prospect of
getting over the bar without detention. One item of mer¬
chandise delayed at the bar was nearly 72,000 bales of cot¬
ton. Many of the vessels had been detained for weeks. A
month later, there were thirty-five vessels inside the bar
waiting to go out, three on the bars, and seventeen outside
at anchor waiting to be towed in. From 1872 to 1877 inclu¬
sive, 417 vessels grounded and were detained at the mouth
of the river, with a total detention of 12,467 hours. It was
during this period that the Government made its most stren¬
uous exertions to open the channel through the bars.
CHAPTER IL
the delta—history—growth—^regimen.
The following ancient and unique map and description,
while perhaps not accurate in geographic or historic detail,
will exhibit the general features of the delta, a century and
half ago.
"An Account of the river Mississippi, with an accurate New MAP of
that river from the sea to Bayagoulas.
HE River Mississippi is, next to that of St. Lawrence, the
chief of all the rivers in North America, and by its easy navi¬
gation, the many fine rivers that fall into it, one of which is the
Ohio, and the fruitfulness of the country on each side of it, it is
preferable even to that of St. Lawrence. It takes its name from an
Indian word which means, The antient Father of Rivers. It was
first discovered in 1654, by our countryman Col. Wood ; and, soon
after the restoration, King Charles made a grant of the country on
each side of its mouth, by which it empties itself into the Bay of
Mexico, which grant was afterwards purchased by Dr. Cox of New
Jersey, who sent two ships, and made a settlement upon it, but was
not able to pursue his projects ; and therefore the French, who had
never discovered the mouth of this river till 1699, began in 1717,
to make a settlement upon it, which they have since pursued with
great vigour and success, as we now feel by their spiriting up and
supporting the Cherokees against us. (See our Vol. for 1747, p.
From other sources we gather information which somewhat
conflicts with the statements made in the above descrip-
568.)"
8
w
u
I-
<
_l
a.
1^1 F, X / 6'
THE DELTA.
9
tion. There is no doubt that the Spaniards discovered and
possessed the delta long before the English or French occu¬
pied it. The records of their discoveries bear date of the
sixteenth century.
In all the French or English records and charts of the in¬
terior of the country, of a date prior to 1680, no sign of the
Mississippi Eiver is found, although the unfortunate but dar¬
ing De Soto was the first to make it a matter of history, by
his enthusiastic description of the great river, as standing on
the overlooking heights near Memphis, it suddenly flashed
upon his sight in all its grandeur. This was in 1539, but the
river and the delta were not thoroughly explored until 1684,
when La Salle, pursuing his explorations from the upper
tributaries, came down the river and encamped on the pres¬
ent site of the City of New Orleans. On the 6th of April, of
that year, he arrived at the head of the passes, and found
at that time three great outlets. He took possession of the
mouth of the river and all its tributaries, and maintained the
claim from Pittsburg to the Eocky Mountains. In honor of
Louis XIV., the king, he called this vast possession, Louisi¬
ana, and named the river St. Louis. De Soto had called it
"Espiritu Santo." The Spaniards knew it as "Escondido
Eio Grande." The Indians gave it various names, one of
which was " Mechacebe " from " Mecha " great and " œbe "
river. This the French corrupted into " Mississippi."
In reference to the changes in the conditions of the Missis¬
sippi Eiver in the past ages, we have but little reliable in¬
formation. While this may not be of importance to a
complete understanding of the subject, yet it is of interest.
At present the Mississippi is essentially a muddy river, but
there is no doubt that formerly it was comparatively a clear
stream. There is every indication that flve thousand years
ago, a spur of the Ozark Mountains, between St. Louis and
Cairo, presented a barrier to the river three hundred feet
10
THE MISSISSIPPI JETTIES.
high, and that the surface of the great lake thus formed was
at the level of Lake Michigan, and connected with it ; that
the extensive prairies of Indiana, Illinois, Iowa and Missouri
were once covered by this inland sea, and that the rich soil,
which characterizes these States, was formed by the sediment
brought down by the Missouri and other tributaries. There
are also indications that the Ohio Biver was obstructed by
similar mountain ranges. It was not until these obstructions
were worn away, as the St. Lawrence is now slowly wearing
away its obstruction at Niagara Falls, that this vast area
was drained of its waters. Then the rivers fell into their nat¬
ural chaimels. The immense amount of sedimentary matter
from the Missouri and Ohio came down through the present
alluvial region of the main Mississippi, and commenced that
rapid and extensive delta formation which we now find at the
mouth of the river, after filling up the estuary, about thirty
miles wide, which extended more than one thousand miles
into the country.
Judging from the mean annual growth of the delta into the
gulf, since the date of the earliest reliable charts, it would
seem to be not much over 4,400 years old.
The original mouth of the estuary of the Mississippi could
not have been far from the coast line east and west of it, and
thus the prolongation of the river into the gulf has been
about two hundred and twenty miles. Until a recent age, it
had advanced in comparatively deep water, until it reached
the head of the passes, and from that point the descent into
the gulf is much more rapid. The late examinations of the
United States Coast Survey show that, nine miles off the
mouth of South Pass, the water is six hundred feet deep, and
twenty-five miles off, three thousand feet deep, while depths
of two and a half miles have been found in some portions of
the gulf.
The process of the delta formation should be described.
THE DELTA.
11
and the causes that produced the obstructions to commerce
at the mouth of the river should be briefly stated, that the
history of the attempts to remove them may be intelligible,
and the discussions that followed these attempts, looking to a
permanent improvement of the channel, may be understood.
This important fact is before us at the outset, that, while the
depths of water in the river are from fifty to two hundred
feet, yet between the river and the Gulf of Mexico, around
the whole cordon of the delta, there is a shoal ground over
which, in its natural condition, the maximum depth is not over
thirteen feet.
From the confluence of its last tributary—the Eed River—
three hundred miles above its mouth, the Mississippi is deep
and comparatively narrow. At New Orleans it has a depth of
more than one hundred and fifty feet, and a width of half a
mile. The deep and narrow channel extends to within fifteen
miles of the gulf, when it gradually widens to a mile and
three-quarters, and its depth diminishes to about thirty feet ;
it here separates into tliree channels or outlets, throwing
them out like tongues into the sea.
At the mouth of each of these passes the waters spread out
to the right and left over a full half circle. Between the
passes are wide, shallow embayments. The river is the car¬
rier to the sea of the washings from the mountain slopes, the
plains and prairies of the great valley. With the principles
that govern the flow of its waters, especially as far as they
relate to the sedimentary matter in them, we are directly con¬
cerned.
It may be stated as a well established fact, that other con¬
ditions being the same, the amount of sediment transported
depends upon the velocity of the current. The river is able
to carry a certain quantity of solid matter in suspension, and
if at any time it is not burdened with this amount, it will
pick it up from the bed and banks, but once loaded to the ca-
12
THE MISSISSIPPI JETTIES.
pacity given by its velocity, it refuses to take a greater bur¬
den, and flows against its banks and over its bed without
eroding them.
The river has power given it for work, just the same as
the waterfall has power to move the wheels, or the steam en¬
gine to accomplish mechanical effects ; the same principles of
dynamics govern all these forces. The river, by the velocity
of its current, has a constant power to transport solid matter
to the sea; the greater the velocity the greater the power.
There are, however, other minor causes at work. The ir¬
regular course of the river and its uneven bed, while they re¬
tard the currents by frictional resistance, assist in giving ver¬
tical motion to the particles of suspended mud and silt, as a
whirlwind by its upward motions often carries aloft heavy
substances and transports them long distances. Yet it is
also a fact, well proven, that even in the smooth, straight
artiflcial channels of canals and mill races, substances that
are heavier than the water will, if forced to the bottom, in a
short distance rise to the surface. It is a common occur¬
rence at times of flood river on the Mississippi, in places
where no irregularities exist, to see water come from near
the bottom to the surface, loaded with a heavier and coarser
sediment than any that is floating there.
Thus the river, by its horizontal currents and its vertical
eddies, by its whirls and boils, transports the mountains to
the sea. At first the rocks come tumbling down into the
creek and cañón beds ; broken by the fall, the dashing tor¬
rent rolls them onward, wearing off the sharp corners and
loosened portions, grinding the rocks into gravel, wearing the
gravel into sand, rolling over and over the sand from one bar
to another, until disintegrated, worn, and ground to an almost
impalpable powder, the river sweeps it out into the gulf, to
be distributed by its ceaseless currents over its vast basin.
Thus forever the river is at work, striving to maintain its
THE DELTA.
13
channel by transporting to the sea the solid matters -which
the rains pour into it through its numberless tributaries.
At extreme high "water the Mississippi Eiver transports to
the sea 1,210,000 cubic feet of water and 2,000 cubic feet of
sold earth in suspension per second.
At extreme low water the volume discharged is about 250,-
000 cubic feet per second, and the ratio of sediment to water
is then very small. It is during the flood season that the
bars at the mouths of the three passes are pushed out into
the gulf at the approximate rate of 300 feet per annum at
Southwest Pass, 260 at Pass à Loutre, and (formerly) 100
feet per annum at South Pass.
When the muddy waters leave the land's end at the mouth
of the passes, and begin to spread out over the submerged
banks and shoals forming in advance, the current, which has
all through the passes flowed at a rapid and uniform rate in
a deep and stable channel, gradually loses its velocity and
drops its load of sediment. As the flow of the water ex¬
pands more and more to the right and left, the depths in the
channel going seaward continually decrease, as the frictional
resistance increases, until the crest of the bar is reached,
where the depth is the least. At Southwest Pass the normal
depth is about 13 feet, at Pass à Loutre 11 feet, and at South
Pass 8 feet. This depth varies little during the year, or from
year to year, unless changes of importance occur in the pass
itself.
At South Pass the upward slope from the land's end to the
crest of the bar was at the rate of one foot in four hundred ;
the slope from the crest to the deep waters of the gulf was
one in sixty. The distance of the crest of the bars from the
land's end also varies with the volume of water flowing in
the pass. At Southwest Pass it is flve miles, and at South
Pass two and a quarter miles. The material composing the
bars is a very fine sand mixed with clay.
14
THE MISSISSIPPI JETTIES.
The gulf into -which the river pours its annual floods is a
great inland sea of salt water. The range of the tides is very
small, not averaging over fourteen inches, and along the face
of the delta they occur but once in a day. At flood river the
fresh -water pushes the salt water out of all the river chan¬
nels and passes, and away from the mouths of the passes,
even to the outermost crest of the bars, and then flows
through a bed of salt water, gradually widening until it be¬
comes a thin, light brown sheet, whose line of demarkation
with the green salt water is clearly defined and can be seen
many miles from land. The river thus continually pushes out
its bars into this almost tideless sea, which in turn by its
waves, tides and littoral currents, exerts a leveling and
eroding influence upon them, especially in low-water season.
To complete this general description it is necessary to
state a few facts of minor importance.
The range between high and low water of the lower Mis¬
sissippi is as follows : at the mouth of the Ohio it is 52 feet ;
at Natchez, 375 miles above its mouth, 51 feet ; at New Or¬
leans 16 feet, and at the head of the passes 2^ feet.
At Natchez, the fall per mile at high water is about 3.2
inches ; New Orleans to Bed River, 1.85 inches ; head of the
passes to Quarantine, 11 inches ; through the Southwest Pass,
2 inches ; and through the South Pass, 2} inches.
At New Orleans the velocity is about 6 feet per second,
and at the head of the passes about 5 feet per second.
At extreme high water the surface of the river is several
feet above the whole alluvial basin, and nothing but the
levees built along the banks prevent a general overflow. For
a distance of thirty-five miles above the mouth of the river,
the country is inundated during every high-water season, and
within five or six miles of the mouths of the passes, the low,
marshy banks, even at low river, are covered by the tidal
overflows.
s.w.TASS.
MISSISSIPPI RIVER ATF'S'PinLlP
W
U
H
<
-I
OL
PASS X LOUTRE
SOUTH PASS
SECTIONS
MISSISSIPPI RIVER
E4SSES
4. «r »
stMK.
*■*■■■' m- m ' m ^ m
tau.
THE DELTA.
15
The following is a table of the dimensions of the main
passes of the Mississippi :
NAME.
Length to
Outer Crest
of Bar.
3Iean
Width.
Mean
Depth.
Mean Area
of
Cross-section.
Proportional
Discharge.
mies.
Feet.
Feet,
Square Feet.
Southwest Pass....
17
1,500
40
00,000
0.45
Pass à Loutre
15
1,000
36
69,000
0.45
South Pass
Í2i
O
O
34
24,000
0.10
On the left bank of the river, three miles above the head
of the passes, Cubitt's Gap—a crewasse, formed in 1863—dis¬
charges a volume into the adjacent bay about equal to that
of South Pass.
The width across the bar at Southwest Pass, from eighteen
feet depth in the pass to the same depth in the Gulf, is one
and a quarter miles. At South Pass it was one and three-
quarter miles. The length along the crest of the bar at
Southwest Pass over which it discharges its volume, is two
and a quarter miles, and at South Pass it was about one
mile.
The approximate amount of solid matter discharged annu¬
ally by the river is 777,805,550,000 cubic yards, equivalent to
a prism one mile square and 268 feet high.
The tidal wave approaches the mouth of the Mississippi
from a southeasterly direction, and creates a current past
the delta which varies from 0.3 of a foot to 2.5 feet per sec¬
ond, the mean being about 0.5 of a foot.
The winds exert an important influence ; they have the
characteristics of the northeast trade winds.
Many of these important facts are taken from Humphreys
and Abbot's elaborate report.
There is found at the mouth of the passes a peculiar phe-
16
THE MISSISSIPPI JETTIES.
nomenon called " mud lumps," or islands, which are pushed
up above the surface of the water near the crest of the bars ;
they rise sometimes ten or fifteen feet above the water, and
vary in size from a few feet in diameter to an area of thirty
acres. They are formed either by gaseous forces or by the
pressure of the advancing bars. The material composing
them is a sticky clay, although a close analysis shows over
sixty per cent, of mineral silt.
The foregoing disconnected facts, and incomplete descrip¬
tion of the delta and its bars are here given, to be supple¬
mented in succeeding chapters by a more definite and con¬
cise description of conditions, causes and forces.
PLATE 4-.
CHAPTEE III.
attempts to impeote navigation at the mouth of the mis¬
sissippi bivee—foet st. philip ship-canal peoject—bio-
geaphical.
Attempts were made, as early as 1726, to deepen the chan¬
nel at the mouth of the Mississippi Eiver, by dragging iron
harrows over the bars ; but the history of the efforts of the
United States Government to remove these obstructions to
commerce dates back only to 1837, when an appropriation
was made by Congress for an extended and accurate survey of
the passes and bars, and for deepening the channels by dredg¬
ing with buckets, a plan which had been recommended by a
board of United States Army Engineers. The appropriation
was small, and was exhausted in surveys and preparations
for the work. No other attempt was made until 1852, when
$75,000 was appropriated. A board of army officers ap¬
pointed at that time was instructed by the War Department
to report a plan of operations. The board recommended :
" First.—That the process of stirring up the bottom by
suitable machinery should be tried.
" Second.—If this failed, that dredging by buckets should
be tried.
" Third.—If both these modes failed, that parallel jetties
should be constructed, five miles in length, at the mouth of
the Southwest Pass, to be extended into the gulf annually, as
experience should show to be necessary.
2 17
18
THE MISSISSIPPI JETTIES.
" Fourth.—Should it be then needed, that the lateral out¬
lets should be closed.
" Finally, should all these fail, a ship canal might be re¬
sorted to.
" The recommendation of the board to dredge by stirring
up the bottom was approved by the War Department, and a
contract was accordingly entered into for deepening the
Southwest Pass to eighteen feet. The contract was success¬
fully executed, and a depth of eighteen feet obtained in 1853.
No further appropriation was made until 1856, and, as antici¬
pated, no trace of the former deepening was left.
" In 1856, $330,000 were appropriated for opening and keep¬
ing open by contract ship channels through the bars at the
mouths of the Southwest Pass and Pass à l'Outre." (See
Humphreys and Abbot's Physics and Hydraulics of the
Mississippi Biver, p. 486.) A contract was awarded to
Messrs. Craig & Eightor, for opening both passes twenty feet
deep and three hundred feet wide, and for maintaining that
channel four and one-half years. They constructed on the
east side of Southwest Pass, a jetty about a mile long, built
of a single row of sheet piling, which, with the assistance of
harrowing and dredging, deepened the channel to eighteen
feet. Failing to complete their contract, the Government
continued the work with the remainder of the appropriation,
and the depth of eighteen feet was maintained at both passes
during part of the years 1859-'60. No attempt was made to
open the channel during the war.
In 1868-69 the Government constructed a steam propeller
dredge, at a cost of $350,000 [Appendix 1]. The propeller
stirred up the mud at the bottom and threw it to the surface
by means of a deflector behind the propeller, the object being
to have it carried away by the currents. A second boat of
similar plan was built soon after. These boats were in almost
constant use for three years. A board of army engineers
BIOGBAPHICAI,.
19
gave their opinion, in the winter of 1873, that the results ob¬
tained did not warrant them in estimating that a greater depth
than eighteen feet could be maintained by dredge boats.
All the methods employed from 1837 to 1875 were simply a
contest with the depositing forces of the river and the wave
forces of the gulf. The channels which had been opened dur¬
ing the season of low river, when the water was free from sed¬
iment, often filled up suddenly when the floods brought down
upon the bars the enormous quantity of solid matter with
which they were loaded. After months of persistent scraping
or dredging, a severe storm, sweeping the waves across this
artificial channel, often filled it up in a few hours with the
heavy sand washed in from the neighboring reefs.
During all these years various plans for a permanent outlet
were proposed by civil and military engineers. These propo¬
sitions were brought before Congress for its action, but with¬
out any practical results.
As early as 1832, Major Benjamin Buisson, Chief Engineer
of the State of Louisiana, designed a plan for a ship canal at
a point a few miles below Fort St. Philip, to connect the Mis¬
sissippi Biver with the waters of Breton Sound. He sub¬
mitted his plan to the State Legislature. They approved it
and adopted the following resolution : " Besolved by the
Senate and House of Eepresentatives of the State of Louisi¬
ana, in General Assembly convened, that our Senators and
Eepresentatives in Congress be requested to bring to the no¬
tice of the General Government the probable practicability
of such a work" (a ship canal connecting the Mississippi
Eiver with Breton Sound), "and to urge an early estimate
and survey of the same by competent officers."
A survey was ordered and reported to Congress by the "War
Department in 1837. In that year Major W. H. Chase pre¬
sented the first well-defined plan for a ship canal. His esti¬
mate for its construction was $10,000,000, a sum entirely too
20
THE MISSISSIPPI JETTIES,
large to be appropriated at that early day for any public im¬
provement. In 1852 a mixed naval and engineer board was
convened. The members of tbe board were Com. W. K. Lat¬
imer, U. S. N., Major W. H. Chase, U. S. A., Capt. J. G. Bar¬
nard, U. S. A., and Capt. G. T. Beauregard, U. S. A. They
recommended that the appropriation of $75,000 available at
that time should be expended in stirring up the bottom, and,
in recommending another appropriation, advised that, if
dredging should prove a failure, the appropriation of $150,000
should be expended in the construction of jetties at South¬
west Pass, and in their report stated that the "project of
jetties is based upon the simple fact that, by confining the
waters, which now escape uselessly in lateral directions, to a
narrow channel, the depth of this narrow channel must be
increased—in other words, the existing bar must be cut
away." The board concludes by saying, that should these
plans fail, a ship canal could be resorted to. (See Annual
Eeport Chief of Engineers, U. S. A., for 1874, Appendix E,
p. 69.)
In 1858 Mr. E. Montaigu, a civil engineer, revived the idea
of a ship canal, which had virtually been slumbering for
twenty years. He made plans and estimates, using the infor¬
mation obtained by Buisson and Chase, and made a personal
examination of the site of the projected canal. He proposed
to construct the work by individual subscriptions, and ob¬
tained the indorsements of the merchants and capitalists of
New-Orleans. " The war and the death of the projector de¬
feated this proposal, but, with the restoration of peace, the
project of a national canal, as recommended by the Legisla¬
ture of Louisiana, was brought forward under the auspices of
some of the oldest and most eminent merchants. A commit¬
tee of the Chamber of Commerce was appointed, which
renewed the recommendation of the work and pressed its
adoption upon the Government." (See Annual Eeport Chief
HISTOBICAL AXD BIOGRAPHICAL.
21
of Engineers, U. S. A., for 1874, Appendix E, p. 23.) In 1871
Congress requested the Secretary of "War to cause surveys
and plans to be made for a ship canal, to connect the river
with Breton Sound. This work was performed by Major 0.
W. Howell. In 1878 a board of army officers was appointed
to examine his plans, and was subsequently instructed to
ascertain the feasibility of improving one of the natural out¬
lets of the river. The members of this board were Genis. J.
G. Barnard (President), John Newton, Q. A. Gilmore, G. K.
Warren and G. Weitzel, Col. Wm. P. Craighill and Major C.
W. Howell. After a personal examination of the site of the
proposed canal, and of the mouth of the river, they made
their report in February, 1874, favoring the canal scheme and
opposing the jetty plan. Their objections to the jetty system
were :
First.—That the jetties would be undermined at the sea
ends.
Second.—That the foundation on which they would rest was
unstable, and
Third.—That there would be a greatly accelerated advance
of the bar after the jetties were constructed.
For these reasons they believed that it would be extremely
difficult to construct the jetties, and impossible to maintain
them. (See Appendix I.)
The majority report was strongly approved by Gen. A. A.
Humphreys, Chief of Engineers, U. S. A., who estimated that
the cost of construction and maintenance of jetties at the
mouth of Southwest Pass to produce a depth of twenty-seven
feet would be $23,000,000 ; at South Pass, $17,000,000, and of
the Fort St. Philip canal, $13,000,000. In reference to the
bar advance after the jetties are constructed, he says : " If
the depth to be maintained is twenty-seven feet at low water,
or twenty-eight feet at high water, it will be found by a sim¬
ilar process that the annual advance will not be less than
22
THE MISSISSIPPI JETTIES.
twelve hundred feet." (See Annual Eeport Chief of Engi¬
neers, for 1874, Appendix E, pp. 87 and 93.)
Gen. J. G. Barnard dissented from the report of the major¬
ity, because
First.—The plans and estimates for a ship canal were not
based on sufficient or reliable data.
Second.—Dredging with suitable appliances would give
twenty-two feet at high tide continuously, and this depth
would relieve the pressing wants of the Mississippi Valley,
and
Third.—It would be desirable to improve one of the natu¬
ral outlets of the river, so that the expensive use of machin¬
ery could be dispensed with.
In reference to the adoption of the jetty system, he said ;
" The question submitted, however, is not so much ' to recom¬
mend its trial' as to recommend its considération and that
scrutiny and survey on which alone estimates can be based."
Comparing the natural conditions existing at the mouth of
the river with those at the mouth of the Danube, where jet¬
ties have not only been successful, but have retarded the bar
advance, he considered the conditions of the Mississippi more
favorable on account of the bold slope of the delta seaward,
and the greater influence of the sea forces. He advised that,-
if the jetty plan was adopted, the works should be built at the
mouth of South Pass—the cost of which, if successful, would
be but a fraction of that of the canal. He closed his report
with the following forcible language, which is almost an ap¬
peal for an unobstructed natural outlet : " The advantages
of an open river-mouth are inestimable. The needs of a nav¬
igation so great as that which now exists, and which in the
future of the great Mississippi Valley must be fifty-fold in¬
creased, demand it. It is said that 'the time has come'
when the needs of commerce demand the canal ; but I answer
that the time will come when there will be the same cry for a
HISTOEICAL AND BIOGBAPHICAL.
navigation unimpeded by locks—An Open Eiver-Moutli—
which we now hear for a canal. But in whatever aspect the
question be regarded, the use of the river-mouth for the next
ten years is simply inevitable. * * * It would be
a rash confidence which would contemplate a realized 'Fort
St. Philip ship canal ' earlier than A. D. 1884." (See Ap¬
pendix I.)
About the time of the earlier surveys and discussions in
1837, looking to the improvement of navigation at the mouth
of the Mississippi Kiver, James B. Eads, then a lad fourteen
years of age, in straitened circumstances, and employed as
a clerk in a mercantile house, spent the evenings in the li¬
brary of his employer, delving in the rich mines of mechani¬
cal and engineering philosophy, storing his mind with princi¬
ples and facts, and disciplining it by hard study to meet the
problems in life which were before him. Later he had a
practical experience with river forces, in his business of
searching for and raising the wrecks of steamboats. He
walked, under the shelter of the diving bell, in hundreds of
places on the bed of the river in all its varying stages and
conditions, and obtained accurate information by a personal
contact with the water, its currents and sediment.
During the war of the rebellion he constructed for the
United States Government seven iron-clad gunboats in one
hundred days, though, when he commenced operations, the
wood of which they were built was still standing in the for¬
est and the iron unwrought. He then built six others wholly
of iron, and made several valuable inventions for hand¬
ling the heaviest guns by steam. After the war he was called
upon, as a civil engineer, to deal with some of the most diffi¬
cult problems ever attempted by the profession, in his suc¬
cessful attempts to carry the piers of the St. Louis Bridge
through a hundred feet of shifting quicksand to the bed-rock,
and then without staging to erect the steel arches, that
24
THE MISSISSIPPI JETTIES.
spanned the openings of over five hundred feet between the
piers.
He first brought his lifelong practical knowledge and ex¬
perience in river hydraulics to bear upon the great question
of hoAv to improve permanently the mouth of the Mississippi,
when in May, 1873, while examining the bars at the mouth of
the river, in company with a large Congressional delegation,
he unhesitatingly declared that the proper way to remove the
obstructions to commerce was by parallel dykes or jetties at
the mouth of one of the passes.
CHAPTEE IV.
civil versus militaey engesteees—canal and jetties—discus¬
sions beeoee congress—appointment oe commission.
For years tlie design and construction of all national
works of improvement, under the control of the government,
had been wholly confided to its military engineers. Mr.
Eads felt assured in his own mind that it would be utterly
useless for a civil engineer to attempt to obtain the control of
such an important national work as this in opposition to the
United States Engineer Corps, unless some extraordinary in¬
ducement were offered to the government ; and more especially
as the plan which he advocated was disapproved of, if not
absolutely condemned by every government engineer then
in the service, except General Barnard, whose position in the
matter has been stated in the previous chapter.
Induced by this motive and the desire to secure to the Val¬
ley of the Mississippi a deep and untrammeled outlet to the
sea, Mr. Eads, in February, 1874, made a formal proposition
to Congress to open the mouth of the Mississippi Eiver by
making and maintaining a channel twenty-eight feet deep be¬
tween the Southwest Pass and the Gulf of Mexico for the
sum of $10,000,000, at the entire risk of himself and his asso¬
ciates. Not a dollar was to be paid by the government until
a depth of twenty feet had been secured, when he was to
receive $1,000,000, and afterward, $1,000,000 for each addi¬
tional two feet, or a total of $5,000,000 when twenty-eight
25
26
THE MISSISSIPPI JETTIES.
feet had been obtained. The remaining $5,000,000 were to
be paid in annual installments of $500,000 each, conditional
on the permanence of the channel during the ten years.
This fair proposition, though perfectly safe to the govern¬
ment, called forth a very active opposition on the part of
the Corps of United States Engineers ; a civil engineer had
appeared upon the stage to contest with them the right to
design and execute the most important civil engineering
work ever undertaken by the government. The importance
of securing the advice of civil engineers in connection with
this undertaking was thus forcibly stated in a speech de¬
livered in the United States Senate, by Hon. Carl Schurz,
who was one of the earliest and warmest supporters of Mr.
Eads's proposition.
" Thirty-seven years ago the Engineer Department of the
army took the matter in hand, and for thirty-seven years
they have been planning and reporting upon the matter,
and scratching and scraping at the mouth of the Missis¬
sippi, and to-day the depth of water is no greater than it
was then. In other words, they have effected nothing.
The population of the Mississippi Valley have long and
quietly submitted to such a state of things. In the mean
time they have grown in numbers ; grown enormously in pros¬
perity and productive power. They have waited long and
most patiently that the engineers of the army would discover
and show themselves able to carry out a plan which would
make the great river what it ought to be, but they have waited
in vain.
" At last, after mature consideration, such as our committee
has devoted to this great subject, it is proposed to furnish
new light to penetrate our councils. Having for thirty-seven
years permitted the engineers of the army to control this
matter—with what success I have already indicated—they in¬
sist that the genius and skill of the civil éngineers of America
CIVIL VERSUS MILITABY ENGINEEES.
27
shall have an opportunity to compete -with the army in the
solution of this great problem. I desire Senators to remem¬
ber the fact, that this is probably the only civilized country
on the face of the globe where such enterprises are left ex¬
clusively to military engineering. Even in those European
monarchies, which are so military in their character, govern¬
ments would not think a moment of excluding the civil engi¬
neer from public works which are not absolutely of a military
nature. On the contrary, almost all, aye, I might say all of
such work, is done by the civil engineer exclusively. Why
should this republic, then, rely upon the military alone ?
We ask for a commission of engineers to examine the differ¬
ent methods of opening the mouth of the Mississippi which
have been proposed ; we ask that the military engineers, who
have occupied themselves so many years with this problem,
shall have two men on that commission to represent their
views ; we ask that another body of government officers of
recognized skill, members of the Coast Survey, shall have two
members ; but then we insist that the civil engineers of
America, more numerous and perhaps more experienced than
either—men who have planned and achieved greater enter¬
prises than either, men who have tunneled our mountains,
run our railroad tracks thousands of feet above the level of
the sea, built the foundations of our magnificent bridges, and
whose triumphs are among the most resplendent glories of
the republic—we insist that they shall have an opportunity to
offer their genius and skill to the country, and have a repre¬
sentation worthy of them on this commission."
The controversy created by Mr. Eads's proposition was not
only personal and professional, but sectional. New Orleans
and St. Louis having equal interests at stake, the one repre¬
senting the Southwest, the other the West and the great North¬
west, were divided in reference to the best methods of
opening the mouth of the river. New Orleans had long be-
28
THE MISSISSIPPI JETTIES.
fore pronounced in favor of a ship canal, and had secured
the indorsement of almost every commercial body and polit¬
ical convention in the Mississippi Valley. She was uncom¬
promising in her opposition to any other plan. For a
generation her orators had pictured in glowing colors the
great commercial prosperity that would come when the hopes
of a canal were realized, and her scientific men had proved,
to their satisfaction at least, that this was the only certain
method of removing the obstruction to commerce. The pub¬
lic had become so thoroughly imbued with this idea that
when the bill for a ship canal and the proposition for the
construction of the jetties were before Congress at the same
time, in the spring of 1874, a most intense interest was ex¬
hibited in the discussions that took place between the advo¬
cates of each project. The contest at first was between the
canal advocates in the Southwest and the United States Engi¬
neer Department on the one hand, and Mr. Eads nearly alone
on the other. Eor while public opinion and the press in St.
Louis and elsewhere in the West supported his project, his
great personal popularity and success as an engineer led
them to do so. They had long ago become weary of waiting
for the engineers of the government to give their commerce
its much needed relief, and they now turned to Mr. Eads as
their exponent and leader.
The controversial arguments on abstruse subjects in hy¬
draulics, which, under other circumstances would have been
tedious and uninteresting, were by these exciting causes filled
with an intense interest. They were circulated everywhere,
and read eagerly by the general public.
Mr. Eads, in a letter dated March 15th, 1874, and addressed
to " Hon. William Windom, United States Senate, Chairman
of Co-^mittee on Transportation Eoutes to the Seaboard,"
and one of the most able and steadfast friends of the jetties,
stated his views of river hydraulics as follows :
CIVIL YEESXÎS MILITABT ENGIXEEES.
29
"The improvement oí the mouth of the Mississippi pro¬
posed by me consists in an artificial extension of the natural
banks of one of the passes, from the point "where they com¬
mence to widen and disappear in the gulf, to the crest of the
bar, about five miles distant.
" This method is indicated as the only proper one, by the
following facts :
" The Mississippi is simply a transporter of solid matter
to the sea. This consists chiefly of sand and alluvion, which
is held in suspense by the mechanical effect of the current.
A small portion, consisting of larger aggregations, such as
gravel, boulders, small lumps of clay, and drift-wood, is
rolled forAvard along the bottom. By far the greatest por¬
tion is, however, transported in suspension. The amount of
this matter, and the size and weight of the particles which
the stream is enabled to hold up and carry forward, depend
wholly upon the rapidity of the stream, modified however,
by its depth. The banks and bottom being chiefly sand and
alluvion, are easily disintegrated by the moA'ement of the
water, hence the amount of load lost by any slackening of
the current at one place, will be quickly recovered in the
first place below where the current is again increased.
"The popular theory advanced in many standard works
on hydraulics, to wit, that the erosion of the banks and bot¬
tom of streams like the Mississippi is due to the friction or
impingement of the current against them, has served to em¬
barrass the solution of the very simple phenomena presented
in the formation of the delta of the Mississippi, because it
does not explain why it is, that under certain conditions of
the water, it may develop with a gentle current an abrading
power, which, under other conditions, a great velocity cannot
exert at all. A certain velocity gives to the stream the abil¬
ity of holding in suspense a proportionate quantity of solid
matter, and when it is thus charged it can sustain no more,
30
THE MISSISSIPPI JETTIES.
and hence will carry off no more, and therefore cannot then
wear away its bottom or banks, no matter how directly the
current may impinge against them.
" In the upper portions of the delta (which, according to
some writers, extends a few miles above Cairo), the width
of the river is very irregular. When a rise occurs, the cur¬
rent is increased, in the narrow parts of the river, and the
carrying capacity of the stream consequently becomes greater,
and it at once takes up an additional load. When, however,
as the stream flows on, it enters a wide expanse, the current
is slackened and the excess of load is dropped to the bottom,
and thus shoals or bars are formed. From such expansion
of channel way, the volume of water, thus relieved of a por¬
tion of its load, passes into another one of the narrow parts
of the channel, and here its current by contraction is again
accelerated, and the increased load which it can carry is
immediately scoured up from the bottom and sides of the
channel. In the bends, the centrifugal force of the water
makes the current more rapid on the concave bank of the
stream, and there it usually gets its additional load, and the
caving in of the bend testifles to the rapacity of the water at
that point of its course. Once loaded, however, it can carry
no more, and hence it may sweep around half a score of
other bends below with equal velocity, without injury to
them. If it encounter another expanse, however, it again
loses part of its velocity, and with it part of its load, to be
recovered again in the narrower parts of its channel below.
It is evident, therefore, that if the channel were at all uni¬
form in size, the current would be more constant, and the
alternate depositing and recovery of part of the burden of
the stream would be prevented. This loading and unloading
is synonymous with caving banks and sand bars.
" The lower part of the river, nearly all the way from Ked
River to the mouths of the passes, is remarkably uniform in
CrVIL VERSUS MILITAEY ENGINEEES.
31
width, and is therefore comparatively free from falling banks
and shoals. This part of the river is transporting its load
with great regularity, and without interruption, to the sea ;
whilst that above, owing to the alternating contractions and
expansions in its channel, transports its burden with great
irregularity, dropping a part here and taking up a part there,
and thus by successive stages, from season to season, it is
borne forward.
"If the volume of water were constant, it is plain that the
river would soon have a current of great regularity ; because
the deposit dropped in a wide part of the river lessens the
capacity of the channel »there, by shoaling it, and re-estab¬
lishes the proper velocity of current, and thus stops further
deposit at that place ; whilst at the contracted channel the
scour soon enlarges the passage, and consequently reduces
the current, and thus further scour ceases at that point.
"In a channel of uniform width, when the river falls, the
stream occupies only the narrower parts of it, and if these be
still too great to maintain sufficient current to transport the
load, the excess is deposited in the channel, which is thus
further diminished until the current is thereby accelerated
to the proper rapidity, after which it ceases to deposit any
more. When the Bonnet Carré crevasse occurred, the river
below it (one hundred and seven feet in depth) was shoaled
up thirty-one feet, because the volume of water in the river,
being lessened by the crevasse, was no longer sufficient to
maintain the normal current in a channel large enough to
carry the entire river ; consequently the current below the
crevasse slackened, and the excess of load was dropped in
the channel until the bottom was filled up thirty-one feet
deep with the deposit. This reduction of channel was suffi¬
cient to re-establish the current and prevent further deposit.
"We see, therefore, that the causes which control the
speed of the stream, and those which give to it the ability to
32
THE MISSISSIPPI JETTIES.
hold its burden of solid matter in suspense, are constantly
acting in opposition to each other, and thus the equilibrium
between them is restored as often as it is disturbed by al¬
ternations in volume, or by irregularities in channel.
" We not only learn from this how simple some of the most
apparently mysterious phenomena of the river really are, but
also how futile it would be to attempt either to enlarge or to
diminish the normal size of its channel, anywhere within its
alluvial bed. As rapidly as the engineer strives to deepen it
without proportionately contracting it, and thus enlarges it
beyond the capacity which these natural forces give it, just
so rapidly will the current be slackened by the enlargement,
and the deposit be dropped there, and thus lessen it again.
And as fast as he may contract it, just so fast will the current
be increased, and the consequent scour enlarge it again by
deepening it. The magnitude of the channel is determined
by forces which it is neither necessary or profitable for the
engineer to encounter. The form of the channel he can con¬
trol and alter. If he widen it, these forces will inevitably
shoal it ; if he contract it, they will just as certainly deepen
it. * * *
" The phenomena presented by the protrusion of the passes
of the river out into the gulf are equally as simple as those
of the river above. A glance at the map shows how remark¬
ably uniform is the width of each of them from their com¬
mencement, until they reach the neighborhood of the gulf.
In the passes, and in the river for several hundred miles
above, the slower shore currents have dropped their excess of
load, until the shores have been built up and narrowed in
to such a degree that all further deposits by them tend to in¬
crease the steepness of the banks ; hence the additional de¬
posit slides down toward the middle of the channel bed as
fast as it dropped. The onward motion of the stream tends
to continually draw in its waters from the shore (which is
CIVIL VEESUS MILITAEY EXGINEEKS.
33
evidenced by the driftwood flowing always in tbe middle of
the channel of the stream) ; hence, the water, after depositing
part of its load near the shore is again made capable of car¬
rying it by the increase of its velocity, when it again gets
near the middle of the stream, and thus the central mass
of water is continually made capable of taking up from the
bottom the excess of load dropped by the shore currents.
At the mouth of the pass this is not the case, for the an¬
gle of rest of the deposit, or the natural slope, is not yet at¬
tained there. ,A-t the Southwest Pass, for instance, after
flowing for several miles thyough a deep channel, with narrow
and parallel banks, the stream widens out from about twelve
hundred feet and a depth of sixty feet, to ten thousand feet
and a depth on the center of the bar of about fifteen feet.
Here the shore currents are continually dropping the sur¬
plus load, which their diminished velocity is unable to hold
up, and thus the shores of the pass are being constantly built
up and narrowed in, and brought to the surface of the water,
where, with reed grass, marine plants, etc., they are gradually
converted into dry land.
The strong central current, however, is maintained intact
by the reduced depth over which the stream passes, as it ex¬
pands, like a fish's tail, out to the bar. The velocity of the
stream being maintained by shoaling in depth as it expands
in width, it is able to transport its entire load out beyond the
bar, excepting only that which it has dropped on the sub¬
merged .and incipient shores of the pass. Although the cur¬
rent is strong out across the bar, it is soon checked because
of its immense width and shallow depth, by which great fric¬
tion in proportion to volume is induced. Hence the load is
deposited just outside the bar, and its constant outward
growth is thus assured, while the growth of the shores of the
pass follow in due order.
" The fact that a given current will keep in suspension a
3
34
•THE MISSISSIPPI JETTIES.
corresponding quantity of solid matter ; that at a less veloc¬
ity a portion of it will be deposited and taken up again at a
greater, is fully recognized in experimental science, and has
been extensively made use of for analysis of soils. An emi¬
nent investigator of this subject. Prof. E. W. Hilgard, of the
University of Michigan, now of the University of California,
Oakland, Cal., has classified silts according to the different
velocities at which they, deposit. This independent line of
research fully confirms the view herein advanced in expla¬
nation of the phenomena presented throughout the alluvial
bed of the Mississippi.
" It is a popular fallacy to imagine that the gulf presents a
barrier to the onward flow of the stream at the mouth of the
pass. On reflection, it must seem reasonable that a river
should flow with less friction between walls of water than be¬
tween walls of earth. At the bar the river has its banks of
earth no longer, but it still flows between banks of salt water,
and over a bottom of brine instead of mud. It has no longer
a descent of a few inches to the mile, however, and hence
must maintain its current in the gulf simply by its mo¬
mentum. Friction on its sides and bottom is the agent which
finally brings it to rest ; but while its momentum lasts, the
widening out into the sea and the final obliteration of the
river will proceed very gradually.
" If from the point where the banks of the pass be twelve
hundred feet asunder, and its depth sixty feet, we should ar¬
tificially prolong them to the crest of the bar, still keeping
them but twelve hundred feet asunder, we would inevitably
have sixty feet depth at the mouth of these jetties. A thor¬
ough comprehension of the laws which control the river will
banish from the mind of any one the erroneous idea that the
construction of the jetties will back up the water, and thus
raise it above them. It will also demonstrate that to be suc¬
cessful the jetties should be parallel—not converging.
CIVIL VERSUS MTUTAEY ENGINEEES.
35
"As doubling the depth doubles the current with the
same inclination of surface, it must be evident that the great
reduction of friction accomplished by narrowing the channel
from ten thousand to twelve hundred feet will enable the
momentum of the stream to be kept up to a greatly increased
distance beyond the bar, and hence the river will be able
to carry to greater depths, and into stronger gulf currents,
that load which it is now only able to deposit just outside
of the bar. That a stream will preserve its individuality for
a great distance, while flowing through the sea or through
another body of water, can be proven by every river which
enters the ocean with a strong and consequently deep vol¬
ume. The upper Mississippi preserves its identity for a
score of miles after having entered the grand channel of the
main river, and the dividing line which separates its clear
waters from those of its more powerful neighbor can be dis¬
tinctly traced, in flood time, far below St. Louis.
"If the truth be once impressed on the mind, that the
river maintains for some distance a distinctive channel
through the gulf, the effect of the feeble tides at the mouth
will be more clearly comprehended. These average less
than fourteen inches in height, and while they simply act
to raise and lower the fluid channel through which the river
flows after leaving the land, they really oppose no barrier to
its onward progress. The average velocity of the current is
maintained; the retardation due to the flood tide being com¬
pensated by the increased speed induced by the ebb.
" A careful study of the above facts should serve to ban¬
ish all fear of a progressive advancement of the bar beyond
the jetties. That the deposit of the river must tend to shoal
the water beyond the mouth, and ultimately to fill up the
gulf itself, is certain; but that it can form a shoal in front
of the jetties, in this or the next generation, is scarcely pos¬
sible. If the stream at the Southwest Pass be made to
36
THE MISSISSIPPI JETTIES.
emerge in a compact form from bet-n-een the jetties into the
gulf, it is not unlikely that its course and current will be
distinctly marked fifty miles from the present bar. Even
now it is said that the river current can be detected twenty-
five miles from the Passes * *
"The solution of the problem of improving the navigation
between the river and the gulf will never be satisfactorily
accomplished except by jetties, and that they will ultimately
be resorted to is as certain as that commerce and agriculture
will increase in the valley."
Soon after the appearance of this letter, the chief of
Engineers, General Humphreys, addressed a rejoinder to it,
dated May 22d, 1874, which was read by the Hon. George W.
McCreary in the House of Representatives. Its concluding
paragraph was as follows :
"It is probably entirely unnecessary for me to say here,
that the statements which Mr. Eads has made in the pam¬
phlets he has published, concerning the conditions existing
in the Mississippi River and at its mouth, are the mere revi¬
val of old assumptions, which experimental investigation
has long since shown to be utterly unfounded in fact."
In view of the fact that the theories embodied in the letter
to Mr. Windom have been most triumphantly sustained by
results which followed the construction of the jetties, it is
quite possible, that General Humphreys now entertains for
Mr. Eads's views a much greater respect than that which is
expressed in the above extract.
In answer to an open letter by Major C. W. Howell, who
stated that certain necessary conditions for success by jetties
did not exist at the mouth of the river, namely—a stable
character of banks and a shore current, and that careful engi¬
neers had disapproved of the jetty system at the mouth of
the Mississippi, and that jetties had once been attempted
there and proved a failure, Mr. Eads shows by quoting from
CIVIL TEESLS MILITAET EXGDÎEEKS.
37
Humphreys and Abbot's Physics and Hydraulics of the
Mississippi Hiver, that sufficient velocity of shore current
does exist ; that the plan of jetties has not really been tried,
and that careful engineers have recommended the trial of the
jetty system, and refers to the Board of 1852 for confirmation
of his statement. He states, that the estimate of General
Humphreys for the cost and maintenance of jetties at the
mouth of Southwest Pass, for a depth of 27 feet, is double
that which he is to be paid, according to his proposition for
constructing and maintaining jetties that will produce 28
feet.
He was supported in his views by several distinguished
civil engineers, whose opinions are given in his argument.
While Mr. Eads was explaining his views to Congress,
every possible interest was brought to bear against him from
New Orleans. Its Chamber of Commerce and other com¬
mercial bodies passed resolutions favoring the canal plan,
and opposing the jetty system.
Their reasons for the canal were, that a long, scientific
and patient investigation had convinced a Board of Army
Engineers that it was the best and most feasible plan. Their
objections to the jetties were, that past experience offered no
inducements to hazard the canal by such a doubtful under¬
taking. The press of New Orleans charged Mr. Eads with
being in collusion with the great East and West railroad
lines, by continuing the blockade at the mouth of the river,
and that all his hopes and fortunes being in the railroad
bridge at St. Louis, it was for his personal interest to defeat
the Fort St. Philip Canal bill.
The leading business men forwarded an earnest appeal to
Mr. Eads to withdraw his proposition, as it would only serve
to embarrass and delay the construction of the canal recom¬
mended by the Board of U. S. Engineers and the Chamber
of Commerce. Their objections to the jetties were, that they
38
THE MISSISSIPPI JETTIES.
would not stand against the storms, would be readily under¬
mined by the current, would be no protection against the
continual extension of the bars, and of no permanent use.
The Chamber of Commerce delegated two of its members
to proceed to Washington and oppose the jetty proposition.
One of these delegates. Prof. C. G. Porshey, a graduate of
West Point, was considered to be one of the leading scient¬
ists of New Orleans, and had devoted much of his life to the
study of the hydraulics of the river and the gulf. The other
—Ex-GoV. P. O. Hebert—was also a graduate of West Point,
a civil engineer of considerable experience, and had been
governor, and afterwards chief engineer of the State of
Louisiana. They appeared before the Senate and House
Committees, and endeavored to refute Mr. Eads's views ex¬
pressed in his letter to Senator Windom. Prof. Eorshey
claimed that they were not practical, not being founded upon
the true formation of the delta, and were contrary to what
his own life-long experience at the mouth of the river had
taught him. Governor Hebert based his opposition to Mr.
Eads's views on the results of his personal examination of
jetties and deltas in Europe and Egypt.
They subsequently addressed a most earnest appeal to
Congress, in which they say : " We have exhausted argu¬
ment, and laid before you the results of science and ex¬
perience. We come now with prayer." Eeferring to the
crevasses through the levees and the immense loss which
the whole alluvial district had sustained, they state that
"every additional inch and half inch of rise in the river
counts in the weight of water against our brimful levees.
Would you, can you, honorable Senators, at such a mo¬
ment, contemplate or tolerate the half-insane proposition
of strangers, who can know nothing of the habits of our in¬
exorable enemy, to dam up his waters at the mouth by
jetties or wing dams, that must inevitably send back the
CIVIL VEESUS MUJTAET ENGDŒEES.
39
flood waters like a tide to tke very city of New Orleans, or
beyond, and complete tke impending destruction ? Of this
result we assure you with an earnestness ground into us by
a life-long experience and observation, and by all the lights
that science and professional investigation are capable of
lending us." * * * "Do not, we pray, permit us to 'be
destroyed, and that without remedy.' "
This supplication was signed by these distinguished scient¬
ists, as civil engineers representing the New Orleans Cham¬
ber of Commerce.
Their labored arguments; their "life-long experience;"
their prayerful supplications not availing to stem the tide
setting so strongly in favor of the jetties, they counseled
earnestly, and at last, at the opportune and critical moment,
promulgated and distributed among members of Congress
this, their final, conclusive, and crushing argument :
40
the mississippi jetties.
MUD LUMP BLOCKADE
AT MOUTHS OF THE PASSES.
Forty-seven vessels blockaded at Southwest Pass, and one
hoisted upon a Mud Lump in the channel that has suddenly
reared its head right across the channel.
Major Howell, directing the great Dredges at Pass a l'Outre,
replies to the prayer for relief that he caimot respond, be¬
cause his own Pass is blocked by a vessel on a new Mud
Lump in the channel, but in two days he feels confident that
he can get her off with his dredges. He is under orders to
work away on that pass, in order to keep it open, and the
Southwest Pass will have to take care of itself.
For Pity and Economy's sake, if not in the interests of the
commerce of the Mississippi Valley, give us the
That all Engineers agree and know will be a PERMANENT
CHANNEL for deep navigation out of reach of the
INEVITABLE MUD LUMPS
That weekly, daily, and hourly menace the Channels at the
mouths of the River.
Him©
Of the Mud Lumps is irresistible, and must destroy any
JETTIES or other works of man under which they are liable
to rise.
Forty-seven Mud Lumps flanked the Bar of the Southwest
Pass on the last Coast Survey.
P. O. HEBERT,
C. G. FORSHEY,
Civil Engineers of Louisiana.
EBBITT HOUSE,
Washington, D. C., April 5, 1874
CIVIL VEESÜS MILITAEY ENGINEEKS.
41
By far the most influential and persistent opponent of the
jetty system was Gen. A. A. Humphreys, Chief of Engineers,
Ü. S. A.
On April 15, 1874, he addressed a long letter to the Secre¬
tary of War, which was transmitted by him to Congress.
The letter was written for the purpose of taking issue with
the views expressed by Mr. Eads. He endeavors to show by
comparing the soundings of Major Howell, in 1873, with those
of Lieutenant Talcott, in 1838, that the gulf is filling up in
advance of the bar at Southwest Pass at the rate of two feet
per year, and that the " littoral current " which was de¬
pended upon by the jetty advocates to sweep away the sedi¬
ment could not exist. " The prominence which has recently
been given to the effects of a littoral current, in connection
with the jetty system, is derived entirely from the influence
attributed to it in the case of the improvement by jetties of
the Sulina branch of the Danube ; and because the South
Pass is the smallest of the passes of the Mississippi Eiver, it
seems to be assumed that the conditions of the Sulina will be
found there at the South Pass. * * * The discharge of
the Sulina, in high water, is about twenty-four thousand
cubic feet per second ; in low water about eight thousand
cubic feet per second. The South Pass of the Mississippi
discharges, in high water, about eighty-three thousand cubic
feet per second, and in low water about twenty-five thousand
feet per second, and carries to the sea ten times as much
earthy matter as the Sulina branch. * * * The small
quantity of earthy matter carried to the sea by the Sulina
branch, joined to the fact of the existence of a littoral current
across its mouth, Avere the two causes which, in the judgment
of Sir Charles Hartley, the engineer of the commission for
the improvement of the mouths of the Danube, made the
jetty system peculiarly applicable there, and led to its suc¬
cess, the jetties causing the earthy matter in suspension to be
42
THE MISSISSIPPI JETTIES.
carried out into the littoral current, which then carried part
of it away." He states further, that the crest of the Sulina
bar remained essentially stationary, so far as any outer move¬
ment is concerned, during twenty-eight years, and that none
of the characteristics of a delta formation exist at the mouth
of the Sulina ; also, that at the mouth of the Mississippi there
are two separate and distinct bar formations ; the one formed
by the earthy matter cdmg the hottoin of the river and
bar, and the other formed by that part of the earthy matter
held in suspension ; but that in the case of the Sulina branch
the amount of earthy matter gnis^ied along the river hed was
always very small, and had no controlling power over the bar
formation, and is now carried by the action of the jetties
into comparatively deep water.
It is in his " experimental theory of the formation of bars "
that he finds the most serious objection to the adoption of
the jetty system. According to that theory, about one-tenth
of all the sediment carried into the gulf is pushed along the
bed of the river. When this material, being composed of
heavier substances, reaches the outer crest of the bars it is
dropped in the "dead angle, or space without currents,"
made by the fresh water rising upon the heavier salt water.
He makes a calculation, based on this theory, by which he
obtains the result that if the jetties contract the channel-way
over the bar from eleven thousand five hundred feet to the
width required to produce twenty-seven feet at low water,
the annual advance of the bar will be not less than twelve
hundred feet.
Referring to views stated by Mr. Eads, he says : " It has
been recently stated by a civil engineer, in a pamphlet con¬
cerning the improvement of the mouths of the Mississippi
River by jetties, that the amount of sedimentary matter car¬
ried in suspension by the Mississippi River is in exact propor¬
tion to the velocity of its current." He quotes at consider-
CIVIL VERSUS MILITABY ENGKEEES.
43
able length from the results of observations made at Carroll-
ton and Columbus, to show that this statement is not correct
and is in direct conflict with these results, for they prove
" that the greatest velocity does not correspond to the great¬
est quantity of earthy matter held in suspension ; on the
contrary, at the time of the greatest velocity of the current
at Carrollton, the river held in suspension but little more
sediment per cubic foot than when the velocity,was least."
He makes a special application of his theories to South
Pass, because Major Howell had recently sounded on its bar
and seaward of it. From these soundings and his own theo¬
ries he deduces the result, that the annual advance after jet¬
ties are constructed will be six hundred and seventy feet.
(See Humphreys and Abbot's Physics and Hydraulics of the
Mississippi Eiver, Appendix M, page 667.)
This argument was reviewed by Mr. Eads in a letter dated
May 29, 1874, addressed to Hon. S. A. Hurlburt, House of
Eepresentatives, Chairman of Committee on Eailroads and
Canals. An abstract of this letter, with some extracts, is
given. He calls attention to the fact, that on April 21st,
the day fixed by the House for the consideration of the Jetty
bill, copies of General Humphrey's letter were circulated
among the members, and says :
" As certain statements in it are based upon unsound theo¬
ries, calculated to mislead the judgment of Congress, it is
proper to correct them. To sustain this theory of bar forma¬
tion and advance, it is absolutely necessary to establish two
facts, which are assumed as the basis of the whole theory :
First, that on the outer slope of the bar a ' dead angle, or
space without currents,' exists between the river water and
the bottom ; and second, that the material to form the bar is
'pushed ' along the bottom. Humphreys and Abbot say, on
page 482 of their report : ' As a velocity of 0.5 of a foot per
second is sufficient to transport the material of which the bar
44
THE MISSISSIPPI JETTIES.
is formed, tlie action of gulf currents in carrying into
deeper water the material by the river into the gulf is
evident—' [the italics are mine]." Professor Forshey, hav¬
ing been engaged in current measurements at Southwest
Pass, says in Appendix G, of the same report : " We have a
velocity at the hottom on the bar, full two miles outside of the
land, of two feet per second." From observations recorded
by Prof. Forshey he finds that at different stages of the river,
and in depths varying from twenty-two feet to forty feet on the
outer slope of the bar, in this " dead angle " the average ve¬
locity was one and three-quarters feet per second, varying
from about one foot to three and one-third feet per second,
and states that these quotations from Humphrey and Abbot's
report disprove the existence of a " space without currents,"
or a " dead angle," on the outer slope of the bar.
To ascertain the amount of pushed material, the means em¬
ployed are given by Humphreys and Abbot as follows : " A
keg similar to that used in collecting water below the surface
was sunk to the bottom of the river ; the current immediately
overturned it, and the valves opening allowed the water to
pass freely through. After remaining a few minutes it was
drawn suddenly up, and was invariably found to contain ma¬
terial such as gravel, sand, and earthy matter." Mr. Eads says :
" Prof. Forshey has informed us, that no investigations or
experiments with a keg, or by any other means, were ever
made by Humphreys and Abbot to determine this question,
and that the principal hydrometrical data in Humphreys and
Abbot's report were supplied by himself.
" To him belongs the honor of discovering, by means of the
keg described by Humphreys and Abbot, the enormous
amount of material pushed on the bottom, and ' of which the
bar is formed ; ' therefore, upon his investigations mainly rest
the fabric of arguments and conclusions respecting the bar
advance published by Gens. Humphreys and Newton.
CIVIL VERSUS MILITAET ENGINEERS.
45
" Frequent examinations of the bottom at ordinary stages
of water " (under the diving-bell), " enable me to declare
that sand and other sedimentary matters are carried in
suspension, and not pzis/ied along the bottom. Driftwood,
balls of clay, or other aggregations of earthy matter are
doubtless rolled or pushed along on the bed", and sometimes
gravel and boulders, but the amount of these passing New
Orleans is very small."
He states that from observations made while sinking the
large caissons of the bridge at St. Louis, and from experience
on the bed of the river in five or six hundred localities, he
knows " that no such material as forms the bars of the passes
is pushed on the bottom of the river in any such quantity as
is requisite to form them, or to serve as a basis for the calcula¬
tions of bar advance under the influence of jetties, as made by
Gens. Humphreys and Newton. Nor is it necessary to cre¬
ate any such special theory of bar formation for the Missis¬
sippi Hiver. The bars at its mouth are not formed by any
process of nature which differs materially from that at the
mouths of the Ganges, the Nile, the Danube, or any other
delta river in the world. The bar at the Danube having
failed to advance in accordance with the ' dead angle ' theory,
under the influence of the jetties, it is absolutely necessary to
show some remarkable difference between that stream and
the Mississippi. Accordingly the statement is made that the
Sulina bar is ' derived chiefly from the deposits of earthy mat¬
ter held in suspension, and not earthy matter pushed along the hot-
torn.' As the specific gravity of the matter suspended in the
Danube is twenty-eight per cent, heavier than that in the
Mississippi (according to Gen. Humphreys the specific grav¬
ity of the matter in suspension in the Danube is 2.5, while that
of the Mississippi is 1.96), does it seem reasonable that in the
stream in which the sediment is heaviest there should be so
very little pushed on the bottom, while enormcms quantities
46
THE MISSISSIPPI JETTIES.
are pushed, along the bed of the stream in which it is the
lightest ? Sir Charles Hartley states, that ' the amount of de¬
posit at the various mouths of the Danube was almost directly
in proportion to the volume of water issuing from theml We
have shown that hy weight the Danube's suspended mat¬
ters are greater, and they are stated by Gén. Humphreys to
be nearly the same as in the Mississippi hy volume. From
these facts it remains for him to explain how the South Pass,
discharging but one-third of the volume of the Danube, can
carry to sea iwo-thirds as much sediment. The statement
made in my letter to Senator Windom, that 'the amount of
this matter and the size and weight of the particles which
the stream is enabled to hold up and carry forward depends
wholly upon the rapidity of the stream, modified, however,
by its depth,' is given by Gen. Humphreys as a verbatim quo¬
tation, but in a mutilated form, leaving out the words ' modi¬
fied, hoivever, hy its depth,' which makes my statement as
ridiculous as though I had asserted that the capacity of the
river bed is in exact ratio to its width, without reference, to its
depth. Long arguments and extensive tables of velocities of
current and quantities of sediment are brought forward to de¬
molish this mutilated proposition, and to refute ivhat I never
asserted. In reference to my real statement, those who are
familiar with the best writers on this subject know that the
ability of the stream to suspend its sediment is believed to be
inversely as the depth,- but Humphreys and Abbot, in coming
to the conclusion that no relation exists between the velocity
and the load suspended, omitted one of the most important
elements in the problem, namely, the variations in the depth
of the stream.
" The whole question really at issue in this matter, is : WiU
the required extension of the jetties he twelve hundred feet per
annum, or any lesser rate of importance ? Gen. Humphreys
answers thi^ question in the affirmative. The views ex-
CrVIL TEESUS MILITAET EÎÎGINEEES.
47
pressed in Ex. Doc. 220, by Gen. Barnard, and those of Col.
Tf. Milnor Roberts, Gen. J. H. "Wilson, Col. Shaler Smith,
and Messrs. Chanute, Bayley, Fiad, Corthell and others, ex¬
pressed to me personally, sustain my faith in the negative ;
for the United States does not contain engineers more able
than this list presents. * * * If these eminent engi¬
neers, who do not believe such rapid advance of the jetties
will be needed, are correct, and the jetties succeed, the nation
secures an inestimable prize, AN OPEN-MOUTH RIVER.
With so much to gain, and so little to lose in accepting my
proposition, can it be deemed wise to decline it ? If Con¬
gress refuses to let me demonstrate the problem at the sole
risk of myself and associates, the valley must wait in patience
for relief."
Notwithstanding the evident fairness of Mr. Eads's proposi¬
tion, the influence of the Engineer Corps of the army was so
powerfully exerted to prevent the control of the improve¬
ment of the mouth of the great river from passing into the
hands of " an outsider," as he was called by Messrs. Eorshey
and Hebert, and the opposition to the proposed jetties was so
intense in New Orleans and on the part of the Louisiana del¬
egation in the House of Representatives, that the bill for the
construction of the Fort St. Philip Canal was actually passed
by a large vote, as a substitute for the Jetty bill, which had
been reported favorably to the House by the Committee on
Railroads and Canals ; the Jetty bill receiving but eighty-
nine votes, while the Canal bill, appropriating $8,000,000 to
commence the canal with, received one hundred and eighteen
votes. The advocates of the canal were of course much elated
with this triumph, and at once hurried the bill over to the
Senate. Here the question of opening the mouth of the
river was in charge of the Select Committee on Transporta¬
tion Routes to the Seaboard, Hon. William Windom being
the chairman.
48
THE MISSISSIPPI JETTIES.
Before this committee Messrs. Eads, Forshey, and Hebert
had been invited to appear about two weeks prior to the pas¬
sage of the Canal bill in the House. Mr. Eads was required
by the committee to open the discussion. He was followed
by Prof. Eorshey and Gov. Hebert. The fate of the Jetty en¬
terprise, at that most critical moment, hung trembling in the
balance, for every effort to defeat it was being made by its
influential and vigorous opposers.
It is needless to say that the committee were deeply im¬
pressed with the force of Mr. Eads's arguments on that most
important occasion, for within forty-eight hours after the
Canal bill was referred to this committee, one of its mem¬
bers—Senator J. E. West, of Louisiana—arose in the Senate
and stated that he had been authorized to ask that the com¬
mittee be discharged from the further consideration of the
Fort St. Philip Canal bill, and to report, as a substitute for it,
a bill authorizing the appointment by the President of a com¬
mission of seven engineers, three from the army, three from
civil life, and one from the United States Coast Survey, to
whom this question as to the proper method of opening the
mouth of the river should be referred, with instructions to re¬
port at the next session of Congress.
If Mr. Eads had failed before the Senate Committee to re¬
fute the arguments of Messrs. Forshey and Hebert, and • to
convince it of the soundness of his own views, there is no
doubt but that the committee, under the great pressure
brought to bear upon it, would have reported the Canal bill
favorably to the Senate, and in that event it would have been
as promptly passed by that body as it had been by the House,
and there would have been an end to the attempt to deepen
the mouth of the Mississippi by jetties.
Congress passed the bill reported by Senator West, author¬
izing the appointment of a commission to decide upon the
proper method of opening the mouth of the Mississippi. On
CrVIL VEESÜS MTT.TTABY ENGINEEKS.
49
this commission the President appointed the following distin¬
guished engineers : Gen. H. G. Wright, U. S. A. ; Gen. B. S.
Alexander, U. S. A. ; Gen. C. B. Comstock, U. S. A. ; Prof.
Henry Mitchell, United States Coast Survey ; T. E. Sickles,
C. E. ; W. Milnor Eoberts, C. E. ; and H. D. Whitcomb, C. E.
This commission of engineers in their report made Janu¬
ary 14, 1875, say : " The interests involved in the proper
improvement of the mouth of the Mississippi are so great,
and the work so costly, that it is imperative to obtain the
best possible knowledge and judgment as to the method to
be adopted. Accordingly, in order that the opinion of the
Board should be based on a full knowledge of what has been
done, and of the latest results obtained elsewhere in this
most difficult branch of engineering, it was decided to visit
the mouths of the rivers mentioned" (several of the most
important rivers in Europe).
3
CHAPTER V.
EUROPEAN JETTIES.
A SUMMARY of the construction of jetties in Europe, and
the results obtained by them, will be of interest, as bearing
upon the question of the adoption of that system at the
mouth of the Mississippi.
The Dvina is a river with many of the characteristics of
the Mississippi, although much smaller. It is a sediment-
bearing river of Russia, discharging into the Gulf of Riga,
a tideless arm of the Baltic. The depth on the bar was
increased by jetties from six feet to eighteen îeet, and there
has been no advance of the bar, although the jetties are
believed to have been built more than one hundred years
ago : how much earlier is not known, as there are no records
in the Department of Public Works at St. Petersburg that
extend back to the date of their construction.
A chart of the mouth of the Oder (a river of Prussia, dis¬
charging into the Baltic), bearing date of 1776, shows jetty
lines, some of which, near the land, are marked 1756. The
depth was increased from seven feet to twenty-four feet.
One of the most important constructions for the benefit of
commerce, at the mouth of a small river, is the artificial
channel at the mouth of the Maas, in Holland, by which the
port of Rotterdam is furnished an outlet to the sea. A
canal was cut through the " Hook of Holland," and jetties
were constructed at the sea end, extending into deep water.
50
EUEOPEAN JETTIES.
51
The Eiver Scheur, a branch of the Maas, was then closed by
a dam, and its waters turned into the new channel. The jet¬
ties were built of willow fascines, combined into mattresses,
and were sunken and loaded with stone. They project into
the sea upon a sand shore to a depth of twenty-seven feet,
and were the first constructions of that kind on the open
sea-shore. They have successfully withstood severe storms
and most violent wave force undisturbed.
The failure of the dykes at the mouth of the Ehone to
give a permanent and deep channel, has been used as an
argument against the jetty system at the mouth of sediment-
bearing rivers. The Ehone discharges into the Mediterra¬
nean Sea through four passes—the main pass, flowing in
the general direction of the river, carrying about one-half
its volume ; the other three passes may be considered lateral
outlets.
Dykes for the improvement of the bar at the principal
mouth were commenced in 1852. The plan consisted in the
closing of the three lateral outlets by a continuous dyke,
extending from the mainland above the point where they
commence to diverge, and extending to the mouth of the
principal outlet. Another dyke, or levee, was built on the
opposite bank, to prevent the escape of the water through
the small bayous and over the lowlands. These dykes termi¬
nated nearly one mile inside the crest of the bar. They are
partly earthen dykes, and partly of stone. The width of the
channel at the sea end of the dykes is thirteen hundred and
twelve feet. The width of the Ehone at the head of the
delta is six hundred feet.
Under the influence of the dykes, which were finished in
1856, the depth increased from five feet to thirteen and a
half feet; but then the bar moved seaward, and the depth
had diminished in 1863 to four and a half feet. The at¬
tempt to maintain the channel by dykes was abandoned. A
52
THE MISSISSIPPI JETTIES.
landed interest, desirous of building a maritime city a few
miles above the mouth of the river, exerted a sufficient in¬
fluence to have a ship canal constructed, which was com¬
menced in 1863. It started at the point opposite the head
of the upper lateral outlet, and extended to the Bay of Foz.
It is two and a half miles in length ; has a depth of nineteen
and a half feet ; required seven years of labor to complete
it, and cost three million dollars.
The closure of the lateral outlets, by which the volume
issuing from the main pass was doubled, also doubled the
amount of sedimentary matter discharged upon the bar.
The process of bar formation at the mouth of the Missis¬
sippi teaches us that the distance of the crest of the bar
from the land's end is determined by the volume issuing
from each pass. Consequently, if the volume of the Rhone
issuing at its principal mouth be doubled, the crest of the
bar would at once assume a new location, more distant from
the land's end than before ; and as the dykes were not built
out to within a mile of the crest of the bar they could have
no influence in checking its advance, nor in permanently
increasing the depth upon it. It is absurd to quote the
Rhone as an illustration of the jetty system. "Where this
system has been successful, the works have invariably been
extended out beyond the crest of the bar into the deep
water.
The River Danube, its delta, its regimen in respect to its
currents and sedimentary matters, the formation of its bars
and the characteristics of the sea into which it discharges,
are similar in many respects to the Mississippi River. For
this reason the jetties constructed at the mouth of one of its
branches, and the results obtained by them, need to be de¬
scribed more fully than those of any other river, in order
that lessons may be drawn from them that will apply to the
solution of the problem at the mouth of the Mississippi.
EUROPEAN JETTIES.
53
The folio-wing facts are taken from two papers read before
the Institution of Civil Engineers of Great Britain by Sir
Charles A. Hartley, Chief Engineer of the European Commis¬
sion of the Danube—one read in 1862 and the other in 1873.
This commission was constituted in 1856, by virtue of the
Treaty of Paris. It consisted of delegates from the seven
contracting powers—Austria, England, France, Prussia, Rus¬
sia, Sardinia, and Turkey—and it was charged to execute the
works necessary to clear the mouths of the Danube and the
neighboring parts of the sea from the sands and other imped¬
iments which obstructed them.
The Danube, after a course of seventeen hundred miles, re¬
ceiving more than four hundred tributaries, and draining up¬
wards of three hundred thousand square miles of country,
passes the Bulgarian town of Isaktcha in a single channel
seventeen hundred feet wide and fifty feet deep. This city is
seventy-six miles from the sea by the Kilia branch, seventy-
eight miles by the Sulina branch, and ninety miles by the
St. George branch. The general character of the delta can
be understood best by an examination of Plate No. 5.
The Sulina abstracts one-fifth of the waters of the Toulcha
branch, or two twenty-sevenths of the whole volume of the
main river. Its navigable width is rarely more than three
hundred feet. During high fioods the inclination of the sur¬
face of the Sulina is three inches per mile. In ordinary high
water the velocity of the current in the main river is between
two and one-half and three miles per hour. At times of ex¬
traordinary floods the velocity is increased to five miles per
hour, and the whole volume of water then delivered b^ the
Danube to the sea is equal to sixty million cubic feet per min¬
ute. "When the waters are most surcharged with sediment,
they bear to the sea as much sedimentary matter as would
be equivalent to a deposit of one cubic inch to one cubic foot
of water. During high river the bars at the mouths of the
54
THE MISSISSIPPI JETTIES.
passes are farther from the shore, their magnitude increased,
and the depths over them diminished. The process is as fol¬
lows : The current, with its earthy matter, by its quickened
speed deepens the channel over the bar, the displaced portion
is pushed out into the shallows beyond, and there the river
current, checked by the nearly stationary waters of the sea,
precipitates the heavier particles of the matter in suspension
to form a new bar, while the lighter particles are carried fur¬
ther and widely distributed over the sea depths beyond.
There are no tides in the Black Sea, into which the Danube
discharges, and the level of the water along the delta is solely
influenced by the opposing action of the land and sea winds.
The Sulina branch having been selected for improvement,
piers were projected across the bar to terminate in a depth of
eighteen feet, in order, in the flrst instance, that the proposed
channel might be deepened by the concentrated action of the
river current, and that afterward a good navigable chaimel
might be maintained between the piers ; it being assumed
that, when the troubled waters of the river were brought into
immediate contact with the littoral current crossing the pier
heads, the fluvial matter would remain suspended until it
was far removed from the entrance. The piers were built of
piles, cribwork, and a protecting slope of rubble stone. The
works at first were provisional. They were commenced in
1858 and finished in 1861. The depth on the bar, before the
construction of the works, varied from seven to eleven feet,
and was rarely more than nine feet. In 1862 there was a
navigable channel of seventeen and one-half feet. In 1866
the commission concluded to convert the piers into solid
structures. This consolidation was completed in 1871. The
provisional works near the pier heads had been beaten down
by the waves, so that they were three or four feet below the
surface of the water. The new works were constructed of
concrete blocks.
EUEOPEAN JETTIES.
55
In 1872 an effective depth of twenty feet was secured, and
that depth has been maintained until the present time, with
often a depth of twenty-one and one-half feet. The effect of
these works upon the growth of the bar into the sea has
been to retard it, for, considering the twenty-four feet and
thirty feet contours, the average extension for ten years, end¬
ing in 1871, was only forty-four feet per annum, whereas
during the eight years immediately previous to the beginning
of the works the same contour lines advanced at the rate of
ninety-seven feet per annum. The reason for this retarda¬
tion is, that at present the silt-bearing waters of the river
issue at once into deep water beyond the pier heads, and are
carried far to the southeast by the littoral current, instead
of flowing into the sea, as formerly, with a feeble and con¬
stantly decreasing current, by numerous shallow channels.
In a letter dated November 30th, 1874, addressed to G. W.
E. Bayley, an eminent civil engineer, and an early and ear¬
nest advocate of the jetty system, and afterward associated
with Mr. Eads in the construction of the jetties as Eesident
Engineer, Sir Charles Hartley compares the Danube and the
Mississippi. He presents the points of resemblance and dif¬
ference, and from them obtains the most cogent reasons for
constructing jetties at the mouth of the latter. He is in
favor of South Pass in preference to the larger passes, on the
score of economy in construction and maintenance, and his
comparisons are mostly drawn between the South Pass and
the Sulina branch.
The flrst objection against the construction of jetties at
the mouth of the Mississippi, namely, the soft and silty
nature of its bars, is readily disposed of ; for the South Pass
bar is described in the report of Assistant G. G. Meade, in
1839, as being principally composed of fine gray sand, mixed
with a very small proportion of mud ; and in Major Howell's
last survey the bank to the east of the bar is described as
56
THE MISSISSIPPI JETTIES.
being of bard sand. Tbis description fits precisely tbe Su-
lina bar, before it was removed by tbe scour of tbe river, and
as jetties were constructed across it without difficulty or
great expense, tbere is no reason wby tbe same advantages
should not attend tbe construction of jetties at South Pass.
Tbe second objection urged against tbe jetty system is, that
tbe waters of tbe Mississippi being charged with more sedi¬
mentary matter than tbe waters of tbe Danube, tbe injurious
effects of precipitation are more to be feared at tbe former.
He shows by lengthy and exhaustive argument.
First. That tbe waters of tbe Danube transport a greater
number of heavy particles of matter to tbe sea, in propor¬
tion to tbe whole weight of sediment, than tbe Mississippi,
and.
Second. Granting that tbe statement is correct that tbe
Mississippi, while discharging only three times as much
water, really discbarges six times as much deposit in weight,
the annual advance of tbe Mississippi mouths " two hundred
and seven feet annually, according to tbe latest surveys," is
nearly at tbe same rate as that of tbe Danube mouths. Tbis
apparent phenomenon is simply due to tbe far greater depths
of tbe sea off tbe Mississippi delta, an advantage which fully
compensates for tbe threefold greater volume of tbe river,
and tbe greater amount of sedimentary matter. Tbe sea
slope of tbe bar of tbe South Pass is one in sixty-six ; that
of tbe Sulina one in two hundred and sixty-four. He meets
tbe third objection, namely, that tbere are no littoral cur¬
rents off tbe Mississippi mouths, by proving that such cur¬
rents do exist. All testimony confirms that tbe prevailing
winds off tbe Mississippi delta are from tbe northeast and
southeast. Tbe resultant of these winds is east, which may
therefore be called tbe prevailing wind.
He points out that a glance at tbe map of tbe alluvial
region of tbe Mississippi shows, that whilst tbe general
EUEOPEAN JETTIES.
57
trend of the river from New Orleans to the head of the
passes is in a southeast direction, the deposit is nearly all
to the west, or in the direction of the current produced by
the prevailing winds ; in the same way that the Danube
deposits take place to the south, under the influence of the
prevailing winds from the north-northeast. The same obser¬
vation applies to the set of the deposits below the head of
the passes, the growth of the delta in a west and southwest
direction being three times greater than in the opposite
direction.
After stating facts, which we have given in a previous
chapter, in regard to observations for shore currents, he says :
" The reasons above given for my full faith in the existence
and efficacy of the littoral and tidal currents justify me, I
think, in saying that the salient position in the gulf of the
southwest and south mouths of the Mississippi—exposed as
they are to the full action of these currents and beat of the
waves—is evidently very greatly in favor of their successful
treatment by means of jetties, and that the rapidly increas¬
ing depths beyond their bars give them—as far as their
improvement is concerned, by the same method—a very
marked superiority over the Danube mouths. If at the
Sulina mouth the inclination of the sea bottom had been as
steep as off the South or Southwest Passes of the Missis¬
sippi, a depth of twenty-eight feet might as easily have been
obtained there, at a slight additional cost indeed, but with
the great advantage that the silt-bearing waters would have
been carried much farther seaward, owing to the increased
depth of the channel, and into such depths that the forma¬
tion of a shoal, such as now forms after a high flood, within
one-half mile of the pier heads, would have been impossible
for many years to come. * * *
" My conviction is, that by increasing the erosive powers
of the current, relatively to the depositing action, the piers
68
THE MISSISSIPPI JETTIES.
■will have the effect not of accelerating the growth of the
accretions of the sea bottom, but of greatly retarding it.
* * * Practically, therefore, I consider that the element
of bar advance may be discarded from the minds of the
present generation."
Without giving further descriptions and details of the jet-
tied mouths of the rivers of Europe, the following table will
serve to show the extent to which the jetty system has been
adopted there, and the success which has attended it.
Conntry.
Original Depth,
Feet.
Komnania (Turkey)....
Holland
Prussia
Prussia
Prussia
Prussia
Prussia
Prussia
Prussia
Prussia
Prussia
Russia
Russia
Russia
Russia
Sweden
Sweden
Sweden
Denmark
7 to 11
00
7
7
7
6
4
4
13
4
10
6
6
4
6
5
6
From the preceding resume of jetty construction we can
see that, for a great many years, all along the shores of the
Black Sea, the North Sea, and the Baltic, Russia, Prussia,
Holland, Sweden, Denmark, and Turkey have built and main¬
tained jetties. The record of their works teaches us plainly
that, whether the bars were caused by the waves of the sea
EUEOPEAN JETTIES.
59
or tlie waters of the rivers, whether they were " drift " or
" delta " bars, the piers, dykes, and jetties, when pushed out
into the deep water, have in every instance not only pro¬
duced the depth needed, but have maintained it permanently
against wave action and sedimentary deposits.
CHAPTEE VI.
eeport op the boaed—passage of the act authoeizing the
consteuction of jetties at south pass.
In the interval between the adjournment of Congress in
July, and its reassembling in December, 1874, a remarkable
change in public sentiment had taken place.
"When Mr. Eads returned from Europe, where he had spent
several months in carefully examining and studying the jetty
system at the mouths of several important European rivers,
and in consulting with the distinguished engineers who had
constructed them, he found the country and Congress ready
for a favorable consideration of his plans. The leading jour¬
nals, especially in New York and in nearly every city of the
Mississippi Valley, advocated the views which he had so
clearly expressed in and out of Congress.
The report of the Board of Engineers was presented to
Congress on January 13, 1875, by the Secretary of War.
The following is an abstract of the report, the full text of
which is given in Appendix 2. In reference to a canal, they
show the advantages and disadvantages of several locations,
and decide in favor of a site near Fort St. Philip, and give an
estimate of the same, which for cost of construction and
maintenance is $11,514,200.
As to the deepening of a natural outlet, they are of the
opinion that no admissible expenditure of money can per¬
manently maintain by the stirring process a depth of twenty
60
EEPOET OF THE BOAED.
61
feet, and that this depth is not adequate to the -wants of com¬
merce. In reference to jetties, they first give the facts on
■which their application at the mouths of the Mississip^Di is
based.
The fact of principal importance is, that as the bars move
out to sea, the river is all the time eroding a channel of the
characteristic deep water cross-section behind and through
them. The object of jetties is to aid and hasten this erosion.
The plan recommended by the Board is to begin parallel
dykes at the banks of the pass, where there is now thirty feet
of water in the middle, and carry them over the bar to thirty
feet of water outside. The river will erode the bottom be¬
tween the dykes till the water-way everywhere has the same
cross-section as at their beginning. The depth of thirty feet
is chosen in order that some time may elapse before the bar,
which will form at the sea end, can have less than twenty-five
feet on it, that being the minimum depth which it is desired
to maintain.
In selecting the pass to be improved, they give the prefer¬
ence to South Pass ; for, while its width is only seven hun¬
dred feet, as against fourteen hundred feet at Southwest
Pass, the former, when improved, will be adequate to the
present and prospective wants of commerce. The estimate
for construction and maintenance of jetties at the mouth of
South Pass is $7,942,110, and for Southwest Pass, $16,053,124.
They are satisfied from their examinations abroad that the
jetties should be constructed of brush fascines and stone, in
the same general way as those at the mouth of the Maas, in
Holland. They discuss the question of the advance of the bar
after the jetties are completed, and give their opinion, that
in one hundred and twenty years the crest of the new bar
will probably be found twelve thousand feet beyond its pres¬
ent location, and for this reason they estimate for the cost of
the average annual extension that will be necessary, $180,000.
62
THE MISSISSIPPI JETTIES.
In comparing a ship canal and jetties they recommend the
latter, and their application to South Pass. They say : " It
would give a good sea entrance about nine hundred feet wide,
and a minimum width in the pass of about five hundred and
thirty feet, while the width of the canal would be about three
hundred feet. It would offer no locks (liable to do or suffer
injury) to delay the passage of vessels through it. It would
give an ample unobstructed waterway to commerce, in place
of a narrow and obstructed one." The Board concludes its
report with a recommendation that if Congress decides to
open one of the passes of the river, the entire sum necessary
to accomplish the work be appropriated at once or in some
way be made available ; for the work, when once begun,
should be pushed as rapidly as possible to its entire com¬
pletion. This report was signed by all the members of the
Board except Gen. "Wright, who stated that, in his judgment,
the chances of success of an attempted improvement of any
one of the natural outlets of the river did not justify the
recommendation of the Board ; but he conceded that if an ad¬
equate and permanent channel could be obtained at any one
of the passes, it would no doubt be preferable to the pro¬
posed canal. Soon after the report of the Board, Mr. Eads
made a new proposition to Congress, to make a channel thirty
feet deep at the mouth of Southwest Pass for $8,000,000, and
maintain it for twenty years for an annual sum of $150,000 ;
the first payment of $500,000 to be made when a channel of
twenty-two feet in depth and two hundred feet in width was
obtained, and $500,000 more when this depth was maintained
for a year ; then $1,000,000 each year for the addition of two
feet permanent depth to the channel until thirty feet was
reached ; the remainder to be retained by the Government,
one-half for ten years and the other half for twenty years, as
a guaranty for the performance of the work.
A bill embodying this proposition was introduced in the
EEPOET OF THE BOAED.
63
House of Eepresentatives about the 8tb of February, 1875.
Like the bill introduced in the previous session, it met the
determined opposition of the Chief of Engineers, U. S. A.,
■who at once presented his views to Congress through reports
to the Secretary of War.
In New Orleans the sentiment of the community had
changed considerably. Many of those who had strongly,
opposed the jetties, when they now saw that Mr. Eads's
proposition was virtually indorsed by the Commission of
Engineers, used their influence to secure the adoption of
Southwest Pass, as proposed by Mr. Eads, instead of the
South Pass, as recommended by the Commission.
Mr. Eads's objections to the South Pass were—
First. That an extensive shoal existed at the head of that
Pass, which it would be difficult to remove, and that the
channel obtained through it would be difficult of navigation ;
and.
Second. That the channel through the pass was too small
for easy navigation, and inadequate to the growing wants of
commerce. Mr. Eads, learning that the Board was likely to
adjourn without inviting him to appear before it, although
its creation was the result of his action, addressed a letter
to its president, in which he expressed the. determination to
press the adoption of the jetty system, regardless of the
decision of the Commission, and suggested the propriety of
its hearing what he had to say upon the subject before mak¬
ing their report. In reply he was promptly invited to state
his views before the Commission. He addressed it for two
and a half hours upon the subject, during which time he laid
before it the facts which he had obtained by his personal
inspection of the jetties at the mouths of the Oder, Wipper,
Persante, Vistula, Pregel, Danube, and the Ehone, and in
conclusion urged the Commission, in the following forcible
language, to recommend the improvement of the Southwest
64
THE MISSISSIPPI JETTIES.
Pass : " It is rarely that gentlemen of our profession liave
sucli an opportunity of so indelibly recording their judg¬
ment. I earnestly trust that you will, on this occasion,
unanimously recommend the imjirovement of the Southwest
Pass, and thus leave, as an imperishable evidence of your
foresight and public spirit, such a deep and broad channel
at the mouth of the grandest physical feature of this conti¬
nent, as shall win for you the thanks and praise of the hun¬
dreds of millions which the Mississippi Valley will hereafter
contain, and whose grand commerce must naturally and for¬
ever seek that route to the sea."
The House Committee on Commerce, to whom the bill
was referred, examined all its features thoroughly, heard all
explanations, listened patiently to all arguments, pro and con,
and studied carefully the wording of the bill, that a contract
so important might be drawn up with correctness and pre¬
cision; and, notwithstanding the fact that the Commission
had recommended the improvement of the South Pass, it
adopted Mr. Eads's recommendation to improve the South¬
west Pass, and reported the bill to the House unanimously.
On February 18, ten days after the introduction of the bill
into the House, it was made the special order of the day.
Ex-Gov. Stanard, of Missouri, made an able speech, full of
facts and arguments, in favor of the measure. He explained
its provisions, showed what it proposed to accomplish, and
demonstrated that the sums to be paid under it were several
million dollars less than the estimates of the Army Engi¬
neers for a canal, and less than that of the Commission for
jetties, and that the interests of the government and the pub¬
lic were guarded with the utmost care, in respect to the pay¬
ments for the work. An able speech was also made by Hon.
O. I). Conger, of Michigan, and the bill then passed, with but
two dissenting voices. "When it reached the Senate it was
amended by the committee there, and made to apply to the
LEGISLATION.
65
small pass, in spite of all the arguments Mr. Eads could use
to prevent it. The reason for this was, that Congress had
obtained the advice of one Commission of Engineers, who
had recommended the Fort St. Philip Canal, and it had then
asked the advice of a subsequent one,- which had recom¬
mended jetties at the little pass. If it refused the advice of
both these councils of experts, and voted to place the jetties
at the great pass, and they failed to accomplish what Mr.
Eads claimed they would. Congress would then have no de¬
fense for having refused the advice of its own experts in the
matter. Besides this reason, which, to say the least for it,
was founded in an unwillingness on the part of the members
of the Senate Committee to take the responsibility of decid¬
ing between experts (Mr. Eads being one, as well as the
Commission), there was the more weighty reason of its cost¬
ing two and three-quarter million dollars less to improve the
little pass. The Senate Committee were immovable in this
decision, and Mr. Eads was informed, that if he would give
the same guaranties, and agree to produce the same depth
of channel Avith the little pass that he had guaranteed for
the big one, and build the works for five million two hundred
and fifty thousand dollars (which was much less than the
Commission's estimate), and guarantee its maintenance for
twenty years for thirty thousand dollars per annum less than
the Commission's estimate for that item, the improvement
should be confided to him; otherwise it would be placed
under the control of the Corps of Ü. S. Engineers, who had
fought him at every step, and whose acting chief had pre¬
dicted tlje failure of the jetty system, if ever tried at the
mouth of the Mississippi.
Thus modified, the bill was reported to the Senate and
passed.
The concurrence of the House in the Senate amendments
was secured just before the final adjournment of Congress on
5
66
THE MISSISSIPPI JETTIES.
the 3d of March, 1875, and on receiving the President's sig¬
nature the bill became a law.
As this law authorized the construction of the work, it is
given entire and verbatim in Appendix 3.
On the 24th of March, 1875, at a banquet in St. Louis,
given to Mr. Eads in honor of this great victory, at which
there were three or four hundred of the representative men
of that city, and many distinguished gentlemen from all parts
of the Mississippi Valley, in a speech, earnest and eloquent,
he explained the secret of that implicit faith which he had
in his proposed plans, and which moved him to undertake the
great work. He said : " If the profession of an engineer
were not based upon exact science, I might tremble for the
result, in view of the immensity of the interests which are de¬
pendent on my success. But every atom that moves onward
in the river, from the moment it leaves its home amid the
crystal springs or mountain snows, throughout the fifteen hun¬
dred leagues of its devious pathway, until it is finally lost
in the vast waters of the gulf, is controlled by laws as fixed
and certain as those which direct the majestic march of the
heavenly spheres. Every phenomenon and apparent eccen¬
tricity of the river—its scouring and depositing action, its cav¬
ing banks, the formation of the bars at its mouth, the effect of
the waves and tides of the sea upon its currents and deposits
—is controlled by laws as immutable as the Creator, and the
engineer needs only to be assured that he does not ignore the
existence of any of these laws, to feel positively certain of
the result he^aims at. I therefore undertake the work with
a faith based upon the ever-constant ordinances of Çrod him¬
self ; and so certain as He will spare my life and faculties, I
will give to the Mississippi River, through His Grace and by
the application of His laws, a deep, open, safe, and permanent
outlet to the sea."
Several gentlemen of considerable means were interested
FINANCIAL AEEANGEMENTS.
67
■with Mr. Eads -when the concession -was granted by Congress.
With such means as they ■were willing to embark in the en¬
terprise, added to his own, it was evident that there would
still be needed a large sum of money to execute that portion
of the works required to insure a depth of twenty feet, at
which period only could government payments be expected.
It is proper to state that the estimates of the Commission of
1874 contemplated the construction of mattress work, as it was
executed at the Maas, in Holland. By the provision in the
act which left Mr. Eads " untrammeled in the design, loca¬
tion, and execution of the work," he was free to exercise his
ingenuity to discover some cheaper and equally effective
method of construction. In this he foresaw the opportunity
of so cheapening it as to leave a large margin of profit at the
price stipulated in the act.
The first step taken by him in solving the financial problem
was to execute a contract with the substantial contracting
firm of James Andrews & Co., by which that company agreed
to furnish, at their own cost, the necessary plant, steamers,
barges, boarding-houses, etc., and place in position fifty
thousand cubic yards of mattress work, and ten thousand cu¬
bic yards of stone, before demanding of Mr. Eads any pay¬
ment whatever. After this amount of work should be exe¬
cuted, one-half the agreed price for it was to be paid in cash,
and the remainder when certain payments should be received
by Mr. Eads from the United States. The prices agreed to
be paid were so high that the contract was limited to three
hundred and fifty thousand cubic yards of mattress work and
the attainment of twenty-six feet of water. We see thus far
two distinct parties interested—
First.—Mr. Eads and his associates, who controlled the
concession, and
Second.—The contractors who undertook to construct a cer¬
tain portion of the jetties.
68
THE MISSISSIPPI JETTIES.
It was necessary to provide for such additional funds as
should be required beyond the personal abilities of these
two parties. Hence a third company was formed, called the
South Pass Jetty Company, which was in reality a limited
partner with Mr. Eads and his associates, from whom it was
to receive one hundred per centum profit on such sums as it
should be required from time to time to advance to Mr. Eads,
and ten per cent, interest on the sums so advanced until they
were repaid. The payment of interest, principal, and profit
were solely dependent on the success of the enterprise, and
were secured to the company by assignments from Mr. Eads
of certain parts of the different payments set forth in the act
of concession. This company was strictly a financial one, and
had no control or voice in the direction of the work.
By the contract between Mr. Eads and the South Pass
Jetty Company, the amount of its advances was limited to
$200,000. This amount was subsequently increased to about
$500,000, owing mainly to the difficulties thrown in the way
of the enterprise by official hostility. The continued doubt
of success, which was sustained in the public mind through
the unreasonable hostility which during the first two or three
years continued to hamper the work, compelled Mr. Eads to
raise such additional amounts of money as were required, at
most exorbitant rates of interest.
CHAPTEE VII.
south pass—location of jetties—construction.
He who lives among the highlands will find it difficnlt,
from any verbal description, to form in his mind a true pic-
tnre of the lowlands of the Mississippi delta. But to him
who dwells among these marshes, descriptions of an upland
country come like restored pictures, bringing again the scenes
of the past. In imagination he stands on some lofty summit,
and beholds the range of mountains losing itself in the blue
hazy distance ; the shaded river meandering down the val¬
ley ; the fields of wheat and corn, that climb yon slopes to
the very summit; the pine-covered hills, clad in perennial
green ; the everlasting rocks, throwing out their jutting crags
against the sky, and the villages dotting the landscape here
and there, diversifying it with their picturesque beauty.
From this imaginative picture he turns with reluctance to
look upon his present surroundings. "With the exception of
the lighthouse, there was, in June, 1875, no elevation within
one hundred miles, nor any building, except a few fisher¬
men's huts, within ten miles of the mouth of South Pass. A
view from the top of the South Pass Lighthouse takes in the
whole country ; a low, flat marsh of mud, reeds, and grasses,
which, in long narrow strips, is thrust out into the gulf.
Except a solitary mud-lump, about two miles away, near an
outlying reef, there is not a spot as far as the eye can reach
that is not overflowed by the river or the tides. There is
69
70
THE MISSISSIPPI JETTIES.
not even a background of liigli land to relieve the monotony
of the scene ; but away to the eastward, just distinguished,
are the low, willow-fringed banks of Pass à Loutre, like a
dim pencil line drawn between the blue waters of Garden
Island Bay and the azure sky above. To the westward is
another dim horizon line, marking tlie course of Southwest
Pass. Around the whole half of the circle, from the north¬
east to the southwest, there is nothing to be seen but the
broad expanse of the Gulf of Mexico.
From the lighthouse, extending ten miles to the north¬
west, in easy, graceful curves, we can follow South Pass
through the yellow marsh, " a silver thread in a cloth of
gold;" and with a glass we can distinguish, nearly hid among
the willows, the lighthouse at the Head of the Passes. Half¬
way up on the west side of the pass, detected by the scat¬
tered clumps of trees along its banks, is Grand Bayou.
The South Pass is a beautiful, natural ship canal. There
is not a shoal, nor a sharp turn, nor a dangerous bank, nor a
snag even, in its whole length. In the presence of the great
river, or of even the two larger passes, it is only a bayou;
but in Europe or on the continent, it would be classed as a
river of considerable magnitude. The pass flows over a bed
and between banks formed of its own deposits. In cutting
its way through them it has shaped its channel to the exact
requirements of the volume and velocity of its waters. The
annual overflows deposit their coarser matters on the im¬
mediate banks, and the finer sediment farther away ; for this
reason the ground next the pass is about one foot higher
than that some distance from it. On the higher banks is a
dense growth of reeds, ten or twelve feet high, forming a
strip next the pass, about one hundred feet wide. A coarse
marsh grass grows in the lower ground. The width of the
land lying between the pass and the bays, in some places, is
not over one hundred yards, in others fully half a mile. "With
/
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"ftte jetties
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LOCATION AND CONSTEUCTION.
71
tlie exception of the higher ground next the pass, the whole
marsh is composed of a material so soft that it is difficult to
walk upon it, and a pole can be forced down into it with the
hand to a depth of five or ten feet. A few willow trees on
the right bank below Grand Bajou, and a few near the head
of the pass, constitute the only growth larger than the reeds
throughout its length.
In June, 1875, the only marks of cirilization beyond the
land's end at the mouth of the pass were a small white flag
here, a temporary platform there, a stake driven into a drift-
log imbedded in the mud, a tall tripod erected on a mud-
lump, or an instrument-stand on a reef; these told us that
the U. S. Coast Survey had just preceded us, and that each
shore and bar, each reef and contour line, each elevation and
depression in the pass, or in the gulf beyond it, had been
carefully surveyed and mapped out by those who for skill
and accuracy have a wide reputation. By a provision of the
jetty act, the Superintendent of the TJ. S. Coast Survey was
instructed to make " as soon as practicable, a careful topo¬
graphic and hydrographie survey of the pass and bar." The
surveying party. Assistant H. L. Marindin in charge, arrived
at the mouth of South Pass with the survey schooner i?e-
searcli, in April, 1875. Although delayed by fogs and rough
weather, he accomplished his work in the allotted time,
and presented Mr. Eads, on his arrival in May, with not
only a complete map of the mouth of the South Pass, but
of the pass itself. Grand Bayou and the Head of the Passes.
The results of his surveys at the mouth of the pass are
shown on Plate A. The plane of reference was mean low
water, as ascertained from daily readings, on a staflf gauge at
the lighthouse, taken during the period covered by the sur¬
vey. This plane was 1.8 feet below that of average flood tide
—the datum plane—subsequently established by the U. S.
Engineers. The soundings have been changed on the chart to
72
THE MISSISSIPPI JETTIES.
agree with the latter plane of reference. The characteristic
soundings only are given, with the most important contours.
The shore lines, and all elevations above average flood tide,
are bounded by full lines. The chart shows that the greatest
depth along the whole length of the bar was 9.2 feet, or at
mean low water 7.5 feet. At flood river the navigable depth
was about eight feet at average flood tide. It also shows that
a plateau, nearly level and about three thousand feet in width,
extended from the outer crest of the bar, back towards the
land's end. On the very crest or shoalest part, nearest the
deep water of the gulf, the material was a flne sand, out of
which the waves and currents had washed all the clayey mat¬
ter, and disposed it in a narrow ridge, about a foot higher
than the remainder of the plateau. Immediately seaward of
the bar-crest was a softer material. This outlying slope was
very uneven, composed of hills and hollows arranged some¬
what uniformly in lines parallel with the outer face of the bar.
These features, and other interesting facts connected with
the geology of the bar, will be discussed in a subsequent
chapter.
Mr. Eads studied this chart, and laid out the lines of the
jetties upon it. He was accompanied at the time of his visit
to South Pass by Mr. James Andrews, who, with his associ¬
ates, had contracted to construct the works, and who imme¬
diately commenced the execution of his contract, for which
he was eminently fitted, by a long and successful experience
on public works—railroads, tunnels, bridges, especially the
foundations of the St. Louis Bridge and the large tunnel con¬
nected with it, extending under the city.
Mr. Andrews possessed those peculiar qualities demanded
of the contractor by a hazardous and difficult enterprise, and
by a work requiring great rapidity in construction, regardless
of financial hindrances and of losses and delays caused by
the destructive forces of the gulf waves and river currents.
LOCATION ÄND CONSTEUCTION.
73
He brought to the work the qualities that had made him so
successful elsewhere, and had won for him the respect and
admiration of all who knew him—great energy and persist¬
ence, an iiiTincible will, a quiet determination, and an un¬
swerving confidence in the success of the enterprise.
The considerations which determined the location of the
jetties were.
First.—To place them at such a distance apart as would
make them secure against any subsidence of the ground on
which they were to rest, that might be induced by the exca¬
vation of a deep channel near them.
Second.—To direct the discharge into the sea across the
littoral current, and not against it.
Third.—To inclose the natural channel within the jetties,
and thus leave the shoalest water on each side of it, in which
to construct the jetties, and thus lessen their cost. In deter¬
mining the width of the jetty channel, Mr. Eads intended
from the first to close Grand Bayou, and, consequently, he
would have to control as much water as there was in the
pass above Grand Bayou. The average width of this part
of the pass is seven hundred, feet, with an average depth of
over thirty feet. Mr. Eads believed that a greater area of
cross-section would ultimately be attained between the jet¬
ties, especially near the sea end, than that which the cur¬
rent of the river alone could maintain in the pass, owing to
the erosive action of the tides, and that it would not be safe,
for this reason, to place the jetties nearer than one thousand
feet from each other.
"With respect to the second consideration, it is an observed
fact, that delta-forming rivers, when they enter the sea, have
a tendency to direct their currents against the littoral cur¬
rents of the sea, for the reason, that the suspended sediment
which they discharge is carried by the sea to the leeward
bank of the river, and the accretions, which are made upon
74
the mississippi jetties.
this bank from the river discharge, cause it to grow more
rapidly than the other, and finally to curve the fluvial
current around against the littoral current. For this rea¬
son the direction of the discharge from the South Pass,
and the direction of the pass itself, is from northwest to
southeast, while the prevailing littoral current is from the
east.
No doubt the direction of the main river, from northwest
to southeast for the lowest one hundred miles of its course,
has been determined by the tendency of the prevailing winds
and the littoral current of the gulf to increase the sediment
embankment upon its western shore, and thus give the cur¬
rent of the river a tendency to oppose the littoral current of
the gulf. To direct the current from the pass completely
at right angles with the littoral current, would have been
very desirable, but it would have involved too great a curva¬
ture in the alignment of the jetties, and the curve which is
thrown into this alignment may be said to be a compromise
between the desire to make the current of the river cross the
littoral current at right angles, and the fear of causing the
deepest part of the channel between the jetties to follow the
concave side of the jetty channel too closely, and thus en¬
danger the stability of the east jetty, in the part where the
curve exists.
The following from the daily journal of Mr. Bayley, the
Eesident Engineer, will serve to introduce the narrative of
the construction work.
" JuneVitli.—James Andrews started from New Orleans
about one o'clock a.m., with a steam tug, towing a floating
steam pile-driver and three flat-boats, one of which was fitted
up as a boarding boat, and the. other two were loaded with
materials for three framed houses, to be erected at Port Eads,
for quarters, warehouse, and oflices, and with other materials
for the works. On the same day, the stern-wheel steamboat
LOCATION AND CONSTEUCTION.
75
Orafton arrived at New Orleans from St. Louis, with a barge
loaded with coal and machinery.
" June —Three mooring piles were driven in the edge
of the pass, and several for the foundation of the houses.
The steamboat Grafton, with coal barge and machinery, ar¬
rived at Port Eads to-day.
" June IMTi to 16f/i.—Piles were driven for a wharf at
' East Point,' at the land's end, on the east side.
" June 11th.—Work on the east jetty was commenced, by
driving piles from the land's end in the direction of the
' wreck ' (shown on the chart)."
The east jetty extended twelve hundred feet from the land's
end, in the direction of the "wreck." It then deflected to
the right or westward one foot in twenty-three feet, in a
straight line, for a distance of two thousand eight hundred
feet; then one foot in sixteen feet, for four thousand one
hundred feet. At this point (eight thousand one hundred
feet from " East Point "), a curve commenced, still deflecting
to the westward, with a radius of eleven thousand seven hun¬
dred and twenty feet, in chords of six hundred feet. This
curve, with the six hundred feet chords, was extended to a
point eleven thousand seven hundred feet from the land's
end. It was then continued with the same radius a distance
of four hundred feet, making the total length of the east
jetty twelve thousand one hundred feet, or nearly two and
one-third miles. This alignment was established by a line
of piling, the first mile of which consisted of two rows,
twelve feet apart, the piles in each row being eight feet
apart. Over the remainder of the jetty line only one row
was driven, and the distances between the piles varied from
ten to twenty feet. With the exception of those in the first
mile, where it was intended to use sheet piling, the piles
were simply guides for sinking the willow mattresses, which
constituted by far the largest and most important part of the
76
THE MISSISSIPPI JETTIES.
jetties. As the " mattress " was a novel and peculiar plan
for using willows in sea-walls and dykes, a description and
sketch of it is given.
About forty-five years ago the river broke through its west
bank, twelve miles above the head of the passes, at a narrow
fisherman's canal that led up to it from the gulf. In a short
time a torrent eighteen hundred feet wide and sixty feet deep
swept through this crevasse. For a long time the river at
flood poured through it with great velocity, and spread its
muddy waters far and wide over the shallow bay. The same
principles that produced a delta at the mouth of the river
formed one here. After the lapse of years there appeared
well-marked channels, three or four feet deeper than the ad¬
joining shoals, which gradually rose to the surface by he de¬
posits of successive overflows. These shoals confined the cur¬
rents still more to the channels, and increased their depth.
The seeds of grasses, flags and reeds that came down with the
river found a lodgment on the half-submerged banks, and soon
covered them with a rank vegetation. This growth caught
the sediment carried into it by the overflowing waters and
built up the banks still higher, on which sprang up a
dense growth of willows, crowding out the weaker vegetation
and taking possession of the whole district. A richer and
more conveniently arranged harvest-field for the jetties than
this great tract of willows could not have been found. This
crevasse is generally known as the " Jump." The passes of
the Jump were sufficiently wide and deep to admit a good-
sized steamboat, and they ramified this sub-delta in every
direction.
The Avillows grow six or eight feet in height every year,
and the more freg^uently they are cut the denser is the
growth. The willows used in the mattresses were from fif¬
teen to thirty feet in length, and from one inch to two and
one-half inches in diameter at the butt. The trees of two or
LOCATION AND CONSTKUCTION.
77
tliree years' growth are straight and free from branches, and
much better adapted for the mattress work than the crooked
limbs of the larger trees. The willows were cut and loaded
on barges. The steamboat Grafton took the empty barges
into the Jump, placed them where needed, and brought them
out when loaded. These barges were from one hundred and
twenty-fiye feet to two hundred and twenty-fire feet in
length.
The men who cut the willows, in order to be near their
work, lived in boarding-boats, that were moved from one
place to another. The task they had was not an enviable
one, as the ground, or rather mud, was overflowed by high
river and high tides, and it was necessary to carry the wil¬
lows in bundles sometimes four hundred or five hundred feet,
the men sinking at every step into the soft mud. The wil¬
lows were piled up compactly ten or twelve feet high on
the deck of the barges, the butts in the middle and the tops
overhanging the sides. When properly loaded, the large
barges carried from four hundred to six hundred cords. They
were towed to Port Eads and placed alongside the mattress
ways on which the mattresses were built. The ways are
shown in plan and elevation on Plate 6, the mattress on
Plate 7.
Piled up near the ways were strips or scantling, of yellow
pine, six inches wide, two and one-half inches thick, and from
twentj^ feet to forty feet in length. They were placed on
small trucks, and run on the platform to the place where the
mattress was to be constructed ; they were lifted upon the
ways and placed side by side, as many as were necessary for
the width of the mattress ; if forty feet wide, nine strips
were used, spaced five feet apart from center to center. The
mattresses were usually one hundred feet in length. To make
that length, the strips were connected by a lap joint, the lap
being the same size as the strip—about six feet long—-and fas-
78
THE MISSISSIPPI JETTIES.
tened to the main strip with five-inch spikes. When this
work was finished, one and one-eighth inch holes, five feet
apart, were bored through each strip. Bound hickory pins
or stakes, about two feet long between shoulders, with the
ends turned to fit these holes tightly, were driven through
the strips. The ends of the pins were cut off flush with the
bottom of the strip, and oak wedges about three inches
long were driven into them, and twenty-penny nails were
toenailed through the strip. The strips were then moved
down the ways, the lowest one being placed near and parallel
with the water's edge. They were spaced with a gauge
four and one-half feet apart in the clear, and held in place
temporarily by an inch board tacked across them.
The willows were then passed from the barge to the
mattress gang, who placed them in the bays between the
rows of pins and at right angles to the strips, the brushy
tops overhanging the frame about three feet. When the
whole surface of the mattress was raised about two-thirds
of its height, another layer was laid at right angles to the
first, and brought up two or three inches higher than the
tops of the pins. Strips, the same size as those in the bot¬
tom frame, were placed across the mattress for binders, in
which holes were bored to receive the tops of the pins,
and the binders were forced down on them by wooden
mauls and levers. The pins were held in place by wedges
and nails, as in the bottom strips. To strengthen the
mattress, longitudinal strips were fastened to the binders
near the edge of the mattress. When the mattress was to
be exposed to heavy seas, iron screw-bolts were used in the
corners in place of hickory pins.
Previous to filling the mattress, a bridle line of rope, two
inches in diameter, with an eye in the center, was arranged
as follows; The running ends were drawn under the frame
to near the upper corner, and fastened temporarily to one of
LOCATION AND CONSTRUCTION.
79
the pins with spun-yarn. The eye of the bridle was outside
of the frame next to the water, and that also was lashed to
a pin, so that it could be reached easily, when the mattress
was ready for launching. Two head lines, one and one-quar¬
ter inches in diameter, and about seventy-five feet long, were
fastened in the end of the frame in the same manner, a trip
line three-quarters of an inch in diameter being spliced into
the end of the head lines.
When the mattress was finished, the running ends of the
bridle were made fast to a piece of mattress strip, about six
feet long, placed across two binders. Similar toggles were
run through the eyes of the head lines, and their running
ends coiled up on the mattress, which was then ready to be
launched. The steam tug came alongside and made fast to
the eye of the bridle, and moving out into the pass launched
the mattress, which was towed, either alongside or astern, to
near its intended position along the jetty piling. The posi¬
tion of the sea end of the mattress previously sunken had
been carefully noted, and the upper end of the new mattress
was brought to that point. The yawl crew ran out with long
lines, tied to the head lines, and made them fast to the
guide piles, some distance above the location of the mat¬
tress. The tug then " let go," and the mattress was swung
by the current to its place along the guide piling. A stone-
barge was then placed against the river edge of the floating
mattress, and the rubble rock or riprap was carried out and
spread evenly over it, until it was nearly sunken beneath the
surface. The rock was then thrown upon the edge next the
barge, which was swung by the force of the current over the
sinking mattress, the rock in the meantime being thrown
upon it rapidly. When the mattress was sunken, the long
lines that held it to the piles were let go, and underrun, to
where they were made fast to the head lines ; the bow-line
was untied, and the head lines drawn up through the mat-
80
THE MISSISSIPPI JETTIES.
tress by tbe trip lines, wbicb liacl previously been made fast
to tbe piles above the surface of the water.
With slight variation in manner of construction, handling,
and sinking, this plan was followed throughout the whole
work.
The plan of these mattresses was the joint invention of Mr.
Eads and Col. Andrews, and was patented by them. With
the strips, pins, and willows, ready at the ways, it was possi¬
ble to make and launch a mattress one hundred feet long,
thirty-five feet wide, and two feet thick, in two hours. By
the Dutch system the same size of mattress would probably
require at least two days for its manufacture.
00 «onoHHi. N0IX03S
CHAPTEK VIII.
consteuction—de8ceipti0n and peogeess op woeks at the
mouth of south pass, feom june, 1875, to june, 1876.
The economy of the jetty system at the mouths of sedi¬
ment-bearing rivers is largely dependent upon the rapidity
with which the works are constructed. The re-formation of
the bar seaward of them is probably hastened, and in some
instances produced by a dilatory construction, and these
evils ai'e prevented by their prompt completion.
This and other important reasons demanded rapid con¬
struction at the mouth of South Pass. By the provisions of
the act the government made no returns to Mr. Eads for his
large outlays until he had secured the prescribed channels.
Again, as the payment for the first channel of twenty feet
depth would cover only a small part of the expenses incurred
in obtaining it, it was necessary that the greater channels, in
fact the maximum channel, should be obtained as quickly
as possible. For these reasons strenuous exertions were
made to push the work forward, both in raising the necessary
capital and in supplying the materials and plant for the
work. The verbal and written instructions of Mr. Eads to
his assistants dwelt constantly on the necessity for rapid con¬
struction.
As he and Mr. Andrews were both unavoidably absent during
the summer and early fall, the general direction of affairs was
given to Mr. Bayley, who was stationed at New Orleans, that
6 81
82
THE MISSISSIPPI JETTIES.
lie miglit be able to attend promptly to tbe finances and sup¬
plies.
The details of the construction work were, under the super¬
vision of Mr. Bayley, intrusted to E. L. Oorthell, the Chief
Assistant Engineer, who was instructed to do all that in his
judgment was considered necessary to hasten the work for
securing the twenty-feet channel at the earliest possible mo¬
ment. As this result depended in a great measure upon the
facilities for building mattresses, the construction of mattress
ways was hurried forward, and in one month from the sink¬
ing of the first mattress, five hundred lineal feet of ways were
completed, and on the 15th of September, eight hundred lin¬
eal feet were ready—three hundred and fifty feet on the east
side of the pass and four hundred and fifty feet on the west
side.
The reeds were cut down on each side of the pass for a
width of seventy-five feet ñ'om the banks, for store-room for
piles, mattress strips, lumber of various kinds, stone, coal,
etc., and the necessary shops, houses, wharves, and walks
were built. The banks, which early in June were uninhab¬
ited and desolate, were now alive with men engaged in their
various vocations, and resounded to the sound of axe and an¬
vil, pile-driving, and the whistling and puffing of the tugs and
steamboats.
The experience of the engineer in charge, gathered from his
letter-book and journal, will show with what urgency both the
preparatory and construction work were pressed, and will ex¬
cuse the absence, in the record of that period, of any scien¬
tific observations which may have been expected of him by
his professional brothers.
Being unfortunately without assistants for some time, he
was superintendent of the works, engineer in charge, transit-
man, draughtsman, chainman, recorder, and calculator. His
daily work consisted in measuring and checking, by instru-
CONSTEÜCTION.
83
mental angles from two stations a mile or more apart, the lo¬
cation of the guide piling of the east jetty, which was being
rapidly extended out to sea by two pile-drivers ; calculating
the distances for the back ranges by which each chord of six
hundred feet was driven; establishing the right angle for
them with a pocket sextant ; making surveys to ascertain the
effect of the mattresses upon the channel, and taking sound¬
ings along the line of the piles each day, and over the whole
length of the piling at least once a week. It often happened
that, while superintending the surveys and at the same time
measuring the angles with a transit set up on "East Point"
wharf, he was obliged to read and answer important dis¬
patches relating to the progress of the work, and reply to
questions from New Orleans about the character and quan¬
tity of material needed, and at the same time direct sev¬
eral gangs that were building mattresses, ways, houses,
wharves, flats, walks, etc., or, in other words, superintending
the numerous constructions carried on by a force of three
hundred men. It was a satisfaction to ascertain later, by the
measurements of the United States inspecting officer, that the
sea end of the guide piling, established under such difficul¬
ties two and one-third miles from the land's end, was cor¬
rectly located within the possible error of one foot.
Throughout the summer the work was greatly delayed by
inability to procure good laborers, and by the failure of the
contractor to furnish willows in sufficient quantities for the
work. These various difficulties were, however," more than
counterbalanced by having experienced and capable foremen ;
by a rigid enforcement of total abstinence from intoxicating
liquors ; by prompt payment of laborers and bills for sup¬
plies, and, by direct communication by telegraph with New
Orleans. These were the personal conditions that affected
the progress of the work. In the meantime the construction
was going forward as rapidly as the circumstances would al-
84
THE MISSISSIPPI JETTIES.
low. A description of eacli work and results accomplislied
during the year will be given briefly.
On September 9th the guide piling of the east jetty was
finished, its terminus being twelve thousand one hundred
feet from the land's end. For convenience the distances
were noted like the stations of one hundred feet used in
railroad construction. The initial point, or zero, for all dis¬
tances and measurements on both jetties was "East Point;"
thus the end of the east jetty was at Station 121. Every
fifth guide pile was numbered and marked, and its distance
noted. The location of the mattresses was plotted on the
profile by knowing their position in reference to those piles.
The foundation mattresses were laid in advance of other
work ; they were from thirty-five to fifty feet wide, two feet
thick, and from seventy-five to one hundred feet long. This
formed a continuous carpeting, which prevented any deepen¬
ing of the bottom in advance of the work as it progressed
seaward.
In order to hasten forward the construction of the east
jetty, near the sea end, the first mile was constructed of
sheet piling, after the base had been protected by a mattress
carpeting. The sheet piles were driven by two traveling
drivers, moving forward on the two rows of piles previously
spoken of, which were cut off to an uniform height about
two and one-half feet above average flood tide. One of these
drivers was arranged like an ordinary pile-driver, the ham¬
mer weighing about tAvelve hundred pounds, and running
between guides or leaders. It was raised by a line running
through a sheave in the head block of the leaders, and thence
to the drum of the engine. In the second driver the ham¬
mer whs raised by friction gearing. • It was composed of aç
iron head weighing three hundred and fifty pounds, with a
Avooden stem about twenty-four feet long attached to it, and
made of three pieces of oak, the whole weighing about
CO
U1
H
<
J
CL
SHEET PILING
¡sffls'iysia
^^Á\i. ; ;
X:'
CONSTRUCTION.
85
twelve hundred pounds. In order to raise the hammer, two
iron friction rollers were forced against the sten^ by a lever
worked by a steam cylinder ; the rollers were then revolved
by a pulley from the engine. When the hammer was raised
to the required height, the pressure on the lever was re¬
moved by exhausting the steam in the cylinder ; the rollers
separated about one-quarter of an inch, and the hammer
thus freed dropped upon the pile. The machinery was
geared to give a quick motion to the rollers, and the blows
were given in rapid succession. The details of the construc¬
tion of the driver, with a section of the sheet piling, are shown
on Plate 8.
The sheet piles were of yellow .pine, from twelve to four¬
teen inches wide, five inches thick at the upper end and three
inches at the lower end. They were from fifteen to twenty-
five feet in length. A waling timber (6" by 12") was fastened
with screw-bolts to the sea side of the river row of large
piles, so that its upper surface was two inches above the da¬
tum plane. The sheet piles were driven close together, edge
to edge, and as near as possible to the top of the waling tim¬
ber, and were then fastened to it with eleven-inch drift bolts.
The average depth driven was twelve feet ; depth of water
nine feet ; fall of hammer fourteen feet ; number of blows
fifteen; number of piles driven per day by the ordinary
driver, sixty-eight ; by the friction driver, seventyrseven. On
one day, in seven and a half hours' work, one hundred and
seventy-six piles were driven by the friction driver. The
sheet piling was commenced the last of August, and com¬
pleted in October, extending to Station 52 + 80.
Wheu the river rose in the winter, it brought a head of
water against the piling on the river side, which at ebb tide
often amounted to four inches. As the foundation was sand,
it was very soon affected by the cuiTent, which forced its way
through the small openings between the piles, and made deep
86 THE MISSISSIPPI JETTIES.
holes under them, in several places washing out the sheet
piles, and in two places both rows of guide piles.
In order to stop this undermining of the work, mattresses
eight feet wide and three and one-half feet thick were built
on skids hung from the tops of the two rows of piles, and
lowered to the bottom between them. Fourteen hundred lin¬
eal feet were protected in this manner. The mattresses be¬
yond the sheet piling in the line of the jetty were laid only
on the river side of the guide piling. As each course was
narrower than the one immediately underneath—the course
at the surface of the water being twenty or twenty-five feet
wide—a slope was formed on the river side. This plan was
adopted for the sake of economy, expecting that the deposits
on the sea side of the jetties would protect them from wave
action.
On the 30th of November two courses of mattresses were
laid to Station 115 ; in February, 1876, to Station 119, and in
March the whole jetty, with the exception of the first mile,
where sheet piling had been driven, was raised to the surface
of the water. Reference is made to cross-sections of the east
jetty, shown on Plate 9, for widths and thickness of the vari¬
ous courses. Previous to construction the least depth of
water on the line of the east jetty was six feet, the greatest
depth thirty feet, and the mean depth eight feet.
The guide piling of the west jetty was commenced Sep¬
tember 21st, at Station 40 + 58, six hundred and fifty-one feet
from " Kipp " Signal Station, and one thousand feet from the
east jetty guide piling, and was extended seaward parallel
with it. Foundation mattresses, thirty-ÜA'e feet wide and two
feet thick, were laid on both sides of the piles to Station 83.
At this point the work was suspended to await the decision
of the Advisory Board of Engineers, which had assembled by
request of Mr. Eads, and to whom he submitted his plans for
the location and construction of the ivorks, with the view of
Section of Jetties.
between EAST POI NT and 6500 resp. 9000 FEET SEAWARD
iScaleoS^eet
lb. li
V
CONSTRUCTION.
87
guarding against the possibility of error. They advised a
radius of fifteen thousand feet for the west jetty curve, its
terminal point at the sea end to be one thousand feet from
the east jetty, and the beginning of the curve to be at Sta¬
tion 69 + 15. (See Appendix 4 for full proceedings of the
Board.)
The piles driven beyond this point were cut off even with
the surface of the mattresses ; the new line was commenced at
the point named, and carried, with its designated radius, over
the crest of the bar to its terminal point at Station 117 + 60,
the distances between the piles varying from sixteen to
twenty-nine feet. Messrs. Eads and Andrews returned to
Port Eads about the last of October. The force was largely
increased, and the work was pushed forward through the fall
and winter with still greater energy.
"Kipp Dam," or the work connecting the west jetty with
the shore line at " Kipp " Signal Station, was finished first.
The length of this dam is five hundred and fifty feet.
The depth of water increased gradually from the shore line
to eighteen feet at the west jetty. A row of piles eight feet
apart was driven, and a waling-strake of 6" x 12" timber was
bolted to them. Foundation mattresses sixty feet wide and
two feet thick were sunk above them. On the first course
wooden aprons sixty feet in length were placed in a vertical
position, rising two feet above the datum plane. These
aprons were sections of wooden dams constructed and sunk
as follows : The ways, on which they were constructed, were
built like mattress ways, but of lighter material, the timbers
being 4" x 4" scantling, placed five feet apart, and extending
back from the river about twenty-five feet. Two battens were
first laid down on the ways at right angles to them, the dis¬
tance between these battens corresponding to the width of the
apron. Three-inch plank laid close together were then spiked
across these battens, the tops being even and the lower ends
88
THE MISSISSIPPI JETTIES.
uneven, to conform to tlie irregular stape of the mattresses
on which they were to rest. Two battens were then spiked
to the upper surface of the planks, immediately over and
lengthwise with those placed underneath. The apron was
then launched from the ways by the tug, and towed to its
place along the dam. The pile-driver then raised it into a
vertical position, the force of the current pressing it closely
against the guide piling. It was then forced down to the
mattresses by means of levers and the pile-driver hammer.
Piles were then driven on the upstream side of the apron and
bolted to the guide piles, thus pinning the apron in its place.
A timber Avas then bolted across above the aprOn to prevent
its rising at flood tide by its buoyancy or by the lifting power
of the Avaves. A second course of mattresses, thirty-two feet
wide and two feet thick, was then laid horizontally on the up¬
stream side of the aprons and against them. The aprons
along the whole length of the dam were put in place in one
day—^November 28th, 1875.
Although the river was very low, yet this sudden obstruction
to the current produced a head of water above the dam which
at ebb tide was between seven and eight inches. This forced
a strong current through the opening between the lower edge
of the aprons and the mattresses, which excavated deep holes
below the dam, where no protecting mattresses had been
laid—at one place increasing the depth from ten feet to thirty
feet, and producing an average deepening along the whole
line of the dam of from eight to ten feet. Although this
deepening did not extend more than sixty feet beyond the
dam, yet it was sufficient to undermine the lower edge of the
mattresses, and at one point to wash out the piles for a space
of fifty feet—carrying the apron through the opening. The
piles along the whole length of the dam were undermined,
and the work was in danger of being swept away.
A second row of piles was driven eight feet apart and ten
CONSTBÜCTION.
89
feet above tbe old row. An attempt to build another tempo¬
rary structure against this row of piling was made, but soon
abandoned, as tbe force of tbe current broke it down. Tbe
dam was tben built to tbe surface as quickly as possible,
witb mattresses laid borizontally, after wbicb tbe deep boles
tbat bad been excavated bebind tbe dam slowly filled up
witb deposits of sediment.
Immediately after placing tbe aprons along Kipp dam, tbe
same kind of work was placed along tbe west jetty, connect¬
ing witb tbe aprons of tbe dam, and extending seaward tbree
thousand and forty feet. Tbe aprons varied in height from
six to fourteen feet, according to tbe -depth of tbe water, and
rested on tbe second course of mattresses.
It was fortunate for tbe stability of tbe jetty tbat mat¬
tresses bad been laid previously along tbe whole length of
this apron work, on tbe sea side of tbe guide piles ; but even
witb this ample protection, tbe bead of water forced tbe
current under tbe apron witb such a velocity as to produce
an overfall at tbe western edge of tbe mattresses, and a
partial undermining of tbem. Had these mattresses not been
laid, there is no doubt all this work would have been under¬
mined and destroyed.
A severe storm, wbicb occurred on December 22d, broke
up several of tbe aprons, after wbicb a third course of mat¬
tresses was laid as soon as possible along tbe whole length
of this work, effectually securing it. Tbe uniform width of
tbe foundation mattresses of tbe west jetty was thirty-five
feet, and extended to tbe sea end of tbe guide piling.
Tbe succeeding courses were narrower, being reduced to
a width of twenty-five feet at tbe surface. Before construc¬
tion tbe greatest depth of water on tbe line of tbe jetty was
eighteen feet ; tbe least depth seven and a half feet ; and tbe
mean depth twelve feet. Tbe whole jetty was raised to tbe
surface of low water about April 1st, 1876.
90
THE MISSISSIPPI JETTIES.
From April to July 1st, the time was occupied in buildii^
up the low places on the jetties ; in reinforcing the river side
of the sheet piling with a course of mattresses ; in placing
stone on the exposed portions of the works, and especially
in constructing wing-dams or spurs at right angles to the
jetties. The immediate object of this latter work was to
hasten the development of the channel, by contracting the
water-way from about nine hundred and fifty feet to seven
hundred feet. There were several localities in the channel
where the material was a tough clay, holding out obstinately
against the eroding force of the current.
A contraction near the sea ends of the jetties was espe¬
cially needed, for there the volume of water was much less
than in the channel above, on account of the cumulative
amount of leakage through and over the jetties, as the sea
end was approached. From this cause thirty-five or forty
per cent, of the volume of water passing "East Point" es¬
caped before reaching the gulf.
Between the first of May and the last of June, eight wing-
dams were built, or in all about twelve hundred lineal feet.
They were located in pairs from Station 90 to Station 118 ;
those on the west jetty being opposite to the corresponding
dams on the east jetty.
The method of construction was as follows : A line of
guide piles was driven out from the jetty about one hundred
and fifty feet towards the channel. Foundation mattresses
were sunk above these piles, connecting with the jetty mat¬
tresses, and extending fifty feet beyond the end of the pro¬
posed dam ; a second row of piles was driven through them,
twelve feet from the lower edge and eight feet apart, and a
waling-strake Avas bolted to the lower side of the piles two
feet above the datum plane. The mattresses for the dams
were seventy-five feet long and from one to two feet thick,
one edge being straight and the other irregular or sloping, to
CONSTEÜCTION.
91
eonform to the depth of water on the foundation mattress.
The mattresses having been towed to near their places above
the dam, were lifted up by a steam pile-driver, which raised
the lower edge sufficiently to allow the current to strike
against the side of the mattresses, forcing them to their
places in a vertical position against the piles, where they
were held in a manner similar to the wooden aprons pre¬
viously described.
These dams did not stop the current completely, but
checked it only. They were intended to be temporary
structures, and to meet an immediate want. They accom¬
plished their object effectually, and proved to be imj)ortant
aids in the final development of the channel.
The concurrent results of the works constructed during
the first year at the mouth of the pass, will be given in the
following chapter; the estimate of the cost of construction
of the mattress work is given in Appendix 5.
CHAPTEE IX.
advisoet board—results of works—financial embarrass¬
ments—government engineers.
The location and plans for tlie construction of the jetties
and other works, determined upon by Mr. Eads, were ap¬
proved by the Advisory Board of Engineers, which met first
at New York, September 2d, and at Port Eads November
18th, 1875. This board was composed of experienced and
distinguished engineers—Gen. J. G. Barnard, U. S. A. ; Gen.
B. S. Alexander, U. S. A. ; Sir Charles A. Hartley ; W. Milnor
Koberts, 0. E. ; T. E. Sickles, C. E. ; Prof. Henry Mitchell,
United States Coast Survey, and H. D. Whitcomb, C. E. On
the motion of Sir Charles Hartley, Gen. Barnard was chosen
President. They decided upon the alignment of the jetties,
and approved of the mattress construction, which, they say,
" is essentially the same as that applied to the jetties at the
mouth of the Oder, and also to the jetties at the mouth of the
Maas, so successfully as to draw from the lower legislative
body of Holland the announcement that ' their complete suc¬
cess has removed all doubts as to the possibility of making
piers at sea on our coast.' "
The Board made a careful examination of the works begun,
and of the location of other works, and, after advising in refer¬
ence to them, gave its general opinion in regard to the pros¬
pects of their ultimate success. In reference to South Pass
93
ADVISOEY BOAED.
93
itself, they believed that it would furnish an open mouth of
ample depth for the largest class of sea-going vessels.
They had previously satisfied themselves that the opinions
expressed by many, that the local peculiarities of the South
Pass bar—its extreme softness, eruptive mud-lumps, etc.—
would thwart efforts to lay upon it substantial and perma¬
nent engineering constructions, were unfounded, and they say :
" It is satisfactory to be able to state positively, after four
months of actual operations, that the work of pile-driving, ex¬
tending from the east land's end to twenty-six feet depth be¬
yond the bar crest, * * * and an examination of the
texture of the bar and of the shoals on which the works are
to rest, furnish the most satisfactory evidence of a bottom
material not only adequate to bear all the necessary works,
but even to suggest that but for motives of economy, the jet¬
ties, as at the Sulina mouth of the Danube, might be made
wholly of stone." They stated that the difficulties were much
less than those attending the construction of several recent
successful works of the kind, on European shores, examined by
the members of the_ Commission. They considered the delta
of the Mississippi and the Danube similar in many impor¬
tant respects, but the mouth of the South Pass of the Missis¬
sippi, owing to the greater sea depths beyond the crest of its
bar, more susceptible of improvement than was the Sulina
mouth of the Danube. They entertained no doubt as to the
efficiency and permanency of the jetties when they should
have been completed upon the location and plans heretofore
approved by them. (See Appendix 4 for full report of the
Board.)
At the end of the first year's work the jetties were simply
walls of uncompressed willows, but even in this unfinished and
unconsolidated condition they effected very important results.
This principle was from the beginning forcibly illustrated,
that with a bed composed of a material that will yield readily
94
THE MISSISSIPPI JETTIES.
to the abrading power of the current, any obstruction, how¬
ever small, will cause a corresponding deepening somewhere
in its vicinity.
The first intimation that such a result had occurred here,
was the deepening noticed in the channel near the foundation
mattresses very soon after they were sunken.
After the construction of Kipp dam and the aproas of the
west jetty, a deepening of two or three feet took place in the
channel near these works, although the river was at that time
at a very low stage, the result being due almost entirely to
the outflow of the ebb tide. The river rose in January, 1876,
and the floods that had hitherto found a wide mouth through
which to discharge their waters now struggled to reach the
sea through a contracted outlet. Finding the bar like a dam
in the channel, they attacked it with great force, the first re¬
sult of which was that wherever there were deposits of
sand a rapid and decided deepening occurred. Over the
whole two and one-third miles from the land's end to the
gulf, a most irregular channel appeared, full of ridges,
mounds, deep excavations, and suddenly appearing and dis¬
appearing shoals and channels, but after a time compara¬
tive uniformity in section and regularity in the course of
the channel took the place of these variable conditions.
Cross sections of the channel at various points, shown on
Plate 10, and the profile of the bar, on Plate 11, will more
clearly illustrate the channel development. For a more de¬
tailed study of the subject, tables in Appendices 6 and 7 are
referred to, which show the progressive changes in the
channel in the line of the greatest depth, and the gradual
disappearance of the bar by the removal of interruptions to
the contour lines of various depths. The improvement of
the channel, for the benefit of navigation, can be clearly seen
from the following table, which shows the draught of water
which could be taken through each two thousand feet of the
PLATE lO.
iSfít/'iOeJ UP y,c u »» .PC UP »00 •o^'^
-
^
^
\ "n
! ■->•■■■ ^7
Sin 105 EJ
^Lc-—
' - '
■\
1 ==;::y-" \ 1 ^
i ! 't>- ^
/
/ / 1 1
' ' 1 ■ ^
. • 1 1
1 i
CROSS SECTIONS
or
JETTY CHANNEL
SHOWING RESULTS DÜRING FIRST YEAR
isra-re
RESULTS OE WORKS. 95
channel below East Point Station, in June, 1875, and in May,
1876:
Distances in feet^
0-2,000
2,000-4,000
4,000-6,000
6,000-8,000
8,000-10,000
10,000--12,100
feet.
feet.
ieet.
feet.
feet.
feet.
Draught, 1875..
23.5
18.7
16,7
10.3
9.7
9.3
Draught, 1876..
33.3
20.8
23.0
23.1
34.1
16.9
The total amount of material scoured out of the bar by the
current and carried into the gulf in one year was 1,711,200
cubic yards. Deducting from this quantity the amount of
shoaling at various points near the jetties, we have 1,519,812
cubic yards, which is the amount to be considered in the
channel development.
The principle stated in a preceding chapter, that when jet¬
ties are commenced at the mouths of sediment-bearing rivers
it is important to hasten them to completion, is forcibly illus¬
trated by the effect upon the bar of the partial contraction of
the waterway during the summer and fall of 1875, especially
upon the crest of the bar ; for in October the depth over it
had diminished from 9.2 feet to 7.5 feet.
During the development of the channel extensive deposits
of sediment occurred on the sea side of both jetties. As
early as August, 1875, examinations showed that deposits were
being made both on and behind the mattresses of the east
jetty, and the land was rapidly forming and extending some
distance seaward of the jetty piling. Gen. C. B. Comstock,
United States Engineers, who had been appointed by the
Secretary of "War, as inspecting officer for the government,
in his report of June 9th, 1876, stated that extensive shoaling
had taken place on the outside of the west jetty, and from a
table of depths given we find that over the first 2,000 feet the
96
THE MISSISSIPPI JETTIES.
depth of shoaling was 8.1 feet, over the second 2,000 feet, 11
feet, over the third 2,000 feet, 8 feet, and over the fourth
2,000 feet, 5.5 feet.
The channel had deepened so rapidly during the months
of January and February, 1876, that Mr. Eads was desirous
of celebrating the 4th of March—the anniversary of the pas¬
sage of the jetty act—by sending the first sea-going vessel
through the jetties. He arranged for the three-masted
schooner Ilattie Atioood, bound for Kevel, Eussia, to go to sea
through South Pass, on that day. She was loaded with
two thousand one hundred and fifty bales of cotton, and her
draught was thirteen feet six inches. On account of a delay at
the head of the passes the tide had fallen several inches before
she reached the jetties, and the channel at this time being very
irregular and changeable, the pilot was unable to keep the
vessel in the deepest water, and grounded her opposite Sta¬
tion 80. The tide falling, she remained on the bar during the
night, but went to sea at noon the following day. .
A little later in the work an incident occurred, appar¬
ently insignificant, but fraught with important results, which
seriously embarrassed the whole enterprise. To apj^reciate
it, one should have been connected with the jetties during
those discouraging days, which, while they brought an im¬
proved channel, were gloomy with forebodings of financial dis¬
aster ; to still better appreciate it, one should have been in the
place of Mr. Eads, on whose shoulders rested the heavy bur¬
den and the responsibility of the success of the undertaking.
Many of the friends of the enterprise in St. Louis, desirous
of seeing the work and forming their opinions of its results
from their own observations, arranged for an excursion to the
jetties on the steamer Grand Repiiblic. They were joined at
New Orleans by many others also interested in the work.
Among the excursionists were several representatives of the
press both of New Orleans and St. Louis.
EMBAEEASSMENTS.
97
The Grand RepuUic left New Orleans for Port Eads on the
morning of April 26th. Interested in such a distinguished
arrival, we watched for the great steamer with deep interest.
But what is that dark speck, moving so quickly toward us
from the head of the passes ; now passing Port Eads, rush¬
ing seaward till almost lost to sight on the bar near the ends
of the jetties ; now galloping across the channel like a race
horse ; now zigzagging here and there in its desultory course
like a swallow skimming over the waters ; now coming up
again through the jetties ; tying up at the lighthouse wharf,
and for an hour lying motionless and quiet as death ? It is
the steam launch of Major Howell, United States Engineers,
in whose little cabin his assistant, with nervous haste, with
note book and protractor, is plotting the soundings just taken,
so as to have them ready for the arrival of the Grand Repub¬
lic. He has left his legitimate work at the mouth of South¬
west Pass, and has hurried here, a distance of thirty miles,
to find facts (?) to controvert the statements made by Mr.
Eads and his engineers, that there is a channel of sixteen feet
through the jetties.
In the mean time the Grand Republic, with its host of
friends arrived. After passing through the jetties and into
the Gulf of Mexico, she returned to the wharf at Port Eads.
By this time Major Howell's assistant had completed his
work ; had made a tracing of his chart ; had placed it in his
pocket, and was ready to be interviewed. He took a conspic¬
uous stand in the saloon of the Grand Republic, and very re¬
luctantly (?) from time to time drew out the chart for inspec¬
tion by reporters and others.
It was a good opportunity for this faithful henchman to
show his fealty, and he used it to good purpose. Although
the act performed by the assistant of Major Howell was in¬
significant and unimportant in itself, it was the cause of a
spirited controversy, and resulted in a remonstrance to the
7
98
THE MISSISSIPPI JETTIES.
Secretary of War, and tlie issuance of orders by bim which
carried with them a severe rebuke to Major Howell and his
superior, the Chief of Engineers, by completely interdicting
them from any further official interference whatever with Mr.
Eads and his work.
In order to refute anonymous statements circulated in
New Orleans, and published in a number of journals through
the country, to the effect that a new shoal was forming in ad¬
vance of the jetties, and that their failure was therefore cer¬
tain, Mr. Eads had, on March 7th, some time previous to this
occurrence, addressed a letter to Hon. C. P. Patterson, Super¬
intendent United States Coast Survey, Washington, D. C., re¬
questing that instructions be given Assistant Marindin, who
was then at the jetties, to survey the outer slope of the bar.
The instructions were given on condition that Mr. Eads would
furnish a steamboat for the survey. Marindin was engaged
in this survey at the time the Grand Republic visited the jet¬
ties.
The apparently reliable and official statements of the assist¬
ant of Major Howell created great distrust in the ultimate
success of the jetties in the minds of the friends of the enter¬
prise, who were on the Grand Republic, and many of the
jetty stockholders in the city of New Orleans, in consequence
of which a large amount of stock subscribed in aid of the un¬
dertaking was actually offered for sale soon after at half its
face value. Realizing the importance of promptly refuting,
by official testimony, the misrepresentations that had been
made, Mr. Eads addressed another letter to Mr. Patterson,
requesting that Marindin take soundings in the jetty channel,
which request was not complied with, on the ground that, as
he said, " the law expressly provides that the inspecting offi¬
cer of the Engineer Corps (Gen. Comstock) shall execute the
class of surveys you wish within the jetties."
The misstatements circulated in New Orleans and St.
EMBAERASSMENTS.
99
Louis having been contradicted by Mr. Eads, in a letter to the
New Orleans Times and in a telegram to St. Louis, Major
Howell, in a letter to the New Orleans Democrcá, May 6th,
made the following statements, in reference to the surveys
made recently by him in South Pass :
" The surveys have been made at government expense, be¬
cause needed to aid in solving the great problem presented
at the mouth of the Mississippi. If the results had been
available before the passage of the jetty contract, it is prob¬
able that the country would not have been saddled with the
adventure. * * * The fact is, that on the day of the
Grand Republic splurge there was at South Pass only a chan¬
nel of twelve feet entitled to be called navigable, while at
Southwest Pass there was a navigable channel of over eigh¬
teen feet.
" I know that on the day the Grand Republic visited South
Pass the nucleus of a new bar existed one thousand feet in
front of the jetties, and that a shoal had made out from the
end of the west jetty three hundred and eighty feet toward
this, and diagonally across the front of the jetties." Also,
" that since the commencement of the jetty work the low
water cross section of South Pass, one mile below its head,
has been diminished one-sixth."
In a letter to Mr. Eads, on May 22d, E. L. Corthell, the
Chief Assistant Engineer, controverts the statements of Major
Howell, and states there has been a very marked and general
increase in the depth immediately in advance of the jetties
for nearly two thousand feet beyond them ; and that the " nu¬
cleus of a new bar " one thousand feet in front of the jetties,
is the remains of a mud-lump existing before the jetties were
begun, and by their action diminished nearly one-half ; also that
recent soundings made across South Pass one mile below the
head of it, show no decrease in section when compared with
the Coast Survey soundings of the previous year ; and he fur-
100
THE MISSISSIPPI JETTIES.
ther states that on the day of the Grand Repuhlic excursion
there was a navigable depth of fully sixteen feet entirely
through the jetties. These statements were concurred in by
Mr. Bayley, Eesident Engineer, and by Max E. Schmidt, As¬
sistant Engineer.
Immediately after the visit of the steamer Grand Eepublic,
Captain M. E. Brown, United States Engineers (assistant of
Gen. Oomstock), commenced a survey of the jettied channel.
Mr. Eads, believing that information in Captain Brown's pos¬
session would completely refute Major Howell's assertions,
asked him for an official statement of the depths. This he
declined to give, stating as a reason that he had not made his
report to Gen. Comstock. Learning that the latter officer
had just gone to the jetties, Mr. Eads telegraphed the Secre¬
tary of "War as follows ; " New Orleans, La., May 9th, 1876.
Hon. Alphonso Taft, Secretary of War, Washington, D. C.
Please instruct Gen. C. B. Comstock, now at Port Eads, to
sound channel between jetties with me ; likewise dredged
channel through Southwest Pass bar, and furnish me with
the results promptly. Major Howell has published a mis¬
statement affecting public confidence in my work, and this
information is required in justice to myself, and will benefit
the public." Gen. Comstock remained at Port Eads one day
awaiting instructions, but as no answer to the message was
received, he left for New Orleans, declining to give any infor¬
mation, for the reason that he had not made his report to
Gen. Humphreys, Chief of Engineers, U. S. A. A dispatch
received from the Secretary of War, four days after, stated
that Gen. Comstock had previously received authority and
instructions for a complete survey of the jetty channel, and a
copy of the results of his soundings would be furnished as
soon as received.
On receiving this message, Mr. Eads, knowing that the re¬
ceipt of the information would be delayed for sixty days
EKBAEEASSMENTS.
101
longer, telegraphed to the Superintendent of the Coast Sur¬
vey, requesting that Marindin be permitted to give the re¬
sults of his soundings in advance of the bar, so as to refute
that portion of Major Howell's statements which referred to
the re-formation of the bar, to which the following reply was
received : " Regret Marindin cannot furnish results. Gen.
Comstock will give all information required by law. Will
write." Being determined to have the official disproof, if
possible, Mr. Eads requested the Secretary of War to obtain
it, and on July 19th the Secretary requested the Superintend¬
ent of the Coast Survey to furnish the War Department
with a comparative chart of the soundings made May, 1875,
and May, 1876, in front of the jetties.
Wishing to avoid a conflict with the United States Engi¬
neer Department, the Superintendent made a verbal declara¬
tion that he would not supply this information, even to the
War Department, as he did not think they had any right to
call for it. Mr. Eads then appealed to the Secretary of the
Treasury to instruct the Superintendent to furnish the chart
and an official statement of the results shown by it. This re¬
quest was refused, on the ground that " provision is made in
the said jetty act for the facts and information desired through
the War Department." Being thus foiled in getting official
disproof of this misrepresentation of Major Howell, Mr. Eads
finally appealed to the House of Representatives, and a reso¬
lution was unanimously passed by that body, directing the
Secretary of the Treasury to furnish the House the specific
information asked for. The following is from the records of
the House : " South Pass, Mississippi River. Mr. Conger,
by unanimous consent, submitted the following resolution,
which was read, considered and adopted : Resolved, that
the Secretary of the Treasury be and he is hereby directed to
furnish to the House the following information : Eirst, a
chart of soundings made by the Coast Survey last May in
102
THE MISSISSIPPI JETTIES.
front of the jetties at the South Pass, in the Gulf of Mexico.
Second, a comparative chart showing the result of the survey
of 1875, made by the Coast Survey, and the result of the last
survey above named, so far as both surveys embrace the same
area in advance of the jetties ; and. Third, a statement of the
average increase of depth in front of the jetties, and within
the area embraced by both surveys, as indicated by a com¬
parison of the soundings shown by the two surveys. July
29th, 1876, page 4,963, Forty-fourth Congress." On August
1st, nearly three months after the first attempt to obtain this
information, it was furnished in a letter addressed to the Sec¬
retary of "War by Superintendent Patterson.
The results of Marindin's survey, given in this letter, com¬
pletely refuted the statements made by Major Howell, that a
shoal was moving out diagonally in front of the jetties, and
that the bar was advancing seaward. The following is an ab¬
stract of the letter, as far as it relates to these two subjects :
"The survey of 1875, as well as that of 1876, shows a shoal
about three hundred yards seaward of the bar. Comparing
the two surveys, the river face of this shoal has receded
thirty yards ; its seaward face and center have advanced but
little. Its contents above eighteen feet was, in 1875, equal
to eight thousand cubic yards, and in 1876, three thousand
seven hundred cubic yards, a decrease of about one half. In
a square of seven hundred yards (or four hundred and ninety
thousand square yards), directly in front of the bar, two
hundred and sixteen thousand five hundred square yards
have decreased in depth, and two hundred and seventy-three
thousand five hundred square yards have increased in depth.
The deposits within the same boundaries amount approxi¬
mately to three hundred and eleven thousand three hundred
cubic yards, and the scouring to three hundred and seventy-
nine thousand seven hundred cubic yards, a difference in
favor of scouring, of sixty-eight thousand four hundred cubic
EMBABRASSMENTS.
103
yards, or an increase of deptli orer the whole area of 0.42
feet."
This square began about one hundred yards beyond the
ends of the jetties. If the soundings of 1876 had been taken
on that portion of the bar immediately at the end of the
jetties, and the square had been located accordingly, a still
greater increase in depth would have appeared ; for on June
5th, Mr. Schmidt made a survey and calculation to ascertain
what changes had taken place since May, 1875, on an area of
fifty-one and seven-tenths acres, beginning at the crest of
the bar and extending seaward two thousand seven hundred
and thirty feet, in the direct line of the river discharge. The
investigation showed that the scour exceeded the deposit by
two hundred and six thousand four hundred and twenty-five
cubic yards, equivalent to an average increase in depth of
2.47 feet.
Mr. Eads being foiled in his efforts to have an official state¬
ment of the depth of the channel furnished to him by the
IJ. S. Inspector, General Comstock, and being refused the
results of Mr. Marindin's survey of the outer slope of the
bar, determined to address an open letter to the Secretary of
War, through which that high officer, and the public as well,
should be made to see the excessive injustice with which
he was treated, in having all official disproof withheld from
him, by which alone he would be able to expose the mis¬
statements made over the official signature of an officer of
engineers, in no way authorized to interfere with or report
upon his works.
Accordingly, on the 23d of May, 1876, he addressed a letter
to the Hon. Alphonzo Taft, then Secretary of War, in which
he referred to the foregoing and other official acts of hostil¬
ity and unfairness, on the part of General Humphreys and
Major Howell. In this letter he calls the attention of the
Secretary to the fact, that " The act directs the Secretary of
THE MISSISSIPPI JETTIES.
War to appoint an officer, whose duty it shall be to report
the depth of water and width of channel secured and main¬
tained from time to time, in said channel, together with such
other information as the Secretary of War may direct. The
grant expressly provides, that ' I shall be untrammeled in the
exercise of my judgment and skill in the location, design,
and construction of the works ; ' therefore, I did not suppose
that another officer of engineers, and one, too, avowedly
hostile to the undertaking, would likewise (without authority
of Congress) be charged with the official duty of observing
any part of our work or its results.
" Least of all did I suppose that he would be permitted to
give to the public with perfect freedom, such unfavorable and
unreliable information respecting it as might best seem to
support the predictions of its failure, previously uttered so
confidently by his chief and • himself, and thus really tram¬
mel its construction by increasing my difficulties in provid¬
ing means with which to carry it on."
He further calls the attention of the Secretary to the fact,
that
" After the jetty system was finally adopted hy the last Con¬
gress, General Humphreys published four essays, termed by
him 'memorandums,' to prove that the jetties would be a
failure ; these were published as a part of his official report
to the present Congress. They were at the same time ex¬
cerpted from that voluminous document, and, illustrated with
maps, were bound in pamphlet form and distributed through¬
out the country five months ago."
Referring to Major Howell's excuse for this remarkable
conduct, Mr. Eads adds :
" Admitting General Humphreys' ability to complete dis¬
cussions left unfinished by Congress, his justification in this
case would have been more satisfactory had Major Howell
informed his readers by what authority an officer of the
EMBABEASSMENTS.
105
United States Engineers presumes to publish his gratuitous
opinions at the public expense, or to indirectly criticise the
President and Congress of the United States, for declining to
be guided by the judgment of General Humphreys and Major
Howell in this matter."
In this letter Mr. Eads makes the following requests of the
Secretary of War ;
"In view of the annoyance and embarrassments already
suffered from the official antagonism of General Humphreys
and Major Howell, and of the fact that their official positions
give them the ability to continue their open or insidious
opposition to this work (the one being Chief of the Corps
of Engineers, U. S. A., and the other stationed in this' city in
charge of important engineering operations in the vicinity),
I have to respectfully ask, that any further officious or
unauthorized official interference on the part of these officers
be interdicted, and that instructions be issued to the inspect¬
ing officer, authorized by the act and ' detailed ' by you to
make the examinations, to promptly supply me with any
official information he may from time to time acquire, re¬
specting these works and their results, which I may deem
important to facilitate us in carrying out the intent of the
grant, or in protecting us from misrepresentation ; and that
his reports hereafter be made directly to the Secretary of
War, instead of through the medium of the Chief of Engi¬
neers, U. S. A., as the Secretary of War alone is, by the words
of the grant, ' authorized and directed to carry into effect the
provisions of the act.' "
The full text of this indignant protest will be found in Ap¬
pendix 8, and it will well repay careful perusal. About the time
it was written Mr. Taft ceased to be Secretary of War, and
the Hon. J. D. Cameron was appointed in his stead. The
following letter will show that the requests of Mr. Eads were
complied with, and Gen. Humphreys and Major Howell were
106
the mississippi jetties.
interdicted from any further connection whaterer with the
jetty works, and Gen. Comstock was directed to report in fu¬
ture directly to'the Secretary of "War.
"Wab Department, ")
"Washington, D. C., Jmw. 28;ä, 1876. j
" Sir,—I have the honor to acknowledge the receipt of
your letter of the 20th inst., requesting in substance :
" First—That in future the inspecting officer contemplated
in the act approved March 3d, 1875, for the improvement of
the South Pass of the Mississippi River, be required to make
his report directly to the Secretary of War.
" Second—That the duty of observing and reporting upon
the progress of the work, the manner of its construction, the
results accomplished by it, and all other matters relating to
said improvement which the Secretary of War may direct,
will henceforth be performed by the said inspecting officer
exclusively.
" Third—That any official publications with reference to
the said improvement will not be permitted from any other
officer of the Engineer Corps.
" Fourth—That the Chief of Engineers be directed, to dis¬
continue all surveys of the South Pass and its bar, that are
not under the direction of the said inspecting officer.
" Fifth—That the said inspecting officer be directed to fur¬
nish you or your authorized assistants any information he
may possess or hereafter acquire, relating to the progress,
effects, permanency, or probable success of the work.
" Your first request has been granted, and I beg to inclose
you a copy of the letter directing it. To the second request
I have to reply that the duty therein referred to will be per¬
formed by the officer assigned to it and his assistants exclu¬
sively. As to third request, it may be stated, as a general
rule, that reports made by officers of the War Department
embaeeassmeots.
107
to the Secretary are not published "without his consent. If
any other officer of the Engineer Corps should be called upon
for a report, notification thereof "will be sent you. Your
fourth request has already been carried into effect, as the
Chief of Engineers on the 8th inst. directed Capt. C. W.
Ho"well, the officer in charge, to make no soundings, current
or other measurements of any kind "whatever, in the South
Pass, or on the bars at its river or sea ends, or in the sea at
and off its mouth, but to limit his observations to the other
passes and the main stem of the river, should such observa¬
tions be necessary in the execution of duties heretofore as¬
signed him.
"Tou will perceive by the inclosed copy of letter that
Major C. B. Comstock, in accordance "with your request, has
been directed to furnish you or your assistant the actual re¬
sults of the soundings that have been or hereafter may be
made under his direction in the performance of the duties as¬
signed him, in connection "with the improvement of the chan¬
nel bet"ween the South Pass of the Mississippi Biver and the
Gulf of Mexico, under the act approved March 3d, 1875.
" Very respectfully, your obedient servant,
" J. D. Cameeon, Secretary of War.
" To James B. Eads, Esq., Washington, D. C."
Before these instructions "were given, the results of the sur¬
veys "were carefully kept secret from Mr. Eads and his assist¬
ants, and were not seen by him or the public until they were
transmitted by Capt. Brown to Gen. Comstock at Detroit ;
by him to the Chief of Engineers at Washington ; by him to
the Secretary of War ; by him to Congress ; by Congress to
the public printer, and by him back to Congress. They
were then so old as to be of little interest or value to any
one. tSee Appendices 8 and 11 for full information on the
preceding subjects.)
108
the mississippi jetties.
The misstatements about the depth and navigability of
the jetty channel, which were circulated at the time of the
visit of the Orand RepvMic, and which made such an injuri¬
ous impression, were most effectually refuted a fortnight
afterward by a measurement of the channel that was more
satisfactory than that of the lead line.
Capt. E. Y. Gager, of the steamship Hvdson, of the Crom¬
well Line, had been from the first a friend of the under¬
taking, and had expressed a wish to run the first steamship
through the new channel. When he went to sea from New
Orleans in April, he requested his bar pilot, Capt. Eichard
Francis, to take careful soundings in the jetty channel prior
to the departure of the steamship from New York, and tele¬
graph him the result.
The Hudson was due at the mouth of the river in the after¬
noon of May 12th, in the morning of which day Capt. Fran¬
cis sounded the channel thoroughly, and satisfied himself
that it had the required depth. About 2 o'clock p. m. the
steamer appeared, coming from the southeast and bearing for
the South Pass. When she arrived off the bar she was
boarded by Pilot Francis, Mr. Eads and others.
The Hudson is an iron steamship, two hundred and eighty
feet in length, with a registered toimage of one thousand
eight hundred and seventy-two tons, and with a draft, at that
time, of fourteen feet seven inches.
In reply to the inquiry of Capt. Gager if there was water
enough for the steamer, the pilot stated that, at average flood
tide, there was a channel of fifteen feet, but that the tide had
turned at 10 o'clock a. m., and was then six inches down, still
falling fast, and creating a strong current through the jetty
channel. Capt. G«,ger promptly gave the order " Head her
for the jetties." The pilot decided to run her straight up
the channel and not to attempt, with so large a vessel, to
make the turns necessary to follow the deepest water. With
EMBABEASSMENTS.
109
intense interest we watched the steamer come in over
the bar. "We knew that nothing but her successful passage
through the jetties could convince the public that our state¬
ments were correct, or restore the needed confidence in the
work.
The pilot straightened up the steamship for the channel
over the bar, the Captain rang the beU for full speed, and on
she came like a thing of life, as if intent only upon proving that
we had a navigable channel of sufficient depth. As long
as she carried that " white bone in her teeth "—^the great
wave that her proud bows pushed ahead of her as she sped
onward—we knew that she had found more than Major How¬
ell's twelve feet, and she carried it continuously through¬
out the entire two and one-quarter miles of jetty channel,
until she checked her course in the deep water at Port Eads.
No event in -the whole history of the jetties gave us such in¬
tense pleasure and satisfaction as the successful passage of
this beautiful ship through the jetties. It is not too much
to say that Capt. Gager, who took the risk and the responsi¬
bility of this trial trip, materially assisted the enterprise in
one of its darkest hours ; for the stubborn facts brought out
by his brave action could not be gainsaid. They restored
confidence in the jetties, and the much-needed loan was soon
afterward secured for the further prosecution of the work
CHAPTEE X.
head of the passes—genekal conditions described.
The problem of bow to deepen the inlet channel at the
head of South Pass was far more difficult of solution than
any presented at its mouth. To get the water out through
one deep channel was a far more simple process than to get
it into a small pass, through a narrow artificially contracted
channel, located immediately between two great natural out¬
lets.
In order to appreciate the difficulties of this problem, and
to understand the plan of the work designed to solve it, a
knowledge of the natural conditions prior to their construc¬
tion is necessary.
The jetties and auxiliary works were artificial factors intro¬
duced into a problem in which were involved the difference
in the length of the three passes, their respective volumes of
discharge, surface slopes and depths and the character of
bed, the bars at their mouths, and the gulf beyond them,
with its currents and waves.
When the natural conditions then existing are more fully
described, it will appear that an artificial change in any one
of them from "Cubitt's Gap" to the gulf, must necessarily
affect all the others. There is scarcely anything in nature
more sensitive than the delicate adjustment of these mighty
forces. The general quantities were known ; the sections had
been calculated from the soundings ; the volumes discharged
110
HEAD OF THE PASSES.
Ill
ascertained by gauging ; the slopes measured by careful ob¬
servations and accurate leveling ; the geological character of
the bed obtained from microscopic examinations and chem¬
ical analysis, and the ratio of the sediment to the -water that
transported it, and the size of the particles of silt, discov¬
ered by delicate experiments and patient investigation.
No problem had ever before been solved in river hydraul¬
ics in which there were such tremendous forces and so many
variable elements. Jetties had been built to deepen the
bars at mouths of rivers, and dykes had been constructed to
change the direction of currents, but the forces controlled by
them were not only far inferior to those at the mouth of the
Mississippi, but several were present here that were absent in
similar works.
The theories evolved by scientists from their miniature ex¬
periments, and published for the use of the world, were in
many cases calculated to mislead, rather than to enlighten.
The conditions at the mouth of the pass have been given
already ; it remains to describe those at the head of the
passes. The sedimentary matter in the flowing water hides
everything beneath the surface. The eye sees only the broad
muddy river, the low banks fringed with willows, back of
them the vast swamps of the delta overgrown with vegeta¬
tion, and in the distance the waters of the bays and sounds.
The river preserves an average width of about half a mile
to within eight miles of the head of the passes. From this
point to Cubitt's Gap it widens to three-quarters of a mile ;
it then widens still more rapidly, and at the two points of
land where the three passes separate, it is eleven thousand
feet wide—more than two miles.
To aid in the examination of the river bed, and to obtain a
clearer idea of its shape, let us suppose the water that now
fills it, to be removed between two points—one, eight miles
above the head of the passes, the other, one mile below it.
112
THE MISSISSIPPI JETTIES.
At the upper end of this basin the deepest part of the river
bed is ninety feet below the surface of the ground, and the
descent to it from either side is about eight feet in one hun¬
dred feet, or one in twelve.
Going down the river to a point just below Cubitt's Gap,
where the width is greater, we find the depth only sixty feet.
As we approach the head of the passes the river widens still
more, and the depth becomes still less. About one mile
above the point where the passes diverge, we notice the be¬
ginning of a more rapid rise of the bottom, not toward the
banks but in the direction of the axis of the river. If we
ascend this slope until we reach the entrance of South Pass,
we find ourselves considerably above the deep channels on
either side ; that on the right is twenty-five feet below us,
that on the left twenty feet, and the greatest depths of
these channels are much nearer the banks of the river
than the elevation on which we stand. If a perfectly hori¬
zontal line could be stretched across between the east and
west bank, it would be fifteen feet above the ground where
we stand, forty feet above the bed of the pass on the right,
and thirty-five feet above that on our left.
The hill or ridge where we are constitutes the shoal over
which the water must flow to enter the South Pass, the chan¬
nels to the right and left are respectively those of Southwest
and à Loutre Passes, and the depths over the shoals into
them were fully thirty feet.
From these channels and shoals, their direction, contour,
and extent, we gather information that will show us how and
where the great volume of the river flows. These are the
marks that it has scored in the past ages, marking- the track
from which, though flowing over a bed of its own deposits,
it has never varied. Whatever the causes are, they have
been sufficiently powerful to hold the successive floods in the
same chaimel year after year.
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TTTíAD OF THE PASSES.
113
At times the relative size of the passes has changed, but
the position of the deep channels has remained the same.
Since the velocity varies approximately as the depth, the
strongest currents of the river are near the eastern and west¬
ern banks, a considerable distance from the inlet channel of
South Pass. According to this same law of velocity, the
current flowing up on this shoal gradually decreases as the
depth diminishes.
With this description of the shoals and channels of the
river, we can appreciate the difficulty in forcing it to turn
aside from its accustomed pathways, and excavate a new
path through this formidable shoal.
Careful and repeated float observations revealed the fact,
that there were well established lines of demarkation be¬
tween the waters of each pass when they reached this shoal.
At this point the depth of the water which entered South
Pass was about thirty feet; its width about seven hundred
feet, and its sectional area about twenty-one thousand square
feet. From this point the neutral axes flared out like the
mouth of a trumpet, until they were ' three thousand feet
apart, where they reached the two points of land which
separated the three passes.
Mr. Eads, with the Advisory Board of Engineers, studied
the subject carefully, discussed the various plans suggested
for creating a channel through this shoal, and as an initial
work, decided upon the construction of a dyke (called East
Dj'ke), three thousand two hundred and fifty feet long, to
extend from the point of land between South Pass and Pass
à Loutre, with its upper end in twenty-four feet of .water,
and about six hundred feet east of the neutral axis betAveen
the currents of these two passes. The object of this dyke
was to intercept a portion of the water flowing into Pass à
Loutre, and deflect it into South Pass. The dyke curved to
the westward with a radius of eight thousand feet. The loca-
8
114
THE MISSISSIPPI JETTIES.
tion will be seen on Plate H, and a cross-section of it on
Plate 12. A parallel dyke was to haye been placed about
eigbt hundred feet to the westward of East Dyke, and was to
extend from the island to a point opposite the upper end of it.
The western channel near the island was to have been finally
closed. The Advisory Commission say on this subject : " The
further prolongation of this work (East Dyke), and the execu¬
tion of works on the west side, to be left for determination
and observation of effects, produced by the construction
recommended."
This design Mr. Eads was compelled to abandon ; and to
see the costly dyke which he had built made comparatively
valueless, in consequence of the unfair treatment he received
at this time from the government (referred to in the preced¬
ing chapter), the effects of which upon this work will be
presently explained.
This dyke was constructed with horizontal mattresses in
the same manner as the jetties, and was well ballasted with
stone. The dyke, as it was built up from the foundation,
caused a retardation of the current near the bottom on the
up-stream or South Pass side, which caused a deposit
throughout the area where this retardation was felt. So
long as the current flowed over the top of the dyke as it was
gradually built up, this shoaling continued; therefore a
change in the progress of its construction was determined
upon. Instead of building it up by continuous courses of
mattresses from end to end of the dyke, the down-stream
end was built up above the surface of the water at once, and
the construction up-stream pushed as fast as possible, finish¬
ing it to its full height as it progressed. As this was done,
an improvement in depth on the channel side was the result ;
but as the dyke was of porous willow construction, the set¬
tlement due to compression, as it became filled with sedi¬
ment, made it difficult to keep it above the surface during
EAST DYKE
SECTION A iUATEM;.
0
LJGKT HOUSE DYKE
0AM N?1
W.
HEAD OF THE PASSES.
115
the river flood, and the water soon passed over the top of it
into Pass à Loutre, several inches deep at low tide, and the
resultant shoaling on the channel side satisfied us that the
closure of the channel on the western side of the island, at
once, would be necessary to produce such a head of water as
would insure a rapid current in the direction of the dyke, and
the desired deepening of the eastern channel. One efiect of
the dyke was to increase, in a slight degree, the flow of
water into the western channel, and this caused an increase
in the depth of that channel from twelve to fifteen inches,
so that it became the better channel of the two. But as it
was still only about seventeen feet deep, it barely sufiiced
to enable the Cromwell steamers to use the South Pass.
As the spring floods were over, it became an imperative
necessity to push the construction of the works at the head
of the pass, so as to have the requisite depth of water there
as soon as twenty feet through the jetties should be secured,
in order that there might be no difficulty in the way of re¬
ceiving from the government the first payment of five hun¬
dred thousand dollars.
As we have stated in chapter IX, Mr. Eads had, in May,
appealed to the Secretary of "War without success, to have
an official measurement and statement of the depth of the
jetty channel published, to refute the misrepresentations of
Major Howell. He had appealed to the Superintendent of
the U. S. Coast Survey soon after, to furnish him an official
statement to refute the same officer's misstatement respect¬
ing the reformation of the bar in front of the jetties, with
no better success. He had appealed to the Secretary of
the Treasury, and finally, on the 29th of July, to the House
of Eepresentatives; before he succeeded in breaking through
the official jealousy and hostility which had locked up from
the public the evidence of his success; and although Mr.
Secretary Cameron had with most commendable decision
116
THE MISSISSIPPI JETTIES.
issued an order effectually interdicting General Humphreys
and Major Howell from any further official interference
with the jetties, and had directed General Comstock, the
inspector, thereafter to report directly to him instead of to
General Humphreys, and had ordered General Comstock,
on the 29th of June and 31st of July, 1876, to furnish Mr.
Eads "the results of actual soundings, that have been or
may be hereafter made under your (his) direction, in con¬
nection with this improvement "—yet it was necessary to
appeal again on the 7th of February, 1877, to the Secretary,
for an order directing General Comstock to instruct his
assistant. Captain Brown, "to give me (Mr. Eads), or my
chief assistant engineer at the jetties, the results of his
soundings," because Captain Brown could not, even with
these orders to General Comstock, furnish, up to that time,
an official copy of his soundings until they had gone from
Port Eads to Detroit (at the great lakes, where General
Comstock was stationed), for his inspection and approval;
nor did he feel authorized, even as late as February, 1877,
until more explicitly instructed by General Comstock, to give
the results of his soundings to the chief assistant of Mr.
Eads, in his absence.
Although the channel through the jetties, as early as July
1st, had attained a depth of at least nineteen feet, Mr. Eads
was deprived of the advantage of having this fact officially
certified to the public by the proper officer, while every
means were used by his enemies to create the belief that no
such channel existed. The only absolute proof of our suc¬
cess up to this time, beyond our own controverted declara¬
tions, was the fact that the New York and New Orleans
CromAvell Steamship Line was using the jetties.
On the 27th of May the steamer Neio Orleans of that line
went out drawing seventeen feet three inches. This was the
maximum depth during that summer in the western channel
TTT-.ATt OF THE PASSES.
117
at tlie head of the pass, while the greatest depth through the
other was at least eighteen inches less.
It was plain then, that if the original plan of improvement
at the head of the pass was carried out, and the western
channel closed, we must give up for several months the only
undisputed evidence we possessed of a substantial channel
improvement—namely, the semi-weekly passage of these
steamers—for the eastern channel would not suffice for them
until deepened. It was, therefore, a question, not so much
of engineering as of finance, that was presented. If the west¬
ern channel were closed, and the Cromwell steamers were
prevented from using the pass, it would at once have been
taken for granted that the statements of our enemies were
correct, and that the improvement of our channel was only
temporary ; that the bar at its mouth had reformed, and
that, the shifting sands had made the channel between the jet¬
ties tcfo hazardous for the Cromwell Line to use any longer.
It should be stated in this connection that the channel
»
through Southwest Pass bar, was being maintained by the
use of the United States dredge-boats, McAUster and Essayons,
two powerful propeller vessels, and that their operations were
conducted under the orders of Major Howell. The jetty
channel had now become so deep as to rival that maintained
at the Southwest bar. Near the latter is situated a village
called Pilot Town, the residence of nearly all the pilots em¬
ployed at the passes. These men were almost without ex¬
ception opposed to the work at South Pass, for they thought
they saw in its success a transfer of their field of labor from
the vicinity of their little town to a distant locality, and a
lesser need of pilots. If the Cromwell line had been forced
from any cause to use the Southwest Pass channel again,
these men would have hastened to publish that fact, to the
injuiy of the jetty enterprise ; and the same may be said of
the towboat interest, which from the first was hostile to the
118
THE MISSISSIPPI JETTIES.
■work. On the other hand, the abandonment of the eastern
channel involved the loss of a dyke three thousand two hun- .
dred and fifty feet long, which had cost $180,000.. For if the
channel were to be made on the western side of the island, this
dyke would be practically useless. Notwithstanding this loss,
Mr. Eads determined under these circumstances to abandon
his original design and deepen the western channel. Had he
been promptly furnished, as in common justice he should have
been, with the official certification of the actual condition of
the channel, as often as it was measured by the United States
inspecting officer, this change would not have been made, and
the channel into the pass would have been a straighter and
better one, as will be seen by examining the alignment of East
Dyke, and noticing its conformity with the direction of the
pass. As it is, East Dyke and the altered plan must remain
forever a monument of official jealousy and opposition.
The explanation of the phenomena which occurred at the
head of the pass about this period—namely, between the time
of closing Grand Bayou, in June, and the 18th of August,
following—is so clearly stated in a report made by Mr. Eads,
on the latter date, to the South Pass Jetty Company, that the
following extract from it is given :
" Our original plan of improvement contemplated the clos¬
ure of Grand Bayou. This outlet is situated midway between
the upper and lower ends of the pass, and discharges twenty-
three per cent, of its volume. Its closure would consequently
add about thirty per cent, to the water passing out through
the jetties, by which the current below this outlet would be
largely increased, while the current in the pass above would
be proportionally retarded, until the channel below the out¬
let should be sufficiently enlarged to restore the normal ve¬
locity. Enlargement and deepening were consequently to be
anticipated below, while shoaling would be the result natu¬
rally expected above.
HT?,AT) OF THE PASSES.
119
" The head of the pass is divided by an island into two in¬
lets of nearly equal magnitude, and the original plan of im¬
provement contemplated the ultimate closure of one of these.
It was believed that if Grand Bayou and one of these inlets
were closed simultaneously, the expected shoaling above the
pass would not occur, because, although the volume entering
the pass would be temporarily lessened by the dam at Grand
Bayou, the size of the entrance into the pass would be re¬
duced in a greater ratio by the closure of one of these inlets,
and the retardation of current across the shoal above the
other inlet would thus be prevented. It was therefore deter¬
mined to close the inlet and bayou at the same time. Some
unavoidable delays, however, retarded the constnxction of the
dam at the inlet until five or six weeks after the bayou was
closed. During this interval the deposit which had been
feared occurred upon the shoal, until the available depth over
it was reduced to about fourteen feet, and the steamers re¬
ferred to were compelled to temporarily abandon the use of
the pass. Since the closure of the inlet, however, the depth
has been increasing, and the large steamers Knickerbocker and
Hvdson, of the Cromwell Line, have again crossed this shoal,
in going and returning through the South Pass during the
last fortnight. From twenty feet on the upper side to twenty
feet on the lower side of this shoal the distance is about one
thousand five hundred feet. The works in course of con¬
struction here comprise one dam one thousand one hundred
feet long ; another one thousand eight hundred feet long ; and
a dyke three thousand two hundred feet long ; all completed
above high water ; also three other dykes in the course of
construction, having a total length of two thousand two hun¬
dred feet. The most effective part of these will probably be
completed within the next thirty days.
" The same principle which has proved so successful at the
jetties, namely : the concentration of the flowing water, forms
120
THE MISSISSIPPI JETTIES.
the basis of the plan for the reduction of this shoal, and the
completion of the works designed cannot fail to be equally
successful, while their execution is far less expensive and
difficult, because they are sheltered by the river banks from
the storms of the gulf. It is possible, however, that the effect
will not be as rapid as we desire, because the low water sea¬
son is approaching, and the river discharge will be dimin¬
ished very considerably, by which the scouring action will be
lessened.
" It has been asserted in some of the public journals, that
the construction of the works necessary to contract the flow
and deepen these obstructions, must have the effect of per¬
manently lessening the quantity of water which entered
South Pass at the time our works were commenced, and
would, therefore, cause a permanent reduction in the size of
the pass. It is important to consider whether there is any
cause for any apprehension of such result, inasmuch as it has
been stated that it has already occurred.
" Bepeated measurements of the pass have been made by
my assistant engineers at three different points, one about a
mile below the head of the pass, one above Grand Bayou,
and one below it. The result of these justifies me in declar¬
ing emphatically that there is no cause whatever for any such
apprehension. A few facts, however, which have been devel¬
oped by our works, will probably be more potent in removing
any fears upon this point, than a volume of theorizing.
" The entrance into Pass à Loutre was contracted six hun¬
dred feet in width by one of our dykes, and it might reason¬
ably be inferred that the temporary flow into the pass being
thereby greatly reduced, a permanent diminution of its size
would occur. The effect of this contraction was to raise the
surface of the water above our works, while hdoiv them the re¬
duced supply caused the surface to be loioered. An increased
slope was thus given to the surface of the water through this
TTF.ATI OF THE PASSES.
121
contraction. Tlie current is caused by the surface slope of
the river. Eesistance to the current results mainly from the
friction between the water and the bed of the stream. This
frictional resistance being lessened to the extent of six hun¬
dred feet, while the impelling force or surface slope was in¬
creased, a greatly increased velocity of current of course
resulted, and induced rapid scouring, by which, in a few
weeks, the size of the pass at the point of contraction was en¬
tirely restored by an equivalent amount of deepening. Un¬
doubtedly, while this deepening was progressing, an increased
quantity of water was being thrown into the two other
passes ; and if this extra quantity had continued to flow into
them, permanent enlargement of each would have resulted,
but experience at the jetties has shown that the enlargement
of channel, which occurs from an increased flow, begins at
the upper end and advances down stream. This result would
inevitably follow an increased flow into either of the other
passes by the contraction of Pass à Loutre ; but before this
enlargement of South Pass and Southwest Pass could extend
any great distance down, the recovery by Pass à Loutre of its
full section was accomplished, and the temporarily disturbed
equilibrium of the three passes was restored.
"A similar result may reasonably be expected from the
closure of the east inlet into South Pass.
" The flow into this pass will unquestionably be tempora¬
rily lessened, and the excess will be temporarily thrown into
the other passes. An enlargement of the upper ends of these
passes must at once commence, but at the same time the con¬
tracted entrance into South Pass must, from the same cause,
commence also to enlarge, and in proportion as the enlarge¬
ment of the latter progresses, the head of water temporarily
raised by the works must be lowered, and the extra flow into
the other two passes must be diminished, and finally cease
altogether. In other words, while the river will have only
122
THE MISSISSIPPI JETTIES.
half a mile in length of enlargement to make at the head of
South Pass to recover its equilibrium, it must enlarge South¬
west Pass through its entire length of seventeen miles before
any permanent alteration in the respective volumes flowing
through the two passes can take place. While the removal
of the shoal is progressing, a considerable portion of it will
be found deposited in the deep water immediately below it,
r where no contraction has occurred, and where the first reduc¬
tion of velocity will be felt, and from whence it will be grad¬
ually removed as the enlargement above restores the velocity
below."
K.O0.Ü \
CHART
HEAD OF THE PASSES
MISSISSIPPI mVER.
SURVEYED BY
U.S.ENGINEEES JUDY 1D79.
Soiindin^$ tape exjwef^ecl inj^^taèà tenfh^t
rmd r^r to the pltzrte t^JiVevct^ Side
indicctietZ hv €t reetdin^ on UM
at ^ dCdcf^ttß/ouse. ' |
CO//jodf^B J
ZO 26 ¿6^ *
iÁcUa jrf'Ie&t I
ifeftí*t Aaiaj¿ajtai¿ria>feftfe¿óiípo' ' ' -'—
CHAPTEE XL
details and eesults of woeks at the head of south pass,
1876-1777.
The locations, witli plans of the foundations of all works
constructed at the head of the pass, are shown on Plate H.
They will now be described in detail, in the order of their
construction.
The preliminary work was commenced on the 3d of June,
1876. This was called " Cross Dyke," and extended from the
island to East Dyke, a distance of one thousand and seventy
feet.
A row of piles was driven eight feet apart, and a waling
strake was bolted to them, against which mattresses were
tilted in a vertical position. During the following night
several of these mattresses were undermined and the piling
washed out.
The causes of this disaster were :
First.—-The high stage of the river.
Second.—The unstable foundation (having been formed by
recent deposits), and
Third.—The absence of any foundation mattresses.
As soon as practicable, mattresses were laid horizontally
the whole length of the dam. Through these a second row
of piles was driven, about ten feet above the old row. After
the irregularities caused by the wash-out had been leveled
up by several courses of mattresses, a new dam of tilted
mattresses was built above the new row of piles.
123
12i
THE MISSISSIPPI JETTIES.
DAM No. I.
This work was begun in July, 1876. Its initial point was
seven hundred and fifty feet below " Cluster." It extended
nine hundred and ninety feet, at right angles with the East
Dyke, and connected with it ; thence seven hundred and
eighty-five feet in a more southerly direction, and at an
angle of twenty-five degrees with the first section. The
depth of water was quite uniform, being about twelve feet,
except at the west end, where it was fifteen feet. Guide
piles twenty-five feet apart were driven fifteen feet below
the line of the dam, for sinking foundation mattresses.
Anchorages or platforms were built one hundred and seventy-
five feet above the line of the dam, and one hundred and
fifty feet apart. They were constructed by driving three
piles, eight feet apart, in the form of an equilateral triangle ;
at a height of two feet above the level of the water, horizon¬
tal timbers six inches by twelve inches, were bolted to them.
On these timbers, which were about eighteen inches below
the tops of the piles, planks were spiked for a platform.
From these anchorages the mattresses were dropped to
their position above the guide piles by means of long lines.
After the mattress had been placed in position, a flat
loaded with rubble rock was lowered from the anchorage,
so as to rest against the up-stream edge of the floating mat¬
tress. The workmen distributed the rock over the mattress
until it was nearly sunken below the surface. They then
threw the rock upon the upper edge of the mattress, which
sunk below the surface ; and the flat, by means of the lines
leading to the anchorages, dropped down over it, the men
in the mean time throwing the rock upon it as fast as pos¬
sible. The sounding lead was used to ascertain when it
lay smoothly on the bottom. The foundation mattresses
HEAD or THE PASS—DETAILS.
125
were one hundred feet long, thirty-five feet wide, and twenty-
two inches thick.
After they were placed two rows of piles were driven
through them, one five feet from the lower edge, with the
piles fifteen feet apart, and the other seventeen feet, with
the piles ten feet apart. A waling strake was bolted to the
down-stream side of the upper row, two feet above average
flood tide. These two rows of piles were braced as follows ;
A round pine pile sixty feet long, was held in a horizontal
position above the water by a steam pile-driver scow. The
braces (five inches by twelve inches) spaced ten feet apart,
the upper ends resting on the waling timber, were abutted
against this horizontal pile, and secured to it by iron straps
or yokes, which passed around the pile and were bolted to
the upper and lower edge of the braces. The pile with the
braces attached was forced to the bottom, where it rested
on the foundation mattress and against the up-stream side
of the piles ; the upper end of the braces was fastened to
the piles of the upper row by screw bolts. The braces
stood at an angle of about forty-five degrees with the
piles.
Near the west end of the dam, where the water was deeper,
round piles were used for braces, to give the dam greater
strength and stiffness. The tilted mattresses were thirty
inches thick, one hundred feet long, and their widths corre¬
sponded to the depth of water. When in position, the upper
edge was about two feet above average flood tide. Small
straight willows were used, so that the dam might be less
pervious to the flow of water. The edge resting on the foun¬
dation mattresses was brushy, the butts of the willows being
placed at the upper edge. Eour rope lashings, twenty-five
feet long and one and one-quarter inches in diameter, were
secured in the upper side of the mattress during its construc¬
tion.
126
THE MISSISSIPPI JETTIES.
The tug pulled the mattress ofif the ways, towed it to the
anchorage immediately above where it was to be placed, and
left it hanging to it by the head lines. The pile-driver scow
was pulled up to the anchorage and alongside the brushy
edge of the mattress, which was lashed to the deck of thé
scow, the lashings being drawn taut by the engine, to keep
that edge partly out of the water. The lashings that had
been built into the other edge of the mattress were crossed
alternately, so as to form two loops or bridles, into which
the pile line and the hammer line were respectively made
fast. The driver scow with the mattress alongside, was
dropped down from the anchorages broadside to the dam.
A strain was taken upon the lines, so as to lift the top edge
of the mattress out of the water. The lashings holding the
brushy or bottom edge to the deck of the driver, were let go
all at once ; the current passing under the driver forced this
edge under the water, and, with the driver scow following
closely, the mattress came quickly against the piles in a ver¬
tical position. If necessary, one end or both, and sometimes
the whole mattress, was raised up by the pile driver engine,
in order to place it in a vertical position. The lashings, with
sometimes chains in addition, were made fast to the waling
strake and piles, to hold the mattress in place. This dam
was finished on August 20th.
During its construction the river fell from 8.5 on the Car-
rollton gauge to 2.0, so that the effect of the dam in deepen¬
ing the channel was very slight.
There was a slight current through the dam, the velocity
being about one-quarter of that in the channel.
This slackening of the current below the dam, and in the
eddy that formed in the channel west of it, caused a slight
deposit between the dam and the island during the low river.
Another effect of the dam was the lowering of the surface of
the water below it to such an extent, that at ebb tide there
TTTgAT) OF THE PASS—DETAILS.
127
was a current over the East Dyke flowing from Pass à Loutre
into South Pass.
Foundation mattresses were laid for a dyke parallel with
the current at the west end of the dam. These mattresses
were one hundred feet by thirty-flve feet by two feet, and
were laid on each side of a central row of piles connecting
with the foundation mattress of the dam, and extending
down stream four hundred feet.
A detailed record was preserved of the materials and labor
in Dam No. I., and in the four hundred feet extension down
stream. The estimate of the cost of this work to the con¬
tractor was made up from this record, and will be found in
Appendix 9. A cross-section of this dam is shown on Plate
12, facing page 124.
DAM No. II.
This dam commenced at the western shore of Sojith Pass,
near the lighthouse, and extended out four hundred feet
into the channel. The foundation mattresses were laid about
the last of August, 1876.
Their dimensions were one hundred feet by thirty-five feet
by twenty-two inches. A row of piles was driven through
them twelve feet from the lower edge, about twenty-five feet
apart, except over the one hundred feet next the channel,
where they were ten feet apart. A waling strake was bolted
to this section, against which a tilted mattress was placed.
Between the shore and the tilted mattress the dam was
raised to the surface by two courses of mattresses laid hori¬
zontally, on which loose willows were placed. The maximum
depth of water was twelve feet, and decreased gradually from
the channel end of the dam to the shore line. The line of a
dyke known as Lighthouse Dyke was established at the end
of the dam, parallel with Island Dyke (the dyke at the west
128
THE MISSISSIPPI JETTIES.
end of Dam No. I.), and eight Inindred and fifty feet from it,
to form the west side of the channel. A line of piles ten feet
apart was driven from the end of the dam two hundred feet
up stream and four hundred feet down stream. Foundation
mattresses thirty-five feet wide, twenty-two inches thick, and
varying in length, were placed on each side of the up-stream
row of piles for the foundation of this dyke. A waling
strake one hundred and seventy-five feet in length was
bolted to the channel side, and tilted mattresses were placed
against the piles on the shore side. This work was finished
September 8th, 1876.
ISLAND DYKE.
In order to reach the twenty feet contour at the upper
edge of the shoal, and at the same time to define the eastern
line of the channel. Island Dyke was extended up stream
eight hundred feet above Dam No. I. A row of piles was
first driven the whole length of this extension, against the
east side of which foundation mattresses were sunk, thirty-
five feet wide and twenty-two inches thick connecting with
the mattress of Dam No. I., and extending sixty feet above
the upper end of the piling of the dyke. At the end of the
row a cluster of twelve piles was driven and drawn together
by a chain, on the top of which a platform was placed
about six feet square, which was used as an instrument sta¬
tion for locating soundings and floats. This station, called
" New Cluster," is shown on Plate H. The main row of piles,
eight feet apart, was driven through the foundation mat¬
tresses, and ten feet east of the row of guide piles. A wal-
ing strake was bolted to the west side of this row, three feet
above average flood tide, against which eight hundred lineal
feet of mattresses were placed, each mattress being one hun¬
dred feet long, twenty feet wide, ,and thirty inches thick.
TTRAT» or THE PASS—^DETAILS.
129
Small choice wiUows "were used, and the mattresses "were
constructed with unusual care to insure compactness. The
ends of the mattresses were pulled tightly together, after
■being raised to a vertical position, and they were securely
chained and lashed to a waling strake. The top of the mat¬
tresses was three feet above average flood tide. Braces of
two inch plank connected the two rows of piles. The work
■svas completed on September 15, 1876. In October another
course of mattresses of the same dimensions was placed
against the first, breaking joints with them. This dyke with
its two courses of mattresses, was nearly impervious to the
flow of the water. An eddy was formed on the west side of
it, extending about three hundred and fifty feet into the
channel.
SOUTHWEST PASS SILL.
It was evident, that, while the original plan contemplated
works in the entrance of South Pass only, the results of these
works would compel an extension of the system so as to
embrace the whole river; a system that would check the
temporary loss of volume, stop the deepening in the other
passes, and restore to South Pass its full normal volume and
maintain it. The only way to accomplish this was to control
and reduce the flow into Southwest Pass and Pass à Loutre.
If this had been done by dykes, built to the surface of the
of the water from the east and west shores of the river
toward South Pass, with no protecting apron on the bed of
the two larger passes, the results, no doubt, would have been
similar to that of East Dyke upon Pass à Loutre ; that is, the
two larger passes would have quickly recovered their sec¬
tional area; their depths and velocities would have been
greater than formerly, and the direct consequence of these
new conditions would have been the still further deterioration
of South Pass, and a further gain of water by the two larger
9
130
THE MISSISSIPPI JETTIES.
passes. Soon after the construction of Dam No. I. and
Lighthouse Dyke, it was decided to build a submerged dam
or mattress sill entirely across Southwest Pass, not with the
intention at that time of contracting its original section, but ■
of preventing its further enlargement, so that on the rise of
the river in the spring, the works recently built should act
more energetically on the South Pass channel, and not
deepen Southwest Pass, as East Dyke had deepened Pass à
Loutre. The location of the sill can be seen on Plate H.
Its eastern terminus was six hundred and forty feet above
the end of dam No. IL Its western terminus was the west
shore line of Southwest Pass. The total length of the work
was three thousand one hundred and seventy feet, or from
the batture, where the first mattress was laid, two thousand
eight hundred and forty feet. The depth of water over this
batture or submerged bank was one foot at the shore line,
and three feet at the edge of the channel at low water. In
the next three hundred feet the water deepened to twenty-
eight feet. From this point there is a more gentle slope, the
depth reaching thirty-three and a half feet, at a distance of
fifteen hundred feet from the shore line ; thence the depth
decreased uniformly to eighteen feet, at the Junction of the
mattress sill with the Lighthouse Dyke.
Work was commenced September 7th, 1876, by building
anchorages, which were spaced one hundred and fifty feet
apart. The guide piles for the lower edge of the mattresses
were driven fifteen feet apart, beginning three hundred and
eighty-five feet from the shore line, in four feet of water.
The first three mattresses were placed September 21st;
their dimensions were one hundred feet by thirty-five feet by
twenty-two inches, and their position was lengthwise with
the piling. The east end of the last mattress was in twenty-
six feet of water. Two days afterward an attempt was made
to sink three mattresses beyond these, each one hundred feet
TTRA-n OP THE PASS—^DETAILS.
131
by fifty feet by twenty-two inches. Although the river was
at a low stage (the reading on the Carrollton gauge being 4.0),
the current was so strong that the mattresses, when nearly
in position, pulled the anchorages over, broke through the
guide piling, and were saved with difiiculty. They were
pulled up along the shore by the tug, and were placed as
second and third tiers on those sunken on the 21st.
The size of the mattresses was then changed to sixty feet
by thirty feet by twenty-two inches. These were handled
very easily if placed lengthwise with the current. After
sinking six, the dimensions were changed to seventy feet by
forty feet by two feet, and this size was carried through the
entire work. In order that the position of each mattress
might be correctly plotted for future reference, every twelfth
pile was located carefully by a transit, and the place of each
mattress in reference to the piles, which were numbered con¬
secutively, was accurately noted.
In order to avoid any more accidents, the anchorages were
built more securely ; the timbers were all six inches by twelve
inches, and were well bolted to the piles. Above the plat¬
form, in a line with the current and at a distance equal to the
depth of the water, two large piles were driven close together.
Into one end of a seven-eighths inch chain, about fifty feet
long, a large ring was forged, by means of which a loop was
formed, which was slipped over the two piles. The running
end of the chain was pulled taut by the engine of the pile-
driver, and made fast to the up-stream pile of the platform.
By this means the anchorages were not only rendered strong
enough to resist the severe strain caused by the pull of the
mattresses, but were greatly stiffened, and the swaying motion
caused by the current was prevented. The remaining two piles
of the platform were used as snubbing and fastening posts for
the mattresses. Two head lines were built into each mattress
in the manner employed at the jetties. When the mattresses
132
THE MISSISSIPPI JETTIES.
were brought from the Jump by the steamboat they were
tied to an anchorage near the shore, about one-half mile
above the sill. The tug, with the assistance of the yawl
crew, brought the mattress to the anchorage immediately
above thé sill, and placed it nearly in its proper position.
The pile-driver scow was placed on the west side of the two
piles that had been driven about twenty-five feet apart in the
eastern edge of the last mattress before it was sunken. The
fioating mattress was brought down to its position and at the
same time hauled closely against these two side guide
piles by means of a line made fast to it from the steam winch
of the pile-driver. The mattress was secured to each of the
piles by rope lashings, which were left sufficiently slack to
slide down the piles. While this was being done the tug
brought down another mattress ; the line was run to it by the
yawl crew of the pile driver ;'it was pulled snugly to its place
against the first mattress, and the two mattresses were se¬
curely lashed together at the upper and lower ends. Fleets
composed of three or four mattresses were thus brought into
position and lashed together while fioating. The pile driver
was then taken to the opposite side of the fleet and two piles
were driven in the edge of the eastern mattress and lashed as
before. This plan, by avoiding gaps and the overlapping of
mattresses, prevented a scour between or under them. There
was one continuous mattress carpet, seventy feet in width,
extending the whole length of the sill.
It was necessary to use great care in sinking the mattresses,
for the impact of the strong current often brought a severe
strain upon the lines leading to the anchorage, and unless
the mattress went to the bottom in a perfectly horizontal
position, neither lines, anchorages, nor guide piles could pre¬
vent it from breaking away from its fastenings. On the 21st
of October, the sill having reached a distance of two thousand
feet, an opening about seven hundred and fifty feet wide was
TTFAT) OF THE PASS—DETAILS.
133
made througli the guide piles and anchorages for the benefit
of navigation. The piles in this opening were broken by the
tug pulling down the piles, which invariably broke off in the
mud at the bed of the river, this being the fulcrum of the
lever. The broken piles were generally secured, hauled
ashore and sharpened to be used elsewhere. The last mat¬
tress of the sill was laid on November 6th. The whole num¬
ber of mattresses placed was seventy. Three thousand and
thirty-three cords of willows were used in their construction,
and one thousand five hundred and fourteen cubic yards of
stone were required to sink and properly load them, the
ratio of stone to mattress work being about one to ten. After
the sill was completed, the guide piles and anchorages were
removed, and nothing indicated to the eye the presence of
this important work, except the difference in the appearance
of the water surface above and below the sill, which, with
certain directions of the wind, could be plainly seen the
whole length of the work, revealing the fact of a head of
water above it, which, though slight (being only the fraction
of an inch), produced important results.
EXTENSION OE LIGHTHOUSE DYKE.
This dyke was extended four hundred and seventy-five
feet to a connection with the sill. The guide piles for the
foundation mattresses, were driven in a line with the piling
of the dyke. Mattresses thirty-five feet wide and two feet
thick were laid on each side of this piling. The guide piles
were then broken off at the top of the mattresses, and per¬
manent piles were driven ten feet apart and fifteen feet east
of the first row. The dyke was then built up on the west
side of these piles to the surface of the water, with mat¬
tresses laid horizontally. This plan gave a foundation fifty
feet wide ; the second course was forty feet wide, the third
134
THE MISSISSIPPI JETTIES.
thirty-five feet, the fourth, thirty feet, and the fifth, twenty-
eight feet. This extension was finished February 22d, 1877.
A protecting mattress apron thirty-eight feet wide, was laid
on'the east side of the foundation mattresses, upon which was
laid a second course, twenty-five feet wide. The rise of the
river about the last of January came very suddenly, rising
on the Carrollton guage in nine days, from 0 to 7.5. The
wave on reaching the head of the passes, found the entrance
of the South Pass obstructed. A very strong current was
deflected from " New Cluster " against the Lighthouse Dyke,
striking it with the greatest force about two hundred feet
above the dam. The surface of the water in the pass was
lowered by the obstructed entrance, producing a head of
water of two or three inches on the Southwest Pass side of
the dyke. At the point where the tilted mattresses of the
dyke joined the horizontal mattresses of the permanent
work, the current broke through, washing out the piles and
throwing down the tilted mattresses. The strong current,
twenty feet deep, that rushed through this opening into
South Pass, was at right angles with the current entering the
pass from "New Cluster." The meeting of these two cur¬
rents produced whirls and vertical eddies, which made an
excavation in the channel, in which there was a depth of
water of about forty feet, still further undermining the mat¬
tresses. The effect of this extraordinary disturbance extended
below the dam, washing out the guide piles over the whole
distance of four hundred feet. The break through the dyke
was filled up with considerable difficulty, by five or six
courses of mattresses laid horizontally. Protecting mat¬
tresses were laid in the channel, extending eighty feet from
the dyke. The whole space between the dam and the per¬
manent dyke was built to the surface with horizontal mat¬
tresses, and afterward raised about three feet above average
flood tide, with loose willows and stone. The interior angle
HT-,AT> OF THE PASS—DETAILS.
135
between the dam and the dyke was reinforqpd by mattress
work.
A cross-section of this work is shown on Plate 12, facing
page 134.
ISLAND DAM.
This dam was intended to take the place of Cross Dyke,
and of a board dam, which had subsequently been con¬
structed below it, but had been quickly washed away. The
new work was a permanent structure, and crossed the east¬
ern channel about one hundred and fifty feet below Station
" O'Brien," and connected the island with the east bank of
the pass. The average depth of water in which the dam was
built was twelve feet ; but near each shore it was eighteen
feet. The foundation on which the dam rested was the soft
material which had been deposited by the river during the
previous year, and later by the dipper dredges which used
this place for a dumping ground.
The dam was six hundred feet long. The first course of
mattresses was laid January 25, 1877, and the dimensions
were one hundred feet by forty-five feet by three feet. The
upper edge of this and the succeeding courses was supplied
with inch boards, placed immediately behind the first row of
pins, to prevent leakage through the willows. In placing the
mattresses they were taken around the foot of the island and
forced against the current by the tug and the pile-driver up
to the lower side of the piling.
The second and third tiers of mattresses were thirty feet
wide, the fourth- twenty-five feet, and they were all three feet
thick. These courses raised the dam to the surface of the
water, except near the banks, where it was raised by mat¬
tresses that were made to fit the irregularities of the surface.
A protecting apron of mattresses was placed above the dam
to stop a scour that had commenced under it. A row of piles
136
THE MISSISSIPPI JETTIES.
was driven through the dam close to the lower edge of the
upper course of mattresses, and a Avaling strake was bolted
to both rows of piles. After the dam had settled below the
surface of the water, a continuous mattress was built in place
on the waling strakes by means of skids placed across them.
The skids were drawn out by the tug and the mattress
dropped to its place. Two courses of mattresses, each two
and one-half feet thick, were built in this way, and the dam
was then raised about two feet above the surface of the water
by loose willows and stone. A cross-section of this dam is
shown on Plate 18.
ISLAND DYKE.
(Between Dam No. I. and the Island.)
About the first of February, 1877, foundation mattresses
one hundred feet by thirty feet by two feet, boarded on the
eastern edge, were laid from the island to a point four hun¬
dred feet below Dam No. I., where they connected with the
mattresses laid the previous year. The total distance from
Dam No. I. to the island was one thousand six hundred and
forty feet. The average depth of water was about twelve
feet.
DEEDGING.
To insure immediate results from the works constructed, it
was decided to dredge a channel entirely through the shoal,
about midway between the dykes. A contract was made with S.
N. Kimball, of Mobile, to excavate forty thousand cubic yards.
He commenced work September 16th, 1876, with a dipper
dredge. On November 16th, two other dredges that had
been chartered from the city of New Orleans commenced
work. A narrow channel about eighteen feet deep was
dredged through the shoal. These three dredges continued
ISLAND DAM
aecTioN 0 »uATt H
or
'""■■.v/ssirpi wS^''^
JcAit OA ^str.
TTTJ.AT) OF THE PASS—DETAILS.
137
to work with intermissions, until February 8d, 1877. The
total number of yards removed was about fifty thousand.
Several lines of soundings taken on February 8d, showed a
least depth through the shoal of twenty-two feet, a maximum
depth of thirty-two feet, and a twenty feet channel one hun¬
dred and ten feet wide. For several days previous the cur¬
rent had been so strong that it was almost impossible for the
anchors to hold the dredges. The whole shoal seemed to be
moving.
KESULTS OF THE WOEKS.
The changes in the eastern channel caused by the East
Dyke have been described.
The effects of the works subsequently constructed were as
follows : The surface of the water was raised above " New
Cluster," and lowered in the pass below the works. While
the slope of the river above the works was only 0.024 foot
per mile, and that of the pass below the island but 0.088 foot
per mile, the slope from "New Cluster" to the foot of the
island was 0.505 foot, more than six inches per mile. This
extraordinary slope through the inlet channel produced a
strong current, quickly affecting the shoal.
General Comstock, in his report of March 16th, 1877, page
4, speaks as follows of the effects of this rise : " The rapid rise
produced a marked scour in the channel between the two T-
heads, and on February 5th, when the reading at the Carroll-
ton guage was 7.60 feet, the minimum width of the twenty-
feet channel into the South Pass was about one hundred and
seventy feet, while twenty-two feet of water could be carried
through. On March 7th, the twenty-two feet curve had a
least width of about two hundred feet, and the soundings,
which are not very close, indicate that 28.9 feet of water
could be carried into the South Pass from the Mississippi
Eiver."
138
THE MISSISSIPPI JETTIES.
The channel developed very rapidly. On the 13th of April
31.2 feet could be carried from " New Cluster " through the
shoal, and the channel above " New Cluster " had improved,
so that 24.4 could be carried from the river into the pass,
and the twenty-four feet channel was about two hundred and
fifty feet wide. A calculation from a survey made June 6th,
1877, showed that four hundred and fourteen thousand four
hundred cubic yards had been scoured out of the shoal at
the head of the pass.
The general effect of our works upon the head of the
passes may be seen from a survey made on February 26th,
1877, from which cross-sections of the three passes were
plotted. In South Pass, on a line drawn from near the end
of Dam No. II. to East Dkye, at a point four hundred and
fifty feet below Dam No. I., there had been a deepening in
the western channel of sixteen feet since May, 1875, and a
shoaling over the eastern channel of ten feet. On a line ex¬
tending east of East Dyke across Pass à Loutre it had
shoaled fifteen feet for a distance of two hundred and fifty
feet, then deepened fifteen feet, with an average deepening of
six feet entirely across the eastern portion of that pass.
In Southwest Pass the average deepening was about two
feet.
The location, description and results of the works con¬
structed at the head of the passes during the first two years
are thus fully given to exhibit the method of solving the
most difiicult problem connected with the enterprise. The
works described, no doubt injuriously affected the channel
development at the mouth of the pass, and delayed its accom¬
plishment many months by temporarily reducing the flow
into South Pass.
GEAND BAYOU.
Some of the effects of the works at Grand Bayou have been
TTF.AB OF THE PASS—DETAILS.
139
alluded to incidentally in the discussion of the head of the
pass question.
The head of this bayou is five and one-quarter miles
above the South Pass lighthouse. It had all the character¬
istics of a pass—a shoal at its head over which there was
twenty feet of water, a channel about thirty feet deep and
five miles in length, and a bar at its mouth with about three
feet of water over it. The width of this bayou was about
two hundred and seventy-five feet, and the area of its section
about five thousand square feet. This bayou discharged
twenty-three per cent, of the total volume of South Pass. In
December, 1875, work was commenced on a dam at the head
of the bayou. A line of piles was driven across it and four
foundation mattresses were placed above them. This loca¬
tion was selected on account of lesser depths, but involved a
diagonal current which interfered with the work so much that
a new location was selected for it, three thousand seven hun¬
dred feet below the head of the bayou, where the width be¬
tween the banks was two hundred and sixty feet and the
central depth thirty-one feet, and where the dam could be
built at right angles with the current.
"Work at this location was commenced on the 16th of
March, 1876. Two substantial anchorages were built two
hundred feet above the lower lins of the dam, dividing the
bayou into three nearly equal spaces. The mattresses in the
foundation course were one hundred feet long, three feet
thick, and of various widths, and were placed lengthwise
with the current. Three tiers of mattresses were laid at this
time. In June a line of piling was driven through the dam
and tilted mattresses were placed against it, but the pressure
was so great (the head of water being about sixteen inches)
that it broke down the piling, and both piles and mattresses
were swept away. Piles were again driven across the bayou
through the dam in two rows, twelve feet apart, which were
140
THE MISSISSIPPI JETTIES.
braced to each other with two-inch plank and piles, the
butts of which rested on the horizontal mattresses. Tilted
mattresses, twenty-six feet in width and two feet thick, were
placed in position against the upper row. Three courses of
mattresses each twenty-five feet in width were laid horizon¬
tally immediately above the tilted mattresses ; then a second
course of tilted mattresses was placed against the first
course, and the dam was built out upon each bank about fifty
feet with willows and stone.
The work soon after showing a tendency to give away, a
third row of piles was driven twelve feet above the second,
and braced to it with plank. Two mattresses, each two hun¬
dred feet long, were tilted against this row, and the space be¬
tween them and the shore was filled with willows and stone.
These mattresses gradually dropped below the surface of
the Avater, so that in January, 1877, the water over them was
seven feet deep.
Examinations made on September 24th, showed a depth of
eighteen feet over the mattresses. In December, 1877, the
dam was again built to the surface of the water by placing
eight tiers of mattresses above the upper row of piles, the
foundation course being fifty-three feet wide and the top
course fifteen feet. Previous to placing these mattresses, the
greatest depth of water was twenty-three feet. In April,
1878, the dam, having settled again, so that there was a depth
of five feet of water over it in the deepest place, was again
built up above the surface of the water with loose willows
and stone.
This Avork was tAventy-five feet wide and five feet thick.
The' total number of mattresses in the dam was seventy-four ;
the total amount of Avillows three thousand eight hundred
and eighty-eight cords ; of stone, one thousand two hundred
and fifty-eight cubic yards. During the construction of the
dam the overfall caused a deep excavation below it, the depth
SECT«05" OF AT GR.\XD BAYOU
Scale oe Feít.
TTT.AT) OF THE PASS—DETAILS.
141
of water about fifty feet below the dam being fifty-seTen
feet.
The accidents, losses and delays in the construction of this
work were due entirely to the absolute necessity for economy
at the time the dam was constructed. A structure with a
foundation two hundred feet wide instead of one hundred
feet, with the entire work built of mattresses placed hori¬
zontally, would have been capable of resisting successfully
the force that so severely tried it. The effect of the dam
upon the bayou above it was to shoal it quite rapidly. In
March, 1878, the maximum depth between the dam and the
pass was 11.5 feet, where originally there was thirty-one
feet. In the spring of 1879 there was so little depth that a
steam launch drawing four feet could not enter the bayou.
The indications are, that in a short time the deposit will
reach the surface of the water ; that the marsh grasses and
reeds will cover the place where formerly there was a depth
of water of over thirty feet, and that nothing will mark the
location of the bayou except the scattered clumps of willows
that grow along its former banks.
A section of this dam is shown on Plate 14
CHAPTEE XII.
development of jetty channel—twenty feet channel ob¬
tained—effects of wing dams.
The processes of construction described in detail in the
]preceding chapters, embrace nearly all the methods employed
at the jetties and the head of the passes, except the works of
consolidation.
The description of the works at the jetties and the history
of the development of the channel were, at the close of Chap¬
ter VIII. brought down to June, 1876.
Tlie channel continued to develop rapidly through the
summer and early fall. A careful and detailed survey made
on October 5th, showed a channel twenty feet deep, with a
least width of two hundred feet, between the pass and the
gulf. This survey was made by Mr. Eads's engineers. The
government inspecting officer was not present, and no report
announcing the obtaining of the channel was made to the
Secretary of War.
It was the opinion of Gen. Comstock that it was neces¬
sary to obtain a channel through the shoal at the head of the
pass twenty feet deep and two hundred feet wide before Mr.
Eads could claim his first payment from the Government.
As the latter held to the contrary opinion, and appealed from
the decision of Gen. Comstock, the President appointed a
commission to decide the question and report to the Secre¬
tary of War. The members of this commission were Gens. J.
G. Barnard, H. G. Wright and B. S. Alexander.
142
DEVELOPMENT OF JETTY CHANNEL.
143
In the letter given them by Secretary Cameron they were
instructed to give their opinion on the following questions :
First—" Is the shoal at the head of the South Pass a part
of that pass, or of the main Mississippi Hiver ? and
Second—" If Mr. Eads obtains a channel twenty feet in
depth in the South Pass, exclusive of this shoal, is he entitled
under the law to his first pavment of half a million dol¬
lars?"
They were also asked to give their opinion upon the depth
and width of channel necessary to be secured through this
shoal ; to interpret the words " average flood tide " used in
the act, as applied to the head of the pass ; decide whether,
in regard to permanency, the jetties were constructed accord¬
ing to the spirit of the act, and to present any general sug¬
gestions which they might consider necessary.
The commission arrived at Port Eads November 12th,
1876, and after making a careful examination made their re¬
port on the 19th.
They state in answer to the first question, "That this
shoal is not exclusively a part of the South Pass, for it ex¬
tends entirely across the river from shore to shore. It is
therefore a shoal common to all three of the passes, but the
channel (or channels) through this shoal, by which access has
been had, or is to be had in future, from the river above into
the South Pass, is a part of that pass."
They answer the second paragraph of this question in
the affirmative, since the obligation of the United States
Government to pay half a million dollars applies exclusively
to the " wide and deep channel, between the South Pass of
the Mississippi River and the Gulf of Mexico," since, in
their opinion, the payments are not affected by the channel
at the head of the pass, unless it should be delayed so long
as to incur the forfeiture of the concession as stated in the
act. They consider a channel twenty-six feet deep and two
144
THE MISSISSIPPI JETTIES.
hundred feet wide as sufficient for a permanent channel
through the shoal at the head of the pass. The plane of
" average flood tide " should refer to the low water stage of
the river, since it is necessary that the full depth should be
maintained through all seasons of the year. In regard to the
stability and permanency of the jetties, they consider that in
general plan they correspond substantially with that designed
by the Board of 1875, and that Mr. Eads has departed from
its detailed plans only as experience has shown to be neces¬
sary, and although a small amount of stone has been used
thus far, the jetties, they say, " except at their sea ends in
deep water, where some damage has been done, have resisted
without material injury the floods, storms and waves,, and
there has been more than a year's exposure, with its winter
and autumnal storms for some portions of the existing
work." That while the jetties do not exhibit the " substan¬
tial and permanent work" ultimately contemplated by the
law, they have been designed and constructed thus far ac¬
cording to its spirit. They offer the general suggestion that
the jetties, especially their sea ends, should be loaded more
heavily with stone and their consolidation hastened.
And they say further : "We are of the opinion that this
enlargement of section at the sea ends and consolidation
throughout by the application of stone should be undertaken
at once, and a reasonable progress therein be made the con¬
dition of the second and all future payments." To make a
compliance with this recommendation the condition of future
payments would have been a direct infraction of the act of
concession, which left Mr. Eads entirely " untrammeled in
the location, design and construction " of the works. This
recommendation caused him to write a letter of remonstrance
to the President of the Commission, Gen. Barnard, in which
he stated in effect that he did not believe he would receive a
single payment on the work unaccompanied with some humil-
DEVELOPMENT OF JETTY CHANNEL.
145
iation on his part or unjust condition. (For the detailed
statements of the Board see Appendix 10.)
This report, with an extended discussion of the first two
questions by Gen. Barnard in behalf of the Board, was re¬
ferred to Attorney-General Taft for his legal opinion. His
conclusions were as follows :
" 1. That Mr. Eads and his associates are bound by the ex¬
press terms of the said condition, on pain of forfeiture of
their privileges, etc., to secure a navigable depth of twenty,
twenty-two, twenty-four and twenty-six feet, within the
periods prescribed, through the channel over the shoal at
the head of the pass, and likewise over th'> bar at its mouth ;
that by necessary implication, they are also bound to secure
a navigable width of the required depth in each instance
through the channel at each of those points ; and that the
provisions in said condition, as to the depth and width, are
the only ones of the kind which apply to said shoal.
" 2. That the provisions in other parts of the statute requir¬
ing specific depths and widths, varying from twenty feet in
depth by two hundred feet in width, to thirty feet in depth
by three hundred and fifty feet in width, relate solely to the
work at the mouth of the pass.
" 3. That the payment of the first and other installments is
controlled exclusively by the terms of the particular provi¬
sions authorizing such payments ; and that since the speci¬
fied depths and widths mentioned in these provisions have
reference only to the work at the mouth of the pass, so soon
as the depth and width required for any such payment are
obtained, it may then be made, provided no forfeiture has
been incurred under said condition.
" Accordingly, the answer I make to your question is, that
the first installment of 1500,000 can be made when the chan¬
nel at the mouth of the pass is twenty feet deep and two hun¬
dred feet wide, although the same depth be not obtained
10
146
THE MISSISSIPPI JETTIES.
through the shoal at the head of the pass, if no forfeiture
shall have arisen by action of Congress, or without action
of Congress, as provided in the condition mentioned."
The deposit of soft mud, which usually occurs in the river¬
bed during the low-water season, slightly reduced the depth
and width of the channel through the jetties, so that there
were several points where it was deficient. This contraction
of the channel occurred before the inspecting officer made
his survey. The three dipper dredges were brought from
the head of the pass to enlarge the channel. Unfortunately,
it was necessary for them to perform considerable work at
the sea end of the jetties, where they were almost constantly
exposed to the waves, which made it dangerous and almost
impossible to work dredges, that required to be anchored to
the bottom by upright posts. Accidents, delays, and great
expense were the results. It was not until December 27th,
that the channel was restored. On account of this delay,
and the discussion of the legal points at issue, payment was
not made to Mr. Eads until the middle of February, 1877,
although he was clearly entitled to it on October 5th, 1876.
In consequence of this delay, and the v/ant of necessary
funds, very important works at the head of the passes were
necessarily postponed, and afterward built at a high stage of
the river, at a greatly increased expense and loss of time.
During the interest and excitement attendant upon the
attempts to secure the twenty feet channel, an event oc¬
curred, which cast a gloom over the Avhole work. This was
the sudden death, by heart disease, of Mr. Bayley, Eesident
Engineer, on December 14th, 1876, at the age of fifty-five
years. His active and useful life deserves a more extended
sketch than is appropriate here. As a civil engineer, en¬
gaged in the location and construction of levees and railroads ;
as a state legislator and a member of the New Orleans Board
of Health ; as a writer on subjects of interest and benefit to
DEYELOPMENT OF JETTY CHANNEL.
147
his fellow-citizens; in all these capacities he exhibited a
great interest, sound judgment, and a de.Yotion to the best
interests of his fellow-men. His long experience and ex¬
haustive studies in the hydraulics of the Mississippi Eiver,
brought to the question of deepening the mouth of the river
a most valuable assistance. During the inception of the
jetty enterprise, his able articles in the public press and his
letters to members of Congress, ably written, with strong
arguments and facts clearly put, had great influence in the
selection of the jetty plan for the improvement.
When the construction of the jetties commenced, his coun¬
sel both in regard to general methods and the details of the
work were invaluable. He was most intensely interested in
the success of the jetties, on which he had publicly staked
his reputation as an engineer. Mr. Eads cherished for him
a most affectionate regard, and the highest respect as an en¬
gineer, and he spoke the sentiments of all Mr. Bayley's as¬
sociates on the works, when, on being presented with the
certificate of the United States Inspecting Officer, stating
that a channel twenty feet deep and two hundred feet wide
existed, he said, " My only regret is that Mr. Bayley could
not have lived to share in our glorious success."
Soon after the death of Mr. Bayley, Mr. Corthell was pro¬
moted to the position of Resident Engineer, and Mr. Schmidt
to that of Chief Assistant Engineer.
In^the following year the construction work at the jetties
consisted mainly in raising them by mattress and willow
work ; by consolidating them, especially near the sea ends
with large quantities of stone, and by the construction of
wing dams for confining the current. The mattress work
over the whole line of jetties had become considerably com¬
pressed by its own weight and that of the sediment lodged
in it, and the rock placed upon it. In many places the sub¬
sidence had become so great that the depth of water flowing
148
THE MISSISSIPPI JETTIES.
over the jetty was from two to three feet. The mattresses
were generally, however, so near the surface of the water
that it was impossible to float another tier over them. Vari¬
ous plans were resorted to for raising the jetties above the
surface of the water.
First.—By building mattresses upon the ways oh shore,
towing them to their location, and then at high tide, by
means of a steam pile-driver, raising one side of the mattress
and forcing it to its place against the guide piling.
Second.—By building mattresses on ways, constructed on
a decked barge. These ways, about one hundred and fifty
feet in length, were built of round pine piles spaced six feet
apart on the deck of the barge, and at right angles with the
edge on which they rested, and which they overhung about
twenty-five feet, and to which each pile was hinged. The
butts of the piles were firmly fastened together. The mat¬
tress, often one hundred and fifty feet in length, twenty-five
feet in width, and two feet thick, was built on these ways.
The barge was then towed to the place required ; a latch that
secured the butts of the piles to the deck of the barge was
"let go;" the overhanging ends dropped suddenly on the
jetty, and the mattress was thus launched to its place. The
barge was then pulled away by the tug, the piles drawing out
from under the mattress. The butts were latched down again
and the barge was towed to Port Eads for another mattress.
Third.—By building mattress work in place on the jetties.
This was done by first cutting hickory pins in lengths to. suit
the irregularities of the top of the jetty, and inserting them into
the cross-binders of the old mattresses. The willows were
then placed between the pins in the same manner as when
built on the ways. Several thousand lineal feet of the jetties
were raised in this manner, and well loaded with rubble
stone.
Fourth.—By building mattresses on skids laid across wal-
DEVELOPMENT OP JETTY CHANNEL.
149
ing timbers, wbich were fastened to the river and sea rows of
piles. This kind of construction was adopted for raising the
end of the east jetty, which had settled from five to nine feet
below the surface of the water. "When two or three hundred
lineal feet of mattress work had been constructed on these
skids, the latter were pulled out by the tug ; the mattress
dropped into the water, on which, while floating, were built
other courses, until the weight was sufficient to ground the
mass upon the submerged jetty. It was then securely held
in place by large quantities of stone.
The wing dams that had been previously constructed on
bath jetties at Stations 100, 112 and 118 were raised to the
surface of the water by mattresses laid horizontally. A spe¬
cial construction was adopted for those at Station 118, by
which a broad base and a slope seaward were obtained.
In all places exposed to the violence of the waves, where
the top tier of mattress work was liable to be thrown off from
the jetty during storms, the mattresses were generally firmly
secured in place by a row of piles, driven close against them
on the river side, and often by a new row of piles on the sea
side, wherever a pile-driver scow could be floated. Near the
ends of both jetties the mattress work was still more firmly
secured by heavy timbers placed across the jetties and bolted
to the piling.
Many new wing dams were constructed, the space between
the river ends of two opposite wing dams being generally
about six hundred and fifty feet, though at some points less
than six hundred feet. On the 24th of July, 1877, twenty-
nine wing dams in all had been built. Some extraordinary
effects on the channel were produced by these structures,
which we will describe more in detail.
On account of the wide expanse above the head of the
west jetty, the current produced but little effect upon the
hard clayey bed. The width between the east jetty and the
150
the inssissrppi jetties.
west shore line Taried from fourteen hundred feet at Station
26 to sixteen hundred feet at Station 40. In order to concen¬
trate the flow of water over this space, wing dams were built
in pairs at Stations 26, 30, 85 and 38 from the east jetty and
from the west shore. Those built from the west shore ex¬
tended into the channel about one hundred and flfty feet be¬
yond the line of the west jetty. They narrowed the water¬
way to about five hundred and seventy feet. This work was
done in the fall and winter of 1876. During the flood season
of the following spring the effect of these wing dams was as
follows : The channel from Station 26 to Station 40 improved
rapidly, but the more marked effect of this concentration yas
seen below the head of the west jetty, where there had been
no confinement of the waterway, and the channel was nearly
nine hundred feet wide. In April the maximum depth in
the channel was thirty-three feet ; on May 25th, it had in¬
creased to seventy-five feet, and a remarkable enlargement
laterally had taken place. On July 5th the depth was ninety-
five feet and the width of the basin thus formed was nearly
eight hundred feet.
In order to investigate the causes of this peculiar phenom¬
enon, float lines were run on June 26th from Station 26 to
Station 66. The river at the time was at the flood stage of
that year, the reading on the Carrollton gauge being about
eleven feet.
Slope observations were made at the same time between
East Point and Station 60. These were made by noting the
surface of the water on gauges set at various points qn the
east jetty by careful leveling. These readings indicated that
between East Point and Station 30 the fall per mile of the
surface of the water was about four inches, between Station
30 and Station 37 eighteen inches per mile, while from Sta¬
tion 37 to Station 60 the surface was nearly level. The re¬
sults of float observations agreed very closely with the slope.
DEVELOPMENT OF JETTY CHANNEL.
151
The average velocity of the central thread of the current
from Station 30 to 50 was nearly three hundred feet per
minute ; beyond that point the force of the current was en¬
tirely broken. The floats moved in nearly parallel lines from
Station 80 to Station 40, from which point they converged
rapidly, until at Station 50 the greatest width between two
floats was not over one hundred and thirty feet, except those
that were caught by the strong eddies that existed on either
side of the straight current, and were often moved quite rap¬
idly up stream, the eddy giving them a circular direction,
drawing them into the straight current several hundred feet
above their point of departure from it.
These strong eddies and the vortices caused by them were
plainly seen, and the line of demarkation between them and
the straight current was very distinct to the eye.
The effect of these wing dains was in accordance with
the established principles of the " vena contracta," the con¬
tracted vein, of Newton, and very clearly illustrates those
principles on a large scale. It also illustrates the extraor¬
dinary force of an eddy current ; for although the velocity of
the current in these eddies was not in some instances over
thirty feet per minute, yet on account of its circular motion
it widened this great basin rapidly, until encroaching upon
the west jetty it undermined the foundation of the mattresses
and caused a crevasse to break through the solid wall of the
jetty about one hundred and fifty feet wide, with a central
depth of thirty feet on the sunken mattresses. This crevasse
being caused by an eddy current, and not by a head of water,
extended .but a short distance beyond the jetty and was
easily closed by mattress work. Using the elements as we
found them, namely the mean velocity, volume, and the width
of the straight current, we find by calculation, that a depth
of ninety-five feet should have existed, and this was the maxi¬
mum depth observed. The river floods subsided in August.
152
THE MISSISSIPPI JETTIES.
and during the fall a deposit took place in the deepest part
of the basin, decreasing the depth to about seventy-five feet
This deposit, however, was very soft, the sounding lead sink¬
ing into it several feet.
During the flood season of 1878 the material deposited in
the basin was quickly removed ; the eddies on either side be¬
came stronger even than they were during the previous
year; the straight current was brought into still narrower
limits, and a depth of one hundred and fourteen feet was
reached. The effect of this great disturbance upon the chan¬
nel was very injurious, heavy deposits of sand being made at
various points from Station 80 to the crest of the bar. The
object for which the wing dams were built having been ob¬
tained, namely, the deepening of the channel opposite them,
they were removed back to the line of the west jetty—thus
increasing the width of the channel one hundred and fifty
feet above Station 40, and remedying the evil.
This basin gave an opportunity to investigate the question
of the stratification of the material comprising this portion
of the bar. An instrument was made, weighing about eighty-
five pounds, which had a sharp steel point for penetrating
the material at the bottomj when dropped from the launch.
This point was fitted into a two and one-half inch gas pipe,
about eight inches long. In the side of the point was an
opening about two inches square with a projecting lip on the
lower edge to catch the material when the sounder was
drawn up. This short piöce of gas pipe was screwed into
another piece about two feet long, so that when the cavity
was filled the point could be unscrewed from the longer piece
and the material removed. A mass of lead was run about the
gas pipe to give it weight sufficient to strike the bottom
with great force. To hold the point downward while falling,
a white pine post about two and one-half feet long was fitted
into the gas pipe and secured to it firmly by side straps of
DEVELOPMENT OF JETTY CHANNEL.
153
iron. A ring with a half-inch rope attached was fastened in
the end of the post and the machine was dropped from the
side of the launch, the rope running through a sheave, set in
a post about five feet above the rail. The material brought
from the different localities and depths was dried, then
pounded up, if clay, and sprinkled on gummed paper. A sur¬
vey was made at the time of making these observations. The
chart of this survey when compared with previous charts
gave the data for making a sketch showing the line of de-
markation between original material and that on any areas
over which shoaling may have taken place since the jetties
were commenced, and on which new deposits must have been
made. On the sketch the points from which the specimens
were taken were located and noted according to whether the
material was clay, sand, mud, half clay, or half sand. On
this chart a characteristic curve was drawn at twenty-six feet
depth, as the line between clay and sand seemed to be ap¬
proximately near this level. A record which was kept of the
depth at which each kind of material was met by a dipper
dredge working at Station 22, shows that the line between
sand and clay at that locality is at about twenty-eight feet
depth.
The size of the sand particles, as ascertained by the sedi¬
ment observations of Captain Brown, United States Engi¬
neers, varies from one-one thousandth of an inch to one-fif¬
tieth of an inch in its largest daimeter, the latter size being
very rare. It is really a fine mineral silt with a small admix¬
ture of alumina.
The pockets of clay, so called, are no doubt very similar
to the material found in the "mud-lumps," which, according
to a careful analysis made by Captain Brown, is composed
of the following ingredients :
154
THE MISSISSIPPI JETTIES.
Silica 58.00 parts.
Alumina 29.67 "
Lime and its Salts 5.34 "
Magnesia 3.50 "
Iron and its Salts 2.46 "
Common Salt 1.00 "
Total 99.97
The hardness and supporting power of the material from
the surface to twenty feet depth, is seen from the record of
the piles driven on the line of the jetties.
The average results are as follo'ws :
Weight of hammer 3000 pounds.
Its average fall 19J feet.
Average number of blows 80
Average depth driven 19|^ feet.
Average distance driven at last blow.... | of an inch.
This is the record of the piles driven along the whole
length of the west jetty ; and the record of those driven on
the east jetty show nearly the same character of material.
CHAPTEE XIIL
financial embaeeassments—desceiption of the deedgè-boat
g. w. e. bayley—twenty-two feet channel secueed—ee-
poet op commission—congeessional action.
The financial embarrassments witb wbicb the work was
hampered during the spring and summer of 1877, not only
rendered its further prosecution difficult, but its completion
doubtful, in the minds of the majority of those interested in
it. The amount of construction work done and its great
cost was far beyond what the concurrent channel results
indicated. The five hundred thousand dollars received from
the government in February had all gone to pay pressing
indebtedness, and to meet obligations and claims that could
no longer be put off. It was necessary again and again,
month after month, to renew, notes and extend the time of
payment for bills of material. Arguments, and appeals even,
were often necessary to obtain the renewal of favors already
granted so many times.
The fickle channel at the sea end of the jetties made these
financial labors still more arduous, and their result more and
more uncertain. It was a very discouraging period in the
history of the enterprise. The most strenuous exertions
had been put forth by Messrs. Eads and Andrews to raise
the necessary means to meet the pay rolls and incidental
expenses, but now every available source was exhausted ; the
pay rolls were two months overdue, while the construction of
very extensive and expensive work, at the head of the passes
155
156
THE MISSISSIPPI JETTIES.
especially, was imperatively necessary not only to obtain the
required channel into the pass, but more im'portant still, to
restore to it the volume necessary for the more rapid de¬
velopment of the jetty channel.
The financial depression at last became so great, that
Messrs. Eads and Andrews, who had gone north for the pur¬
pose of making the necessary arrangements for money to
carry on the work, telegraphed Mr. Corthell, the Eesident
Engineer, on August 7th, as follows : " Discharge the whole
force except those necessary to protect property, unless
they are willing to work for certificates, payable on receipt
of the twenty-two feet payment." All the employees were
immediately summoned to appear at the office ; the situation
was briefly explained to them, and without any attempt at
persuasion, those who were willing to remain on the condi¬
tions named were asked to come forward and sign an agree¬
ment to that effect. It was a gratifying proof of confidence
in the work on the part of these men, that only two out of
the seventy-six refused to accept the terms. The fairness
with which they had been treated; the promptness with
which, until now, they had received their monthly pay ; the
evidence of final success, which they saw in the steadily
improving channel, and in the constant sight that daily met
their eyes in the rush and whirl of the swift waters, as they
cut their way through the sand and clay to the deep waters
of the gulf, and more than all, the interest in and devotion to
the work on which they had been so long engaged ; all these
reasons made them nearly unanimous in their resolve to
remain.
The scene that was witnessed at Port Eads on that sultry
afternoon in August, was extremely interesting and exciting.
Little did the great valley realize that its vast commercial
interests were being advanced by a few laboring men at the
mouth of the Mississippi Kiver, to whom great credit should
EFFECTS OF WING DAMS.
157
be given for the devotion to duty and faith in the ultimate
success of the jetties exhibited by them in the calm and
determined spirit with which they came up and signed that
compact.
Although the jetties were generally raised to the height of
average flood tide, they were by no means impervious to the
flow of water. Through the openings of the mattresses the
head of water forced a strong current. Float observations
showed that at least thirty per cent, of the volume passing
" East Point " was lost through and over the mattress work
before reaching the sea end of the jetties. It was evident
that, to secure the full benefit of the confined current, the
interstices of the mattresses must be closed by the consolida¬
tion of the works, but more especially by inducing the river
to deposit or bank up its sediment along the slope of the jet¬
ties. The latter result was slowly, but very effectually ob¬
tained by the wing dams. They did not stop the entire flow
of the current ; they simply checked it, turning the larger part
into the jetty channel and passing the remainder with the
sediment in suspension through the meshes of. the tilted
mattresses Avith a feeble current, which, unable to hold up
the suspended matters, dropped them behind the dams and
along the jetties. This process, carried on continually
through the period of high river, slowly built a batture or
bank against the river side of the jetties, rising higher and
higher, until in many places the surface of the water was
reached.
The same effect was seen on the sea side of the jetties as
far seaward as Station 80 on the east jetty and Station 95 on
the west jetty. Each season showed new deposits of this
kind, and every cubic foot of material thus deposited against
the jetties helped to hold back in the channel, for its devel¬
opment, the waters that otherwise would have escaped and
become useless.
158
THE MISSISSIPPI JETTIES.
By the 30th of July, while no increase of depth was seen
on the outer bar, the channel had improved so much that
twenty-two feet in depth by two hundred feet in width could
be carried from " East Point " to Station 105, or ninety per
cent, of the whole distance through the bar. The least width
of the twenty-one feet channel was two hundred and fifteen
feet, and only four thousand cubic yards of material remained
in the way of a channel twenty-two feet by two hundred feet.
Hoping to remove this obstruction by the ordinary means,
Kimball's dipper dredge, on September 22d, was fitted up and
set at work at the sea end of the jetties (where nearly all the
work was to be done) with good prospects of success at first,
but, stormy weather intervening, the sea became too rough
for a dredge of this kind, and after several weeks of unavail¬
ing efforts to work against the elements, the attempt was
abandoned.
To meet such an emergency as this, and to provide for the
future maintenance of the channel, Mr. Eads constructed a
dredge boat, which in general plan and in most of its details
was his own invention, and which combined all the requi¬
sites demanded of a dredge compelled to work in deep water,
in a strong current and in the sea-way often found at the end
of the jetties. It was evident that for some time to come, at
least until the final development of the channel, two condi¬
tions were at any time liable to arise to require a change to
be made in the channel by artificial means.
First.—A channel much deeper than required but too nar¬
row.
Second.—A channel of greater width than was necessary
but of too little depth.
In other words the current might recover the full section
required for its wants, but such a section might not conform
to tùe exact dimensions in depth and width demanded by the
legal and arbitrary specifications of a Congressional enact-
DEEDGE-BOAT BAYXET.
159
ment, so that, without some means of increasing slightly the
depth and width at certain points, although a few yards only
of material should need to be removed, the payments both
for obtaining and maintaining the channel might be delayed
for months as they had been in this case. There is no doubt
that on the 20th of September, two days' work by a suitable
dredge would have secured the twenty-two feet channel.
The new dredge-boat constructed at Pittsburg, Pa., by D.
"W. C. Carroll & Co., and named " G. W. R. Bayhy," ar¬
rived at Port Eads November 15,1877. After some delays
in making necessary alterations, she commenced work on the
22d.
Peculiar conditions which exist at the mouth of the jetties,
already alluded to, render the use of a dredge-boat which
can buffet the waves a necessity—the ordinary dredge-boat
used in still water would be almost useless for the purpose.
It was for this reason that the dredge-boats Macadester and
Essayons were designed.
These boats had been for several years in operation in
Southwest Pass and Pass à Loutre. They operate by having
the propeller arranged to be lowered below the line of the
keel, where it stirs up the mud and sand, and the current
from the propeller is thrown against a sheet iron shield,
which causes it to rise to the surface of the water, charged
with the deposit from the bottom.
The theory upon which they work is based on the assump¬
tion that the current will carry to sea the sediment which is
thrown up into it. The theory upon which Mr. Eads based
his plans at the mouth of the South Pass is founded on the
assumption that rivers flowing over deposits of silt, which
deposits they have made themselves, are continually charged
with a quantity of sediment proportional to the velocity of
the stream. Hence, if the water be already charged with its
normal quantity of sediment, any additional amount thrown
160
THE SnSSISSIPPI JETTIES.
up into the stream will quickly fall to the bottom again, and
therefore dredges operating on the plan of the Essayons and
Macadester can only deepen a bar of any considerable length
by repeatedly throwing up near the surface of the stream the
sediment which the propeller disintegrates at the bottom.
This principle was well illustrated by the fact that the
dredge-boats were only operated during the ebb-tide, when
the current is the strongest, and when it has not had time to
gather up from the bottom the additional quantity of sedi¬
ment which it is then capable of supporting in suspension.
It was to be expected, therefore, that the plan of the Bayley
would be entirely different in principle from that of the gov¬
ernment dredge-boats.
In the case of the Bayley, the water is made the vehicle of
transporting the deposit from the bottom of the river
through a large suction pipe and a powerful centrifugal
pump, into capacious tanks built in the body of the boat,
which transports the dredged material to back of the wing
dams or out to the deep water in front of the bar, where it is
discharged through the bottom of the tanks.
The principal obstacle which has interfered with the suc¬
cessful pumping of sand or silt from the beds of streams, has
arisen from the difficulty of proportioning the quantity of
solid matter to the volume and velocity of the stream which
is made to transport it. A given volume and velocity of
water through the suction-pipe is capable of sustaining in
suspension a definite amount of solid matter. If too great
an amount of solid matter be admitted into the suction-pipe,
the stream is unable to transport the excess ; the pipe be¬
comes clogged, and the pump ceases to throw either water or
sand.
To remedy this difficulty, the end of the suction-pipe
which rests upon the bottom of the river is curved into the
form of a flat scraper, four feet in width, which is armed with
DEEDGE-BOAT BATLEY.
161
a steel plate, forming a bit, wliieb may be fairly compared to
the bit in a carpenter's plane. To preyent this bit from mak¬
ing too deep a cut in the sand, the end of the pipe is sup¬
ported on a horizontal plate, -svhich rests upon the sand in
advance of the bit or scraper. To insure the proper quan¬
tity of water in the suction-pipe with the sand, the horizontal
plate just described forms the bottom of a water chamber,
into which the water is admitted from above on both sides
of the pipe. This water is drawn into the suction-pipe
through a narrow opening as wide as the scraper. The end
of the suction-pipe, therefore, is continually scooping in a
stream of sand four feet wide, and a stream of water of the
same width, immediately above the sand. The cut made in
the sand is eight or ten inches deep. The water enters about
three inches in depth of stream, and the sand, which is pass¬
ing in over the top of the scraper, is therefore kept fluid by
the water. The scraper is designed to be moved at a speed
of from ten thousand to flfteen thousand feet per hour.
The centrifugal pump in the Bayley is the largest one of
the kind ever constructed in the United States, and is known
as the Andrews Cataract Pump. It was built by Mr. Joseph
Edwards, 14 "Water Street, New York, on the patent of Wm.
D. Andrews, and is of the same character as the two which
furnished the magnificent cataract, which our readers will
remember to have seen at the Centennial. The one in the
Bayley is twice the capacity of the two referred to, combined.
The fan is six feet in diameter, and three feet wide. This is
driven by an eight-inch steel shaft, actuated by two engines,
each twenty inches stroke, and twenty-four inches diameter
of cylinder. The steam is supplied by four four-flued steel
boilers, each twenty-six feet long, and forty-two inches in
diameter. The pressure allowed upon them by the United
States inspecting officer was fixed at one hundred and fifty-
nine pounds per square inch. The working pressure is, how-
11
162
THE MISSISSIPPI JETTIES.
ever, limited by Mr. Eads to one hundred and twenty-five
pounds, to insure additional safety. All the engines exhaust
their steam into a large surface condenser, in which a twenty-
six inch vacuum is maintained. The boilers are placed for¬
ward of the tanks, in the hold of the boat.
The suction-pipe is twenty-seven inches in diameter, of
one-quarter inch wrought iron. It is attached to the hull of
the boat, in a recess four feet wide, which extends from the
stern twenty-five feet forward. It joins the boat immediately
above the bottom, and is attached to it by a universal joint
of peculiar construction, not being hemispherical. The ball
and socket joint for pipe of such size, with the lateral and
vertical movements to which it would be subjected, became
so unwieldy in size as to necessitate the present novel device,
which is the subject of one of Mr. Eads's patents on the boat.
This joint admits of a motion of the pipe of sixty degrees in
any direction ; that is, thirty degrees from the line of the
axis when straight, without the area of the pipe in the joint
being reduced by this deflection.
The working position of the suction-pipe for twenty-six
feet of water, is an angle of about thirty-five degrees from
the horizontal. When the dredging ceases, the end of the
suction-pipe is raised up above water, and securely housed
under a fan-tail extension of the main deck of the boat, which
projects some fifteen feet beyond the stern-post. The dis¬
charge pipe is thirty inches in diameter.
The pump stands just forward of the universal joint ; the
center of the shaft is exactly four feet above the boat's bot¬
tom, and the engines which turn the shaft stand about eight
feet forward of the pump. A few feet forward of these en¬
gines the tanks commence. These are sixty feet long and
nineteen feet wide, and the tops of them are twelve feet above
the main deck of the boat, the boat having ten feet depth of
hold, and thirty-two feet beam.
DKEDGE-BOAT BATLET.
163
The tanks are divided into four compartments, each of
which terminates in a hopper at the bottom, having an open¬
ing four feet in diameter through the bottom of the boat.
These openings are closed by valves of similar diameter,
having a vertical rise and fall of thirteen inches. Each valve
is suspended by a single rod in its center, which is attached
to a hydraulic jack, six inches in diameter, firmly secured in
the upper portion of the tank on a strong oak timber. The
power of the jack is regulated to twelve and one-half tons,
which insures close fitting of the valves. The jacks are ex¬
ceedingly simple in construction, and are all four supplied
by a hydraulic ram, which is a modification of the Cameron
pump, first designed by Mr. Eads in the construction of the
St. Louis bridge. The steam piston of the ram is seven
inches in diameter, while the plungers are but two inches,
and are simply extensions of the piston-rod, running into a
strong horizontal pump-chamber, at each end of the steam
cylinder. By this arrangement, a constant pressure of about
one thousand pounds to the square inch is always ready to
be used in closing the valves of the tanks. The ram being
automatic, remains at rest with the steam pressure upon itj
until one of the valves is opened at either one of the hydrau¬
lic jacks, when it immediately supplies the quantity of" water
needed in the jack. To facilitate the discharge of the sand
from the tanks, a powerful Cameron pump is placed on board,
the suction-pipe of which is nine inches, and the discharge
pipe six inches in diameter. This supplies two jets, of one
and one-quarter inches diameter, near the bottom in each
hopper.
It is sometimes desirable to discharge the dredged mate¬
rial from the centrifugal pump, not into the tanks, but on
either side of and at a distance from the boat. For this pur¬
pose two discharge pipes are provided, one on each side of
the boat, which can be^swung out from it by means of a der-
164
THE MISSISSIPPI JETTIES.
rick, and tkrougli wliich the sediment may be carried and
discharged from the side of the boat. The discharge pipe
of the pump is arranged so as to connect, by a curved joint
of pipe, -with either of these outside discharge pipes, or with
the central pipe leading into the tank. The boat is built
entirely of iron, and is considered a very superior job. It is
about two hundred feet in length over all, and is propelled by
two horizontal engines, each seven feet stroke, and twenty-one
inches diameter, turning wrought iron shafts with wrought
iron wheels, twenty-five feet in diameter. The paddles are
of wood, eleven feet long, and fourteen inches wide. The boat
is surrounded by an iron bulwark, about thirty inches high,
set back five and a half feet from the side of the hull. The
tanks have an estimated capacity of six hundred and fifty
tons of dredged material and water. Two overflow gates are
provided for the tanks, which allow the water to escape when
they are filled to the overflow level, the sediment settling to
the bottom. The pump raises one hundred and thirty tons
of water per minute, twelve feet high. The boat draws about
five feet, with coal on board ready for work. The engines
were non-condensing engines at first, and those that drove
the pump had oscillating cylinders, twenty by twenty inches.
These were defective, and were exchanged after the first year
for the present ones, and condensing apparatus was added.
Since these alterations the boat has given entire satisfaction.
Her total cost was a little over one hundred and fifty thou¬
sand dollars.
To avoid turning the boat at the end of each trip, she is
provided with a rudder at the bow, and one on each of the
two parts of the hull at the stern, where it is divided, to
enable the suction-pipe to be housed. The dredging is done
by moving the boat through the channel, down stream, at
about two and one-half miles per hour, with the scraper
down. As soon as the tanks are filled the scraper is raised.
TWENTY-TWO FEET CHANNEL.
135
and the boat proceeds with her load to the place chosen for
dumping it. About two-thirds of the time is lost in dump¬
ing and returning to position. The tanks are usually filled
in from six to eight minutes, about one-half the contents
being dredged material. In sand, she will easily excavate in
this way three thousand five hundred cubic yards in ten
hours, and in mud five thousand cubic yards. If steadily
pumping and discharging the material overboard, without
going with her burden to dump it elsewhere, she raises it at
the rate of ten thousand five hundred cubic yards of sand,
or fifteen thousand cubic yards of mud, in ten hours.
The Bayley is especially adapted for her peculiar work,
and is superior to the powerful dredges used on the Clyde,
at Glasgow, for a similar purpose, and under somewhat simi¬
lar conditions, and which have been considered the best in
the world. They have an endless belt, on which are a great
number of buckets or scoops, which, passing through a recess
in the hull of the boat, dig into the bed of the river, bring
up the material, and discharge it into tanks. Their maxi¬
mum performance in good material, in ten hours work, is
about twelve hundred cubic yards.
A survey, made on the 15th of December, showed that a
channel twenty-two feet deep, and more than two hundred
feet in width, existed from the deeper water in South Pass,
to the deeper water in the gulf.
The certificate of Captain Brown was given on the 17th, to
confirm which, and to decide certain questions for the Sec¬
retary of War, a commission composed of Gens. J. G. Bar¬
nard and H. G. Wright were instructed to proceed to Port
Eads to make the necessary examinations, and answer the
following interrogatories.
First.—" What depth and width of channel have been
secured through the South Pass of the Mississippi Hiver,
to deeper water of the Gulf of Mexico?"
166
THE MISSISSIPPI JETTIES.
Second.—" Has such depth and width of channel been ob¬
tained by the action of such jetties and auxiliary works, as
are contemplated by the terms of the act of Congress afore¬
said ? "
Third.—" Are the jetties and auxiliary works constructed,
or in process of construction, permanent, sufficient, and thor¬
oughly substantial, within the meaning of said act of Con-
- O
gress t
Fourth.—"Have the conditions prescribed in said act of
Congress been fully complied with by said James B. Eads,
in so far as he has proceeded with the work?"
Fifth.—James B. Eads, in your opinion, entitled to
receive the five hundred thousand dollars, which, by the
terms of said act, was to be paid him, when, having fully com¬
plied with the conditions prescribed by said act, a channel
twenty-two feet in depth, and two hundred feet in width, shall
have been obtained by the action oï said jetties and auxiliary
works ? "
In their report, dated Port Eads, January 5th, 1878, made
after carefully examining the works and directing a survey,
they confirm the statement of Captain Brown, and further
state in answer to the first interrogatory, that the twenty-two
feet channel at the jetties, between the South Pass and the
Gulf of Mexico, varies from two hundred feet in width to
more than five hundred feet, and that a practicable channel of
22.4 feet exists through the whole extent of this portion of
the pass ; that at the head of the pass a channel two hundred
and sixty-four feet wide and twenty-two feet deep exists,
with a practicable channel of twenty-three feet, and that in
the main, body of the pass no material changes have occurred
since the survey of the United States Coast Survey, in 1875,
which statement conflicts with that made the previous year
by Major Howell. In answer to the second interrogatory,
they discuss the question of dredging as an auxiliary. They
EEPOBT OF COMMISSIOK.
167
refer to the report of Humphreys and Abbot, and to the re¬
port of the Board of 1874, in both of which dredging is
recommended, as a necessary accessory to jetties. The act
under which the jetties were constructed clearly intends that
jetties and auxiliary works shall be the effectual agents in ob¬
taining the " wide and deep channel," but at the same time
allows of dredging as a legitimate auxiliary, and they say :
" If we look at the actual facts presented by the proscution
of this work, we find that where two and a half years ago
there was a bar at the mouth of the South Pass of over two
miles in extent, measured from twenty-two feet of water in¬
side to the same depth outside, over about half a mile of which
there was but eight fe&t of water, a ' wide and deep chan¬
nel ' of twenty-two feet depth now exists, and a result inferior
in physical magnitude but no less in importance at the head
of the passes has been obtained. And these results are so
exclusively due to the ' jetties and auxiliary works,' that the
auxiliary aid of ' appliances,' if in such we include dredging
machines, is utterly insignificant, consisting mainly indeed in
a slight widening at two points and widening and deepening
at a third. By the erosion of the current, due entirely to
the jetties and their fixed auxiliaries, about two and one-half
millions of cubic yards of bottom material have been re¬
moved, leaving in its place the ' wide and deep channel.' Of
this amount one million of cubic yards have been removed
by the same agency since the twenty feet depth on the bar
was obtained. By the action of the dredge-boats (see Capt.
Brown's recent report to the honorable Secretary of War),
from twelve to twenty-eight thousand cuhic yards have nominally
been removed by dredging. But it cannot positively be as¬
serted that to the creation of the channel now existing even
this insignificant amount has been contributed by dredging.
* -X- ir yy-g ]ja,ve discussed the point of dredging at much
length, because we conceive it to be the real one involved in
168
THE MISSISSIPPI JETTIES.
the third interrogatory ; and we conclude by answering that,
according to the construction above given, the depth and
width of channel has been obtained by the action of such jet¬
ties and auxiliary works as are contemplated by the terms of
the act of Congress."
Upon the question of permanency, embodied in the third
interrogatory, they refer to the report of the Board of 1876,
and state that as far as the works have been constructed, they
are of such a character as to be both substantial and perma¬
nent when completed according to the design. They answer
the fourth and fifth interrogatories in the affirmative, after
which they submit some general views and recommendations,
mostly referring to the sea-end of the jetties, which will be
alluded to in a subsequent chapter.
During the winter and spring the construction work con¬
sisted mainly in consolidating the jetties with rubble stone,
in building up the low places with loose willow s, and in main¬
taining the wing dams. The progress of the channel devel¬
opment can be traced in the tables in Appendices 6 and 7,
and by the cross-sectioná" and profile of the bar on Plates No.
20 and 21. (Facing page 212)
It became very evident that the maximum depth and width
of channel prescribed by the act of Congress could not be
obtained with safety either to the pass or the jetties. The
specifications were drawn up for the Southwest Pass, and
were in every way applicable to it, but in regard to the South
Pass they were in some respects very severe and entirely un¬
necessary.
On May 7th, 1878, Mr. Eads submitted a statement to the
Secretary of War relative to the amount of work executed by
him, and asked that certain modifications be made in the
conditions imposed by the act. The grounds on which this
request was based were as follows :
First.—The proportion of the entire outlay necessarily ex-
LEGISLATION.
169
pended to secure the present depth had greatly exceeded all
expectations ; and
Second.—A necessity for relief in the times of the payments
on account of serious financial difficulties under which he
was laboring, and without which relief he could not further
prosecute the work.
He estimated that he had completed at least eighty per
cent, of the entire work, and stated that he had received thus
far only $1,000,000. He asked for a modification in the man¬
ner of the payments and also in the widths of the channel.
In his argument he alluded to the fact that he undertook
the construction and maintenance of the work for $692,110
less than the official estimate of the Commission upon whose
report the act was passed. He had assumed the whole risk
of their failure in the face of the predictions of official and
other experts that they would be unsuccessful, and had teken
all the risk of their destruction by storms and other causes—
dangers believed by many to be insurmountable. He had
not been permitted to improve the pass of his choice, with
its normal depth of fifteen feet, but had been given one only
one-quarter as large, with but eight feet depth. In spite of
natural difficulties and unusual financial prostration, he had
carried the enterprise to a point where its complete success
was acknowledged even by its opponents. He had changed
the little pass into a grand channel of commerce sufficient for
the largest shipping that visits the port of New Orleans.
He says further: "We ask no increase in the price of the
work, nor do we ask to be relieved of the obligations to create
a permanent channel thirty feet deep through the jetties, and
that shall be fully as wide as the size of the pass will justify.
We ask no legislation to retrieve forfeited privileges or lapsed
concessions, nor the assumption of any risk of outlay for
doubtful benfits. We ask simply that a reasonable portion
of moneys actually expended may be repaid to relieve embar-
170
THE MISSISSIPPI JETTIES.
rassments resulting from provisions in the law unusually se¬
vere and oppressive, and which cannot now be retained with¬
out injuriously reacting upon the commercial and industrial
interests of the country. We have striven to carry through,
by private means and individual hazard, the largest and most
important public work ever undertaken by the government ;
and have forborne, under many discouragements, to ask re¬
lief from the stringent conditions of the law until the official
reports of the most eminent engineers of the government
have confirmed the public faith in our complete success ; and
now that sheer necessity compels us to do so, we only come
after the changing tides of commerce attest the substantial
benefits already reached, and after the people are assured
that private enterprise and courage have promptly se¬
cured, at moderate cost, ' an open river mouth,' for the Mis¬
sissippi, in lieu of the more costly and dilatory method
proposed of a canal with locks. And with this record we ask
no payments on the work that will not leave in the hands of
the government an ample amount of our compensation to in¬
sure the entire completion of the jetties." (For the full text
of this letter, see Appendix 12.) This communication of Mr.
Eads was referred for examination and report to Gens. Bar¬
nard and Wright. They did not agree with him in his state¬
ment that eighty per cent, of the work was completed, but
they said : " We, as members of the Commission of 1876,
and as ourselves constituting the Commission of 1877, have
expressed our opinion that the work is being constructed ac¬
cording to the spirit of the act." * * * "We believe,
moreover, that the work is now so far advanced and its suc¬
cess so far pronounced, that it is for the interest of the gov¬
ernment and the country, not only to have the construction
carried on, but pushed with the utmost possible vigor to
such a point at least as shall insure their security and utmost
efficiency of action in increasing the capacity of the channek
LEGISLATION.
171
* » * ijjjg depths and Tvidtlis specified as desired by
the petitioner will fulfill measurably the needs of commerce.
* * * A draft of twenty-three feet (and it must be borne
in mind that at the mouths of the Mississippi nearly all the
depth on the bar can be realized in actual draft) will include
probably eighty-five per cent, of the sea-going vessels of the
world ; while over the bar of New York harbor twenty-six
feet is about the maximum for regular traffic, and twenty-
eight feet (and a small fraction) the maximum ever carried
over (the case of a war vessel, the Spanish Numancia, we be¬
lieve)." See Appendix 12.
Congress was not willing, without further investigation and
report by the engineers of the government, to fully comply
with this request of Mr. Eads, but showed its confidence in
his integrity and in his ability to complete the work, by vot¬
ing at once an appropriation for him, of one million dollars ;
(five hundred thousand dollars of which was to be expended
on the work), and by authorizing the President to appoint
a Commission to report on the progress and probable cost of
completion of the works, on the results produced and likely
to be produced, their permanency, and the advisability of a
change in the terms of the contract, in regard to the depths,
widths, and payments.
During this discussion in Congress, General Humphreys,
Chief of Engineers, IT. S. A., in a letter addressed to Hon.
E. "W. Eobertson, Chairman House Committee on levees and
improvement of the Mississippi Eiver, made another attack
on the jetties, under the pretext of opposing the passage
of a bill authorizing the appointment of the Mississippi
Eiver Improvement Commission, of which he claimed Mr.
Eads was to be made president. As he alleges, the reason
for such an extraordinary course on the part of Congress was
the success claimed to have been achieved by Mr. Eads at
the South Pass, he endeavors to prove that the jetties are a
172
THE MISSISSIPPI JETTIES.
failure. He states that the bar beyond the jetties has ad¬
vanced, but not as rapidly as he had predicted, on account of
crevasses, and of the low stage of the river at the flood dur¬
ing the previous three years ; that " the usual flood reading of
the river at CarroUton is aiove fifteen feet;" that in 1876 its
highest point was only 12.7 feet, and that "the broad, thick
sheet of earthy matter moving along the bottom of the
passes " during flood river, was not present in any consider¬
able quantity during those years.—(The foundation of this
argument is destroyed by correcting his statement of facts.
The records show the following : The average of high water
marks on the Oarrollton gauge for eight years, from 1872 to
1879, was 12.26 feet. The only crevasses of importance since
that of Cubits gap, in 1863, was Bonnet Carré crevasse, in
1874, and the average of the high water marks for the two
years previous was 12.44 feet.)
He states that the favorable report of Captain Brown,
in reference to the advance seaward of the bar, was made
in December, 1877, immediately after a new and powerful
dredge, designed to work on the newly-grown bar seaward of
the jetties, had been employed for a month. After giving an
historical summary of the jetties and their results, he empha¬
sizes the following statement : " Tlte foregoing historical sum¬
mary sufficiently proves that the results actually attained at the
South Pass disprove the vieivs advanced hy Mr. Eads, and con¬
firm those of the engineer department. Hence, any claim that he
should be intrusted with the control of the Mississippi River, in so
far as it rests upon the results thus far achieved hy him, has no
proper basis." (For the text of this letter, see Appendix 13.)
This extraordinary letter of General Humphreys was re¬
viewed by Mr. Eads, in a letter addressed to Hon. Mr. Rob¬
ertson. He states that the only bill reported in the House
provides, that three of the five engineers shall be taken from
the army, and that one of these three shall be president of
LEGISLATION.
173
the Commission. He quotes from reports of Captain Brown
to show that no such adyance of the bar has taken place as is
stated by Gen. Humphreys, but that, on the other hand, in
the report of August 1st, 1877, in which Gen. Humphreys
claims to find the proofs of his statement, the following lan¬
guage occurs : " Averaging, the twenty feet curve has receded
about two hundred feet ; the thirty feet curve about three
hundred feet ; the forty feet curve has remained nearly sta¬
tionary on the whole." These curves indicate the form or
contour of the outer slope of the bar. He also shows, from
the same report, that the entire area, for a distance of a mile
from the end of the jetties, lying in the track of the river
discharge, has deepened on an average one foot, three and
seven-tenths inches. The Commission of Engineers ap¬
pointed to decide, among other questions, that of the admissi¬
bility of dredging refers for authority for so doing to the
opinion of Gen. Humphreys, expressed in the Physics and
Hydraulics of the Mississippi Kiver, and they state that the
amount of dredging done at the jetties is " utterly insignifi¬
cant."
Mr. Eads quotes the following paragraph from Gen. Hum¬
phreys' letter : " Yet the facts exhibited by the rejsorts of
the officers inspecting the South Pass, show that the views
expressed by many engineer officers, the chief of engineers
among them, that a new bar would form at the sea end of
the jetties, and that it would extend into the sea more rapidly
than the old bar, are correct, even during the changes going
on under the scouring power of the jetties, aided by dredg¬
ing between and seaward of them." By extracts from the
reports of the U. S. inspecting officer and the Commission
of distinguished engineers, Mr. Eads clearly disproves the
foregoing statement, and says : " I have shown conclusively,
from the official reports on the jetties, that there has been no
advance of the bar ; that it has not been necessary to extend
174
THE MISSISSIPPI JETTIES.
them, and that there has been no shoaling in front of them;"
and he further states, that instead of having to advance the
jetties six hundred and seventy feet every year, as predicted
by Gen. Humphreys, they are two hundred feet shorter than
they were originally located.
In closing his forcible and convincing argument, he says :
*' In absolute defiance of the plainest official evidence to the
contrary. Gen. Humphreys makes the astonishing statement,
that Hive, results actually attained at the South Pass, disprove the
views of Mr. Pads, and confirm those of the engineer depart¬
ment while the safety and ease with which the heaviest
draught ships already use the jetty channel, and the immense
benefits resulting to commerce should convince even him of
the wisdom of the government, in rejecting the advice of the
chief of engineers, when deciding on the problem of improv¬
ing the mo-uth of the Mississippi Eiver." (See Appendix 14,
for full text of this letter.)
CHAPTEE XIV.
TTTi'.ATi OF THE PASSES—WOEKS DESCEIBED—FINAL BESÜLTS GIVEN,
1877 TO 1879.
In returning to the description of the works at the head of
the passes, a brief resume will be given of the works con¬
structed previous to the spring of 1877, and their attendant
results.
First.—The construction of the East Dyke and its results.
Second.—The construction of Dam No. I., Island Dam, and
Lighthouse and Island Dykes, that marked the lines of the
channel, and
Third.—The extension of these dykes, and then, in order
to restore the volume diverted by these works, the construc¬
tion of Southwest Pass Sill.
The remarkable improvement of the channel through the
shoal attested the wisdom of the plan adopted.
As soon as the necessary funds were obtained from the
government, a sill was also constructed across Pass à Loutre.
Later in the work, as the results showed it to be necessary,
the plan was still further extended by raising the sill across
Southwest Pass ; by the construction of Upper Dam, about
two thousand feet above Dam No. I., by the extension of
Island Dyke up stream to connect with this dam, and down
stream to connect with the island, and by rebuilding the ex¬
tension up stream of Lighthouse Dyke. An examination of
Plate H will show the location of all these works.
The various works constructed from the spring of 1877 to
175
176
THE MISSISSIPPI JETTIES.
tlie completion of the work in July, 1879, will now be given
in the order of their construction, and the final results will
be described.
PASS 1 LOUTEE SILL.
The location of this sill and its alignment were determined
by fioat observations, with a view of presenting a line at
right angles to the current. The first mattresses were laid
on March 31, 1877, and were connected with the old founda¬
tion mattresses at the up-stream end of East Dyke. The con¬
struction of this work was attended with greater difficulties
than any other ; for the mattresses were laid at flood river,
the Carrollton gauge reading 7.5, when the work commenced,
and reaching 11.0 before it was finished.
The process by which the mattresses were placed was sim¬
ilar to that employed on the Southwest Pass siU. Eor about
one-third of the distance guide piling was used for the lower
edge of the mattresses, with a waling strake stirruped to it,
but it was ascertained later that the mattresses sank much
more freely by using the side piles only. The size of the
mattresses was at first 70' by 40' by 2', but the river continu¬
ing to rise, it was found impossible to handle mattresses of
these dimensions, and the width was reduced to twenty-five
feet.
The water was from twenty-eight to thirty feet in depth ;
the current was at least three miles an hour, and its velocity
uncei'tain, on account of the irregular fluctuations of the tide ;
the piles, on which the whole success of the work depended,
were unfortunately weakened by age ; large masses of drift¬
wood often collected above the guide piling or endangered
the stability of the anchorages by striking against them ;
the mattresses were unwieldy masses containing about five
thousand six hundred cubic feet, with a vertical surface of
DESCEIPTION AND FINAL EESULTS.
177
eighty square feet presented to the current ; the unsupported
guide piling, and even the anchorages that were stiffened in
every possible way, swayed back and forth in the strong
current ; all these causes made the greatest care and watch¬
fulness necessary. Every line and its fastening, the move¬
ments of the tug and stone flat, and the handling of every rock
needed to be carefully watched, for when the mattresses
were in position and being loaded, both lines and anchorages
were very severely strained. On one occasion, on account
of a defective link in an anchorage chain, a fleet of six mat¬
tresses was lost, that had been placed in position and nearly
sunken. The chain broke ; the two anchorages which held
the mattresses were broken down ; the guide piles gave
away ; the lines snapped, and the mattresses went down the
pass.
The last seven mattresses connecting the work with the,
east shore, were put in place May'8th. The location of the
sill can be seen on Plate H. The estimate of the materi¬
als used and the detailed cost of the work appear in Ap¬
pendix 15.
LIGHT-HOUSE DYKE.
In April, 1877, the dam and dyke, both having settled be¬
low the surface of the water, were raised by loose willows
and stone to nearly three feet above datum. The dyke was
extended up stream three hundred and eighty feet above its
junction with the sill, or to a point one thousand and'twenty
feet above the dam. The depth of water where this work
was built was about twenty feet.
The work was commenced by driving a row of guide piles
about twenty feet apart, curving gently to the eastward.
Seven tiers of mattresses were laid along the west side of the
piles, connecting with the old work. The first two courses
were thirty-three feet wide and the last twenty-one feet. One
13
178
THE MISSISSIPPI JETTIES.
course of mattresses, thirty-three feet wide, was laid on the
eastern side of the piles, as a protecting apron. The upper
part of the foundation of this work, not being of sufficient
width, was undermined by the strong current that flowed
around it into Southwest Pass. Several vessels ran into
the dyke, carrying away the guide piling and disturbing the
mattresses, and an excavation, with thirty-flve feet of water
in it, was made by the current on the west side of the dyke.
In the winter of 1878 the work was rebuilt, in doing which
a wide protecting apron was flrst placed on the Southwest
Pass side of the dyke, extending from the sill to a point flfty
feet above the upper end of the work. This apron con¬
formed in its outlines to that of the deep excavation, its
widest point extending one hundred and sixty feet from the
guide piling of the dyke. The whole work was again raised
above the surface of the water by loose willows and stone.
A cross-section of the dyke is shown on Plate 13, facing
page 136.
ISLAND DYKE.
The construction of this dyke to "New Cluster," in the
fall of 1876, caused the remarkable deepening in the chan¬
nel, which has already been spoken of, but it had its disad¬
vantages and dangers. The head of water, caused by it,
directed the current towards Lighthouse Dyke, endangering
it, and a large eddy resulted below the head of the dyke,
producing an extensive shoal, which extended almost to the
center of the channel.
To remedy these evils the tilted mattresses of the dyke
between Dam No. I. and "New Cluster," were torn down in
April, 1877. This removal widened the water way, dimin¬
ished the velocity of the current, and deposited the sand in
the deep channel.
Before the removal of this part of the dyke, the average
DESCBIPTION AOT) FINAL EESULTS.
179
depth of the channel opposite it was thirty-five feet. In July
it had shoaled to an average depth of twenty-eight feet. A
shoal also formed on the west side, extending diagonally into
the channel, reducing the depth over the area covered by it
from twenty-three feet to nineteen feet. The depth in the
channel above "New Cluster" also decreased, and until this
work was rebuilt, the shoaling was generally progressive, as
will be seen by the following table :
21-feet channel.
24-feet channel.
Date.
Depth through shoal.
Open.
Closed.
Width between curves
Curves interrupted.
Feet.
Feet.
Feet.
1877.
February 8
24.8
150
. . .
17.
24.2
200
April 13
25.0
300
June 14
22.7
310
September 21
23.1
. . .
300
December 23
22.5
* . .
310
1878.
April 1
22.5
. . .
400
September 16
21.7
1000
1879.
July 17
27.2
450
1880.
April 23
30.1
30-feet channel
. . •
open. Width be¬
tween curves
250 feet.
No work was done at the head of the passes from May,
1877, to July, 1878, when preparations were made for com¬
pleting the construction, the necessary funds having been
provided by the legislation of June of that year.
The inconvenience and expense in towing mattresses from
the Jump was so great that mattress ways were constructed
about one mile above the head of the passes, on the batture,
180
THE MISSISSIPPI JETTIES.
on the west side of the rÎTer. The work on them was sus¬
pended during the summer on account of the yellow fever
epidemic, but was resumed in December of the same year.
The timbers of the ways were round pine piles about fifty
feet in length, placed six feet apart, at right angles with the
current. The slope of the timbers was one foot vertical to
six feet horizontal. The depth of water alongside the wavs
was nine feet. Their length, measured along the river, was
two hundred and thirty-five feet, so that three mattresses
seventy feet long could be built at the same time. Above
and below the ways, and connecting with them were two
wharves for storing mattress lumber and other material, and
adjoining these a boarding-house was erected on piles.
SOUTHWEST PASS SILL.
On December 5th, 1878, preparatory work was commenced
for sinking two courses of mattresses on those laid in the
fall of 1876. A dyke of loose willows and stones was built,
extending from the shore line to a point about folir hundred,
feet from the river bank, where the depth was four feet.
Previous to laying the mattresses, examinations were made
on, above and below the sill, which showed that the sand and
mud had filled in among the willows and rock over the western
half of the work ; over the eastern portion of it the depth
immediately above it was two or three feet greater than it
was before the sill was laid, but below it there had been but
a slight increase in depth.
The plan of construction consisted in laying two courses of
mattresses, the first of which was sixty feet long, and from
thipty-three to thirty-eight feet wide. At the down-stream
end they were qne foot thick ; fifteen feet from the lower end,
two feet thick, and the same at the upper end. The lower
line of the first course was forty-five feet above that of the
DESCEIPTION AlîD FINAL EESULTS.
181
old sill. The lower line of the next course was fifteen feet
further up stream and the dimensions of the mattresses
were «imilar to those of the course beneath it. The total
height of the submerged dam or siU was nearly eight feet,
the old SÜ1 acting as a protecting apron against the over-fall
of the two ûpper courses. A sudden rise in the river during
the construction of this work brought with it the same diffi¬
culties and dangers that had been experienced in the con¬
struction of the Pass à Loutre sill. Much of the difficulty
was, however, overcome by the adoption of a very simple ex¬
pedient for towing and handling the mattresses so as to keep
' the ends where the lines were fastened above the surface of
the water. The plan consisted in placing two water-tight
barrels under the upper edge of the mattress, while it was
on the ways, so arranged that they could be released from
their position before the mattress was sunken. It was pos¬
sible by this simple means to sink mattresses of any ordinary
size in a current of four miles an hour without difficulty.
The first mattress was placed on December 9th, and the
work was finished January 31st, 1879. The first course of
this new work extended to a point eighteen hundred and
fifty feet from the shore line. The second course seventeen
hundred and eighty feet, and the third course seven hundred
and ninety feet.
ISLAND DYKE.
Erom the table on page 179, showing the changes that
occurred in the channel after the destruction of the dyke
between Dam Ko. I. and New Cluster, the necessity for re¬
building this work is apparent. This was done in March and
April, 1879. The upper terminus of the dyke, however, was
located about forty feet east of " New Cluster," in order that
its direction might be nearer the axis of the current than was
that of the former dyke. A broad foundation was first laid,
182
THE MISSISSIPPI JETTIES.
sixty-five feet in width at Dam No. I., and one hundred feet
at New Cluster. On this was erected a dam of tilted mat¬
tresses, with board sides, which rested against a row of
piles. Four hundred and fifty feet of this work above Dam
No. I. was strengthened with several courses of mattresses
laid horizontally. The construction of this dam caused an
immediate improvement in the channel.
The down-stream extension of this work, between Dam
No. I. and the island, sixteen hundred feet in length, was
raised to the surface by a substantial dyke of willows and
stone. An extensive deposit had occurred, since 1877, over
the whole line of this part of the work, and the foundation
mattresses that were laid at that time were covered with
mud several feet in depth, so that the average depth of the
water was only two and one-half feet.
UPPEE DAM.
The construction of Dam No. I., in 1876, and of other
works later, on the east side of the channel, had produced a
very extensive growth up stream, of the shoal lying between
Pass à Loutre and the inlet channel of South Pass. To still
further encourage this formation, and thereby induce a still
larger fiow into South Pass, Mr. Eads decided to construct
another dam, at right angles with the current, twelve hun¬
dred feet above New Cluster, one half of it in the South Pass
current, the other half in that of Pass à Loutre. This was
called " Upper Dam," and was constructed between the mid¬
dle of April and the 30th of June, 1879. Its length is six¬
teen hundred and seventy-five feet, emd the depth of water
previous to construction varied from twelve feet at the center
to twenty feet at each end of the work, the average depth
being sixteen feet.
A large part of the work was constructed by laying one
MISSISSIPPI RIVER
SHOWING THE: CHANGES BETWEEN
MAy 1875 / JUNE 1879
y/oT£
ßhatiecl Jiortiou^ rndicate éhoaling-.
Jílejioviioti^ not ^hacleót indcate/cout^ctnd
the included denote the amount of
changv inject and tenth/.
bcctà,^i9è«t
ikiÉWt '
HEAD OF PASSES
C OMPARATIVE CHART
or THE
PLATE J.
SeeTextPage 183
DESCEIPTION AND FINAD EESULTS.
183
course of foundation mattresses, and erecting tilted mat¬
tresses upon them, with tight board sides; but the ends of
the dyke were built mostly of mattresses laid horizontally.
The plan of the construction is shown on Plate H, the
cross-section on Plate 18, facing page 136. Island Dyke
(a cross-section of which is also shown on Plate 13) was
extended to connect with the west end of Upper Dam.
The quantities of willows and stone used on all the works
at the head of the passes, will be found in Appendix 16.
FINAL EESULTS OF THE WOEKS.
All the works at the head of the passes have now been
described. The comparative chart, Plate J, exhibits all the
changes of importance that have resulted from their con¬
struction.
A study of the three charts of the head of the passes.
Plates B, H, and J, which exhibit respectively the original
depths, the final depths, and their increase and decrease,
will show more difficult engineering than is often met with.
The problem, Avhich, in the earlier description of the head
of the passes, was analyzed, its known quantities stated, and
its unknown quantities pointed out, has been most success¬
fully solved.
The comparative chart, Plate J, shows how rapidly depos¬
its have been made, wherever the current has been checked
by our works ; the shaded portions on it showing deposit
since 1875, and the unshaded portions showing deepening in
the same period. The figures on the chart show in feet
and tenths of a foot, the amount of deepening and deposit
over their respective areas.
As at the jetties, so at the head of the passes, the works
have simply assisted nature in opening channels and in build¬
ing banks. Several of the works are already completely
184
THE MISSISSIPPI JETTIES.
buried in extensive deposits of sediment. Eeeds, grasses,
and Avillows now grow where deep water formerly flowed.
Plate 15, showing the inlet channel as surveyed by Mr. C.
Donovan, U. S. Assistant Engineer, April 23d, 1880, when
compared with Plate H, will show a general improvement of
the channel since July, 1879. The normal volume of the
pass is nearly restored; for careful gauging of the three
passes in January, 1880, showed that the percentage of flow
into South Pass was nearly equal to that found by Marin-
den, in January, 1875. The power to accomplish all that is
required to restore the full volume, and more if needed,
lies in the works. The channel into South Pass is now the
only one in which the natural forces of the river can effect a
further enlargement. This enlargement is confldently antici¬
pated, and it will be necessary within a short period, to lay
a sill across the entrance of South Pass, to prevent too great
development of the improved channel. When this is done,
the entire volume of the great river will be under perfect and
easy control. Light and inexpensive additions to the height
of these submerged sills will produce any desired change in
the volume discharged by either one of the three passes.
The materials were combined into convenient forms by
methods entirely simple, yet novel, and the cheapness with
which this was done, and the effectiveness of their applica¬
tion was so surprising, that this system of controlling silt-
bearing currents has since been adopted by the army engi¬
neers throughout the valley of the Mississippi, and it may
be advantageously copied by the older nations of Europe,
where the same materials have been long used for similar
purposes, but with much less economy and benefit.
When we contemplate the fact that these works are com¬
posed almost wholly of light willows, with a large portion of
the mattresses standing on edge, simply as screens to check
the current and cause deposit, they constitute a remarkable
PLATE 15.
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SA, ■'"■s
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sr,
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.
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S.T a
SA a
SSM
sst V
•*<fj Ait
rs.
tsr
u.
s», -As»
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rvs
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CHAHT
Of ENTHANCt CffANNH
HM Of Off ^0100.
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If.SAstX ife»""
DESCEIPTION AND FINAL KESULTS.
185
illustration of liow completely the immense forces of nature
may sometimes be controlled by a wise use of the most
inexpensive and unsubstantial materials, which nature seem¬
ingly places within convenient reach of man for the very pur¬
pose.
Here, by the gentlest influences, the mighty current is
swayed and directed completely obedient to his will. There
is no instance, indeed, in the world where such a vast volume
of water is placed under such absolute and permanent con¬
trol by the engineer, through methods so economic and sim¬
ple as those adopted at the head of the passes of the Mis¬
sissippi Eiver.
CHAPTEE XV.
woek belayed by yellow feyee—consolidation of sea ends
of jetties by conceete and ceib woek—eepoet of com¬
mission and passage of amendatoey act.
It is with reluctance that we draw aside the veil from the
face of the dark days of August, 1878, for they reveal a sad
and mournful spectacle. Many of the men who, one year
before, so nobly came up and agreed to stand by the work
were summoned, not to further hardships and work, but to
their reward.
No sooner had the finances of the work been placed on a
sound basis for vigorous construction, by the passage of the
act of June 19th, than the work was suddenly stopjied by the
yellow fever, which made its appearance in New Orleans
about the middle of July. Every efibrt was made to prevent
its entrance into Port Eads. Every avenue was guarded by
rigid quarantine restrictions, which were enforced against
pilots, tow-boats, and mail-boats. A case of fever was, how¬
ever, inadvertently brought to us by one of our own boats,
which we were compelled to send to New Orleans for mate¬
rials and supplies. On August 6th, a few days after, three
new cases appeared, and on the next day nine. The indica¬
tions were that the dreaded disease would sweep through
the crowded quarters occupied by the workmen. The con¬
viction that delay would bring sickness and death to this
crowd of human beings, far away from sufficient medical
help, and that, in any event, the work must stop, led the
186
JETTIES COMPLETED.
187
resident engineer, on the 6th and 7th of August, to discharge
the whole force, except a few acclimated persons, and 'send
them away at once, before the place became infected with the
disease. Several of those, however, who left at that time were
taken sick either in New Orleans or St. Louis, and some of
•them died. At Port Eads the disease spread, until sixty-four
persons, about one-half of the whole population remaining,
were taken sick, eleven of whom died.
Among the latter was Mr. O. D. Parmely, ássistant of Cap¬
tain Brown, who had been left by him in charge of the inter¬
ests of the government. He was deeply lamented, for he was
not only a most efficient and faithful engineer, but a noble
and true man, esteemed by every one who knew him.
Among those who died at St. Louis was Captain William
S. Nelson, who for many years had been connected with Mr.
Eads in his various enterprises, but especially in the wreck¬
ing business, and as superintendent of the construction of
fourteen iron-clad vessels, built by Mr. Eads during the civil
war. He had superintended the construction of the Bayley,
and had since then been in command of her. Only a word
can be said here, when pages could easily be written, of the
sterling qualities of this intelligent, faithful, and valuable
man, who never shrank from, but always sought for the hard¬
est and most exposed work. His mechanical skill, his long
experience in hydraulic machinery and works, his entire for-
getfulness of self, and his iron constitution, made him inval¬
uable to the jetty enterprise, and in his death Mr. Eads lost
not only one of his most faithful assistants, but one of his
best and most cherished personal friends.
This roll of honor, if space permitted, would include
nearly one hundred more, who had been faithful workmen in
almost every department, who had been willing and prompt
to do any and every hard work, and who had never been
found wanting in the hour of need. Some of them covered
188
THE MISSISSIPPI JETTIES.
now by the sands lie in their resting-places near Kipp signal
station, keeping watch, as it were, of the work they stood by
until death cut them down.
Captain Geo. "W. Adams was placed in charge of the work,
and employed the laborers, as they recovered, in placing rub¬
ble stone on the jetties and wing dams.
During the fall Mr. Eads laid his plans for the completion
of the work, and made all necessary arrangements for its
vigorous prosecution, by constructing machinery for manu¬
facturing concrete blocks, and in ordering supplies and all
kinds of materials.
Much thought and examination were necessary to obtain
the best means of consolidating the sea ends of the jetties,
through and over which there was still much leakage. Dur¬
ing easterly storms, large quantities of sand were washed over
the low jetty from the reefs, seriously shoaling the channel by
heavy material, which the current could only move very slowly.
These causes delayed the enlargement of the channel on the
(»•est of the bar. Experience had shown that rubble stone
and even large dimension rock, could not withstand the lift¬
ing power of the storm waves, the sea very often picking up
the smaller stone, and drifting them in piles like the sand.
Large stones weighing about three thousand pounds had some
time previously been placed on the surface of the jetty as an
experiment. A few days afterward a severe gale occurred,
and they were thrown by the waves entirely off the jetty.
The only plan which it was thought would answer the re¬
quirements of the case was the construction, in place, of
large blocks of concrete or hhton, which in shape, position,
and weight, would be able to withstand the most violent
wave force to which they would ever be subjected. The
following description of this concrete work is largely taken
from a paper by Mr. Max. E. Schmidt, C. E., Chief Assist¬
ant Engineer of the jetties, written for the annual conven-
plate d.
CONCRETE MIXER on EAST JETTY
102,00'^ below Eastpoint
SELTtxr.PAeE 189
SIDE ELEVATION
LOOKING- EAST
Scale »S 5®«^
JETTIES COMPLETED.
189
tion of the American Society of Civil Engineers, June, 1879.
The exact and thorough statements, presented so forcibly in
that paper, were the result of much patient investigation.
The jetty enterprise is greatly indebted to him for his ear¬
nest work, for his dispatch and accuracy in surveys, and
for his systematic arrangement of results.
The wharves, railroad tracks, machinery, and implements
for the construction of the concrete work, are very clearly
and fully shown in the accompanying sketches. Plate 16
represents the immediate surroundings of the concrete mixer,
on the east jetty. It is located at Station 102. The storage
wharf for cement, macadam, gravel, and sand is built upon
about four hundred piles, driven at intervals of eight feet,
capped, and floored with three-inch plank. The mixer (see
Plates C and D,) is placed immediately over the jetty, and is a
five feet and nine inches cube, constructed of one-quarter inch
boiler iron, strengthened with angle iron. This box is sus¬
pended on two hollow cast-iron trunnions, seven and one-
half inches in diameter, riveted from the inside of the box to
two diagonal corners, and resting in a tower or frame-work,
built substantially of heavy timber. The center of the trun¬
nions is twenty-two feet above the datum plane, and the
mixer is revolved by a steam-engine, which stands on the
wharf. An examination of the sketch will show that one
corner of the mixer has been cut off for the purpose of mak¬
ing an opening for admitting and discharging the material.
The materials are brought by wheelbarrows and carts to a
steam elevator, the box of which is at the level of the wharf ;
it is then raised above the mixer, and the materials are
discharged from it through a trap-door into the mixer. The
water is let into it from a tank, placed upon a platform above»
by a pipe passing through the hollow trunnions. After about
a dozen revolutions of the mixer, the trap-door is opened
and the concrete discharged into a dumping-car. The tanks
190
THE MISSISSIPPI JETTIES.
or receivers on tile cars are six and one-half feet long, four
feet wide, three feet three inches deep, and are nearly semi-
cylindrical in form. They are built of one-quarter inch
boiler iron, and the axles on which they turn are three inches
in diameter, and are riveted by a round plate to each end of
the receiver. By means of levers attached to these plates,
two men can easily overturn the car and dump the con¬
crete. The car is taken by a small locomotive to the place
where the block is to be built. The jetty is prepared for the
molds, or boxes, in which the concrete block is built, by first
throwing the rubble-stone to one side, cutting away, if neces¬
sary, the old mattress work, filling the interstices with gravel
or small broken stone, and leveling it off carefully to a fixed
height, generally about six inches below datum. The box, a
sketch of which is shown, see Plate E, is then placed upon the
bed thus prepared, and the concrete, in suflicient amounts to
fill it, is deposited in it from the car. These boxes are so
constructed, that the sides can be easily removed after the
concrete has become well set, and sufl&ciently hard to meet
the force of the waves without disintegrating. The bottom
of the box is made of inch boards, and the sides of two-inch
plank. About two cubic yards constituted one charge for
the mixer. The proportions for the ingredients varied some¬
what, but not materially, according to the materials and loca¬
tion of the blocks. The usual proportions were :
Three parts cement.
Three parts sand.
Three parts gravel.
Fifteen parts broken stone.
The amount of macadam was often reduced, and a small
proportion of rubble stone was thrown into the concrete after
it had been placed in the molds. At first the material was
tamped, as soon as it was dumped into the molds, but this
was found to be unnecessary, as the force of the fall from
Storaoe: Platform
LANDING
R I
F? S i
■O
r
>
H
m
Ô)
of immediale surroundings
of the
CONCEIETE MIXEE «n EAñTJ ETTY
loaoo''-below Eastpdnt
,ShOVVINI> LOCATION OF WHARFS , WHAREHOUSE,
ELEVATOR , MIXER, CONCRETE
AND RAiLPOAO
Sii-lLXr Pao el
3ca.Vft o3
CHANNEL
Fl a I,
Mould Box for Concrete. Blocks
k
cd
it
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JETTIES COMPLETED.
191
the dumping-car was sufficient to thoroughly compact the
concrete.
During the progress of the consolidation of the jetties, the
Board of Army Engineers, which had been appointed in
accordance with the act of Congress, of June 19th, 1878,
arrived at Port Eads. The members of this board were
Genl's J. G. Barnard, J. N. Macomb, Z. B. Tower, and H. G.
Wright, and Col. William E. Merrill.
They addressed a letter to Mr. Eads, stating the subjects
on which they were to report, and requesting him to furnish
a statement of his plans for completing the jetties and auxili¬
ary works, with his estimate of their probable cost, and also
to present his views of what depth these works would ulti¬
mately produce, and to state what modifications of the act
he desired, in regard to dimensions of channel and terms of
payment.
In reply Mr. Eads submitted drawings of all works pro¬
posed for completion, with an estimate of their cost, which
was three hundred and sixty-two thousand one hundred and
ten dollars and sixty-seven cents. The following is an ab¬
stract of his letter. It is his belief that the natural discharge
of South Pass will create and maintain a channel of a central
depth of thirty feet, but no larger. In regard to the modifi¬
cations of the terms of payment, he alludes especially to the
fact, that they were arranged in the act to save the govern¬
ment from any loss, while the jetties were considered a
doubtful experiment. As they are no longer an experiment,
but a success, he should be paid for at least ninety per cent,
of the work done. On this basis he calculates that the
amount unpaid of the sum actually earned, is two million two
hundred and eighty-seven thousand eight hundred and ninety
dollars, with one million dollars still held in reserve by the
government, as security for maintenance of the channel for
twenty years, and that even on the basis of channel results.
192 THE MISSISSIPPI JETTIES.
already obtained, the government should pay him $1,773,000,
and that this sum will not suffice to discharge all the indebt¬
edness created in the construction of the work.
The Board report on six different subjects ;
First.—Progress made in the construction of the works.
They give a description of theiñ, with the estimate of the
materials used in them.
Second.—Probable cost of completion.
They believe the estimate of Mr. Eads is sufficient for the
completion of the works as designed by him, but state : " It
(the Board) is unable to predict what will be the resulting
depth on the bar, and as the only standard of completion is
the attainment of a channel over the bar thirty feet deep and
three hundred and fifty feet wide, it follows that an estimate
of the probable cost for works necessary to produce such
channel, if it ever can be produced, cannot now be made."
Third.—Results produced.
They give a table taken from Capt. Brown's report of De¬
cember, 1878, showing at various dates the depths in the
channel. A copy of this table, extended to include depths
obtained in July, 1879, is shown in Appendix 17. In refer¬
ence to the bar beyond the jetties, they say : " Outside of the
jetties there is no present appearance of bar advance, and
though during the past year soundings indicated variable
conditions during different months, at the end of the year
a scour of twenty-two inches is shown in the one and one-
quarter square miles just seaward of the jetties, where dur¬
ing the preceding year there had been a resultant average
fill of five inches."
Fourth.—Results that may probably be produced.
They doubt the ability of the jetties, even after consolida¬
tion and prevention of leakage, to obtain a depth of thirty
feet, and a permanent channel twenty-five or twenty-six feet
is all that can be expected. They refer to the probable ex-
JETTIES COMPLETED.
193
tension of the jetties on account of bar advance, as a subject
to which pre-eminent importance has been attributed. They
refer to the report of Capt. Brown, in which the subject of
scour and fill in front of the jetties is treated, and to the ad¬
vance and recession of the contours, to show that up to July,
1878, there had been a deepening, and instead of an advance
of the contours, an absolute retrogression and a disappear¬
ance of bar material in front of the jetties.
Probable permanency.
Wave action and destruction by the teredo are the princi¬
pal destructive elements. As the effect of wave action thus
far has been mostly superficial, and such action is by no
means as violent as in similar exposures on the Atlantic
coast, they think that the concrete work, flanked by enrock-
ments of heavy stone on palmetto-log grillages, will resist
the sea action. They do not believe that the teredo has pen¬
etrated or can penetrate far into the interior of the mattress
courses, on account of deposits of sand and mud in them.
They say : " In the ordinary sense of the word permanency,
that is, capability of endurance of destructive forces, the
works may be said to possess the attribute, to a reasonable
degree."
Sixth.—Advisability of modifying terms of payment and
dimensions of channel.
On this point they say : " The Board of 1874, instituted by
act of Congress to determine the best method to secure an
outlet from the Mississippi River to the gulf, either by a
canal or by the improvement of one of its natural outlets, re¬
ported in favor of improvement of the South Pass at an esti¬
mated cost of $5,342,110, declaring that while its estimate
was designed to cover every possible contingency of cost,
it was believed the work could be done for a much less
sum. No reason is known why Congress, which adopted this
recommendation, should not have left the execution of the
13
194
THE MISSISSIPPI JETTIES.
work to its own agents, except that the present contractor,
Mr. James B. Eacts, offered to accomplish the results con¬
templated hy the Board without payment unless those results
were secured.
" It would seem, therefore, that this proposition of pay¬
ments for results only influenced Congress to award the con¬
tract to Mr. Eads, instead of leaving the execution of the work
to its usual agents."
This extract is very suggestive.
It plainly indicates that the Board considered Mr. Eads as
simply executing works which were planned by the Board
of 1874. He is deprived of any credit of originality in the
matter, and is considered simply as an interloper, who had
wrested from the usual agents of the government, by the at¬
tractive proposition to produce results before payment, the
direction and execution of works which'they had originally
designed and recommended to Congress for adoption.
The results which followed the execution of the works are
most favorably reported upon ; but the moment the question
arises as to whether Mr. Eads should be paid any portion
of the one million and three-quarters, which he clearly
shows the government would be safe in advancing, the spirit
of the report is totally changed, and the sum of $250,000 is
recommended to be advanced, not to relieve his necessities
but to be strictly applied to the further execution of the
work.
The unanimity with which the United States Congress,
soon after receiving this report, voted $750,000 to Mr. Eads,
to be paid at once, in addition to the $1,000,000 voted to him
during the previous session, without any restrictions what¬
ever as to its use, shows that it fully sustained the criticism
which he published upon the recommendation of the Board,
and in which he refers as follows to the claim of originality
set up by this Board for the Board of 1874, all of whose
JETTIES COMPLETED.
195
members, it is proper to state here, were, when appointed, in
favor of the Fort St. Philip Canal :
"I urged this plan" (the jetty plan) "of improvement as
the only proper 07ie, upon the attention of a large number of
the members of the Forty-third Congress, in May of 1873,
during their visit to the mouth of the river, and in the win¬
ter following I made a formal proposition to Congress to
deepen the mouth of Southwest Pass by the jetty system,
and offered to guarantee its complete success, lefore any mem¬
ber of the Corps of Engineers (so far as I can learn) had ever
expressed ofiicially or publicly any preference ichatever for this
method of improving the mouth of the Mississippi over that
of a canal, and long before the Commission of 1874 was ever
thought of ; indeed the very creation of the commission was
the result of my proposal, and the opposition it evoked from
some of the prominent engineers of the army." * « *
" The unusual severity of those provisions of the jetty act,
by which an almost entire completion of the work was really
required for a total payment of less than one-third of the
agreed price, can only be attributed to the hostility evinced
by some of the members of the Engineer Corps of the Army.
Their arguments against the plan and their determination that
this great work should not be intrusted to me, gave birth to
all kinds of predictions of evil and failure. Their antago¬
nism naturally enough alarmed Congress, and resulted, first,
in the enactment of the severe provisions referred to ; and
second, in requiring me to accept the South instead of the
Southwest Pass. The bill, as it passed the House, provided
for the improvement of the Southwest Pass. In the closing
hours of the session, liowever, the Senate Committee, as ad¬
vised by the Commission, substituted the South Pass, but
against my own protestation, and without the advice of experts,
it insisted on my agreeing to produce at this little pass,
depths and widths of channel similar to those I had pro-
196
THE MISSISSIPPI JETTIES.
posed for a pass four times as large, or else see the execution
of my project put into the hands of its opposers." * * *
"I think the members of the Forty-third Congress will
dissent from the inference sought to be created by the
Board, namely, that the method of improvement adopted by
that Congress was originated by the Commission of 1874, and
that but for my proposal the engineers of the army would
have been intrusted with the building of the jetties, for the
facts show that the Commission of 1874 would not have been
created but for my proposal, and that if I had not made it,
and urged the jetty system with all the ability I could com¬
mand, the 'usual agents of the government,' instead of being
intrusted with this work, would, in all probability, now be
digging in the sickly marshes of Louisiana, the canal recom¬
mended by a prior commission.
" Of that stupendous project. General Barnard, when ad¬
vocating ' an open river mouth,' said, ' It would be a rash
confidence that would anticipate a completed Fort St. Philip
Canal earlier than 1884.'
" From these facts it is evident that if it had not been for
my proposition to deepen the mouth of the Mississippi River
by the jetty system, the commerce of the vast empire which
constitutes its valley would to-day, and for years to come,
be fretted and hampered by the bars at the mouth of the
river, or be compelled to seek expensive and unnatural
routes to the seaboard." * * *
" It remains to be seen whether an American Congress is
prepared to put the stamp of condemnation upon individual
enterprise, and decline to act with justice and liberality
toward one who, in the face of unprecedented difficulties, has
secured to the Valley of the Mississippi, and to the whole
country, a deep and permanent outlet from the river to the
sea."
It is proper to state as a matter of history, that General
JETTIES COMPLETED.
197
Barnard, early in tlie controversy between Mr. Eads and cer¬
tain engineers of the army, took sides in favor of the appli¬
cation of the jetty system to the mouth of South Pass, and
doubtless contributed largely by the influence of his well-
earned reputation as an accomplished engineer, in securing
the adoption of that system. He was, however, at no time
in favor of confiding the work to Mr. Eads ; yet its success
was of the utmost importance to his professional reputation,
as upon it depended the evidence of the correctness of his
views upon the subject, and throughout the entire enterprise
he was deservedly recognized as one of its warmest friends ;
but there is no foundation whatever for the claim of original¬
ity set up in favor of the " usual agents" of the government,
in the report of the Board of 1879, of which Gen. Barnard
was President. It is true that a Board of which he was a
member, in 1852, recommended a trial of the jetty system at
Southwest Pass ; but it was only as an alternative to be tried
in case of the failure of a trial by the dredging and stirring
process, which was recommended by that Board to be first
tried. Certain it is that no oflicer of engineers, from that
time forth until 1875, put himself on record in favor of the
jetties; not even Gen. Barnard himself, who had given to
the subject much more study no doubt than any other mem¬
ber of the Corps of United States Engineers ; for while Mr.
Eads had arrived at the conviction in the summer of 1873,
that the jetty plan was the only correct method of improving
the mouth of the Mississippi, and had given Iris opinion the
most unqualified expression by proposing to guarantee its ab¬
solute success, in January, 1874, we find Gen. Barnard still
hesitating to put himself squarely upon the record in favor of
the jetty system, and in a letter addressed to the Chief of En¬
gineers, April 29th, 1874, explaining the motives that actuated
him in submitting a minority report, which had been severely
criticised by Gen. Newton, the ranking member of the ma-
198 THE MISSISSIPPI JETTIES.
jority of the Board, he states : " I would in the first place
remark, from first to last I felt myself charged with a gravely
responsible duty ; that I approached the questions presented
to the Board perfectly unprejudiced ; if in any luay biased it
was in favor, not against, the canal as a great engineering
structure, outdoing in magnitude and interest the remarkable
work I had recently visited in Holland, and, moreover, with
the most conscientious desire not only to arrive at the true
and best solution, but to do so in harmony and co-operation
with the other members of the Board." See letter of May
22d, 1874, from Chief of Engineers to Secretary of "War,
transmitting letter of Gen. Barnard, dated April 29th, 1874.
On other subjects treated by the Board, Mr. Eads alludes
First.—To the question of bar advance, on which he says:
" Prominent among the evils which were prophesied by the
enemies of the jetties was that of the formation of a bar at
their mouth. It was declared that if a deep channel could be
obtained, it would have no permanent existence, but would
soon be rendered valueless by an advance of the bar. So
persistent has been the cry of BAR ADVANCE, in
official and unofficial publications, and so widely has it
been circulated through the medium of the press of the
country, that these predictions have given rise to grave
doubts upon the subject in the minds of many of those who
were deeply interested in and who sympathized with this
effort to give relief to the commerce of the Mississippi River.
Pacts were not wanting to dispel these doubts. The reports
from time to time of the government officer in charge of the
works (Capt. Brown), and the charts which he submitted
from official surveys made by himself, conclusively demon¬
strated the utter falsity of all allegations in regard to a ' bar
advance ' ; but in the face of these reports and accompanying
charts, the enemies of the work have persisted in repeating
their assertions to the contrary. The report of the Board of
CTETTIES COMPLETED.
199
Engineers, which we are now considering, certainly puts for¬
ever at rest this much vexed question, and dispels all doubts
upon the subject."
Second.—The results within the jetties.
" The next important matter settled by the Board is that
relating to results produced within the jettied channel. The
opponents of the jetties, as we have seen, started with the
prediction that no reliable results would be achieved, and
sought to induce the belief that the improvement from time to
time in the channel was not a general one, but that a deepen¬
ing in one place involved a shoaling in another. The report
of the present Board disposes very summarily of all such as¬
sertions. After quite an elaborate detail of the results pro¬
duced, the Board says :
" ' The maximum bar depth that has been obtained pre¬
vailed December 14th, 1877, when it was 23.7 feet. At the
date of the latest survey, December 28th, 1878, it was twenty-
three feet. This slightly decreased bar depth by no means
indicates actual retrogression in the progress of results. On
the contrary, there has been constant progressive general improve¬
ment in the jettied channel, at no time more evident than at pres¬
ent: "
In reference to that portion of the report which refers to
the channel dimensions, he states that, as the question was a
vital one, it should have had careful attention given it by the
Commission, also that they have greatly misunderstood him
when they allude to his expressed ability to attain the depths
and widths of channel prescribed in the act ; for he strongly
inferred in his letter that they could not be obtained without
forcing more water through the pass and thus endangering it
and the jetties. He says : " That two members of the Board
at least had settled convictions upon this important question,
and that the entire Commission of 1874 fully agreed with
them, is evident from the testimony given by these two
200
THE MISSISSIPPI JETTIES.
members (Gens. Barnard and "Wrigbt) before a committee of
the Senate in 1878. Gen. Barnard, in his testimony, said ;
" ' Question.—Suppose the scouring force between the jet¬
ties should deepen it from seven to twenty-three to twenty-
four feet ; now suppose the scouring force with the present
water in it is exhausted, at twenty-four feet, would it be safe
to turn in any water from the Southwest Pass, and from Pass
à Loutre from the main river, through this South Pass, to
add to the scouring to make it thirty ? ' Answer.—' I have
no confidence in it ; nor was that ever recommended by the
Board of 1874. I do not say it cannot be done, but to be
safe, I would say it should be a slow process. It would re¬
quire much labor and great expense. It would create an
additional " head," and the results in the case of that kind
are not easily foreseen. If done at all, I would adrise it to
be done very carefully and slowly, and in that way probably
more water would be directed in the pass. It would have to
increase its own section all the way down in order to carry
that water.'
" Gen. Wright, in answer to the question as to the advisa¬
bility of forcing more water into the South Pass, in his testi¬
mony said :
" ' The Commission of 1874, which got up the original plan
of the jetties, discussed that ihatter at great length, and it
was, I think I may say, the unanimous opinion of the mem¬
bers that the size of the pass could not be interfered with :
that what we wanted was that the regimen of the pass should
not be disturbed ; and to that end there is put into the esti¬
mates a certain amount—I don't remember whether specifi¬
cally or not, though I think it was—to prevent any en¬
largement of the pass at all.'
" In face of this record further comment is unnecessary."
In reference to the recommendations of the Board he says :
" Having thus given the facts found and submitted by the
JETTIES COMPLETED.
201
Board, we come to consider its recommendations. These are
in brief as follows : 1. That $250,000 of the twenty-six foot
payment be advanced to me, to be expended under conditions
similar to those imposed by the third section of the act of
Juno, 19, A. D., 1878 ; and 2. (in the language of the Board),
' As every additional foot in depth of channel is a benefit to
commerce, we would suggest the advisability of a change in
the terms of payment in the original act, so as to allow of
payments for each additional foot gained, instead of for every
two feet, the channels and payments to be as shown in the
following table.' * *
" In the face of the great results accomplished and about
to be accomplished, and with less than one-third of the price
of the works paid, the Board recommends no action whatever
by Congress which would really afford me the relief which
my necessities demand. The report is rich in expressions of
approval of the work—poor only in its recommendations.
Of what avail to me would be the advance of $250,000 ham¬
pered by the condition that it be expended only on the
works ? Would it serve to relieve me from the mountain of
debt which I bear? Would it pay, even to a small extent, the
contractors whom I have employed, and who have devoted
their whole fortunes and years of labor to this great work ?
The liberality of this recommendation of the Board is only
equaled by that of its second recommendation, which in
plain English may be stated thus ; ' The works will not, we
believe, produce a greater depth of channel than twenty-six
feet ; wo recommend that for every additional foot over twenty-
six feet secured, Mr. Eads be paid the' following sums of
money.' * * *
" The Board, in its report, uses the following language :
" But it shoidd be remarked that a channel, of less depth
than eighteen feet at South Pass was not necessary. * * *
" The useful result accomplished is, therefore, ' a channel
202
THE MISSISSIPPI JETTIES.
from eighteen feet to twenty-three feet.' In this connec¬
tion the Board might have added that a permanent channel
eighteen feet in depth was worth to the government $250,000
per annum, as it cost about that amount to maintain the un¬
certain channel at Southwest Pass."
For full text of the report of the Board and Mr. Eads's re¬
view of it see Appendices 18 and 19.
Soon after the presentation of the report of the Board and
the review of it by Mr. Eads, the Senate Committee on
Transportation Boutes to the Seaboard reported favorably
on a bill of relief, and an act was passed by Congress and ap¬
proved by the President of the United States on March 3d,
1879, whose general provisions were a payment in cash at once
of $750,000, a payment of $500,000, when a channel twenty-
five feet by two hundred feet is obtained, $500,000 when a
channel twenty-six by two hundred feet is obtained, and
$500,000 when thirty feet is obtained, without regard to
width.
For the full text of the act, see Appendix 20.
The construction of the concrete blocks was pushed for¬
ward as rapidly as possible on both Jetties ; the work being
confined to those portions seaward of Station 102.
Afterward the work was extended above the mixers to
Station 90 on the west jetty, and to Station 65 on the east
jetty.
The size of the blocks varied from three and a half feet
wide, three feet thick, and sixteen feet in length at Station
65, to thirteen feet wide, five feet thick, and fifty-five feet in
length at Station 117. The weight of the concrete when dry
is about one hundred and fifty pounds per cubic foot, so that
the heaviest blocks, which were placed at the sea end of the
east jetty weigh over two hundred and sixty tons.
The concrete work of the east jetty extends from Station
65 to Station 118, or about one mile in length. On the west
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JETTIES COMPLETED.
203
jetty it extends from Station 90 to tlie end of tlie jetty, about
half a mile. The blocks on both jetties gradually increase in
size toward the sea ends. A continuous parapet of concrete
is built on the blocks of the east jetty rising to a height of
five feet above datum at Station 65, and nine feet at Station
118. A portion of the parapet is built of rubble masonry.
There are seven thousand three hundred and twenty-six cu¬
bic yards of concrete on both jetties, and four hundred and
sixty-three cubic yards of rubble masonry.
In order to render the work stable and durable, the very
best materials were obtained for its construction.
The macadam is a hard compact limestone, weighing about
one hundred and fifty-five pounds to the cubic foot. It is
broken so as to pass through a three inch ring. The gravel
is a clean wash gravel from the bed of the Mississippi River,
about one hundred and thirty miles above NeAV Orleans, be¬
ing deposits from a creek near by ; the pebbles A^ary in size
from one-thirtieth of an inch to one and one-half inches in
diameter. The sand is moderately coarse and sharp grained,
the diameter of the grains averaging one-fortieth of an inch.
It is obtained from the shores of the Mississippi Sound, be-
tAveen New Orleans and Mobile. The sand found at the
delta of the river is not suitable for concrete work, being
composed of fine round particles about one one-thousandth
of an inch in diameter, and generally mixed Avith clay.
The value of concrete depends so much upon the bond
which exists between the ingredients, that the cement which
performed this ofiice should be described.
It Avas believed that the ordinary light weight cements
would not be suitable for Avork exposed immediately to the
action of salt Avater, and the violence of the Avaves.
The folloAving specifications were therefore determined
upon :
Fir6t.—That the cement must resist without fracture a ten-
204
THE MISSISSIPPI JETTIES.
sile strain of two Inindred and fifty pounds per square inch
seven days after the specimen briquettes of two and one-
quarter inches sectional area were made, during six days of
which they must be immersed in water.
Second.—That at least eighty per cent, of the cement must
pass through a sieve of two thousand five hundred meshes
to the square inch ; and
Third.—That the weight of a struck bushel must be at
least one hundred and ten pounds.
Careful inquiries and examinations were made to find a
cement that would not only conform to these specifications,
but would be recommended by those who had used it under
similar circumstances.
The tests made by Mr. W. W. Maclay, of the Department
of Docks of New York, showed that Saylor's American Port¬
land cement was fully equal to these requirements, and
ranked with imported Portland cements. As large quantities
had been used by that department, and had given satisfaction,
a contract for delivering seven thousand barrels was made
with the general agents, Messrs. Johnson & Milson, 93 Lib¬
erty street. New York.
As this cement has performed an important part in the
construction of the concrete, a description of its manufacture
will be given. The material and works are in Pennsylvania.
It is manufactured by what is termed in Europe the dry pro¬
cess. The stone, as it comes from the quarry near by, is
ground in steam crushers and mills to an impalpable powder.
It is then thoroughly mixed in an iron mixer on its way to the
pug mills, where it is tempered with water. The product is
then treated in a manner similar to the English method of
making Portland cement, namely : it is spread out upon dry¬
ing floors, and when stiff is cut up into blocks the size of
bricks ; these when dry are placed in the kilns, with alter¬
nate layers of coke, and burned. The clinker is then care-
JETTIES COMPLETED.
205
fully selected, the pulverulent scorified and the underburnt
taken out ; it is then ground and conveyed to the store¬
rooms, the area of which is nineteen thousand square feet,
where it is left a few weeks to sweat. It remains in bulk in
store until needed, and is then packed in barrels well lined
with paper, to protect it from dampness—a provision espe¬
cially needed in the damp climate found at the mouth of the
Mississippi Eiver. This cement, as shown by chemical
analysis, is composed of the following ingredients : silica,
22.04; alumina, 10.11 ; sesquioxide of iron, 1.61 ; sulphate of
lime, 1.78 ; lime, 61.93 ; magnesia, 2.18. Total, 99.60.
Eleven kilns are used for the manufacture of Portland ce¬
ment, with a capacity of five thousand barrels per month.
The ordinary natural cements differ from Portland cement in
the following particulars. They are simply the quarried ce¬
ment rock, ground once only, in which are wanting several
of the ingredients enumerated above, viz. : Silica, Alumina,
etc. (The tensile strength of cements, given following, is from
tests made seven days after mixing, if not otherwise specified.)
Natural light weight ceipents, gauged neat, give about seventy
pounds per square inch tensile strength, and weigh about
seventy-five pounds per struck bushel.
Careful tests applied to about one-tenth of the twelve
thousand two hundred and seventy-five barrels of Saylor's
Portland cement received at Port Eads, give the following re¬
sults : Percentage of fineness, eighty-eight ; average weight of
struck bushel, one hundred and twenty-two pounds ; average
tensile strength (one part cement two parts sand), one hun¬
dred and two pounds per square inch ; maximum one hun¬
dred and thirty-three and one-half pounds ; average tensile
strain, neat cement, two hundred and sixty-two and one-
quarter pounds per square inch, and the average of the max¬
imum breaking strains of each lot, of about ten briquettes,
three hundred and twenty-five and one-quarter pounds per
206
THE MISSISSIPPI JETTIES.
square inch. Since, on account of the difficulty of manipula¬
tion, it was almost impossible to obtain perfect parallelism
between the line of strain and the larger axis of the bri¬
quettes, this latter test may possibly reveal the actual
strength of the cement more nearly than the average of the
breaking strain of the whole number in each lot. All the
briquettes were two and one-quarter inches in sectional area,
and were moulded to fit the clamps of a Eiehlè testing
machine.
The cement, either in briquettes or in work, increases in
strength and hardness with age. Tests made by Mr. Maclay
show a tensile strength of five hundred and ninety-nine
pounds per square inch with briquettes ten months old, and
at the manufactory the cement, gauged neat, withstood a ten¬
sile strain of eight hundred and sixty-six pounds without
fracture with briquettes nineteen and one-half months old.
The quality of the cement was remarkably uniform. In the
actual construction of the blocks, and in the severe tests
given the concrete in sixteen months of exposure to the
waves, the cement has proved itself to be first-class in every
respect. It has so hardened and solidified the blocks that
even the edges and corners exposed to the sea are as clean
cut to-day, as when, two weeks after construction, the plank
moulds were removed and the waves commenced to dash
against them.
The construction of concrete generated new wave forces
which the rubble stone or even the dimension rock could
not withstand. The waves which previously swept over the
jetties and expended their force, were by the concrete blocks
converted into racers, which in storms swept along the jetty
with terrific force, picking up the rock which lay upon the
slopes, scattering it in every direction, and, where an obstruc¬
tion opposed its further course, piling up the rock upon it,
and at times hurling them over the concrete blocks. To pre¬
vent this action of the waves, which, if continued any length
JETTIES CÖHFLETED.
207
of time, would undermine tlie jetties, spur cribs were built
and placed about one hundred feet apart, on both sides of
the jetties, wherever they were exposed to the racers. These
cribs were loaded with rubble stone. The crib work for pro¬
tecting the ends of the jetties was constructed of palmetto logs.
The palmetto is a species of the palm. Its wood is very
fibrous, tough and corky. The fibers are intricately inter¬
woven with each other, and the wood resists the attacks of
the teredo. It weighs about forty pounds to the cubic foot.
The plan and manner of constructing these cribs are seen in
figures 4 and 5, Plate E. Before building them, careful ex¬
aminations were made to ascertain the depth of the water and
the irregularities of the bottom. A plan was made accord¬
ingly from which the crib was constructed.
" Eeferring for an example to the one on the drawing, there
are fifty-one palmetto logs (A—A, see Figs. 4 and 5), each
twenty-two feet long, which are placed in one row one foot
from center to center, on the inclined ways formerly used for
mattress building. This being the floor of the crib, a second
row, consisting of five logs (B), is placed to break joints with
the flooring, at distances of five feet from center to center.
In the same manner the third row is placed, consisting of
eleven logs, sixteen and one-half feet long, at distances of five
feet between the centers, and breaking joints with the lower
row. Augur holes are then bored, and the rows bolted to
each other by three-quarter inch bolts. The fourth and fifth
row of logs is then laid, as shown on the illustration, and
drift-bolted to the lower layers. The crib is braced by short
logs (C, C,) standing upright against the corners of the cells.
Their lower ends are flattened and tightly wedged between
the flooring, whore they are fastened by bolts. In addition
to these, stirrup bolts are used at every alternate comer of a
compartment, which tie all the logs from the bottom to the
top. The compartments are four feet square in the clear,
and large enough to admit the largest boulders tha are
208
THE MISSISSIPPI JETTIES.
brought to the jetties. The cribs are pulled off the ways
into the river by a tug, which takes them to the place for
which they are built. Here a row of guide piles has been
driven, about ten feet from the jetty embankment, to which
the vertical edge of the crib is lashed. The sinking then
takes place. The compartments are finally closed by large
boulders, which, are lifted into position by a derrick. The
remaining space, of about ten feet in width, between the ver¬
tical edge of the crib and the jetty embankment, is filled with
ston'e until it appears above water."
The above description and the plates of concrete and crib
work are from a paper of Mr. Schmidt, entitled " The South
Pass Jetties," read before the annual convention of the
American Society of Civil Engineers, held at Cleveland,
Ohio, June 17, 1879.
The sea end of the wast jetiy is entirely inclosed by this
crib work for a distance of about three hundred feet above
the end. As the end of the east jetty is still more exposed to
the waves, a more extensive plan has been carried out. It is
necessary for the stability of the work that it should be built
with very flat slopes, so that the waves will meet no vertical
obstructions to pound against. A cross section of the pier¬
head at the end of the east jetty is shown on Plate 18.
This shows the combination of the different kinds of ma¬
terials and work. A longitudinal section of the pier-head
would show the same plan of construction ; a broad base, a
flat slope, and the very best arrangement of the most suitable
and durable materials in order that the permanency of the
work may be assured. Landward from the concrete work on
both jetties the final capping consists of rubble stone,
rounded into a crown, under which, in a trench about six feet
wide, gravel was worked into the mattresses, to prevent leak¬
age. The height of this section of the jetties is about eigh¬
teen inches above datum.
The three principal materials used in the construction of
JETTIES COMPLETED.
209
the jetties and auxiliary works were willows, lumber, and
stone, the distribution of which is giren in a detailed esti¬
mate in Appendix 16.
The total amount of each was : willows, six hundred and
sixteen thousand one hundred and twenty-six and thirty-
nine one hundredths cubic yards ; lumber, thirteen million
feet, board measure ; stone, including concrete, ninety-nine
thousand eight hundred and twenty-fire and ninety-fire one
hundredths cubic yards.
The places where the willows were obtained hare been de¬
scribed in Chapter YII. The lumber, with the exception of
about one million feet obtained at New Orleans, was fur¬
nished by Messrs. Poiterent & Parre, of Pearlington, Miss.,
who from their promptness and reliability in supplying ma¬
terials are entitled to great credit.
Nearly all the lumber for the jetties was delirered by
schooners, carrying from forty to fifty thousand feet. By the
course run, the distance from Pearlington (where the mills of
Poiterent & Parre are situated) to Port Pads is about one
hundred and fifty miles.
The stone was obtained from rarious places ; from New
Orleans and Port Pads, where it was discharged from sea¬
going ressels as ballast; from the banks of the rirer at
Vicksburg, Miss., but by far the largest quantity from Eose
Clare, Indiana, fourteen hundred miles abore Port Pads,
where it was quarried from the hard blue and gray limestone
bluffs of-the Ohio Eirer.
The firms of Dippold and McDonald, and J. Sharp McDon¬
ald & Co., of Pittsburg, Pa., quarried the rock, and delivered
it at Port Pads in coal barges, carrying about three hundred
and seventy cubic yards, in fleets of from twelve to nineteen
barges. The weight of the largest load delivered was about
eleven thousand net tons.
The total amount delivered by these parties was sixty-
two thousand four hundred and forty cubic yards.
14
CHAPTEE Xyi.
FmAIi EESULTS.
By comparing the description given in chapter seven, of
the mouth of South Pass, as it appeared in June, 1875, with
the bird's-eye view of the jetties and Port Eads, given with
the present chapter, we can appreciate the external changes
that have been made since the work began. Wharves, build¬
ings, jetties, and sea-going vessels have taken the place of
the desolation characteristic of the mouth of the Mississippi
Eiver at one of its unused passes. But there are other
changes not shown on the sketch.
In the winter of 1878, ballast arriving in vessels was often
discharged on the banks at Port Eads. During the winter of
1879 two steam derricks were built for this purpose, each of
which in ten hours removes from one hundred and fifty to two
hundred tons from the hold of a vessel, and places it upon
the bank. The material thus discharged is brought from
all parts of the world ; dirt from the bluffs at Cape Town,
Africa ; gravel from the Thames ; granite from Eio de Ja-
niero ; sand from France and Spain, and a great variety of
material from many other ports. About twenty-eight thou¬
sand five hundred tons of ballast have already been placed
upon the banks at Port Eads.
A good foundation, half a mile in length, and from sixty to
one hundred feet in width, has been prepared for storing
materials for future construction. The deep Avater close
against the bank, the fact that its surface level is affected
210
0)
111
h
<
J
Q.
eiñOSEYE VIEW OF POET E A OS ANO JETTIES.
1 South Pass. Z.Chand Bayou 5. S.W. Pass.
FIGURES IN CHANNEL EXPRESS DEPTHS IN FEET
PLATE F.
SeeTej^tPage 211
86.-^
06ö
V
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i <y(\i \
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324 '
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/ /
/¡22<t
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', \ »«■' Z«.
üA hct-O I "'/ßiy 23S gS5 ,
/ zfl« 3®^ «S® 23-' 32
S 6 8^ y ^ i l; ZS 6 23 0
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CIIAKT
OF THE MOUTH OF
^2.5
íi'
/,2-3
za/as.
',,6 3"® .Al„^« 287
^.3 3^;ö ,/
35J) """" 38®
3ÍS '"Mr ^5
«W >V5®
^.3
33V 268 2^/5^/26'
270 2.8® 26" ^ 1
Souuitín^ are mjtjiressed. inJeeftaid ientba,
aíu¿ v^trr to the /lleras C/iood 3i<ie
indiccrterí 6y a veettimcf ^ 2.7Ô on ll-^
yttu^ at ^uitt tÀfss JUcfhi'ÑouAe.
'Aidions of jetties u/keee C£A«£Mr Blogns ■
are ietid are indifated thus mv
CO/ZTOl^
— 2e'_-.¿roi—
SOUTH I»ASS
Mississippi RIVER
SURVEYED BY
IT.S.ENGINEERS JULY 1879.
30.8
877 /~s, äl.-r
í«3>+ 307 í-^y
8^® 3i®u/a5
î'® (^^J) 31® ' 5,^
/
,.2 5»
^ EostLump.
S¿o 4A0 SÓJ aAa ?¿o HAH mtn
FIKAL EESTJLTS.
211
but sligbtly by the tides and river floods (oné foot on the
gauge at Carrollton raising the surface five-sixths of an inch
at Port Eads) ; the deep channel, seven hundred feet wide
and of an indefinite length, where a large fleet can ride at
anchor with perfect safety, and the saving in towage ; these
all give great advantages to Port Eads, as a shipping port
for the cereals of the upper Mississippi, and the cotton and
|ugar of the lower valley. This is one of the incidental bene¬
fits that commerce will reap by opening the mouth of the river.
The progressive and final cliannel results are seen more
clearly by the study of the plates, than by any verbal state¬
ment. The successive changes in the area^of the cross-sec¬
tion, and in the shape of the channel, and the increasing
depth in the line of the deepest water, are shown on Plates
20 and 21. (facing page 212).
The first exhibits the development of the channel by five
cross-sections, and the second by a profile of depths in the
line of the deepest water. An examination and comparison
of Plates A and F will show, in a more general way, all the
changes that have occurred in the channel. The first is the
chart of the U. S. Coast purvey, of May, 1875. The second
is the survey of July, 1879, by Captain Brown; it shows a
depth of nearly thirty-one feet through the entire length of
the jetty channel.
During the construction of the concrete blocks; the chan¬
nel developed rapidly near the sea end of the jetties, the
increase in depth on the bar keeping pace with the extension
of the blocks seaward. Between January 20th and April 8th,
1879, the east jetty concrete was extended from Station 105
to Station 115, and the west jetty concrete from Station 102
to 112. During the same period the depth on the bar in¬
creased from 23.9 feet to 27.2 feet. The spring floods pro¬
duced a development the' entire length of the jetties, which
resulted on April 7th, in a channel twenty-five feet deep, and
212
THE MISSISSIPPI JETTIES.
two hundred feet wide, which was certified to by Captain
Brown. On June 18th, a channel twenty-six feet deep and
two hundred feet wide was obtained, and on July 10th a cer¬
tificate was given by Captain Brown, as follows : " I certify
that on the 8th day of July, 1879, there was a channel at the
mouth of South Pass, through the jetties, thirty feet in
depth, without regard to width, measured at average flood
tide, and extending from a wider and deeper channel in
South Pass, to deeper water in the Gulf of Mexico." This
was the maximum channel demanded by the law.
Por examination by those who desire to fallow more
closely the successive changes in the channel, three tables are
given in Appendices 6, 7 and 17. The first shows the depths
in the line of the deepest water on twenty-seven sections,
between East Point and Station 128, beyond the ends of the
jetties, and at twenty-eight different dates between May,
1875, and January, 1880. The second gives the total dis¬
tance, in feet, that the various contours were interrupted by
shoaler water. These contours, eight in number, extend¬
ing from twelve to thirty feet, are drawn from surveys made
at twenty-five different dates. The third, taken from the
report of Captain Brown, of July 1st, 1879, shows the depths
that could be carried through each distance of two thousand
feet, between East Point and the ends of the jetties. The
table is made up from fifty-four surveys. A study of these
three tables will show fluctuations in depths and distances,
increase and decrease, advance and retrogression, but yet
a general progressive development. The fluctuations were
due.
First.—To the variable conditions of the river ; its chang¬
ing volume and its sediment differing in amount and charac¬
ter; and
Second.—To the construction work which was hurried for¬
ward or delayed by the various causes previously mentioned.
PLATE ao.
äi*tiJoa sj
OF
JETTY CHANNEL
SmWÏSG RESULT OF/fORSS
18r5-7»
PLATE G .
S ee Text Page 213.
C OMPAIL\TTVE ( HART
OF THE MOUTH OF
SOUTH PASS
MISSISJSJPP/ RIVER
SHOWINO THE CHANGES BETWEEN
MAY 1875 / JUNE 1879
«,
, fHiHithnt
«S Bo
fAnie ^
WO ip<»o '
(> fíttui Jjumjí
FINAL EESULTS.
213
The relation existing between the progress of the construc¬
tion work and the channel development is shown on Plate 22,
where the materials used in the work during each year, and
the concurrent results which they accomplished in the re¬
moval of the materials composing the bar, and in increasing
the depths of the channel, are exhibited graphically by four
squares, each divided into four years, that the eye may catch
at a glance the progress of the construction and its results.
It will be seen by an examination of this plate, that the
amount of material removed from the bar in four years was
three million two hundred and eighty-three thousand one
hundred and twenty-three cubic yards. This represents the
excess of scour over deposit in the formation of the channel,
in the whole space between the jetties, in the entire distance
from East Point to a point one thousand feet beyond the sea end
of the jetties. The central portion increased in depth as the
channel developed, and over the spaces on each side exten¬
sive deposits took place. Discarding this item of deposit, the
current moved in all seven million six hundred and seven
thousand one hundred and fifty-one cubic yards of material
from the bottom, and carried it seaward.
Plate Gr still further illustrates this subject, and shows the
extent, of the scouring and depositing influences. The un¬
shaded areas on the plate show where there has been deepen¬
ing since May, 1875 ; the shaded areas show where deposit
has taken place since the same date. The figures on the
chart show the increase or decrease in the depths.
An examination of Plates A and F, in connection with the
comparative chart just alluded to, will show to what extent
land has been formed on the sea side of the jetties. For
nearly a mile beyond the old land's end at East Point, the
new growth is above the level of average flood tide, and
grasses and reeds cover it.
On the west side of the west jetty the same process is go-
214
THE MISSISSIPPI JETTIES.
ing on, and clumps of grass here and there indicate that in
a short time the whole area included between the west shore
and the jetty, as far seaward as Station 90, will be above the
tides and covered by vegetation.
"We have endeavored by these various charts, sketches, and
tables to show; the results accomplished in the channel and
on either side of it. Some of the channel results have been
obtained by dredging, but the amount of material moved by
this means has been so small, being only about one per cent,
of the whole, that we have not included it in the exhibition
of results. This artificial appliance has simply hastened a
result which the current had ample power to accomplish,
as is evident from the fact that it is now able not only to
maintain the channel secured, but to still further enlarge
it.
The unsuccessful attempts made at various times during
the construction of the jetties and auxiliary works to per¬
manently increase the size of the channel, when the condi¬
tions did not exist for maintaining it, show how utterly futile
it is to attempt anything beyond slight changes in its shape ;
and they also prove the truth of the theory advanced by Mr.
Eads, before the jetties were commenced, that it is impossi¬
ble to permanently deepen the channels of sediment-bearing
rivers without proportionately contracting them.
The engineer can control only the form of the channel.
Dragging chains, harrows, and ploughs over the bar at
times, when channel enlargement was particularly needed,
resulted in some instances in a temporary increase in depth,
but with no permanent increase of channel dimensions until
the current itself had become sufficiently strong to make and
maintain an enlarged channel.
The material of which the bars at the mouth and head of
the pass is composed, is so easily moved by the current that
the slightest increase in velocity results in a deepening of
PLATE 22.
GRAPIHCAL £XH/IÍITION
WORK DONE RESULTS OBTAINjED
Willows
1«79
1oUlyOxit2.l9 CoTffs
187fl 1STT-T8
Siwe^ Cement. JbiiRl¡67.j79]aCt'.
1870 isro 18T7 1876 ^
MtierM Beinoved. Total,A.ísa.Ká.eoÜ^. httrmse in depths mt Crest et Bar '4e.sh.
18TÖ 18TT 1ÄT6
FIXAL KESULTS.
215
the chaniiel, so thai it may be stated as practically true that,
whatever size of channel the current will maintain-, it will ob¬
tain if only a reasonable time be given it to accomplish the
desired result ; except in cases of tough clay, where its re¬
moval may be hastened by artificial means. These principles
have been well proven by the effects of the works at the head
of the pass, and the following illustration is given to show
the impracticability of maintaining any artificial enlarge¬
ment of the channel without contracting it. In the spring of
1878, after the entrance channel had shoaled on account of
the destruction of Island Dyke, alluded to in Chapter XIV.
Capt. John G-rant, of New Orleans, who had had long experi¬
ence in dredging, conceived the idea of deepening the chan¬
nel by artificially increasing the velocity of the current at
the bottom. He constructed a machine for this purpose.
On a flatboat about eighty feet long, he erected a strong
framework and arranged long posts, eight or ten in number,
to be lowered or raised vertically by being geared to a shaft
revolved by an engine. Attached to the foot of these posts
was a board apron, about three and one-half feet wide, ex¬
tending the whole length of the boat, and inclined outward at
an angle of about thirty-five degrees with the posts.
The boat, with the posts and apron raised to the surface of
the water, was towed above the place to be deepened, and
then swung across the current by the tug which was towing
it alongside ; the apron was lowered to the depth which it
was required to produce over the shoal, and the boat, with
the tug still alongside to hold it broadside to the current,
drifted down stream until the posts, Avhich projected about
one foot below the apron, caught on the shoal and stopped
the boat. The current, obstructed by the apron and forced
under it with increased velocity, quickly excavated the ma¬
terial, thus allowing the boat to drift slowly down stream
over the shoal, deepening it as it went. The water was
216
THE MISSISSIPPI JETTIES.
usually about two feet deeper immediately above the aprou
than at the down-stream side of the boat.
When the boat had thus drifted over the shoal and washed
the material either into Southwest Pass, or into the deep
channel of South Pass between the dykes, it was towed back
to the starting point and allowed to drift again over the
shoal. When a deepening of about six inches had been
effected over the whole area required, the apron was lowered
still deeper, thus planing or shaving off the shoal by succes¬
sive cûts. Owing to delays, caused by accidents to the posts
and by bad weather, the dredge did not work continuously.
Although a deepening of about two feet and the removal of
about five thousand cubic yards of material from the channel
was effected, the causes that produced the shoal restored the
lesser but normal depth, and thus the channel which had
been deepened by this artificial appliance, shoaled again so
rapidly that the project was abandoned.
The results in the gulf beyond the jetties demand our care¬
ful attention on account of the necessity for their mainte¬
nance. The controversial arguments before Congress and in
the public press alluded to in preceding chapters have given
the subject greater prominence than it deserves. The views
and prejudices of the opponents of the jetties, during the in¬
ception of the enterprise, had such an influence everywhere
that the facts given by official reports during the progress of
the work were scarcely credited by many.
There are two methods of illustrating the results.
First—By means of curves that show at various dates the
position of the outer face of the bar in reference to fixed
points, and
Second.—By calculations to ascertain the scour or deposit
over the area in front of the jetties, in the track of the river
discharge.
The changes in curves of twenty and thirty feet depth at
PLATE K.
See Text Page 21 7.
FINAL EESÜLTS. 217
the sea end of the jetties are shown on Plate K. In order to
understand the movements of these curves, their alternate ad¬
vance and recession, an explanation of the plate is necessary,
for on it the conditions and causes that affect them, and on
which they depend, are illustrated. These few irregular, and
to the casual observer unmeaning lines, are the results of
much careful investigation, and they present graphically many
important facts. The vertical lines on the plate divide the
whole time into monthly periods. The readings of the sur¬
face of the river on the Carrollton gauge, from May, 1875, to
December, 1879, are plotted from the daily records.
The horizontal lines represent every four feet on the gauge,
and the points of the curve are plotted carefully by the scale,
so as to represent the exact reading given by the record.
The curve of mean velocities, extending from February, 1878,
to December, 1879, is obtained by ascertaining the mean
depth velocity at the time of making the sediment observa¬
tions. The curve showing ratio of sediment to water is
plotted from results obtained by taking specimens of water
from the pass at Port Eads, at various depths, the sediment
being separated from the water and its relative weight ascer¬
tained. The points on the curve are the means of a great
number of observations. The dotted curve immediately un¬
der it, showing the ratio of sand to water by weight, is the
result of observations by Capt. Erown, with a microscope of
two hundred diameters, by which the sand, or silicious par¬
ticles, is separated from the clay and its ratio to the whole
mass estimated.
The high and low waters indicated by the readings on the
United States Engineer's gauge at Port Eads are also plotted,
and the line of average flood tide is drawn through the curve
of high waters. The material removed in the channel devel¬
opment, which has already been illustrated in the graphical
squares, is also plotted on this chart. The points on the
218
THE MISSISSIPPI JETTIES.
curve are ascertained and plotted from surveys made at char¬
acteristic conditions of the river—at low, high, and medium
stages. The results are obtained by calculation. Compara¬
tive charts are made at each date, on which are drawn the
areas showing scour and deposit since the previous surveys ;
the whole chart is divided into squares of one hundred feet,
and the amount of scour or deposit at each corner of each
square is ascertained by placing the charts of the two sur¬
veys one over the other and ascertaining the difference in
depths. The total amount of material scoured or deposited
is then ascertained, either by calculating the prism between
parallel sections one hundred feet apart, or by measuring the
areas of scour and deposit and multiplying them into the
mean depths.
The two curves which remain to be explained are the
twenty and thirty feet curves, which show the position of the
outer face of the bar. They are obtained by means of twenty-
one parallel ordinales, fifty feet apart, and drawn at right
angles to an assumed fixed line, which at about Station 115
extends from the east to the west jetty. A skeleton plan, on
which these ordinales are drawn in heavy black lines, is
placed under the chart (which is plotted on tracing linen)
and the distances are then measured on these ordinales from
the fixed line to the point where the curves intercept them.
The average of these twenty-one distances establishes the
mean position of each curve, and gives us the points which
are plotted and through which the curves are drawn. An
examination of the plate will show how closely all the curves
depend upon that of the Carrollton gauge, which indicates
the rise and fall of the river one hundred and fifteen miles
above Port Eads. All the curves rise and fall with it. Thus
the current, its velocity increased by the rise of the river at
Carrollton, accelerates the current at Port Eads ; produces a
scour in the channel, where the waters are confined by the
FINAL EESÜLTS.
219
jetties ; brings with itself a larger amount of sediment, which
added to the material scoured from the jetty channel, pro¬
duces a deposit at the end of thé jetties and pushes out tem¬
porarily the twenty and thirty feet curves. Then as the
curve of the Carrollton gauge descends, all the other curves
on the plate descend with it—for the velocity of the current
is diminished, its ability to transport sediment reduced, its
abrading force weakened, and the bar, no longer pushed out
by sedimentary deposits, recedes by the action of the waves
and littoral currents.
The results exhibited on this chart, gathered from contin¬
ued and careful investigation, conclusively prove the theory
advanced by Mr. Eads during the earlier discussions of the
jetty principle, that there is a direct and intimate relation
between the velocity of the current and the amount of sus¬
pended sediment carried by it, so intimate, in fact, that the
latter depends solely and entirely upon the former, if the
depth and the local conditions remain the same.
It will be noticed, that, as the irregularities in the curve of
the "material removed " become less marked, the twenty and
thirty feet curves show less movement, especially during the
last year, when the channel had more nearly attained its full
development. An examination of the twenty and thirty feet
curves, shows that the former has receded about one hundred
feet and the latter advanced about one hundred and twenty
feet, or in other words, that the outer face of the bar in De¬
cember, 1879, was practically in the same position that it
was in June, 1875.
The curve method of ascertaining the changes that have
occurred beyond the end of the jetties is open to criticism,
for it embraces only the one thousand feet immediately at
the sea end of the jetties.
The second method, by which the difference between scour
and deposit beyond the sea end of the jetties is obtained,
220
THE MISSISSIPPI JETTIES.
in cubic yards of material or in feet of depth, is more satis¬
factory. In making this calculation we shall confine our¬
selves to the area lying in the track of the river discharge.
In elucidating the results we refer,
First.—To Plate 23, which shows the increase and decrease
in depth that has occurred over an area of 178.53 acres be¬
tween the surveys of 1875 and December, 1879, the former
by the United States Coast Survey, the latter by the Assist¬
ant Engineer of the jetties, Mr. A. O. Wilson.
On account of the soundings being irregularly spaced, es¬
pecially on the Coast Survey chart, the whole area was di¬
vided into one hundred feet squares and the soundings for
each corner of each square obtained by calculation.
The table in Appendix 21 gives the result of the calcula¬
tions. Taking the whole area into consideration, the excess
of scour over deposit is one million five hundred and ninety-
two thousand and fifty-five cubic feet, or an average increase
in depth of 0.2 feet. A large part of the area, however, lies
on each side of the track of the river discharge, and in the
spaces where the current is checked by the jetties. By an
examination of the table and chart it will be seen that the
mean gain in depth depends upon its position in reference to
the outflowing waters ; thus in combination A, which em¬
braces an area one thousand feet in width, and two thousand
five hundred feet in length immediately in front of the jetties,
the mean gain in depth is 1.1 feet; and
Second.—A more extended area has been surveyed at vari-
•ous times by Capt. Brown (see Plate 24). This area is_ fan-
shaped, and extends seaward from the jetties about one mile.
Its smaller base is three thousand five hundred and fifty-six
feet in length, and its larger base, one mile distant, is nine
thousand nine hundred and three feet. It has twenty-one
subdivisions. By combining those that lie more directly in
front of the jetties (viz. : seven to nineteen inclusive), and
PLATE 23.
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FINAl BESÜLTS.
221
making a comparison between the surveys of 1876 and 1879,
we find an excess of scour over tbe wbole area of seven hun¬
dred and seventy thousand and eighty-seven cubic yards, and
a mean increase in depth of 1.22 feet. The details of the
calculation are given in Table 1, Appendix 22. On the chart
the characteristic soundings only are given. If the subdivi¬
sions fifteen to nineteen inclusive are used as a basis for cal¬
culation, and the mean depths of the survey of 1879 are
compared with those of the Coast Survey of 1875, we find a
total scour of sixty-seven thousand one hundred and eight
cubic yards, and a mean increase in depth of 0.63 feet. (See
Table 2, Appendix 22.)
In June, 1879, Capt. Brown made a deep sea survey in
front of the jetties extending to a depth of three hundred
feet. A similar survey was made in August, 1876.
The soundings were taken on radial lines over a fan-
shaped area, extending a considerable distance eastward
of the jetties.
While the surveys will answer for an approximate compar¬
ison of results, the soundings do not give the exact depths
for two reasons :
First.—The distance which the heavy lead sinks into the
soft mud is a variable and unknown quantity.
After describing the method employed, which was that of
an ordinary lead and line, Capt. Brown states in his report ;
" The results are as reliable as can be obtained, except by
the slow and costly use of the accurate apparatus employed
by the Coast Survey, losing an iron shot at each cast. Still
it must be borne in mind that we have very little knowledge
of how far the lead sinks into the bottom, and we know that
this distance cannot be uniform over the whole area sur¬
veyed, and that it may not be quite the same in a certain lo¬
cality at different times." (See Annual Eeport of Capt.
Brown, June 30th, 1879, page 12.)
222
THE MISSISSIPPI JETTIES.
Second.—Cross currents exist in tlie gulf beyond tbe jetties,
which are caused by the outflowing current of fresh water
and the littoral or shore current of salt water nearly at right
angles with it.
This salt water current, having a velocity varying from one
to three feet per second, is sufSciently strong to sweep the
lead line to one side, making it impossible to obtain accurate
soundings. These currents are so variable at diflferent depths
and at different periods, that the ordinary methods of obtain¬
ing soundings cannot be relied upon in depths greater than
one hundred feet. The comparison of the two surveys, con¬
sidering five lines that nearly coincide in position, shows an
average advance of the contours seaward of four hundred and
ninety-five feet. On one of the five lines compared, the dis¬
crepancy between the two dates is so great that it ought not
to be included. Two of the lines are far to the eastward and
beyond the deepening influences of the jetties. The two re¬
maining lines lie in the track of the river discharge ; are
nearly in the prolongation of the jetties seaward, and from
their uniformity are alone capable of a fair comparison ; they
show, that instead of an advance of the contours seaward,
there has been a recession landward of three hundred and
forty-eight feet. Probably a greater recession would have
appeared had both surveys been made at the same time in
the year.
The channel results have been described and illustrated,
extending from May, 1875, to July, 1879. From the latter
date to the present time the channel has continued to im¬
prove. In several localities, especially between Station 6
and Station 100, where the twenty-six feet channel was but
very little more than two hundred feet in width in 1879, and
where the thirty feet channel was very narrow, the twenty-six
feet channel has now a least width of two hundred and sixty
feet, and the thirty feet channel has a least depth of thirty-
FINAL EESULTS.
223
one feet and a least width of sixty feet, with a width of three
hundred and sixty feet just inside the sea end of the jetties.
At the head of the passes a navigable channel twenty-six
feet deep and one hundred and sixty-five feet wide was ob¬
tained and certified to by Capt. Brown, on July 10th,
1879. Since that date the semi-monthly surveys show a con¬
stant increase both in depth and width. The twenty-six and
thirty feet curves on the west side of the channel, above the
dyke, have disappeared entirely. The thirty feet channel
now connects the deeper water of the river with that of the
South Pass, and its least width is over three hundred and
fifty feet. The channel into the pass is straight and navi¬
gable for the deepest draught vessels.
Thus very nearly the same depths and widths of channel
have been obtained at the head of the passes and at the
jetties.
The bar at the head of South Pass, described in Chapter
X., and which, with only fourteen feet of water over it, lay
like a formidable dam in the entrance channel, lias been com¬
pletely removed, and the depth of water into South Pass is
nearly two feet greater than that into the two larger passes
on either side of it.
At the mouth of South Pass the current, which in 1875
struggled feebly against the frictional resistance of the bar
that obstructed it, became by the construction of the jetties
a strong and living force, which, attacking the obstacle in its
way, swept it far out into the great depths of the gulf, and
carved out for itself a deep and wide channel more than equal
to the wants of commerce.
CHAPTEK XVII.
peemanency of woeks and eesults.
The permanency of tlio results obtained in the channel
through the jetties and in the gulf beyond them is a subject
of paramount importance.
The jetties have been built ; will they endure ? The chan¬
nel has been deepened ; the bar has disappeared, and the
whole sea-going commerce of the valley passes through the
jetties. Are these beneficial results permanent ? The sedi¬
mentary matters of the South Pass have for five years been
swept so far out to sea that no trace of them has been discov¬
ered in front of the jetties. Will those conditions continue ;
and will the causes that produced them exist in the future in
all their force ?
Many of the reasons for the permanency of all these re¬
sults have been given incidentally in the progress of the nar¬
rative. The wisdom in adopting the jetty plan has appeared
all through the history of the work, and we believe that, if
nothing further was said, the candid judgment of our readers
would uphold us in the opinion that the results described are
certain to be permanent. We will, however, state more fully
the conditions existing in the river and the gulf, that affect
the permanency of the works and their results.
The principal destructive forces to guard against are the
gulf waves and river currents.
During their construction the jetties have at times suffered
from the violence of the waves. On September 15th, 1875, a
224
PEEMANENCT OF WOEKS AND EESÜLTS.
225
severe storm visited South Pass. The vind vas from the
southeast, with a velocity of fifty-two miles per hour. The
waves wrecked about one thousand one hundred lineal feet of
mattresses that were floating in position along the east jetty
near Station 70, where they had been left for several days to
sink by accumulation of sediment in them. On December
30th, 1876, a violent storm from the southeast demolished
several of the temporary wing dams near the end of the jet¬
ties. The waves lifted off and destroyed the top courses of
the mattresses on both jetties beyond Station 115. On Sep¬
tember 17, 1877, a storm reached the jetties, lasting three
days. The maximum velocity of the wind was fifty-seven
miles an hour. Its direction at first was west southwest,
then changed to southeast, and from that point veered around
to the north. A damage of about $1,200 was inflicted on the
jetties by loss of stone and shattering of mattresses. Three
other violent storms subsequently visited the jetties, injuring
to some extent the top courses of mattresses. These storms
were generally accompanied and followed by storm tides,
which raised the surface of the water from one foot to eigh¬
teen inches above its ordinary level. These losses and dam¬
ages occurred during the incomplete state of the work, when
generally the mattresses, loaded with stone suflScient only to
sink them, presented an unprotected vertical face to the
waves. Since the construction of suitable slopes of mattress,
rock, and crib work around the sea ends of the jetties, and the
building of the massive blocks of concrete, there has been
no loss nor damage, although several violent storms have
brought a terriflc wave force against the works.
The height of storm waves at the mouth of the Mississippi
is from twelve to fifteen feet, measured from trough to crest.
Their force is considerably broken by the long gradual slope,
over which they travel before reaching the crest of the bar.
No danger from undermining of the jetties by the river cur-
15
226
THE MISSISSIPPI JETTIES.
rent need be apprehended, for by the construction of the
■wing dams, the channel has been located at a distance from
the jetty walls and nearly midway between them. The tend¬
ency has been and will continue to be, to form- deposits back
of the wing dams, and along the river side of the jetties,
which Avill remove the strong currents still further from the
permanent works. But even without the assistance of the
wing dams the channel would haA'e been formed nearly mid¬
way between the jetties, or at least such would ha^-e been its
permanent location. The same causes that formed the slop¬
ing banks of the river and passes, and placed the deepest
part of the channel equally distant from the banks, where the
course of the current is straight, would have accomplished
the same result in the jetty channel, with the bank on the
east slightly steeper than that on the west, owing to the curv¬
ature of the jetties. The currents near the jetties, sloived
by the friction of the rough mattresses and by the bottom
in the shoal water near the works, would have dropped
their sedimentary matters near the jetties, and thus still
farther increasing the velocity of the current in the centre
of the channel, would have slowly deepened it. The wing
dams hastened a result that natural causes would have pro¬
duced, so that when these temporary structures are allowed
to go to decay, the normal forces of the river will not only
preserve the present form of the channel, but still further
reduce the depth of water near the jetties and increase it
at a distance from them, and gradually rectify any irregu¬
larities in the channel alignment that the wing dams may
have produced.
Another destructive element, to which works built along
Southern sea coasts are generally subjected, is the " Teredo
Navalis," or sea worm, ivhich lives upon unprotected wood¬
work.
Captain Brown's examinations of willows obtained on the
PEEMANENCT OF WOEKS AND EESULTS.
227
sea side of tiie end of the east jetty, from a depth of about
eighteen feet, show, as he states, that the teredo enters the
willow stick when young through small holes no larger than
the puncture of a pin, and works along through the willow
lengthwise with the grain. " The avenues made by the
worms finally leave the willows a compact mass of nearly
parallel tubes, lined in many places with a calcareous sub¬
stance * ^ * much like a thin shell. This seems to
lend some degree of toughriess and strength to the damaged
wood. * * * Where considerable sediment has settled
on either flank of the jetties, the mattresses are mostly filled
with mud and sand, * * * and all specimens of wood I
have seen, known to have been completely buried in the mud,
are entirely free from worms or their traces."
The reports of the Boards of 1877 and 1879 confirm the
opinion of Capt. Brown, that the teredo cannot penetrate
into the body of the work, and they say : " The teredo does
not attack wood where the free access of sea Avater is im¬
peded. Those portions of a stick buried in mud or sand, or
packed around with mud or sand, are secure. We have no
reason to believe that the teredo has penetrated or can pen¬
etrate far into the interior of the mattress courses ; we have
pretty good reason to believe that the foundation matresses
are and will remain secure ; and probably also the bulk of
the interior of the masses of willow work." (See Appen¬
dix 18.) '
The subsidence or settlement of the jetties, especially at
their sea ends, is a subject of considerable importance.
It is evident from the record of the pile driving, given in
Chapter XII., that from the land's end to the crest of the
bar, any settlement recorded must be due to compression of
the mattress work.
Beyond the crest of the bar, where more recent deposits
had taken place, there is no doubt that during the earlier
228
THE MISSISSIPPI JETTIES.
stages of the work the foundation mattresses, on account of
the superposed weight of other mattress work and stone,
settled several feet into the foundation of mud on which they
rested, and it is possible that the foundation itself also set¬
tled from compression.
Oapt. Brown, in his report of July, 1877, speaking of the
end of the east jetty, which he says until lately had been
gradually sinking into the soft bottom beneath it, says : " The
former rapid rate of settlement has intermitted, at least, and
its cessation may be permanent." In his report of May, 1878,
he states that in five and a half months the subsidence of the
jetties is about six inches. In his report of June 30,1879, he
stated that the concrete blocks seemed to be sinking at an
average rate of from six inches to one foot yearly, but that it
was difficult to ascertain how much of this settlement was
due to condensation of the mass of the work, and how much
to other causes.
Levels taken by his assistants every month since the con¬
struction of the concrete blocks show, that between Station
103 and the end of the east jetty, the average settlement in
ten months was about five and one-half inches. The least
amount of subsidence of any one block was two inches, and
the greatest amount eight inches. On the west jetty the
average amount in nine months was four inches, the least
three-quarters of an inch, and the greatest eight inches.
The least subsidence of three-quarters of an inch occurred
about four hundred feet from the sea end of the jetty.
The irregularity in the degree of settlement in the blocks
of both jetties, shows that the subsidence is caused mainly
by compression of the mattress work, and not by its sink¬
ing into the foundation on which it rests, nor by the subsi¬
dence of the foundation itself, for if either of the two latter
were the causes, the settlement of the blocks would be
uniform, or at least in a gradually increasing ratio toward
PEEMANENCÏ OF WOEKS AND EESULTS.
229
the ends of the jetties. (The amount and rate of subsidence
of the concrete work is shown in detail in Appendix 23.)
Thus we see that the four destructive forces to which the
jetties are exposed, namely, gulf waves, river currents, the
teredo, and subsidence of the works, have not seriously
affected them during their construction and while incomplete
and unprotected.
The expected increase in the volume of water flowing
through the jetties will serve not only to perpetuate the re¬
sults obtained, but even to enlarge the channel. The full
normal section is not yet obtained. The average area of the
section of the pass above Grand Bayou was, in 1875, about
twenty-four thousand square feet. The present minimum
section of the jetty channel is twenty thousand square feet.
After the contraction of the entrance channel at the head
of the pass, there was during two years a gradual contraction
of the channel between the head of the pass and Grand
Bayou. Since 1878, the increase in the volume entering the
pass, due to the continued enlargement of the section between
the dykes, has not only prevented further contraction, but has
commenced an enlargement. The enlargement of the section
of the pass below Grand Bayou has been progressive since
the construction of the dam across that outlet. This is
shown very clearly by the annual surveys of the pass by Capt.
Brown.
The average depth of scour over the whole width of the
pass during the four years between June, 1875, and June,
1879, was 1.13 feet, and the amount of the material removed
was seven hundred and thirty-seven thousand five hundred
and thirty-six cubic yards.
The area of section in the jetty channel will, no doubt,
eventually be fully equal to that of the pass above Grand
Bayou. Mr. Eads and Sir Charles Hartley have from the
first contended that the channel through the jetties will be
230
THE MISSISSIPPI JETTIES.
even larger than that of the pass itself, and, in support of
their opinion, allude to the eflfect of the jetties at the Sulina
mouth of the Danube, which, though six hundred feet apart,
have produced a depth greater than that which exists in the
pass, where the Jjanks are but four hundred and fifty feet
apart.
The conditions at the mouth of the South Pass are still
more favorable on account of the tidal fiow, which sometimes
at the bottom attains a velocity of 1.5 feet per second, when
fiowing in, and a much greater velocity when flowing out.
The constant deposition of sediment, which has been going
on since the work commenced, will no doubt continue until
the embankments against both sides of the jetties have
everywhere, except at their extreme sea ends, reached the
height of average flood tide. This natural action, with the
artificial embankment of gravel, that has been placed above
the datum plane on the slope of rubble stone and against
the concrete blocks, will make the whole work impervious,
and render the jetties as tight as the. earthwork of the best
reservoir embankments.
The enlargement of the channel during the last ten months
is shown by the fact, that during the first five months after
the maximum channel was obtained, the channel was reported
by the inspecting officer to be deficient thirty-one days either
in width or in depth, but during the second five months not
a single day. There is every reason to anticipate a channel
much wider and deeper than now exists. The restoration
of the normal conditions at the head of the passes ; the in¬
flow of a greater volume of water ; the permanent closure of
Grand Bayou ; the final imperviousness of the jetties, and
the maintenance of these favorable conditions by the stabil¬
ity of the jetties and auxiliary works, insure for the future a
channel whose dimensions will be much beyond the require¬
ments of the law.
PEEMAKENCY OF WOEKS AOT) EESÜLTS.
231
In discussing the permanency of the results obtained in the
gulf beyond the jetties, it will be necessary to understand,
First.—The natural conditions that exist at the mouth of
the South Pass, and
Second.—The new conditions that haye been introduced by
the construction of the jetties.
The natural process and order of bar formation at the
mouths of the passes have been described in preceding chap¬
ters, in the description of the delta and in the discussions of
the causes that produced the bars. At the mouth of South
Pass the conditions differed in some respects from those of
the two larger passes. The volume of its discharge, and con¬
sequently that of its sedimentary matters, was much smaller ;
the slope of the outer crest of the bar was much steeper,
and the mud lump formation had nearly ceased.
The bars at the mouths of the two great passes are largely
composed of mud, while the bar at the mouth of South Pass
is of hard sand. The cause of this difference is to be found
in the fact that the power which wave action gives to sea
water to suspend sedimentary matters decreases with the
depth.
If we assume any given area, say one mile square, in front
of either one of the passes, it is fair to assume that for equal
depths the waves give to the water over such area an equal
•power to sustain the sediment. The lesser depth formerly
existing at South Pass would give a greater power of suspen¬
sion than that which the water possessed over the bars at
the greater passes.
The Southwest Pass discharges about four times the vol¬
ume of the South Pass ; therefore the wave action at the
Southwest Pass is less able to hold up in suspension and
leach out the lighter or muddy portions of the sediment dis¬
charged by the river. At the South Pass this leaching out
process being thoroughly accomplished, the sand alone re-
232
THE MISSISSIPPI JETTIES.
mains to form the bar, the lighter portions having been
swept far out to sea.
The existence of a littoral or shore current at the mouth
of South Pass, which has been most emphatically denied by
the opponents of the jetties, is clearly proven by the follow¬
ing facts :
In February, 1875, Prof. Henry Mitchell, of the United
States Coast Survey, made observations to decide this ques¬
tion. At the date of these observations the weather was
calm with a slight breeze from the north. He established
one section across the pass at the lighthouse, and another
about two thousand two hundred feet in length in twenty feet
of water, immediately beyond the crest of the bar, and paral¬
lel with the face of it. Careful gauging of the volume pass¬
ing through these sections gave twenty-three thousand five
hundred and forty-seven cubic feet per second at the light¬
house and one hundred and seven thousand five hundred and
ninety-six cubic feet per second at the section outside the bar.
This was more than four times as much as the former, although
a considerable portion of the volume had escaped laterally
over the outlying reefs before reaching the crest of the bar.
The average velocity, from surface to bottom, was thirty per
cent, greater than that at the lighthouse, and the maximum
velocity of the six feet depth was one hundred per cent,
greater. A defiection of the current to the westward Avas no¬
ticed. These observations proved the existence at that time
of either a littoral current or a race of the sea. (See U. S.
Coast Survey Keport, 1875, Appendix No. 11, page 189.)
On May 27th, 1874, Mr. Bayley published a letter in the
New Orleans Picayune, in which he gave some facts relative
to a littoral current. He referred to the captains of steam¬
ships and to the experience of fishermen, to prove that there
is a regular coastwise westerly current, except only when tem¬
porarily checked by westerly or southwesterly gales, and that
PERMANENCY OF WORKS AND RESULTS.
233
steamers make better runs westward tban eastward. He re¬
ferred to the Coast Survey report of 1853, to show that impor¬
tant changes at the Grand Pass entrance to Barrataria Bay
were caused by the strong westerly currents of the gulf. He
says further " modern current charts correctly represent the
great equatorial current, as sweeping in its resistless course
around the Gulf of Mexico, across and near the mouths of the
passes, and that an eddy current commences there and flows
westward along the Louisiana coast."
Observations and experience during the construction of
the jetties show that the shore current which exists there
is not always westward, but under the influence of westerly
winds, has sometimes been found to be qliite strong to the
eastward.
On March 13th, 1878, Captain Brown found a current of
three feet per second at the bottom, moving to the eastward.
The location of his observation was six hundred feet beyond
the end of the jetties, in twenty-eight feet depth of water.
The surface current of fresh water was moving straight out.
But the prevalence of the westerly current, which is doubt¬
less due principally to the prevailing winds, is shown by the
fact that the drift logs of the Mississippi Eiver, drift lumber
from the jetties, and the buoys along the delta that break
from their fastenings, are found invariably along the coast of
western Louisiana and Texas.
We have thus given the natural conditions, as far as relates
to bar formation, wave force and current action. The jetty
construction has, however, brought with it the following new
conditions :
First.—Wheve there was formerly a sluggish river current
about eight feet deep, there is now at flood river a swift cur¬
rent over thirty feet deep ; and
Secotwl.—The protrusion of the jetty walls into the salt
water currents has greatly increased them on the same prin-
234
THE MISSISSIPPI JETTIES.
ciple tliat a dyke built out into a river current will greatly
increase its velocity opposite the end of the dyke. The
strong volume of fresh water flowing out of the jetties can¬
not be thrust aside at once by the cross current of salt water,
nor can the volume of salt water sweeping with great force
past the end of the jetties be held back by this volume of
fresh water, which, like a great obstruction, is thrust out into
it. The result of these two forces, meeting at right angles
nearly, is a depression of the salt water current into the un¬
stable gulf bottom, and a consequent scour and removal of
the material to restore the sectional area. This action at
high river nearly counterbalances the depositing action,
and dui'ing low river the quickening of the gulf currents
caused by the jetty walls projecting into the sea, is shown by
the marked deepening that always occurs at such seasons,
and by the invariable recession of the face of the bar. The
influence of the new conditions created by the works of im¬
provement upon the outlying ridges, shoals and lumps was
very clearly exhibited by two models prepared in plaster for
the Paris exposition of 1877, by Mr. Schmidt. These models
represented the condition of the South Pass bar in 1875 and
1877 respectively. The marked elevations existing at the
former date beyond the crest of the bar, had been leveled
and reduced in all their dimensions by the deeper flowing
volume of the river and the stronger cross currents of the
gulf.
Thus the leveling and disturbing influences of the waves,
and the eroding influences of the salt water currents and the
river floods, have for five years prevented an advance of the
bar. In place of pushing the bar into the gulf at the rate of
six hundred feet per annum, or a total distance of three thou¬
sand feet, as was predicted by Gen. Humphreys, the jetties
have not only cut the bar entirely away and stopped its ad¬
vance, but have deepened the gulf beyond them.
PEEMANENCY OF WOEKS AND EESULTS.
235
The commercial benefits obtained by the construction of
the jetties have been no less marked than the natural results.
Five years ago the vessels, when loaded to eighteen feet
even, were with great difficulty towed through the narrow
ditch dug by the government dredges at the mouth of the
Southwest Pass, or were delayed for days while the bar was
blocked with other vessels. Now the Great Eastern can pass
in or out with safety. A record of the navigation of South
Pass is given in Appendix 24. A study of this table shows
the following : namely, that since the opening of the pass to
navigation in 1877, and the discontinuance of work by the
government dredge boats at Southwest Pass in August of
that year, there has been a considerable increase in the num¬
ber of vessels crossing the bar, especially of steamers, and
also a great increase in draft.
The steamers increased in number from five hundred and
eighty-seven in 1877, to eight hundred and forty in 1879, and
the number drawing from twenty to twenty-four feet in¬
creased from eleven to one hundred and thirty-four in the
same period, of which number fourteen drew twenty-three
feet and over. The maximum draft of 24' 6" was that of the
steamship City of Bristol, of the Inman Line, on October
31st, 1879.
The increase in exportation from one source alone may be
seen by the followmg extract from the annual statement of
the " Trade and Commerce of St. Louis " for the year 1879
reported to the Merchant's Exchange of that city. " Direct
shipments to foreign countries from St. Louis, in tons, by rail
through the Atlantic ports, and by river through New Orleans :
1879.
1878.
1875.
Total, in tons, by rail
185,881
73,091
16,825
Via river, to New Orleans to Europe
176,531
154,060
6.857
236
THE MISSISSIPPI JETTIES.
This statement shows that the increase in exports via the
mouth of the river is three times greater than that by rail to
the Atlantic seaboard in the time mentioned.
The benefits that have accrued already to the agriculture
and commerce of the Mississippi Valley are clearly shown
by the following extracts from a letter dated New Orleans,
La., May 28th, 1880, and addressed to the author by Gen.
Cyrus Bussey, an eminent merchant and President of the
Chamber of Commerce of that city, and one of the early
friends of the jetty enterprise :
" Since the completion of the jetties there have been no
complaints of detentions at the mouth of the river. Vessels
of the largest class pass through the jetties fully loaded with¬
out touching the bar ; to illustrate, reference is called to the
steamship Australian which sailed from New Orleans, May
the 11th, drawing twenty-three and a half feet, with a cargo
of four million and eighty-six pounds, equivalent to eight
thousand two hundred and twenty bales of cotton.
" During the month of May vessels drawing twenty-three
and one-half feet have arrived at this port, bringing large
cargoes of merchandise, which have greatly increased the
value of the imports at the port of New Orleans since the
completion of the jetties. The effect of the jetties on the
transportation lines of the country cannot yet be estimated ;
that the effect has been to lower the rates on all transportation
routes from the Mississippi Eiver to the seaboard, cannot be
denied. Prior to the construction of the jetties the commerce
between New Orleans and foreign countries was carried on
by vessels which could not load deeper than eighteen to
nineteen feet, and then they ran great risk of detention for
an indefinite time before getting to sea. These facts prevented
many vessels from coming to this port ; those that did come
demanded and received high rates of freight, five-eighths
penny to seven-sixteenths penny per pound for cotton to
PEEMANENCY OF WOEKS AND EESULTS.
237
Liverpool, and twelve pence per bushel for grain. During
the past season the rates have been one-quarter penny to
three-eigbtbs penny per pound for cotton, and seven pence
per bushel for grain, while the exports have been largely in¬
creased, amounting to over one million seven hundred thou¬
sand bales of cotton against one million four hundred thou¬
sand last year, while the shipments of grain have more than
trebled those of the year 1878, and are rapidly increasing.
" Large fleets of barges are being built to carry grain from
St. Louis and other points on the Mississippi Eiver to New
Orleans; while at this port the facilities for handling and
storing grain are being greatly increased ; floating elevators
of immense power are being constructed, while new elevators
of very large capacity are to be constructed on land ; the
large elevator which stood empty for years before the jetties
were constructed, is now full, and there is a demand for stor¬
age capacity equal to half a million bushels, which cannot be
supplied.
" The low freights made possible by the jetties have
effected this large increase in the exports from this port.
The saving on the freight on the cotton, grain, cotton seed,
oil, oil cake, and other articles, including staves, etc., ex¬
ported from New Orleans for the year ending 31st August,
1880, will exceed $4,000,000 over the freights that would have
had to be paid, if the jetties had not been constructed. This
is not the only saving ; there has been a reduction in the
rates of insurance, and a perceptible saving in time, which is
an important consideration, as the value of the cargo of a
ship is on interest until it is delivered to the consignee and
sold. There being no longer any detention on the bar at the
mouth of the river, we hear no complaints of heated cargoes
of grain arriving in foreign ports from New Orleans. The
good character of the grain shipments from this port is fully
established. If, in addition to other advantages, we consider
238
THE MISSISSIPPI JETTIES.
the reduction in freights on the river transportation, caused
by larger cargoes being cari-ied, owing to the increased de¬
mand caused by the jetties, we may safely estimate that the
sum saved to the producers in the Mississippi Valley, on that
portion of their productions finding a market through New
Orleans, amounts to five million dollars annnally. The value
of the jetties to the commerce of the whole country cannot
be estimated."
Not only should the reduction of freights on products that
are shipped via New Orleans be credited to the jetties, but
also on all those products whose natural route to market is
by the Mississippi River, but which find their way to the
Atlantic seaports by the various railway lines, for they have
been forced by the jetties to reduce their rates to compete
with those of the river. Therefore, the annual saving as es¬
timated by Gen. Bussy as resulting from the jetties should
be largely increased.
"Westward the course of Empire takes its way." Already
three-eighths of the whole cotton crop of the United States is
grown west of the Mississippi River. In 1849 the center of
the wheat-growing belt was east of Cleveland, and that of the
corn-growing belt between Cincinnati and Louisville.
At the present time the center of both belts is west of the
Mississippi; the production of wheat reaching now about
400,000,000 bushels per annum, and corn about 1,500,000,000.
This westward movement of the grain center increases the
cost of transporting the grain to the Eastern ports by rail,
and draws these immense productions toward their natural
outlet to the world, via the Mississippi River.
These natural and inevitable tendencies of agriculture and
commerce have already accomplished the improvement of
the month of the river, and they now demand the removal of
all obstructions in this great commercial highway of the
nation, from New Orleans to St. Louis.
CHAPTEE XVHL
conclusion.
As this history draws to a close, it is proper to mention
those who have been the friends of an enterprise, that by
overcoming all financial and natural obstacles, has accom¬
plished results of such great importance to the country.
The record commences with those to whom this work is
dedicated. In no legislation during the past ten years has
the wisdom of our lawgivers and the executive officers of the
government been more clearly shown, than in the enactment
and execution of those laws that pertain to the work that has
given the commerce of the Mississippi Valley an open eiveb
mouth.
Among the merchants, bankers, capitalists, manufacturers,
and others who assisted the enterprise in various ways, stand
out prominently the individual associates of Mr. Eads and
the stockholders of the South Pass Jetty Company, who in¬
vested their money in the jetties at a time when they were
considered a doubtful experiment, and who were willing to
trust to the success of the enterprise for the return of their
investment.
The civil engineers of America and Europe, with a few ex¬
ceptions, favored the jetty plan and gave it their hearty sup¬
port. The members of the American Society of Cml Engi¬
neers, especially, evinced a deep interest in the work, and
visited it during their annual convention at New Orleans in
1877. They, above all others, have reason to honor the
239
240
THE M SSISSIPPI JETTIES.
illustrious member of tbeir society -wbo, in Congress, gained
for tliem a signal victory by establishing the precedent of in¬
trusting our national hydraulic works to civil engineers, who
are especially fitted by education and experience for the dis¬
charge of such important duties.
The laborious scientific investigations of Capt. M. E.
Brown, United States Inspecting Officer, constitute a valu¬
able contribution to the science of civil engineering, and while
they reflect credit upon the patience and skill of that officer,
they furnish proof of the correctness of those theories upon
which the expectation of the success of the works was based.
Though a great sufferer from health impaired on other
works, he performed faithfully for four years the duties de¬
volving upon him. He died at his home in Lawrence, Mass.,
April 10th, 1880.
During his long and enforced absence at various times, the
surveys and office work were intrusted to Mr. C. Donovan,
his chief assistant, whose experience and good judgment es¬
pecially fitted him for the peculiar and difficult position in
which he was placed.
The author, as the resident engineer, desires to place on
record the efficiency and faithfulness of his own Engineer
Corps—Max E. Schmidt, W. Leslie Webb, W. S. Morton,
H. W. Parkhurst, E. A. Gladding, A. O. Wilson, and Willard
Lawes—whose zealous interest in the performance of their
duties greatly lightened his own labors and responsibilities.
In closing this record of honorable mention we allude
briefly to the employees, who by arduous and faithful labor
established a claim to high regard. The list of their names,
which, if space permitted, might be greatly extended, is given
in Appendix 25, that wherever this record of a great work
goes, it may be known whose faithful labor performed the
work that has accomplished such beneficial results.
More than to any other person engaged in the construction
CONCLUSION.
241
tlie jetties are indebted to Mr. James Andrews. He not
only embarked his private fortune in the work, and aided it
by his knowledge and long experience on public Avorks, but
with a remarkable energy he pushed it forward to comple¬
tion. Through all the vicissitudes of the work, often dis¬
heartening, he preserved not only a steadfastness of purpose
and an integrity of character, but such a persistent determin¬
ation to achieve success in spite of all opposing influences,
that he inspired and maintained confidence in the minds of
all his associates in the enterprise, and thus contributed
most efficiently to its successful issue.
However great the praise due to others, too high a tribute
cannot be paid to James B. Eads, who conceived the jetty
project and secured its adoption, and to the triumphal com¬
pletion of which he so earnestly deA'oted himself.
The deep and permanent channel at the mouth of the Mis¬
sissippi Kiver is an imperishable monument to his genius.
With a few words to express our utmost confidence in the
principles which have been demonstrated by the works we
have described, and whose success we have chronicled, we
close this history of their construction.
In a score of centuries the South Pass jetties may be bur¬
ied beneath the vast deposits, which the rh^er floods will ac¬
cumulate upon and even beyond them, as the delta advances
into the gulf, and it may be necessary for some generation in
the distant future to repeat the work of this ; but the jetty jjrin-
dple has been so clearly proven to be in perfect harmony with
the laws of nature, that either at the mouth of the South Pass,
or some pass of the Mississippi Eiver, jetties will be main¬
tained forever. So long as the husbandman tills the soil
of the great valley, so long shall he find for his produc¬
tions a natural highway to the world through an open river
mouth.
16
APPENDIX.
APPENDIX 1.
(See page 21)
Exteacts from Reports upon Fort St. Philip Canal and Construction
of Jetties for the Improvement of the Mouths of the Mississippi;
being Appendix R (in part) of the Annual Report of the Chief op
Engineers foe 1874.
Beport of Board of Engineers on the improvement of the passes as an alterna¬
tive to, or in connection with the canal.
New York, January 13, 1874.
The Board of Engineers convened by Special Orders No. 83, headquarters
Corps of Engineers, Washington, D. C., dated June 30th, 1873, to report upon
the project of a ship-canal to connect the Mississippi River with the deep
waters of the Gulf of Mexico, having had the matters referred to them extended
by the following instructions, viz. :
Office of the Chief op E.ngineers,
Washington, D. C., October 3,1873.
Sir : In reply to your letter of the 24th ultimo, I am directed by the Chief
of Engineers to say that it is allowable and desirable to have the views of the
Board of Engineers on the question as to the expediency of improving the nav¬
igable outlet of the Mississippi, by the Port St. Philip Canal, as an alternative
to, or a simultaneous measure, perhaps, with the improvement of the passes.
The report of Capt. Talcott, of January 30th, is in the hands of the copyist,
and will be furnished you as soon as possible.
Very respectfully your obedient servant,
John G. Parke,
Major of Engineers ;
Col. J. G. Barnard,
Corps of Engineers,
have the honor to submit this report :
The improvement of the passes has usually been discussed in reference to
the application to them of the jetty system, or of dredging, in conjunction
243
244
THE MISSISSIPPI JETTIES.
■with each other, or separately, and the board propose to confine their attention
to these methods.
The depth o£ ■water over the bar to serve for commercial, naval, and mili¬
tary purposes, it is assumed, should be the same as that selected for the
draught over the miter-sill of the proposed ship canal, viz., twenty-five feet at
extreme low water of the gulf. The pass to be improved is assumed to be Pass á
Loutre ; this having been selected by several engineers advocating the improve¬
ment of the mouths of the Mississippi as the best adapted to the application of
the jetty system.
In order to advance the low-water twenty-five foot curve of the channel of
the pass from the point where this depth ceases to obtain to the bar, it would
be necessary to construct parallel jetties, of the same distance apart as the
shore-lines of the pass where the required depth is excavated.
These considerations fix the length of each jetty at about twenty-four thou¬
sand feet, and the distance apart two thousand two hundred feet.
The top of the jetties must be held low, not higher than the banks from
which they extend, because additional height, while adding to their cost, would
not induce the passage of more water between them so long as the banks of the
river above are at a lower level. An elevation of the jetties above the banks
from which they spring would, in fact, endanger the latter in the presence of
a rise overtopping them, especially at the points where the jetties and banks
unite.
The debouch of Pass à Loutre by two mouths makes it necessary to close
one of them, and this operation is supposed to be performed by the north jetty,
constructed across the northern mouth.
An inspection of the map of the pass, to fix in the mind the necessary
course of the northern jetty, will show that thé present direction of the run¬
ning waters will be deflected by this work, which forms a concave bend to re¬
ceive them, and a considerable scour of the bank must necessarily ensue,
causing the foundations of the jetty to be undermined, unless eSective meas¬
ures are taken to prevent such catastrophe.
The Board are unable at this time to suggest any remedy except to sink the
foundations deep enough to be out of reach of these influences. As to how
great this depth should be to insure safety, the Board have no certain means
of judging, but it may be twenty-five feet, or even more.
The closing of the northern mouth, which, following the line of jetty would
be a work operating to deflect the present direction of the currents, and over
seven thousand feet in length, is an undertaking of great delicacy, the cost of
which, in a soil of the character pertaining to this locality, might prove to be
excessive. Success in this operation is, however, necessary to the application
of the jetty system t» the pass under consideration, and must be sought at
whatever cost, in order to accomplish the desired improvement of navigation.
It is important to say that the advance of the jetties, step by step, will cause
deep holes to form at their extremities, due to the escape of the waters as soon
as released, and a consequent excavation of the loose soil, which will much in¬
crease the depth and cost of these works.
The dislodgment, by the operation of the jetties, of the immense quantities
of material from the sides and bottom of the channel would bring the scouring
force into contact with the interior of the banks and shoals, which consist gen-
BOARD OF 1874
245
erally of soil inferior in hardness and fii-mness ; and it would be impossible so
to fix the limits of this disturbing action that it might not often reach the jet¬
ties themselves.
The long, low banks and the shoals of the delta do not owe their existence or
permanence to anything inherent in the strength and consistence of the soil
composing them—for on these points all testimony agrees—but upon the action
of the waves and currents, constituting an area of equilibrium, in which the
particles are deposited and retained.
But as these forces are not always as to effect, but only periodically, in
equilibrium, it necessarily follows that changes in the shoals and banks are
constantly occurring, not enough, indeed, to interfere with the general devel¬
opment of the delta, which appears to advance by virtue of uniform laws, but
quite sufficient to endanger and even destroy the most skillfully designed works.
This consideration of the unstable and treacherous nature of the shoals and
banks is necessary in order to fix the mind upon the cost and risk as well as
upon the disappointment which would likely attend an attempt, upon such
foundations, to construct works to coerce or control the currents of the passes.
An estimate has been prepared by Capt. Howell, engineer in charge of
the jetties described in this report, supposing them to rest upon the natural
bottom, without settlement, as follows :
Fascines and ballast, at $5 per cubic yard $2,545,320 00
Riprap stone, $7 per ton 2,241,097 CO
Total $4,780,317 CO
If settlement and the other probabilities enhancing the cost of this work, as
already discussed, be considered, it appears entirely within limits to state that
the above estimate should be doubled.
Assuming that it will take about four years to complete the jetties to the
present twenty-flve-foot curve outside the bar, and estimating the least yearly
advance of the bar at two hundred and fifty feet, it would be proper to add to
the estimate already the cost of two thousand linear feet, equal to $68,888.
There is, besides, the estimate for future annual extensions to keep pace
with an increased advance of the bar, which by the same authority would be
$1,013 per linear foot of jetty.
The next step in order is to consider the effects of these jetties, supposed to
terminate at the curve of twenty-five feet outside the bar, upon the depth of
water in the channel and upon the bar; and it will be first supposed that the
jetties, if projected too far apart, should near the bar be brought together '
sufficiently close to insure the desired scouring effect upon the bar.
Would this state of things, thus produced, endure for a considerable time,
or for a period sufficient to fill up the deep space ahead in the gulf to a dis- '
tance equal to the present interval between the termination of the twenty-flve-
foot curve in the channel and the outer crest of the bar ?
The principles upon which a reply to these questions depends have been ex¬
haustively treated in Chapter VIII of Humphrey's and Abbott's Report on the
Physics and Hydraulics of the Mississippi River; and there is nothing more to
add, except the conclusions which follow from that report.
Let us suppose, as the first effects of the jetties, the twenty-flve-foot curve
246
THE MISSISSIPPI JETTIES.
to have advanced to the original enter crest of the bar. It will be found that
the position of the crest has already advanced, due to the large amount exca¬
vated from the sides and bottom of the channel, and the ordinary supply of
materials which are rolled on the bottom and deposited on the outer slope ; and
it is not certain that there would be a full depth of twenty-five feet at the new
crest, on account of the tendency to form the upper surface of this deposit co¬
inciding with the angle at which the river waters emerging from between the
pier heads would be defiected upward by the waters of the gulf, an effect
which the spread of the river waters, after their release from the confinement
of the jetties would increase. The succeeding flood, while advancing the bar,
should upon the same principles, still further decrease the depth over its outer
crest; and every advance of the bar would be followed by a similar result.
Hence the jetties, in order to retain the depth gained, should keep pace in
their extension with the progress of the bar. At high water of river, the de¬
posits are made exteriorly; at low water, interiorly. During the changes
from high to low water, the deposits are made between these two, or on what
is ordinarily considered the bar.
A condition of things likely to occur periodically, whereby a medium stage
of the river, without high floods, might be maintained, would cause unusual
deposits upon the bar; and hence an additional reason for the conclusion, ap¬
parent already from the first portion of thia discussion upon the bar, that in
order to secure, at all times, a depth of twenty-five feet, provision should be
made in the arrangement of the jetties to excavate to a depth greater than
that. « * * *
The difficulties at the mouth of the Mississippi, so far as concerns the im¬
provement by jetties, resolve themselves into three sources :
1. The absence of a littoral current.
S. The yielding nature of the banks and shoals.
3. The abundance of deposits.
The first and third combine in the yearly and rapid extension of the bar,
and compel the works of improvement to continue at a heavy annual cost un¬
til their entire abandonment.
The second makes their construction difficult and their maintenance improb¬
able, unless deeply founded at a very heavy expense.
All the principal objections to the improvement of Pass à Loutre necessarily
apply to the Southwest Pass. * * * *
Upon a review of the practical difficulties which the adoption of the jetty
system of improvement at the mouth of the Mississippi would entail, and a
due consideration of the original cost of construction and of annual extension,
entertaining doubts, moreover, of the successful issue of the attempt, the
Board does not consider it advisable to recommend it.
With regard to the cost of this operation, owing to the uncertain nature of
the problem, made so by the peculiar risks attending it, the Board find it im¬
possible to fix any Reliable limits.
The estimate in this report, made upon a hypothesis favorable to the pro¬
ject, indeed, but which does not exist, is useful only to convey to the mind
some idea of the magnitude of the undertaking.
As an auxiliary to the improvement by jetties of the mouths, dredge-boats
must be employed to remove mhd-lumps.
BOAEß OP 187á;
247
The other means of improving the depth at the mouths, by the stirring-up
process, has already been put to the test of practice. * # *
The effect of the stirring-up process is to sift out the finer, leaving on the
bottom the heavier, sandy particles, thus forming a surface harder than the
natural one of the bar. Nevertheless, vessels puUed with powerful tugs are
drawn through with a draught greater by one foot than the depth of the chan¬
nel. This operation would not generally succeed with long, sea-going steamers.
The results so far do not warrant the Board in estimating a greater depth
than eighteen feet at extreme low water as capable of being maintained at the
passes by means of the stirring process. This is inadequate to the require¬
ments of the naval, military, and commercial services.
Although the stirring-up process cannot, therefore, be made a substitute for
a project affording the proper depth, it should be continued until such project
shall have been completed.
It is understood that one member of the Board of 1853—Maj. Chase (now
deceased)—was in favor of the canal project, (Note D.) Another member,
Maj. Beauregard, has expressed his opinion very emphatically in favor of a
ship-canal, and doubtfully as to the jetty system. This testimony is valuable,
as springing from the matured judgment of an experienced engineer, well ac¬
quainted with the subject he discusses, and is an evidence of a prevailing con¬
viction which points to the fact that the time has come for obtaining an outlet
to the ocean of depth sufficient to meet the necessities of the great valley of the
Mississippi, and that the canal offers the best and most certain means of attain¬
ing this result.
JoHX Newton,
of Engineers, Brevet Maj. Ben.
Q. A. Gilumore,
of Engineers, Brevet Maj. Gen.
Wm. p. Craighill,
Maj. of Engineers.
G. "Weitzel,
of Engineers, Brevet Maj. Gen.
C. W. Howell,
Capt. of Engineers, Brevet Maj.
Not fully concurring in the above, my views will be submitted in a separate
report.
J. G. Barnard,
Col. of Engineers and Brevet Maj. Gen.
Minority Report of Col. J. G. Barnard, Corps of Engineers.
In turning to the subject of jetties, I do not know how I can better define
at the outset my position in relation to them than by quoting from the draught
of a report which has been submitted to the Board, and which has already
passed through your hands :
I can only reason on probcdiilities deduced from study of the river and the
Lieut. Col.
Maj.
Maj.
248
THE MISSISSIPPI JETTIES.
lights of experience; and so long as to establish the negatÍTe there has heen,
I need not say, no trial of the system, but not even a survey accompanied with
a careful study and experiments, directed expressly to develop the cost and
character of the work needed, I feel that \ am justified in recommending it as
probably furnishing the most speedy attainment of a deep-water channel, and
one which will have some features of permanence.
In a passage already quoted from the report of the Board of 1853, the ra¬
tionale of the jetty system is explained. I further cite from the " Physics and
Hydraulics of the Mississippi " the following:
" The development of the laws which govern the formation of the bars has
removed all uncertainty as to the principles which should guide an attempt to
deepen the channel over them. The erosive or excavating power of the current
must be increased relatively to the depositing action. This may be done either
by increasing the absolute velocity of the current over the bar or by artificially
aiding its action. To the first class of w orks belong jetties and the closure of
lateral outlets ; to the latter stirring up the bottom by suitable machinery,
blasting, dragging the material seaward, and dredging by buckets. These
plans are all correct in theory, and the selection from them should be gov¬
erned by economical considerations."
Such is the theory, and no engineer has yet expressed a doubt as to the
fact that concentration of the waters of one of the passes by jetties carried
out to deep water would excavate the required deep channel. The difficulty
and the cost of construction, the alleged necessity of costly annual extension,
furnish the arguments why this method should not be resorted to. While the
general laws which govern the formation of bars at river-mouths are universal,
there are peculiarities in the formation duo to the natural differences of char¬
acter of the rivers and of the sea-shore where the mouth is situated. If the
shore be itself sand or gravel, and not rock, a bar always forms, whether the
river brings down sediment or not. The latter material cannot, therefore, be
regarded as in any sense the cause of the bar, though when it exists it is found
to be the material of which the bar is composed. The most intractable bars
are usually found to be of the former class; and yet, with few exceptions,
every harbor on our northern lakes constituted by a river or creek mouth has
been improved by the construction of parallel jetties. That those jetties need
sometimes to be is no denial of their efficacy. * * »
On the other hand, the very rapid deepening of the Gulf immediately off
the bars, and the favorable exposure of their external slopes to the action of
the sea-waves and currents generated by easterly storm-winds, are circum¬
stances decidedly favorable. Surely there is ground here, especially when
we weigh the inestimable benefit of an open river kouth, to pause at least
long enough for a mature study and investigation, not merely on paper,
but by surveys and measurement at the localities, to collect the special data
which bear upon the application of the project to them, instead of, by a hasty
pre-judgment founded on inadequate knowledge, deciding that there is no
remedy to the evils but the gigantic and costly alternative of a ship-canal.
It is proper, however, to allude to the more prominent objections. One of
them is based upon the following, from "Physics and Hydraulics of the Mis¬
sissippi : "
" If the excavating power and depositing action of the Southwest Pass had
EOAED OF 1874,
249
been equal when the yearly advance of the bar was seven hundred feet instead
of three hundred and thirty-eight feet, the least depth upon it would have been
twenty-one feet. This increase of excavating power may be obtained by con¬
structing two converging jetties, beginning where the depth of twenty-two
feet is found, and extended to that depth outside the crest of the bar, which
would give them a length of about 3.5 miles. # * * ♦
" The depth of twenty-one feet thus obtained must be maintained by the
annual extension of the jetties seven hundred feet into the Gulf."
This dictum is founded upon a theory of bar-formation, which is doubtless
true, and yet does not contain the whole truth ; for were the Gulf waters fresh
and of same specific gravity as those of the river, there would still be a bar;
moreover, the stretching of any theory of so complicated phenomena to nu¬
merical results is generally putting upon it more than it will bear. * *
I am not called upon to make a plan or an estimate. If successful at all,
(and I have endeavored to show that success is promised,) the cost will be a
small fraction of that of the canal. On the other hand, the advantages of an
open river-mouth are inestimable. The needs of a navigation so great as that
which now exists, and which in the future of the great Mississippi Valley
must be fifty-fold increased, demand it.
It is said, that " the time has come " when the needs of commerce demand
the canal ; but I answer that the lime will come when there will be the same
cry for a navigation unimpeded by locks—an open eiver-jiouth—which we
now hear for a canal. But in whatever aspect the question be regarded, the
use of the river-mouth for the next ten years is simply inevitable.
The conditions of the location and execution of a canal have received no
adequate study. The plan, boldly and ably, yet so imperfectly, sketched out
nearly forty years ago by one for seventeen years my commanding officer or
professional associate, W. H. Chase, is yet, in its engineering features, the best
plan extant ; and the grave objections to that apply with even greater force to
the present project, and demand new studies of location and an entire revision
of plans of execution. It would be a rash confidence which would contem¬
plate a realized "Port St. Philip Ship-Canal " earlier than A. D. 1884.
In the mean time shall the routes of commerce of the great West be yet
more eSectually than now diverted to the Atlantic ports; or shall the public
confidence be directed to the present adequacy of the operations upon the bars ;
and shall the problem, which sooner or later must come, of na open river-mouth,
be solved ?
Respectfully submitted.
J. G. Barnard,
Col. of Engineers and Bvt. JUaJ. Gen., President of Board.
Brig. Gen. A. A. IIumphreys,
Chief of Engineers, U. S. A.
Minority report of May. G. K. "Warren, Corps of Engineers.
Engineer's Office, United States Army,
Newport, R. I., Januaiy 15, 1874.
General; As a member of the Board of Engineers considering the Fort
St. Philip Canal project for connecting the deep waters of the Mississippi
250
TEE SnSSISSIPPI JETTIES.
River and the Gulf of Mexico, directed bv you to also consider the alternative
proposition of making this connection by deepening the water over the bars in
the natural outlets, I beg leave to say that on this last proposition I do not
feel possessed of the data for a detailed report, nor do I see how these can be
obtained but by costly experience. Any conclusions reached now must un¬
avoidably rest upon what is, in a measure, assumed, and opposite conclusions
will be reached by others using the same liberty.
My mind, however, is fixed upon the idea that the canal is the only project
that will meet the commercial, naval, and military demands of the United
States. Its feasibility has never been doubted by any one, and only on account
of its cost have other methods been heretofore recommended. These other
methods have always been regarded as experiments, and the reliance has been
that, if they failed, the canal, as a final resort, was certain.
I believe the time has come when that which appears certain should be tried
first.
The cost of the canal will not be great compared with the end to be gained;
and there is no certainty that we will not have to come to it after great delay
and expenditure upon other methods, none of which, when abandoned, will
have aided in the least toward constructing the canal.
Very respectfully,
G. K. Warren,
Maj. of Engineers, Bvt. Maj. Oen. U. S. A.
Brig. Gen. A. A. Humphreys,
Chief of Engineers, U. S. A.
APPEXDIX II.
(See page 60.)
Report op Board of Engineers Relating to Improvement of the Mouth
of the Mississippi River by Jetties ; being Appendix S (in part) of
the Annual Report of the Chief of Engineers for 1875.
(General Orders No. 74.)
War Department, Adjutant-General's Office,
Washington, July 2, 1874.
Lieut. Col. H. G. Wright, Lieut. Col. B. S. Alexander, and Maj. C. B. •
Comstoek, Corps of Engineers, United States Army; Professor Henry Mitchell,
United States Coast Survey; T. E. Sickels, W. Milnor Roberts, and H. D.
Whitcomb, are, by the President, hereby appointed a board of engineers under
provisions of section three of the act approved June 23, 1874, entitled "An
act making appropriations for the repair, preservation and completion of
certain public works on rivers and harbors, and for other purposes," for the
purpose of making "a survey of the mouth of the Mississippi River, with a
view to determine the' best method of obtaining and maintaining a depth
of water sufficient for the purposes of commerce, either by a canal from said
river to the waters of the Gulf, or by deepening one or more of the natural
outlets of said river." They are hereby directed to assemble at New York
City, N. Y., on the 20th instant, or as soon thereafter as practicable, for the
purpose of organizing and entering upon the performance of their duties.
Lieut. Col. Wriglit is designated as president of the Board.
H. D. Whitcomb is designated to disburse, under the direction of the Board,
the money appropriated to defray the cost of the survey.
The following is the section of the act of Congress above referred to :
" Sec. 8. That a board of engineers, to be composed of three from the Army,
one from the Coast Survey, and three from civil life, be appointed by the
President ; which said board shall make a survey of the mouth of the Missis¬
sippi River, with a view to determine the best method of obtaining and
maintaining a depth of water sufficient for the purposes of commerce, either
by a canal from said river to the waters of the Gulf, or by deepening one or
more of the natural outlets of said river; and said Board shall make a full and
detailed estimate and statement of the cost of each of said plans, and shall
report the same, together with their opinion thereon, showing which of all
said plans they deem preferable, giving their reasons therefor, to the Secretary
251
252
THE MISSISSIPPI JETTIES.
of War, to bo presented at the commencement of the second session of the
Forty-third Congress; and that the sum of twenty-five thousand dollars, or so
much thereof as may be necessaiy, is hereby appropriated, out of any funds in
the treasury not otherwise appropriated, to defray the cost of said survey."
Approved June 23, 1874.
By order of the Secretary of War :
Thomas M. Vincent,
Assistant Adjutant-General.
New York, January 1^, 1875.
Sir : The Board of Engineers, constituted under section 8 of an act of Con¬
gress, approved June 23, 1874, having completed its labors, has the honor to
submit the following report :
The act of Congress referred to required that the Board should make plans
and estimates for the cost of obtaining and maintaining a depth of water
sufficient for purposes of commerce at the mouth of the Mississippi River,
either by a canal from said river to the waters of the Gulf, or by deepening one
or more of the natural outlets of said river, and to report the same, together
with their opinion thereon, showing which of all said plans they deem prefer¬
able.
The Board was ordered by the Secretary of War to meet on July 20, 1874, at
New York City. It met on that day and commenced its duties.
As there has been no example in this country of the improvement of a large
river-mouth so as to give an outlet to the sea with much deeper water than
naturally exists on its bar, the Board, in its consideration of what experience
has elsewhere shown to be practicable In such a case, has found its only exam¬
ples in the mouths of European rivers.
There has been great difference of opinion among engineers, not only in this
country, but in Europe, as to whether the best method of securing a deep-
water outlet from a sediment-bearing river which empties, like the Mississippi,
the Vistula, the Danube, and the Rhone, into a nearly tideless sea, is by jetties
or by a lateral canal.
At the Vistula, after vain attempts for many years to improve the natural
mouth, the river formed a new outlet, and the old one, turned into a lateral
canal, has long given the needed water-way to the important port of Dantzic.
At the mouth of the Danube, after the canal system and the jetty system
had each been proposed by eminent authorities, and neither adopted, as a
final plan it was decided, in order to do something, to try feeble jetties as a
provisional scheme. The results were far better, than the engineer expected,
and the jetties made permanent, give an admirable outlet to the Danube to¬
day.
At the mouth of the Rhone, the engineers, after trying for many yeare to
secure a good outlet by dykes, which, however, never reached the bar, aban¬
doned that plan and built a lateral canal, which is more than adequate to the
wants of commerce.
While the results were so contradictoiy, the information at the command of
the Board about the above-named foreign rivers was, except for the Danube,
not recent, and very meager.
■ The interests involved in the proper improvement of the mouth of the
BOAED OF 1875.
253
Mississippi are so great, and the work so costly, that it is imperative to obtain
the best possible knowledge and judgment as to the method to be adopted.
Accordingly, In order that the opinion of the Board should be based on a full
knowledge of what has been done, and of the latest results obtained elsewhere.
In this most difficult branch of engineering. It was decided to visit the
mouths of the livers mentioned, and, as bearing on a canal and a harbor, also
the North Sea and Suez Canal.
The result of these examinations abroad (while additional information has
been gained on almost every point relating to the problem before them) has
been to largely strengthen their estimate of the value for jetties, at the mouth
of the Mississippi River, of the fascine-dikes used In Holland by Caland in
the improvement of the Maas mouth of the Rhine.
After returning from Europe, the Board met in New Orleans, spending about
three weeks, of which eight days were employed in examinations at the
mouths of the Mississippi River, and at the site for a canal proposed by Cap¬
tain Howell.
After this history of the proceedings of the Board, the conclusions reached
will be given.
I.—CANAL.
A number of locations for a canal were considered by tno ooard, among
which may be mentioned the one proposed by Capta,ln, Howell, near Port
Saint Philip; one leaving Pass à l'Outre, about six miles Inside Its bar, and
running north Into deep water; one leaving Southwest Pass, about six miles
inside of its bar, and running east into deep water ; and one obtained by closing
the South Pass at Its head by a dam and entering It by a canal and lock from
the Southwest Pass, and opening Its mouth by dredging, the mouth being pro¬
tected by jetties.
The advantages of the sites at Southwest Pass and Pass il l'Outre are,
that the difference of water-level at the two ends of the canal will rarely exceed
a foot, and may often be so small that the use of the lock-lift would be
unnecessary; that the canals would be only about three miles long, and, being
near navigable passes, all light-draught vessels would go through the passes;
and that these canals would debouch into deep water at once, while at a dis¬
tance of six miles from the Gulf outlet of the Port Saint Philip Canal there
are only 28 feet of water at low tide.
The objection to the site at the Southwest Pass is, that its délmvchê would
gradually silt up in the advance of the delta, and that the cost of the harbor
covering Its entrance would be excessive. The same objection of excessive
cost for protection of entrance applies to the site at Pass à l'Outre, while the
proposed outlet of the Port Saint Philip Canal is largely protected by Sable
Island, and does not need expensive works to cover its entrance. The sites
below the head of the passes do not give the same promise of permanence as
that near Fort Saint Philip. The plan of canalizing the South Pass would
involve the difficulty of opening and keeping open its mouth, which is the
main difficulty sliould jetties be applied.*
* One member is of opinion tlmt the site for a canal between the Southwest Pass and East
B.iy has a decided advantage over the Fort Saint Philip site.
254
THE MISSISSIPPI JETTIES.
After a careful consideration of the several sites, that in the vicinity of
Fort Saint Philip was adopted, with one dissenting member. Aside from the
question of cost, it offers greater hopes of permanence than the other sites. It
does not seem probable that the river will ever deviate very far from its pres¬
ent position at the head of the proposed canal, and a comparison of the 84-
foot curves at Sable Island on Taloott's map of 1838 and Captain Howell's map
of 1873 show no important change. The Board decided, then, that the canal,
for which plans and estimates should be made by them, should leave the Mis¬
sissippi at a point about five and a half miles below Fort Saint Philip, at such
an angle with the river that vessels would be able to enter it easily; that about
a mile from its beginning there should be a basin of 1,000 feet by 3,500
feet ; that before reaching the basin, and near it, there should be a lock, 500
feet long between its miter-sills, of 65 feet clear width, and with 37 feet of
water on its miter-sills at mean low tide ; the part of the look in the vicinity
of the gates to be of masonry, on a piled foundation, with heavy grillage;
the rest of the prism of the lock to be of earth, with revetted slopes of one
upon one ; guard-gates to be placed above and below the lock ; the canal to be
200 feet wide on the bottom, 87 feet deep at mean low water, and with side-
slopes of i, (or one vertical on two horizontal,) allowing these to flatten if they
will, (the bank of Cubett's Gap stands on a slope of nearly one on one to a
depth of 60 feet) ; leaving the basin, the canal to run in a straight line to the
little bay behind Sable Point, beginning to widen when it reaches 6 feet of
water in the Gulf, and widening to 1,400 feet at 24 feet of water; beyond the
depth of 13 feet in the Gulf, the canal to be without banks. As, in spite of
every precaution, accidents might occur which would make it impossible to
use the look for a considerable period of time, a second entrance from the
river to the basin should be begun as soon as the canal is completed ; this
second entrance having its own lock and guard-gates. As there will be a
tendency to silt up at the river end of the canal, and also in the cut at the
other end, leading to deep water in the Gulf, some dredging will be necessary.
Should that at the Gulf end prove large, it might become advisable to build
dykes along the sides of the out. The cost of the dredging and the cost of
working the canal have been capitalized, and added to the first cost in the
following estimate :
The first cost of the canal complete is estimated at $10,396,500
The annual cost of maintenance is estimated at $60,885, which,
capitalized at 5 per cent 1,217,700
Giving for the sum needed to build and maintain canal $11,514,200
The canal is about six and a third miles long, passing through a country
of which no part is more than 3 feet above tide, and much of its route lies
through shallow lagoons. At 3 or 8 feet below the surface, the delta at and
below the site of the canal is everywhere of bluish mud or clay, into which a
pole can be thrust, by hand, from 5 to 15 feet. On the bars, the wave-action
has sifted out and left the coarser sand in thin layers, and such strata, per¬
haps from the same cause, are found elsewhere in the delta.
BOAED OF 1875.
255
Borings 100 ieet deep show the same clay, becoming more compact, and
mixed with occasional sand. At Port Saint Philip Canal, low water of the
river is 0.7 foot above the mean level of the Gulf, and high water 7 feet above
the same plane. It is estimated that high water of storms at Sable Point is
sometimes 7 feet above mean level of the Gulf. The lock is therefore planned
for a lift of 7 feet; but as the water at Sable Point will never be higher than
that of the river at the other end of the canal, except for a few hours
during violent storms, no provision is made for locking down into the Missis¬
sippi. Guard-gates near the lock are provided to prevent currents rushing in
either direction through the canal.
For details as to plan of canal and estimates, see Appendix A.
II.—DEEPENINQ NATURAL OUTLET.
The methods which have been proposed for opening a passage through a
bar at one of the mouths of the Mississippi are two :
Piret, by stirring up in some way the material of the bar, so that the cur¬
rent shall sweep it away into deep water ;
Second, by confining a mouth of the river by jetties on the bar, so that,
aided, if necessary, by dredging or stirring up, the water shall be able to
scour a channel through the bar, and to maintain it when once formed.
Judging from the results thus far obtained, the board is of the opinion
that no admissible expenditure of money can permanently maintain by the
stirring process a depth of 20 feet at mean low water at the mouth of the
Mississippi ; and as they do not consider this an adequate depth, they deem
the first process named inadmissible.
In considering the method by jetties, it may be well to state the facts on
which their application at the mouths of the Mississippi is based. On exam¬
ining a map of the mouths of this river, it will be seen that each pass through
the greater part of its length has a nearly constant width, but that it widens
toward its bar, so that on its outer crest it has several times its ordinary
width, while its depth is less in something like the same proportion. The
cause of this change seems to be the following ; The river-water as it ap¬
proaches the bar is somewhat above the level of the Gulf, and so tends to
dh'erge, the stream thus becoming thinner and wider. This thinning and
widening is aided by the greater density of the salt water, which makes the
fresh water rise over it on a slope that is steeper as the velocity of the river-
water is less. This thinned sheet of water forms its own banks as the bar
moves out to sea ; but, as in this wide, shallow stream the friction is great
near the banks, deposits begin there, the stream is narrowed and deepened,
and in time that part of the stream obtains the form already assumed by the
portion above, which allows the water to pass with least resistance. To-day,
while there are but 7 feet of water on the outer crest of the South Pass bar, it
is yet only about 12,000 feet from the bar to 30 feet of water above the bar,
and it follows, if the bar's progress into the Gulf has been for the last one
hundred and twenty years the same as for the last thirty-six years, (about 100
feet per annum,) that one hundred and twenty years ago the outer crest of the
South Pass bar was where now there is a deep channel. As the bars move
out to sea, the river is, then, all the time eroding a channel of the character-
256
THE MISSISSIPPI JETTIES.
istic deep-Tvater cross-section, behind and through them. The object of
jetties is to aid and hasten this erosion. If, starting from a point in a pass
above its bar, where there are now 80 feet of water, we build jetties which so
confine the pass that it shall have the width all the way to deep water it now
has at the starting-point, we shall be helping the pass to assume the deep-
water cross-section it would ultimately take, and by aiding it, if necessary, by
dredging, should be able to reduce at pleasure the time required for the pro¬
cess.
This plan is then adopted for the improvement of a natural outlet, namely,
to begin parallel dikes at the banks of a pass where there are now 80 feet of
water in the middle, and carry them over the bar to 30 feet water outside
(unless the depth is obtained before the dikes have reached the 30-foot curve),
allowing the river to erode the bottom between the dikes till the water-way
between them everywhere has the same cross-section as at their beginning,
aiding the erosion by dredging or stirring if it is not rapid enough without.
The Board considered the question of limiting the water-way to the cross-
section of 30 feet maximum depth, by converging jetties on the bar, and by
spur-dikes in the pass above, instead of by parallel dikes. In view of the
lack of experience in such work in this country, and of the danger of exces¬
sive scour around the ends of spur-dikes, it was deemed advisable to adopt
parallel dikes as offering fewer contingencies and less difficulty of construc¬
tion. The depth of 80 feet has been chosen, in order that some time may
elapse before the bar, which will form at the sea-end of the jetties, can have
less than 25 feet at mean low water upon it, that being the minimum depth
which it is desired to maintain.
Having adopted a general plan for the improvement of one of the natural
outlets, it remains to fix on that one. As the improvement of any will be
costly, but one should be improved, and that should be made adequate for
all purposes.
The passes which have been most carefully considered are the South and
Southwest.
In comparing these passes, it is seen that while the average width of the
body of the South Pass is 700 feet, that of Southwest Pass is about 1,400.
The greater width is more favorable to navigation ; but, in the opinion of the
Board, the South Pass, when improved, will be adequate to the present and
prospective wants of commerce. The estimated sum required for the con¬
struction and maintenance of the works for the imjirovement of the South
Pass is $7,942,110, and for Southwest Pass is $16,058,124. It is assumed
that the Southwest Pass bar advances about three times as fast as the South
Pass bar.
The South Pass being entirely adequate, the much greater cost of improving
the larger pass would not, in the opinion of the Board, be warranted either by
the somewhat greater ease of entering it in storms, or of navigating it when
once inside. The former is 12.9 miles long, the latter being 18 miles, and is
lengthened only about one-third as fast as the latter.
The cost of improving Pass à Loutre would also be far greater than for
South Pass, without advantages sufficient to justify the increased cost. The
South Pass has the advantage that the works for its improvement, which would
require at least two or three years for their execution, would in no way interfere
BOAED OF 1875.
257
with commerce. The board is, therefore, of opinion that if any natural outlet
is improved, it shoidd be the South Pass.
The South Pass of the Mississippi is 12.9 miles long, has an average width
of 730 feet, and a minimum interior channel depth of 29 feet. It is 11,900
feet from the 30-foot curve inside the pass across the bar to 30 feet outside.
The minimum depth on the bar is 7 feet. It discharges at its mouth about
57,000 cubic feet of water per second, and about 22,000,000 cubic yards of
sediment in suspension per annum. It has a shoal at its head, with a minimum
depth on it in channel of 17 feet.
For the improvement of the South Pass, the Board recommends parallel
dikes or jetties, constructed of brush, fascines, and stone, in the same general
way as those used by Mr. Caland at the mouth of the Maas.
These dikes should begin at the two banks of the pass, about 1,050 feet be¬
low the South Pass light-house, where the river has a width of nearly 900 feet
and a maximum depth of 30 feet. They should run in straight lines, parallel
to each other, in the direction of the pass, to where the water is 30 feet deep
outside of the bar, provided it should be necessary to carry them so far to
secure 30 feet depth. The dikes for the first 7,100 feet should be 10 feet wide
on top; should then widen gradually to 20 feet in a further distance of 2,050
feet ; should then gradually widen to 50 feet, which is to be the width in 30
feet of water. At present, this last length would be about 2,750 feet, and the
total length of each dike 11,900 feet. The first 7,100 feet of the dikes to have
side-slopes of j, (two vertical to three horizontal,) the rest to have side-slopes
of ^ down to 15 feet below water, and beneath that depth slopes of i. The
top of the dikes to be rounded and paved, the crown rising to high-water of
spring-tides.
The question of the average annual expense of prolonging the jetties is a
very serious one ; it depends on the annual advance of the 25-ioot curve, that
depth being required. At present, the muddy water issuing from the South
Pass spreads out in somewhat of a fan-shape, the handle of the fan being at
the mouth of the pass and (ho ribs several miles in length.
If the proposed jetties were instantly completed, and the new channel
scoured out, essentially the same amount of sediment would be spread out in
fan-shape, but, from the greater velocity of the issuing water, the ribs of the
fan would be longer, while the handle would be narrower. More of the sedi¬
ment would at first be deposited far out in the gulf than before.
But with the present rate of advance, the 25-foot curve one hundred and
twenty years ago was about 12,000 feet above its present position; and if the
volume of water carried by the pass is kept the same, neglecting the slight
difference in slope of the gulf bottom outside the j)resent bar, in about one
hundred and twenty years a new end for the pass will probably be formed of
the same general shape as the lower 12,000 feet of the'present pass. It makes
little difference, in the whole time required to accomplish the work, whether
the same volume of water flows out at starting over the present shallow bar or
from between two dikes which force the water to take a depth of 30 feet. In
an average of*many years, the rate of progress must bo about the same as now,
namely, 100 feet per annum, the volume of water being kept as at present ;
and it is on this basis that the average annual cost of extension, namely,
$130,000, has been computed,
17
258
THE MISSISSIPPI JETTIES.
It has already been stated that it is proposed to obtain a depth of 30 feet
between the jetties, in order that some years may elapse before the shoal which
will form beyond the jetties can have on it less than the required depth of 25
feet in the channel through it. There are no precise data for estimating this
period. Going seaward from the upper end of the proposed dikes, the slope
of the bottom of the South Pass is about This slope doubtless depends
mainly on the velocity of the water flowing through it, and on the lifting of
the fresh water by tiie salt. As the causes remain essentially the same, it
would seem natural that the new end of the South Pass, to be formed by the
sediment passing through the jetties, should at least have the same bottom
slope. If this assumption were true, the bottom would at last shoal from
30 to 25 foot in a distance of 5 x 440 = 2,200 feet, and the time required would
be about 22 years. This time would be shortenetl by two causes. First, there
are about 3,000,000 cubic yards of material to be scoured out between the jet¬
ties, thus increasing the general bar-accretion by that amount and hastening
the advance of the pass. As the scour would be distributed over several years,
and as the South Pass carries about 22,090,000 cubic yards of sediment in sus¬
pension annually to the Gulf, the effect of this 3,000,000 yards cannot be
relatively large. Secondly, at and below the point where it is proposed to
begin the jetties, the river velocity now diminishes very slowly, as it is confined
by a slowly widening channel, while, when the jetties are completed and the
channel scoured out, the water issuing from them will, having at first no banks
to confine it, spread out more rapidly, thus, perhaps, losing velocity more
rapidly, and formirg a steeper seaward slope on the bottom than now exists at
the upper end of the proposed dikes. This steeper slope seaward from the 30
feet of water between the jetties would give a shoal of 25 feet at a distance of
less than 2,200 feet, and in a period of less than 22 years. The period is un¬
certain ; experience alone can determine the precise time. Different estimates
made by this method, and others by different members of the board, vary
largely, and 10 years have been assumed for the purpose of estimate. In 10
yeai-s, then, it is assumed that the jetties will have to be lengthened 1,000 feet.
As shoals will have formed at the ends of the jetties, it has also been assumed
that the extension will be in water averaging 15 feet in depth.
It has been stated that there is a shoal at the head of South Pass, with but
17 feet of water on it. At present, this shoal is scouring out. Should that
scouring not give a depth as great as at the shoalest point below in the pass,
the construction of a dike to deflect more water into it would become neces¬
sary. Should the South Pass increase much beyond its present size, it might
become necessary to put an apron on the bottom and sides of the pass, near
its head, to stop that increase.
Estimates of the cost of the jetties and of the works which may be needed
at the head of the pass are given in Appendix B.
First cost of jetties at mouth of South Pass, of dredging, and
of works at head of pass $5,342,110 00
Average annual cost of extension, including removal of mud-.
lumps, should they rise, $130,000, which, capitalized at 5 per
cent., gives 2,600,000 00
Cost of construction and maintenance of improvement $7,042,110 00
BOAED OF 1875.
259
The Board also made an estimate of the cost of improving the Southvrest
Pass, the result of which is as follows :
First cost of improving Southwest Pass by jetties $8,253,124 00
Average annual cost of extension, $390,000, which, capitalized
at 5 per cent., is 7,800,000 00
Sum required to improve and maintain Southwest Pass $16,058,124 00
III.—METHOD KECOMMENDED.
The Board has now given plans and estimates for improving the mouth of
the Mississippi either by a canal or by opening one of the natural outlets. It
is also required to give its opinion as to which plan is preferable. Leaving
cost aside for the moment, and assuming that one plan can be as easily exe¬
cuted and maintained as the other, there is no question that the improvement
of the South Pass would be best. It would give a good sea-entrance about
900 feet wide, and a minimum width in the pass of about 530 feet, while the
width of the canal would be about 300 feet. It would offer no locks (liable to
do or suffer injury) to delay the passage of vessels through it. It would give
an ample unobstructed water-way to commerce in place of a narrow and cb-
stmoted one.
If the question of cost and maintenance be considered, we have for the
canai $11,514,200 against $7,942,110 for the South Pass.
The only remaining question is whether the two plans can be executed and
maintained at about the estimated costs.
For the canal, the difficult points are to maintain a coffer-dam and secure a
stable foundation on which to build the masonry. By proper examinations, it
is believed that sites can bo found where coffer-dams can be maintained ; and,
although the masses of masonry are heavier than any which have been built in
that region without settling, it is believed that, by the plan proposed, injuri¬
ous settling would bo prevented. The Board is therefore of opinion that the
canal can be built at the estimated cost.
In the improvement of the South Pass, the difficult points are the control
of the water entering it, the removal of the shoal, and the maintenance of a
channel at its head, and the execution and maintenance of that part of the
jetties lying outside of the outer crest of the bar. While the proper method
of control of the water at the head of the South Pass must be learned mainly
by trial, great difficulty is not anticipated, as such control was readily ob¬
tained on the Sulina. The construction and maintenance of the jetties
beyond the crest of the bar is a difficult work, in which there will be contin¬
gencies arising from the action of heavy storms, either on the jetties them¬
selves or on the material on which they rest, and from settling. A liberal
allowance has been made for such contingencies, and the Board sees no reason
to increase its estimate. Indeed, it is of opinion that experience in construc¬
tion may very probably show that the cross-section of the dikes may bo
reduced, thus lessening the cost. If the jetties are constructed and main¬
tained, the ends being prolonged as becomes necessary, the board has no doubt
that the desired depth will be obtained.
260
THE MISSISSIPPI JETTIES.
It therefore recommends that the South Pass of the Mississippi River be
improved by the plan already given.
The Board concludes its report with the recommendation that, if Congress
.decides to open one of the passes of the river, the entire sum necessary to ac¬
complish the work be appropriated at once, or in some way be made available.
If the mouth of the river is to be improved by jetties, the work, when once
begun, should be pushed as rapidly as possible to its entire completion.
The Board is of opinion that the works it proposes for the improvement of
the South Pass can be completed in three years.
Respectfully submitted.
B. S. Alexander,
Lieut. Col. of Engineers, Bvt. Brig. O en., TI. S. A.
C. B. CO.TISTOCK,
Major of Engineers and Bvt. Brig. Oen.
Henry Mitchell,
U. S. Coast Survey.
T. E. Sickles.
W. Milnor Roberts.
H. D. Whitcomb.
I concur in so much of the report as refers to the selection of the South
Pass for the trial of the jetty system of improvement, if that system is to be
adopted; also, to the plans and estimates for both canal and jetties; but as, in
my judgment, the chances of success of an attempted improvement of any one
of the natural outlets of the river do not justify the recommendation of the
Board, I have withheld my signature from the report.
If an adequate and permanent channel could be obtained at any one of the
passes, it would no doubt be preferable to the proposed canal.
As the ship-canal project does, in my judgment, offer reasonable chances of
success, I must give it the preference over the jetty project recommended by
the Board.
H. G. Wright,
Lieut. Col. of Engineers, Bvt. Maj. Oen.
Hon. W. W. Belknap,
Secretary of War, Washington, D, C.
APPENDIX III.
(See page 65.)
THE GEANT
from the
UNITED STATES,
authorizing the construction of
THE JETTIES.
Be it enacted hy the Senate and House of Representatives of the United States
of America in Congress assembled :
Sec. 4. That James B. Eads, of St. Louis, Missouri, be, and he is hereby,
authorized, with such others as may be associated with him, on the conditions
hereinafter mentioned, to construct such permanent and sufBeient jetties and
such auxiliary works as are necessary to create and permanently maintain, as
hereinafter set forth, a wide and deep channel between the South Pass of the
Mississippi River and the Gulf of Mexico, and for that purpose he may con¬
struct, in the river, outlet or pass, and likewise in the Gulf of Mexico, such
walls, jetties, dykes, levees, and other structures, and employ such boats,
rafts, and appliances as he may, in the prosecution of said work, deem neces¬
sary: Provided, That no such structures or means employed shall hinder, de¬
lay, or materially interfere with the free navigation of said pass ; and, to
protect his said works, he may build and maintain such levees, or embank¬
ments as may be necessary to secure their permanency along the banks of the
river or South Pass ; Provided further, That unless the construction of the
proposed work shall be substantially commenced within eight months from
the date of the approval of this act, and prosecuted with due diligence, the
provisions contained herein in relation to the said South Pass shall be null and
void; and unless the said Eads and his associates shall secure a navigable
depth of twenty feet of water through said pass within thirty months after the
201
262
THE MISSISSIPPI JETTIES.
date of the approval of this act, Congress may revoke the pri^dleges herein
granted in relation to the said South Pass and cancel the obligations herein
assumed by the United States. And Congress may revoke the privileges
herein granted in relation to the said South Pass, and cancel the obligations
herein assumed by the United States, unless the said Eads and his associates
shall, after securing twenty feet of water, secure an additional depth of not
less than two feet during each succeeding year thereafter, until twenty-six feet
shall have been secured ; and in case said Eads and his associates shall fail to
comply with the foregoing conditions, as to depth of water, and time, for any
period of twelve months in excess of the time fixed, as aforesaid, then the
privileges herein granted, and the obligations herein assumed in relation to
the said South Pass, shall absolutely become null and void without action
by Congress.
Sec. . That the conditions herein prescribed being fully complied with,
the United States hereby promise and agree to pay to said Eads, or to his as¬
signs or legal representatives, five million two hundred and fifty thousand dol¬
lars for constructing said works and obtaining a depth of thirty feet in said
channel, and the annual sum of one hundred thousand dollars for each and
every year that said depth of thirty feet shall be maintained by the jetties and
auxiliary works aforesaid in said South Pass during twenty years after first se¬
curing the said depth. Payments shall be made on certified statements of an
engineer officer, who shall be detailed by the Secretary of War, and whose
duty it shall be to report the depth of water and width of channel secured and
maintained from time to time in said channel, together with such other infor¬
mation as the Secretary of War may direct. When a channel of twenty feet
in depth, and of not less than two hundred feet in width, shall have been ob¬
tained by the action of said jetties and auxiliary works, five hundred thousand
dollars shall be paid; and when a channel of twenty-two feet in depth and
two hundred feet in width shall have been obtained by the action of said jetties
and auxiliary works, five hundred thousand dollars shall be paid. When a
channel twenty-four feet in depth and not less than two hundred and fifty feet
in width, shall have been obtained, there shall be paid five hundred thousand
dollars; and after said depth and width shall have been maintained during
twelve consecutive months, there shall be paid two hundred and fifty thousand
dollars, with five per centum per annum interest from the date when said
twenty-four feet were first obtained. When a channel twenty-six feet in
depth, and not less than three hundred feet in width shall be obtained, there
shall be paid five hundred thousand dollars; and when a channel of said
depth and width shall have been maintained for twelve months consecu¬
tively, two hundred and fifty thousand dollars shall be paid, with interest at
five per centum per annum from the date when said channel was first ob¬
tained.
When a channel twenty-eight feet in depth, and not less than three
hundred and fifty feet in width shall be obtained, there shall be paid five
hundred thousand dollars; and after said depth and width shall have been
maintained for twelve months consecutively, two hundred and fifty thousand
dollars shall be paid, with interest at six per centum per annum from the date
when said twenty-eight feet were first obtained. When a channel thirty feet
in depth and not less than three hundred and fifty feet in width shall be ob-
ACT OF CONCESSION.
263
tâined, there shall be paid five hundred thousand dollars; and after said depth
and width shall have been maintained for twelve months consecutively, there
shall be paid five hundred thousand dollars with interest at five per centum
per annum from the date when a channel of said depth and width was first ob¬
tained; making a total aggregate of four million two hundred and fifty thou¬
sand dollars for the aforesaid payments, the respective depths and widths of
channel being measured at average flood tide, as ascertained and determined by
the Secretary of War. When a channel thirty feet in depth, and three hun¬
dred and fifty feet in width, shall have been obtained by the effect of said jet¬
ties and auxiliary works aforesaid, the remaining one million dollars shall be
deemed as having been earned by said Eads and .associates; but said amount
shall remain as security in the possession of the United States for the purpose
hereinafter set forth, interest at five per centum per annum on the same being
payable to said Eads, his assigns, and legal representatives, semi-annually,
from the date when a channel of thirty feet in depth and three hundred and
fifty feet in width shall have been first secured, so long as said money, or any
part thereof, is held by the United States.
Sec. . That after said channel of thirty feet in depth and of not less than
three hundred and fifty feet in width shall have been sectired, one hundred
thousand dollars per annum shall be paid in etpial quarterly payments during
each and every year that said channel of thirty feet in depth and three hun¬
dred and fifty feet in width shall have been maintained by said Eads and his
associates by the effect of said jetties and auxiliary rvorks aforesaid in said
pass, for a period of twenty years, dating from the date on which said channel
of thirty feet in depth and three hundred and fifty feet in width shall be
first secured: Provided, however, that no part of such annual compensation
shall be paid for any period of time during which the channel of said pass shall
be less than thirty feet in depth and three hundred and fifty feet in width, as
hereinbefore specified.
Sec. . That the said channel of thirty feet in depth .and three hundred
and fifty feet in width having been maintained for ten years, one-half of the
one million dollars hereinbefore mentioned shall be released and paid to said
Bads, his assigns, or legal representatives; and said depth and width having
been maintained for ten additional years, the remaining half of s<aid one mill¬
ion dollars shall be released and paid as aforesaid. And if any of said money
shall have been paid under the provisions of this Act as hereinafter provided,
then the residue shall be paid at the times above stated.
Sec. . That in case said Eads and associates, in order to maintain a chan¬
nel of thirty feet in depth and three hundred and fifty feetin width, shall deem
it necessary to expend on such work, during any one or more of said twenty
years, any money in excess of the annual payments received by them during
said year or years under this Act, the Secretary of War shall, on satisfactory
proof of such expenditures, authorize, as often as such extra expenditures may
require, the payment of the same from the said money in pledge, to said Eads
or his legal representatives. And such payments shall be made from the five
hundred thousand dollars to be released at the end of ten years before any pay¬
ment shall be made from the five hundred thousand dollars to be released at
the end of twenty years; and if any failure to maintain said channel of thirty
feet in depth and three hundred and fifty feet in width shall occur, the date
264
THE MISSISSIPPI JETTIES.
for releasing the said money licld in pledge shall be postponed for an
equal period of time, and the compensation for maintaining said channel shall
cease until said depth and width shall be again restored, the maintenance of
a channel thirty feet in depth and three hundred feet in width for twenty years,
exclusive of all such periods of failure, being intended by this act. And at any
time after said Jetties shall have been completed, and said channel of thirty
feet in depth and three hundred and fifty feet in width shall have been ob¬
tained, that the United States may elect to pay the said one million dollare,
and stop the payment of said interest and said annual sum of one hundred
thousand dollars for the maintenance of said depth and width, said United
States shall have the right to. do so on payment of said money held as security
and in pledge as aforesaid, together with the interest and annual compensation
for maintenance which may be earned at the date of such final payment ; and
on such jiayment being made by the United States, the supervision and main¬
tenance of said jetties and auxiliary works by said Eads and associates, and all
liability on their part, shali cease and determine.
Sec. . That in order to facilitate the proper location of said jetties, which
shall not be less than seven hundred feet apart, and to correctly determine
such effects as may be produced by them, the Chief of the Coast Survey shall,
as soon as practicable, cause a careful topographic and hydrographie survey to
be made of said pass and bar, and shall submit the same to the Secretary
of War, who shall furnish to said Eads the results of any such survey.
And the sum of five thousand dollars is hereby appropriated out of any
money in the Treasury not otherwise appropriated for said survey and ex¬
amination.
Sec. . That any person maliciously or intentionally injuring said works,
or interfering with the construction thereof, shall be deemed guilty of a mis¬
demeanor, and may be tried for such offense before the District Court of the
United States for the district wherein such offense may be committed; and, if
found guilty, he shall be liable to a fine not exceeding one thousand dollars, or
to imprisonment for not more than two years, or to both fine and imprison¬
ment as aforesaid, for each offense.
Sec. . That the said Eads and his associates shali have the right under
such regulations as the Secretary of War shall prescribe, to use any materials
on the public lands of the United States that shall be suitable for, and may
be needed in, the construction of said works.
Sec. . That in case of death or other disability of said Bads before the
completion of said works, the same shall be prosecuted and completed by his
legal representatives and his associates aforesaid, with the same powers, rights,
obligations and compensations as if done by him in person.
Sec. . That the Secretary of War be, and is hereby, authorized and di¬
rected to carry into effect the provisions of this Act on behaif of the United
States, and, when the said Eads and his associates shall, from time to time,
have fulfilled on their part the several foregoing conditions of this Act, to
draw his warrants upon the Treasurer of the United States in favor of said
Eads, or his legal representatives, in payment of the aforesaid amounts as they
respectively become due by the provisions of this Act. And it shall be the duty
of the Secretary of War to embody in his annual reports the payments made
from time to time under this Act, and the probable times when other payments
ACT OF CONCESSION.
265
will become due, and to report during the construction of the work herein
authorized all important facts relating to the progress of the same, the mate¬
rials used, and the character and permanency with which the said jetties and
auxiliary works are being constructed, to the end that the Congress of the
United States may be kept fully advised as to the faithfulness and efficiency
with which the said works are being executed by the said Eads and his associ¬
ates, it being expressly understood that while said Eads shall be untrammeled
in the exercise of his judgment and skill in the location, design and construc¬
tion of said jetties and auxiliary works, the intent of this Act is not simply to
secure the wide and deep channel first above named, but likewise to provide
for the construction of thoroughly substantial and permanent works by which
said channel may be maintained for all time after their completion. And in
case the Secretary of War shall be of the opinion that this work is not being
constructed according to the spirit and intent of this Act, he shall report the
same to the President, who shall appoint a commission, consisting of an officer
of the Army, an officer of the Navy, and a competent person from civil life,
to inspect and examine the works being constructed by said Eads and his as¬
sociates; and in case the said commission shall report that the works are being
constructed upon a design that will not be of a substantial and permanent
character when completed, all the facts in the case shall be laid before Con¬
gress at the earliest possible moment, and payments upon said works shall be
suspended until Congress shall otherwise order.
Sec. . That the option of discharging the obligations herein assumed by
the United States, either in money or bonds, is expressly reserved; and the
Secretary of the Treasury is hereby directed to issue the bonds of the United
States, bearing five per centum interest, of the character and description set
out in the act entitled "An Act to authorize the refunding of the public debt,"
approved July fourteenth, eighteen hundred and seventy, to said Eads or his
legal representatives, in payment at par of the aforesaid warrants of the Sec¬
retary of War, unless the Congress of the United States shall have previously
provided for the payment of the same by the necessary appropriations of
money : Provided, That in no ease shall the Government of the United States be
liable for any losses incurred by said Eads and his associates in the perform¬
ance of the work herein mentioned, nor shall any payments thereon be made
in excess of the sums nor contrary to the terms hereinbefore prescribed.
Approved March 3, 1875.
APPENDIX IV.
(See page 93.)
PROCEEDINGS
op the
ADVISORY COMMISSION OF ENGINEERS
convened bv
JAMES B. EADS,
to consideb his plan fob the impbovemext of the
MOUTH OF THE MISSISSIPPI RIVER.
Minutes of the Proceedings of the Board :
New Yoek, September 3, 1875.
" The first point considered was the proper line for the eastward jetty, and
after examination and discussion it was recommended by the Board to fix
the line as follows, viz. : Begin about 6,380 feet from the Land's End, and
about 1,080 feet beyond the mattress laid September 1st, and in the line sub¬
mitted by Mr. Eads ; thence curve southward, on a radius of 30,000 feet, to
the 30-foot contour line without the bar. Total curvature, 17' 30; and
course of tangent at proposed end of jetty, S. 37i° E., approximately."
September 3, 1875.
The Board then proceeded to discu the proper width between the jetties
at their outer ends, and recommended that it remain as proposed by Mr.
Eads—at 1,000 feet at water surface at ordinary high tide. A discussion as
to the proper line of the west jetty then followed, and pending the discussion,
the Board adjourned."
266
ADVISORY BOARD.
267
September 4, 1875.
" The line of the eastern jetty was reeonsiderecl. Mr. Eads stated that the
piling on the line of the east jetty had already been driven to tvithin 3,400
feet of the jetty head, and a change in the radius of the curve to 20,000 feet,
as recommended by the Board on the 3d inst., would involve considerable
additional expense and some delay. He proposed a curve with a radius of
16,000 feet, beginning in the straight line at or near station 73 + 70 feet, curv¬
ing southward, and passing through a point in the line of the jetty submitted
to the Board, 11,700 feet from the signal station. The Board concurred with
Mr. Eads in his views, and modified the recommendation of September 3
accordingly.
"The consideration of the line of western jetty was then resumed.
"The Board having decided that 1,000feet is an advisable width between
the jetty heads, and having fixed the alignment of the east jetty, is unani¬
mously of opinion that a strictly parallel alignment for the western jetty is in
accordance with the theory of jetty action; that departures from such align¬
ment would be advisable, if at all, only on the grounds of economy, facility,
and rapidity of construction; they concur in the alignment proposed by Mr.
Eads, and leave that matter to his discrimination, aided by the experience
gained on the spot; and as regards the length of the western jetty, the Board
think it advisable that the eastern, being the windward jetty, should overlap
the western by at least 800 feet."
September 6, 1875.
" After an examination of the map, showing the changes of depth which
have occurred in the South Pass since the works were begun, a discussion fol¬
lowed as to the proper point for terminating the east pier, and also as to the
construction of the jetties. As two members of the Board were absent, the
Board adjourned at 4 p.m., these subjects being still under consideration."
September 7, 1875.
" The Board resumed the consideration of the construction of the jetties,
and adopted the following recommendations, viz. ;
" That with regard to priority of construction, the Board recommends that
the seats of both jetties, and of the spur joining the west jetty with the right
bank, be protected throughout their entire length, and that then the foun¬
dations of the east jetty be carried up to the water-line before raising the mat-
tress-work of the west jetty to the same level.* The construction details of
the pier head to be left undetermined until the Commission can meet at the
jetties in November.
"The Board then adopted the following:
" After an attentive examination of the plan of construction, consisting of
a combination of willow mattresses and stone, now in execution by Mr. Eads,
the Board find it a modification of methods long in use in Holland and else-
* Sir Charles A. Hartley is of opinion that the cast Jetty should be brought up to the water-
line (.to its full height), as far as a depth of at least 20 feet, before raising the mattress-work of
the west Jetty to the same line.
268
THE MISSISSIPPI JETTIES.
■where. It is essentially the same as that applied to the jetties at the month
of the Oder, and also to the jetties at the mouth of the Maas, so success¬
fully as to draw from the lower legislative body of Holland the announcement
that ' their complete success has removed all doubts as to the possibility of
making piers at sea on our coast.' It is, moreover, essentially the same as
that adopted by the recent Commission for these works.
" The Board farther advise that Bayou Grande be left open for the
pi'esent.
" The consideration of ■works necessary at the head of the pass was then
begun; pending this, the Board took recess, to meet at 8 p.m."
September 7, 8 p.m.
" After a very thorough consideration of different projects, the Board recom¬
mended unanimously the construction of one jetty immediately ; starting on a
tangent to the east bank of entrance to the pass, i.e., to a meridian line near¬
ly, and curving then to the westward on a radius of 8,000 feet, till it reaches
the 24-feet contour line. The further prolongation of this work, and the execu¬
tion of works on the west side, to be left for determination after observation of
effects produced by the construction recommended."
September 8, 1875.
" The minutes of the Board from the first were read and approved, and the
Board adjourned to meet at New Orleans November 10, 1875."
Copied from the Minutes.
(Signed) R. S. Elliott.
FIISTAL PEOCEEDIXGS OF THE COMMISSION".
Port Eads, La., JVbv. 18, 1875.
The commissioners. Gen. J. G. Barnard, Sir Charles A. Hartley, W. Mil-
nor Roberts, Prof. Henry Mitchell, and H. D. Whitcomb, assembled in New
Orleans, November 15th, and proceeded to Port Eads on the 17th. After
visiting the works in progress, the Commission held a meeting at Port Eads on
the 18th.
Present, Gen. J. G. Barnard, President, and Sir Charles A. Hartley, W.
Milnor Roberts, Prof. Henry Mitchell and H. D. Whitcomb.
Communications were received from General Alexander and Mr. Sickles,
stating that pressing engagements prevented their attending the meeting.
The President read the minutes of the meeting of the commissioners in
New York in September.
After some discussion, it was recommended by the Board that the space of
six hundred feet between the north end of the west jetty and the shore, across
which piles are now driven and mattresses being laid, should not be closed
ADVISOIIT BOAED.
269
until the east jetty shall have been raised to its full height out to twenty feet
depth of water.
Mr. Bads having intimated to the Board that it is of importance to himself
and his associates that a depth of twenty feet should be obtained at the mouth
of the South Pass as soon as possible, the Board recommend, in consideration
of Mr. Eads's representation, that provisional jetty heads one hundred feet in
length be established in a depth of twenty feet in the line of both jetties, and
that the construction of these works be in conformity with the cross section of
a jetty presented by Mr. Bads. .
This drawing indicates :
1. That the said jetty heads shall consist of stone and fascine work, having a
width of twenty-six feet at the water line, with a slope of three to one on both
sides to a depth of sixteen feet.
2. That below this depth the base of the work shall have a width of two hun¬
dred and twenty-two feet, and including revetment of stone, be four feet
thick, thus giving an apron fifty feet wide at the foot of each slope.
3. That the apron and slopes shall have a revetment of stone at least two
feet thick ; and
4. That the work be crowned with paving stones, weighing not less than
one ton each, carried up to a height four feet above mean low water.
The Board further recommend that the exposed sea ends of the temporary
jetty heads should have the same inclination as the side slopes, it being under¬
stood that the bottom out to the depth of thirty feet in the proposed line of the
east jetty is already covered with at least one layer of mattresses.
With reference to the permanent jetty heads, the Board is of the opinion
that their construction, as regards profile, fascines, stones, and piles, should be
nearly as possible identical with that of the jetty heads at the new mouth of
the Maas, where the stones employed in exposed positions averaged one hun¬
dred and twenty pounds each, and where each cubic yard of mattress work
was charged with half a ton of stone. The Board also considers that a like
covering of stone on the mattress should be employed in constructing the jet¬
ties at the South Pass, wherever they are liable to be attacked by heavy seas.
The Board then adjourned.
Port Bads, Mov. 19, 1875.
The Board met at 9 p.m. Present, same commissioners as on the 18th.
Pi'esent also, Mr. Bads. After conversation and discussion, the Board ad¬
journed without action to 9 a.m. the 20th.
Port Bads, JVov. 20, 1875.
The Board met according to adjournment. Present, the same members as
on last evening.
The following letter was submitted to the Board, and read, and ordered to
be spread on the minutes. The personal examinations on the work made by
the Board confirm the correctness of Mr. CorthelTs statement :
270
THE MISSISSIPPI JETTIES.
" Poet Eads, Kov. 19, 1875.
" Mr. G. W. R. Bayley, Resident Engineer :
" Dear Sir :—The following is a statement of work at this date :
"There have been driven as guide piles for mattresses about 2,500 piles,
extending on the east jetty to a point about 12,100 feet from East Point signal,
and about 11,500 from same point on west jetty—measured on jetty lines.
The length of foundation mattresses laid in east jetty is 11,560 feet.
The length of second tier mattiesses laid in east jetty is 2,850
The length of foundation mattresses laid in we^t jetty is S,200 "
The length of foundation mattresses laid in cross dike is 600 "
Total linear feet 23,210* •'
" In which there are seventy-five thousand cubic yards of material all firmly
secured in its position by stone ballast. Sheet piling in the east jetty has been
driven a length of three thousand six hundred feet.
"There have been constructed eight hundred lineal feet of launching ways
for mattresses. Houses and boats lor the accommodation of three hundred
and fifty men have been placed on the west side of the pass, and on the east side
a large house for headquarters' residence has been built, and all the shops, walks,
and wharves necessary for works. The plant in the work consists of two float¬
ing pile-drivers, three sheet pile-drivers, five derricks, eight model barges,
eight flats, two stern-wheel steamboats, two tugs, three steam launches, with
yawls and other small boats.
" At the head of the passes about two hundred piles have been driven on
the line of the deflecting dike, and at the Jump two hundred lineal feet of
mattress ways have been constructed, with accommodations in each place for
all the men required for the work.
"I am sir, yours truly,
"E. L. CORTHELL,
" Chief Assistant Engineer.
" Respectfully submitted to the Chief Engineer.
"G. W. R. Bayley,
" Resident Engineer."
"Whilst the Board appreciates the preparations made for carrying on the
works with vigor, it is unanimously of opinion that a rapid delivery of stone
on the works is essential to obtain a speedy depth on the bar, and for the pro¬
tection of the jetties where they are exposed to the violence of the waves. It
therefore directs Mr. Eads's special attention to this subject, with the sugges¬
tion that a deposit of at least 10,000 cnbic yards of stone be.piled on the river
banks, near the mouth, as a reserve deposit to meet emergencies during the
construction of the jetties in deep water.
November 20, 1875.
The Commission adopted the following general report, and ordered it to be
entered into the minutes of its proceedings.
After having devoted three days to examining the works in progress and in
* Note.—Equal to a length of four miles, fifty feet wide and two feet thick.
ADTISOEY BOAED.
271
conference with Mr. Eads and his engineers, the Commission presents the fol¬
lowing general summary of its views ;
Upon personal examination of the locality and observation of the work
which has been performed, the South Pass of the Mississippi is found by the
Commission to more than fulfill the expectation of its members in regard to its
fitness for furnishing an open mouth of ample depth for the largest class of
sea-going vessels to the Mississippi River by means of jetties.
In making this statement, reference must be had to the fact that two of the
members have never before examined the locality with a view to this particular
question, one indeed having never before visited the spot. Of course, on all points
concerning difficulties of execution of the works recommended, they had had
no actuai local experimental results, while, on the other hand, opinions were
rife among many that the local peculiarities of the soil, such as its extreme
softness, its eruptive "mud-lumps," etc., would effectually thwart efforts to
lay upon it substantial and permanent engineering constructions.
The members of the Commission had, indeed, satisfied themselves, that
such opinions were unfounded; but it is satisfactory to be able to state posi¬
tively, after four months of actual operations, that the work of pile-driving,
extending from the cast land's end to twenty-six feet depth beyond the bar
crest, along a line two and a quarter miles in length, covering nearly the whole
length of the eastern jetty, and an examination of the texture of the bar and
of the shoals on which the works are to rest, furnish the most satisfactory evi¬
dence of a bottom material not only adequate to bear all the necessary works,
but even to suggest that but for motives of economy (quarries being far dis¬
tant) the jetties, as at the Sulina mouth of the Danube, might be made wholly
of stone. The. Commission therefore unhesitatingly announces that the sup¬
posed or attributed engineering difficulties of construction of engineering
works at the South Pass of the Mississippi, as depending on peculiarities of the
Mississippi delta, are illusory.
In fact, the execution of the works is far less difficult than that of several
recent successful works of the kind on European shores, known to and exam¬
ined by the members of the Commission. This facility of execution arises, in
a measure, from the fact that the broad, lateral shoals, almost bare at low
water, which extend seaward from the land's ends, marginal to the channel,
form very good protection to the proposed works, and almost reduce them to
the grade of mere river works until the outer edge of the bar is reached. The
deep water portions, outside the bar of the proposed jetties, are comparatively
short. While these portions must have the dimensions and strength of exposed
sea works, they offer no difficulty not common to other similarly exposed works
now existing.
It would seem proper in this connection to say a few words as to the South
Pass itself, in reference to its capabilities to furnish an open mouth to the
main stream, and thus form an adequate connection between the sea and the
thirty thousand miles of inland navigation which ramify from the river.
The South Pass is the middle one of three great passes into which the
river, after having for many hundred miles rolled in a single channel, divides
a few miles before it finally discharges its waters into the Gulf of Mexico.
It is but twelve miles long, being the shortest of the passes. Prom its
point of division it carries its waters in a channel everywhere five fathoms
272
THE MISSISSIPPI JETTIES.
or moro in depth, with a straigiitnesô oí course and a uniiormity of section
and depth such as almost to suggest to the voyager that he is navigating a
canal of unparalleled dimensions, of a width averaging seven hundred feet,
sufficient for the convenient transit of the largest sea-going ships, and of the
congeries of vessels which constitute a tow for the powerful tug-boats in use.
No sharp bend, no shoal, no reef, embarrasses its navigation.
At the origin—the head of the passes—a shoal indeed lies in advance of its
entrance. This shoal lias, however, a natural depth equal to that over the bar
at Southwest Pass, and the Commission anticipates no serious difficulty in
effecting over it the required depth. From this point the adequacy of depth
continues unbroken for ten miles, till the seaward extremities of the land mar¬
gins (the natural jetties which thus far maintain it) are reached. Here, released
from confinement, the current diffuses itself ; the depth diminishes until at
two miles further (about) the bar, having but seven feet depth, is reached ;
beyond which, seaward, depths of six, twelve, twenty-four and more fathoms
are found in quick succession. The sjtecific engineering work which the gov¬
ernment of the United States has committed to Mr. Eads is by the well-known
method of jetties, or otherwise called parallel piers, to supply artificially
throughout this two miles from the land's ends to the outer slope of the bar
the confining barriers which shall prolong to the sea the uniformity of section
and depth which the natural barriers for the preceding ten miles have secured.
This is not the place to discuss the abstract merits of a well-known method
which has elsewhere, in reference to its application here, been thoroughly dis¬
cussed and disposed of, and in which the individual members of the Commis¬
sion have had each one his own part to take. What has been said in former
paragraphs suffices to exhibit the strengthened confidence with which personal
examination of the spot and of the works now in progress has imbued the mem¬
bers of the Commission.
The Commission considers the present an opportune moment to record its
opinion—first, that the physical characteristics of the delta and bars of the
Mississippi and Danube are similar in many important respects ; and sec¬
ondly, that owing to the greater sea depth immediately beyond the crest of
its bar, to the existence of tide-water, to the apparent greater abrading forces
along the coast, and to the extreme fineness of the sand of which the bar is
composed, the mouth of the South Pass of the Mississippi is more susceptible
of successful improvement, notwithstanding the greater turbidity of its fluvial
current, than was the Sulina mouth of the Danube when, in 1858, thé construc¬
tion of parallel piers was commenced which secured to the navigation "of that
.river a depth of 17J feet in 1801, and 201 feet at the present lime, or five feet
more than the works were originally designed to obtain ; and this at the mouth
of a river-arm dischai-ging less than one-third of the volume of water dis¬
charged by the South Pass.
We now turn to the works actually at this time executed by the grantee,
Mr. Jas. B. Eads, under the act of Congress authorizing him to improve the
South Pass of the Mississippi River, and we find that they have been laid out
and thus far carried on substantially in accordance with the plans submitted
to and approved by this Commission at the time of their session in September
last.
Considering that only the short period of five months has elapsed since the
ADTISOKY BOAKD.
273
beginning of operations at the South Pass, ■we are struck -with the amount of
■work which has been accomplished ; and although much that has been done is
provisional, to be supplemented by other work, it is all necessary and condu¬
cive to the end in view, which is permanently to confine the flow within the
space of one thousand feet between the crests of the jetties.
We find from the records of the pile-driving, and from the manner in
which the piles have thus far withstood the action of the waves and currents,
that the material of the bar is even more solid than we had ventured to antici¬
pate it would be, as we have already remarked. We do not entertain any
doubt as to the'eiflciency and permanency of the jetties, when they shall have
been completed upon the location and plans heretofore approved by this Com¬
mission. If the arrangements made by the contractors, Messrs. James An¬
drews & Co., for the early delivery of additional large quantities of stone for
weighting the mattresses, and for the protection of the jetties against the action
of the sea, are successfully executed, we see no reason for doubting the realiza¬
tion of definite and permanent good results at an early date.
It is hardly within our province, if it were even in our power, to offer any
specific opinion respecting the period when a given depth across the bar may
be reliably calculated upon, since so much necessarily depends upon the char¬
acter of the season, the stage of water in the river, and the vigor with which
the works are prosecuted ; but judging from the amount and character of the
work already accomplished in advance of the date at which Congress required
it to begin, we are very favorably impressed, believing that there is a prospect
of early and complete success.
The lines of the jetties are now distinctly marked out by the rows of piles
extending seaward on the east side beyond the crest of the bar into twenty-six
feet of water, and on the west side to about twenty feet depth, indicating the
extent and shape of the new entrance.
While it would have been unreasonable to have anticipated at this early
period in the progress of this important undertaking, even as much as has
already been effected, we desire to be careful lest we should ourselves under¬
value or cause others to view lightly the difficulties which yet remain to be
.overcome before the final grand result shall have been attained.
Care should be exercised to strengthen the works already commenced, in
order to enable them to resist the gales of winter ; and too much haste to call
in the river forces for the execution of deepening must be avoided. It is
much safer, while the foundations of the jetties are insufficiently protected by
stone, to allow the present escape of water by lateral avenues.
From what has ali-eady been said, it will have been clearly enough seen
that the Commission did not expect at this early stage in the progress of the
work that much scouring effects would have been produced. Such results
cannot be expected to exhibit themselves in a very marked manner until, by
the closure of the opening (six hundred feet in length) at the heäd of the west
jetty, and by the raising of both the parallel piers to the water surface through¬
out some considerable length, the water shall be confined to its destined chan¬
nel. From the eastern land's end to near the head of the west jetty, the east¬
ern jetty is now for the most part thus raised, while the west bank itself imper¬
fectly fulfills the function of its parallel pier. Throughout this length—say
for four thousand four hundred feet—a marked scouring effect has taken place.
18
274
THE MISSISSIPPI JETTIES.
At this season of the year, when the river is low, the scouring action of the
current is reduced to its minimum. This, while it is the least favorable to the
exhibition of results from the jetty works thus far executed, is the most favor¬
able to their safe and rapid construction. It is quite undesirable that any con¬
siderable deepening of the bar should occur before the spring shall find the
works in a condition to resist and turn to useful account the flood that may
then be expected.
On motion,
Mesolved, That a copy of the minutes and of the foregoing resume be fur¬
nished to Mr. Eads by the Secretary.
Whereupon the Commission adjourned sine die.
J. G. Barnard, President.
Charles A. Hartley,
B. S. Alexander,
W. Milnor Koberts,
Henry Mitchell,
T. E. Sickles,
H. D. Whitcomb.
A true copy from the minutes.
H. D. Whitcomb, Secretary.
APPENDIX V.
(See page 91.)
ESTIMATE OF THE DETAILED COST OP ONE CORD OP MAT¬
TRESS-WORK.
basis of calculation is 53,415 cords, constructed and placed on the
jetties and auxiliary works. from june 30, 1875, to june 30, 1876.
Kinds of Work or Ma-
terial.
Mattress Ways
Guide Piling -J
Mateiials.
Willows
Strips
Pins
Wedges
Cut Spikes, 5-in
Nails, 20íí...!
Rope
Transportation.
Barges (cost, repairs,
pumping)
Transporting
Constr'n Alattresses..
Towing and Placing
Stone.
Delivered
Handling
Barges and Plats....
Towing
Sinking Matts
Total Quan¬
tity.
Detailed Cost.
Am't to One Cost p'r
Cord. Cord
1,300 lin. it. $3.59 pr. lin. it.
2,663 piles. ( Q-i.-r i;-, rt
90,666 lin. it. \ "pr.lin.lt.
58,415 cords.
2,400m it.B.m.
214,000
428.000
20,707 lbs.
23,324 lbs.
74,900 lin. ft.
18,500 cu.yds
14.00 per m.
.02i
.00,',,
.031'n per lb.
.03 per lb.
.06,"uperlin.it.
45 ft. B. M.
4
10
0.5 lbs.
it lbs.
1.4 lin. it.
3.31 cubic yd.
.06 cubic yd.
.43 cubic yd.
.65 cubic yd.
Total $6 330
l,'o lin. it.
0.35 cub. yd
$0.087
0.360
1.480
0.630
0.080
0.010
0.016
0.015
0.092
Total
Co.st p'r
Cord.
|0 087
0.360
2.323
0.340
0.355
0.695
0.800
0.800
0.338
0.338
1.158
0.021
0.150
0.227
1.556
0.171
Waste and Incidentals, 10 per cent 0.633
General Construction Account, 15 per cent 1.044
Cost per cord of Mattress Work.
. $8.007
Cost per cubic yard Mattress Work $1.687
Cost per cubic yard to Mr. Eads 8.972
275
APPENDIX VI.
(See pages 94 and 212.)
DEPTHS (COMPARATIVE) IN LINE OF DEEPEST WATER IN CHANNEL, IN FEET AND TENTHS.
to
c:-
istauco.>
from
May
Dec.
Jan.
Feb.
Mar.
Anl.
May Jiim-
July
-Aug. Sept.
Oct.
Dec.
Mar.
EusC Point.
187'5
1875
1876
1876
1876
a
1
18ÎÔ
1876
1876
1876
1876
1876
1876
1877
East Point.
31.8
37.0
37.0
38.0
38.7
38.0
37.5
37.1
37.1
33.7
33.6
30.0
32.(j
1,000 foot.
21.0
28.3
28 0
28.0
vH.O
28.0
28.5
28.7
2Ü.U
28.8
29.0
27.0
28.4
2.000
21.8
22.8
23,0
23.0
23.2
25.0
23 9
24.0
25.0
24.2
25.5
23.5
25.6
3,000
18 8
22.5
22.0
21.8
21.2
22 3
21.4
21.9
21.6
h'.o
23.9
22.1
25.1
3,500
18.0
20.0
20.0
20.0
20.2
2L8
21.4
21.9
21.1
22.8
23.0
20.9
24.3
4,OJO
18.0
22.3
22.4
22.5
27.4
28.8
37.9
38.5
39 5
39.7
34.9
34.3
33.5
4,500
18.0
23.3
22.9
23.5
22.9
23.3
21 5
23.3
30.3
26.9
25.0
23 5
24.5
5,000
17.9
23 0
21.4
28.5
25.4
27.1
28.0
28.2
30.3
26 3
29 9
26.8
32.0
5,500
10.0
19.8
21.4
23 3
24.9
25.1
27.0
2.). 5
26.8
28.0
27.0
25.2
31.5
6,000
14.3
18.8
22.2
22.6
25.4
m.i
30.6
29.1
27.3
28.5
27.3
25.2
27.5
6,00)
14.0
10.2
18.1
17.2
23.2
24.2
28.1
30.1
26.8
29.3
28 8
24.7
26 2
7,000
13.0
15.6
20.1
24.5
23.4
24.0
24.4
26.0
26.0
25.9
26 4
22 0
23.6
7,484
11.8
13.5
14.6
24.0
22,5
21 8
24.7
27.4
24.9
25.9
26.7
22.3
23.8
8,000
11.0
13.0
14.1
18.0
18.0
22.4
26.9
28.3
26.4
26.6
27.1
22 7
2:5.5
8,200
"
11,0
13.0
14.5
18.0
18.2
28^0
32.4
30.3
28.9
35.1
32.4
25 7
28.8
8,500
"
10.9
13.3
13.1
15.0
20.4
23.2
25.S
27.6
23.9
27.9
26.5
23.7
23.0
9,000
"
10.5
11.8
13.0
15.0
18.0
23.2
26.9
26 8
27.6
28.8
28.9
27.8
2(> •)
9,500
10.8
10.8
11.0
13.0
17.4
20.3
47.3
4.5.0
38.8
309
31.1
29.7
28.1
9,900
10.0
11.0
12.6
14.0
16 0
22.S
33.9
34.0
42.8
38.3
37.0
27,0
29.1
10,500
9.5
9.3
12.0
16.6
18.7
19.8
32.7
38.0
30.8
32.1
29.7
25.1
26.8
11,000
9.2
9.8
12.0
14.6
18.0
19.2
24.5
26.2
28.3
27 0
26.5
21.9
24.2
11,500
9.2
11.3
12.0
15.0
15.9
18 2
22.7
21.5
20.8
23.5
23 3
24.2
21.6
26.0
11,700
"
9.2
16.8
17.0
18.0
15.0
17.0
18.0
21.0
22.4
23 5
22.3
23.0
218
22.6
11,900
12,000
11.8
15.0
18.0
18.5
19.0
18.0
16.5
18.3
22.8
22.5
27.3
34.0
24.5
23.0
20.8
40.8
34.2
13.2
20.8
23.0
m.-i
30.5
20.0
23.0
26.1
25.3
21.0
12,400
"
31.0
40.0
35.0
30.0
47.0
42.0
25 0
20.0
22.8
21.0
44.0
43.4
40.4
12,800
**
35.0
41.8
39.7
44.1
43.4
39.4
Apl.
Juno
July
Sept. Dec.
Feb.
Apl.
May
July
Dec.
Mar.
Jnly
Dec.
Jan.
1877
1877
1877
1877
1877
1878
1878
1878
1878
1878
1879
1879
1879
1880
31.8
35 4
39.7
37.5
37.8
35.0
38 0
32.7
37 6
3() 3
:I3.9
33.9
29.9
31 3
.32.0
m.ñ
li2 4
33.0
31.9
30.4
31.0
30.5
:ii.8
3:3.0
24.4
26.3
26.2
26.4
28.3
211.0
:io.o
31 9
:^().l
30.5
;w.i
33..5
25.1
' 25.8
25 2
28.2
38.8
33.0
38.0
34.7
40.6
40.6
38.6
:3().5
24.2
25.2
27.7
25Ï3
27.3
28.7
29.0
30.7
m.ry
32.4
40,3
42.7
41.5
32.5
27.2
28.3
29.3
31.8
34.7
36.0
:i7.6
35.7
49.9
47.7
:3r).3
41.8
29.4
36.4
76.2
73.6
89.0
91.1
1Ü4.5
100.2
70.3
80.6
84.2
75.4
74.:3
27.7
89.5
85.0
808
79.3
79.2
89.7
85.5
61 3
75.0
82.2
69.3
76.3
55.6
57.5
56.1
65.4
(ir 3
64.0
69.5
55.8
58.5
68.7
61.3
56.8
3().8
38.3
86 3
47.0
.53.3
48.5
50.5
44.8
(>4.5
69.2
61.3
61.3
34.3
35.0
29.3
37.8
39.2
39.5
40 4
51.0
51.3
55.5
56.2
45.7
45.0
24.7
25.5
25.8
25.5
2^1 i
27.0
27.6
31.3
Hi.n
33.0
49.7
47.8
47.0
27.5
30.0
31.2
28.8
28.7
28.1
30.1
30.1
27.:i
28.0
30.5
32.8
35.3
31.6
32.4
30,0
26 8
29.7
31.0
32.1
32.7
2-.3
44.0
36.2
33.0
39.1)
29.8
30 2
30.5
388
32.7
34 6
33.0
34.7
29.5
U.O
36.0
34.9
40.0
28.7
26.0
•-6.7
25.3
26.7
27.1
:^6.2
28.1
28.2
29.0
32.2
32.9
44.0
28.6
30 2
31.0
2 .0
29.0
30.9
:^o.o
30.1
26.4
37.5
37.2
33.8
38.9
29.6
29.0
28.6
30.0
27.9
33.0
31.5
31.0
27.7
30.1
30.5
32.2
36.2
23.0
23.0
26.1
25.3
28.9
31.9
35.5
30.0
27.7
30.4
30.5
32.9
35.3
27.0
28.2
26.0
26.0
31.3
28.:^
:-3.5
34.0
29.4
27.2
35.4
33.2
31.6
31.6
24.3
31.9
27.2
2^.1
24.7
28.1
28.5
37.3
34.0
31.5
31.6
23.3
25.0
25.0
23.4
24.2
28.1
26.1
29.5
26.0
36.3
31.2
32.4
31.7
21,8
25 3
23.0
24.6
24.2
27.0
28.4
29.8
26.3
33.1
30.5
32.9
34.7
20.1
25.7
26.0
29.0
27.1
26.0
30.2
20.4
30.0
31.0
34.2
37.1
39.9
24.2
:32.0
29.1
37.0
35.2
36.0
34.0
34.4
32.5
32.5
33.2
38.1
40.2
38.3
44.6
40.1
45.0
37.2
45.1
40.0
41.0
40.0
30.3
36.3
37.0
40.0
39.4
40.2
37.9
43.5
46.2
48.1
45.2
44.4
42.5
41.0
41.0
41.3
42.1
APPENDIX VIL
(See pages 94 and 312.)
INTERRUPTION OP CONTOURS.
EECOBI) OF DISTANCES IN FEET THROUGH THE BAR BETWEEN THE CONTOUR LINES.
Which Contour.
Î2 Feet
15
18
20
22
24
26
30
May
1875.
4,305
5,925
7.000
9-035
9.G50
10.485
10.585
Dec.
1875.
Jan
1876.
50
4.400 4,175
5,692 4.480
6,215 5.425
9,675 9,650
10,400 10.450
11,225,11,225
Feb.
1876.
0
2,175
3.960
4,490
9.650
10.450
11,225
Mar.
17,
1876.
Mar.
29,
1876.
•450
2.575
3,2.55
7.300
7,9.50
9,600
50
1.180
2.955
5.270
7,600
11,750|ll,700|ll,7ü0]ll,70ü 10,960 .
.April May
1876. 1876.
0 ... .
750 175
2.200 720
3,995 1,9.52
5.975 3,120
7.975 5,5.50
10,325 8,960
July Ang^.
:30, 14.
1876. 1876.
0 ...
75 0
1,350 975
2,750 2,5.50
5,650
8,695 ....
Sej).
1876.
400
2,4.50
4.3.50
9,950
Oct. Dec.
18:6. 1876.
Mar. July
1877.1877.
100 1,0.50 325 200
1,740 5.5.50 3.000 325
4,340 8.6.50,6.500 2,675
9,775,11,150 9,200 0,225
Sep.
1877.
Feb.
1878.
1.50 0
4.50 225
2,40« 1,610
7,250 6,500
Apl. May
1878. 1878.
170 390
300 540
4,650 4,550
July
1878.
Dec.
1878-
0
250
3,650
540
6,250
Mar.
1879.
0
3 525
July
1879.
Dec,
1870.
Jan.
1880.
f>
§
-4
APPENDIX VIII.
(See page 103.)
LETTER PROM JAS. B. EADS TO THE SECRETARY OP WAR.
New Orleans, 3Iay 23, 1876.
Hon. Alphonso Taft, Secretary of War, Washington, D. 0. ;
Sir :—My duty to those who have been and are now supplying me with
money to consummate the grant made by the Porty-third Congress, compels
me, very reluctantly, to call your attention to the inclosed letter (marked A),
signed C. W. Howell, Captain of Engineers, U. S. A., dated May 6, 1876,
and published in the Repuhliean and Democrat, of New Orleans.
I desire to submit with it, as briefly as possible, the following facts :
During the Porty-third Congress, two plans for the improvement of the
Mississippi were presented for consideration. The one known as the Fort St.
Philip Canal was urged chiefly by Gen. A. A. Humphreys, Chief of En¬
gineers, U. S. A., and Major Howell, United States Engineers; and the other,
the Jetty system, by myself and others. The subject was referred by Congress
to a mixed commission, composed of seven distinguished military and civil en¬
gineers, who, after careful deliberation, reported (one member only dissenting)
in favor of the Jetty system : whereupon, Congress- granted to myself and asso¬
ciates the right to improve the South Pass, an outlet unused for commerce;
the grant expressly stipulating that we are to be paid nothing in case of fail¬
ure to secure twenty feet depth of channel through the pass to the gulf, within
a stated period. The act directs the Secretary of War to appoint an officer
" whose duty it shall be to report the depth of water and width of channel
secured and maintained from time to time, in said channel, together with such
other information as the Secretary of War may direct."
The grant expressly provides that " I shall be untrammeled in the exercise of
my Judgment and skill in the location, design, and construction of the works,"
therefore I did not suppose that another officer of engineers, and one, too,
avowedly hostile to the undertaking, would likewise (without authority of Con¬
gress) be charged with the oflflcial duty of observing any part of our work or
its results. Least of all did I suppose that ho would be permitted to give to
the public with perfect freedom such unfavorable and unreliable information
respecting it as might best seem to support the predictions of its failure pre¬
viously uttered so confidently by his chief and himself, and thus really tram¬
mel its construction by increasing my difficulties in providing means with
which to carry it on.
278
MB. EADS TO SECKETAEY OF WAE.
279
Anonymous statements circulated in this city, and subsequently sent hence
by telegraph, have been published in a number of newspapers through the
country, to the effect that a new shoal was forming in advance of tlie jetties,
and that their failure was therefore certain. This report, being persistently re¬
peated, was publicly denounced by me, with perhaps too much feeling, as a
"malicious falsehood," but without supposing that Major Howell was at all
responsible for the statement. Appreciating the importance, however, of re¬
futing such reports by evidence that could not be challenged, I addressed the
Superintendent of the United States Coast Survey as follows:
New Orleaxs, JIarch 7, 1876.
Capt. C. P. Patterson, Supermtendent U. 8. Coast Survey, Washington,
D. C.;
Dear Sir:—Last year Lieut. Marinden made soundings on radial lines sea¬
wards from the bar of South Pass. I very much desire that these radial
soundings should be repeated before Lieut. M. leaves here, and I think j-ou
will agree with me that it is important to know where the one or two millions
of cubic yards of sandy alluvion, which have been swept out of South Pass
from its bar, have been carried and deposited, and what changes, if any, have
occurred in the contour lines off the mouth of South Pass.
Radial lines of soundings should be made from the east and west lands' ends
out to two or three miles off shore.
Hoping that you will kindly oblige me by ordering this work to be done by
Lieut. M., I remain, with sentiments of high esteem, yours very truly.
Jas. B. Eads.
In answer I received the following reply:
U. S. Coast Survey Office, )
Washington, March 10, 1876. f
Dear Sir :—Yours of the 7th is just received.
Authority will be given to Assistant Marinden to run such radial lines as you
may wish, but as he has not the control of a steam launch this season, only his
boats avail for the purpose, and consequently he should run merely such lines
as may be absolutely necessary.
If you could furnish him the use of a small steamer, the work could be
executed more rapidly, and doubtless with more satisfaction to you and himself.
The state of our funds does not enable us to incur the expense of a steamer.
# * * ht *
Yours respectfully,
C. P. Patterson,
Sup't U. 8. Coast Survey.
Jas. B. Dads, C.E., New Orleans, La.
I agreed to furnish the necessary steamboat, and these soundings have now
been nearly completed.
On the 26th ult. a large party, comprising many inffuential gentlemen,
visited the jetties on the mammoth steamer Grand Republic. It was stated in
280
THE MISSISSIPPI JETTIES.
the New Orleans Times, after the return of the boat to New Orleans, that an
assistant of Major Howell had gone on board the boat at the jetties, with a
chart of soundings just taken by him, which he exhibited and explained to the
passengers. I was assured by several prominent citizens of New Orleans, whose
names will be given if desired, that his apparently reliable and oiRcial state¬
ments had created great distrust in the ultimate success of our work through¬
out the whole city, as it was generally believed Maj. Howell's surveys revealed
a rapidly forming shoal in advance of the jetties. 1 was reliably informed
that a large amount of stock subscribed in aid of our undertaking was actually
offered at the time at half its cost in consequence, and I myself received at the
same time a letter asking the release of one of the parties aiding it, from his
obligation to pay a large balance due on his subscripiion.
Knowing the importance of promptly refuting by official testimony these
misrepresentations, I immediately addressed the following additional request
to the Superintendent of U. S. Coast Survey:
Port Eads, La., April 27, 1876.
Capt. C. P. Patterson, Waslimgton, D. C. ;
Dear Sir;—As the changes within our jettied channel have been very great
since Assistant Marinden surveyed the bar, I would respectfully suggest the
importance of having his party sound the depth within the jetties and within
a thousand feet of their mouth.
This work can be done with much greater ease and much quicker now than
before, as I have signal ranges and stations established by which my assistant
engineers make these soundings in two days' time generally. I will be much
obliged if you will order this work to be done as early as possible, and instruct
Assistant Marinden to furnish me a copy of the results. He is now here pre¬
paring for the radial soundings beyond the jetties. I will loan him facilities
for all the work.
^ 4:
Very respectfully.
Jas. B. Eads.
Peeling indignant and outraged at the unwarranted conduct of Maj. Howell's
assistant, I published a letter in the New Orleans Times, herewith inclosed
(marked B), in which I again pronounced the reported shoaling in advance of
the jetties as absolutely false. I had, however, so much confidence in Major
Howell's honor, and in the delicate sense of propriety which characterizes gen¬
tlemen of the army, that I exonerated him in the following language, in the
letter, from any complicity in this effort to injure me and my associates. I
said :
"But as these works are not under the supervision of Major Howell, it is
unjust to him to infer that he has authorized any of his assistants to make an
' official ' survey of the South Pass bar at the Government's expense, or that
he would countenance on the part of his assistant any effort to create in the
minds of the visitors by the Grand Republic, or in those of any other persons
whatever, the false impression that this bar, which has thus far been removed
by the effect of the jetties, is being reformed in advance of them, or that he
would, as readers of your editorial might possibly suppose, permit the draft of
ME. EADS TO SECEETAEY OF WAE.
281
such soundings to be exhibited on the Grand RepuUic or in his office with any
show of ' official sanction.' "
An editorial herewith inclosed (marked C) shortly after appeared in the
New Orleans Democrat, containing statements that could only have been ob¬
tained in IMajor Howell's office, and which apparently sustained this false
report. I immediately answered the editor of the Democrat by letter, a copy
of which is herewith inclosed (marked D), that this and similar reports had
their origin either in ignorance or malice, as they were absolutely untrue. I
did not, however, even then charge Major Howell with being the author or
prompter of them. ' "
This second letter was followed by the publication of the inclosed objec¬
tionable letter of Major Howell, before referred to. Major Howell declares in
this letter;
" On ray own part this considerate silence would not have been broken but
for the recent insidious attacks of Mr. Bads, and after this date I shall feel at
liberty to either repel further attack or let the violence of Mr. Bads of itself
gradually disgust the public."
As "the recent insidious attacks of Mr. Bads " seem to be the only justifica¬
tion offered by Major Howell, you will, after reading my published letters
herein referred to, be able to judge of the merits of this excuse. Of course I
cannot reply to Major Howell's personalities, for when an officer of the army
makes statements that are untrue, and uses.his offlgial signature to give them
additional weight, discussions that might otherwise be justified between us
are at once forbidden. These untrue statements are as follows :
" The fact is, that on the day of the Grand Republic splurge there was at
South Pass only a channel of twelve feet entitled to be called navigable, while
at Southwest Pass there was a navigable channel of over eighteen feet."
"1 know that on the day the Grand Republic visited South Pass the
nucleus of a new bar existed 1,000 feet in front of the jetties, and that a shoal
had made out from the end of the west jetty 380 feet towards this, and diagon¬
ally across the front of the jetties."
"I know that since the commencement of the jetty work the low water
cross section of South Pass, one mile below its head, has been diminished
one-sixth; that the velocity at this point has relatively decreased, and that the
volume of discharge of'the pass which, before commencement of the jetties,
was found to be fifteen per cent, of the total discharge of the three passes, is
now but eleven per cent. Mr. Bads has probably discovered ^these facts, hav¬
ing such a serious bearing on the ultimate success of his work, and knowing
that they will soon be made public through official channels, seeks in advance
to break their force by crying out 'malice,' 'falsehood,' etc."
A direct and positive refutation of four of these untrue and injurious state¬
ments will be found in the following letters from three of the gentlemen
assisting me in the engineering department of the work, and who are no less
respected for their veracity than for their professional abilities.
New Orleans, May 32, 1876.
Capt. J. B. Bads, Chief Engineer South Pass Jetty Works, New Orleans, La.;
Dear Sir ;—The statements of Major Howell, United States Bngineers,
282
THE MISSISSIPPI JETTIES.
contained in his letter recently published respecting this work, having been
referred by you to me for examination, I have to state that there has been no
shoaling in advance of the jetties, but, on the contrary, there has been a very
marked and general increase in the depth immediately in front of the outer
slope of the bar in advance of the jetties, as far out as we have made accu¬
rate examinations, nearly 3,000 feet beyond the jetties. I amable to assert this
in the most positive manner, as we have a number of carefully located ranges
covering the bar and the deep water in front of it, and I have made careful
soundings all .over it at least once and sometimes twice a month for several
months past, each sounding at the moment it was taken being located instru-
mentally from fixed and well verified points of observation. I am able to
state positively that there has, at no time since we commenced work, been any
shoal making out diagonally from the west jetty toward the so-called "nu¬
cleus of a new bar " in advance of it, as stated by Major Howell.
I can also state positively that what he terms "the nucleus of anew bar,"
one thousand feet in front of the jetties, is the remains of a lump shown on the
Coast Survey map before we began the jetties, and from approximately correct
estimates made by me, after comparing, as carefully as possible, the depths
over it a year ago, with those now existing on it, that the cubical contents of
it above a plane thirty feet below the mean level of the gulf, have diminished
nearly one-half. The depth on the shoalest part of it, which is a mere point
or apex, was last year fully three feet less than it is at present. This lump
seems to be soft, tenacious clay. It has deep water all around it, and consti¬
tutes no impediment to the safe and easy navigation of the jettied channel.
I have further to state, that I have made recent soundings across the
South Pass, one mile below the head of it, at the point referred to by Maj.
Howell, and compared them with those of the Coast Survey of last year. I
find no such diminution of its section as Maj. Howell has stated. It has cer¬
tainly not decreased at this point, since the jetties were commenced. I have also
made careful soundings across the pass below Grand Bayou, before the section
of the bayou was reduced by the dam now partially completed, and which now
throws an additional quantity of water into South Pass, and found it consider¬
ably larger than the size shown by Coast Survey soundings made last year.
I would further state that on the day when the Grand Republic visited
the jetties, there was a navigable depth of fully sixteen feet entirely through
the jetties at high tide. It was measured by myself and several other persons
on that day and the day previous.
Very respectfully, etc.,
B. L. CoRTHELL,
Chief Assistant Engineer.
I fully concur in the statements made by Mr. Corthell, and certify to
their correctness. I myself superintended the taking of a line of soundings
into the pass between the jetties, on the day the Grand Republic visited
Port Bads, and in no place found a less depth, at average high water, than
sixteen feet, with only one place so shoal as that.
Very truly yours,
G. W. R. Bayley,
New Orleans, La., May 32, 1876. Resident Engineer.
MB. EADS TO SEOEETAEY OF WAE.
283
Poet Eads, La., May 33, 1876.
Capt. Jas. B. Eads, Nevj Orleans, La. :
I have assisted Mr. E. L. .Corthell in all the surveys that have been made
under his direction at the mouth of South Pass. I have mapped them out
carefully, and from my own studies of the changes that have occurred inside
and outside the jetties, I can fully indorse Mr. Corthell's statements, and tes¬
tify to their correctness.
Very respectfully, your obedient servant.
Max E. Schmidt,
Assistant Engineer South Pass Jetty TVorfe.
About the time Maj. Howell published his letter, I received the following
courteous refusal of my second request from the Superintendent of the Coast
Survey :
United States Coast Survey, )
Washington, D. C., May 1, 1876. j
Dear Sir;—Your letter of April 37th is duly received. I would cheerfully
comply with your wishes, but the law expressly provides that the inspecting
oiBcer of the Engineer Corps (Gen. Comstock) shall execute the class of sur¬
veys you wish within the jetties. ,
The radial lines from the outer ends of the jetties were run at 3'our request,
for the purpose of finding, if possible within their limits, the deposit of re¬
moved material.
I shall be glad to oifer any assistance in my power to Gen. Comstock,
should he express a wish for the survey to which you refer.
Yours respectfully,
C. P. Patterson,
SiipH U. S. Coast Survey.
Jas. B. Eads, Esq., New Orleans.
Immediately after the visit of the Grand RepuUic, Capt. Brown, U. S.
Engineers (assi.stant of Gen. Comstock), commenced a survey of the bar, and
believing that information in his possession would completely refute Major
Howell's assertion, 1 asked him for an official statement of the depths of chan¬
nel at that time. This he declined to give, stating as a reason that he had
not made his report to Gen. Comstock. Learning that the latter officer had
just gone to the jetties, I telegraphed the Secretary of War as follows :
New Orleans, La., May 9, 1876.
Hon. Alphonso Taft, Secretary of War, Washington, D. C. :
Please instruct Gen. C. B. Comstock, now at Port Eads, to sound channel
between jetties with me ; likewise dredged channel through Southwest Pass
bar, and furnish me with the results promptly. Major Howell has published a
misstatement, affecting public confidence in my work, and this information is
required in justice to myself, and will benefit the public.
Jas. B. Eads.
284
THE MISSISSIPPI JETTIES.
I proceeded to the jetties, and met Gen. Comstock on his way bacK. I
urged his return, that he might measure the channel with me, if so author¬
ized by the Secretary of War. On my urgent declaration that a wrong had
been done me, and one that was seriously affecting the prosecution of the work,
Gen. Comstock consented to return, and remained during the day at the jetties
awaiting instructions ; but as no answer to my dispatch came, he left that
evening for New Orleans. He declined to give me any infoi-mation respecting
the depths in question, for the reason that he had not yet made his report to
Gen. Humphreys. Four days after sending my dispatch to the Secretary of
War, I received the following telegram :
Washington, May 13, 1876.
Mr. Jas. B. Eads, New Orleans, La. :
In accordance with the law. Gen. Comstock received authority and instruc¬
tions for complete survey and examination of the South Pass improvement
before leaving Detroit. A copy of the results of his soundings will be fur¬
nished as soon as received.
Alphonso Taft.
On receipt of this telegram I dispatched to the Superintendent of the Coast
Survey, requesting that Mr. Assistant Marinden be permitted to inform me of
the result of his soundings just made, chiefly at my own expense, in advance
of the bar. In reply I received the following telegram :
» Washington, May 16, 1876.
Capt. Jas. B. Bads :
Regret Marinden cannot furnish his results. Gen. Comstock will give all
information required by law. Will write.
C. P. Patterson,
Sup't, etc.
It will be seen that I have been unable at the end of three weeks to obtain
from any Government officials the facts in their possession or control, with
which CO defend this enterprise from the persistent and injurious misrepresen¬
tations which have appeared anonymously, semi-offlcially, and authoritatively
during the last few weeks, and that I have been refused the request to di¬
rect Gen. Comstock, when on the spot, to measure and certify to me the depth
of channel, to right a wrong done by his brother officer. In prominent con¬
trast with the difficulties I have encountered in getting this official infor¬
mation, which would have been of great value to me if promptly obtained, I
quote the following from the letter of Major Howell regarding his surveys ;
" The surveys have been made at government expense, because needed to
aid in solving the great problem presented at the mouth of the Mississippi.
" If the results had been available before the passage of the jetty contract,
it is probable that the country would not have been saddled with the ad¬
venture.
"My charts, observations for velocity of currents, amounts of material
carried in suspension by the river water, and volumes of discharge, have
always been open for the inspection of any courteous gentleman interested in
seeing them. In this there is no impropriety, as Mr. Eads would insinuate."
ME. EADS TO SECEETAET OF WAE.
285
I have no reason whatever to complain of the course pursued by Capt. Pat¬
terson, Gen. Comstock, or Capt. Brown in this matter, as it has been, I believe,
in strict accordance with official propriety.
Major Howell says;
" I know that between distances two and a half and seven and a half miles
seaward of the outer end of his jetties, the gulf has shoaled at a rate which, if
continued, will in eighteen high-water seasons bring the gulf bottom to the
surface, and necessitate the prolongation of the jetties at least seven and a half
miles."
When it is understood that this reputed shoaling was known before the
jetties were commenced, and that no soundings have been made over it since
last November, to determine whether it is increasing or diminishing, at which
time the eroding action of the jetties had scarcely begun, its " serious bearing
upon the ultimate success of his (my) work " can be estimated, as well the
fairness of the writer in leaving his readers to infer that this shoaling is an
evidence of the truth of the prediction of himself and his chief regarding the
reformation of the bar.
An extension of the jetties of seven and a half miles in eighteen years, or
nearly six feet per day, would not be incompatible with the following assur¬
ance given to the New Orleans Chamber of Commerce by Major Howell, and
which will be found in his letter to Mr. J. H. Oglesby, president, that, as no
littoral current exists at the mouth of the Mississippi, " jetties would have to
be built further and further out, not annually, but steadily every day of each
year, to keep pace with the advance of the river deposit into the gulf, pro¬
vided they are attempted, and the attempt warranted by having the relative
character of bed and banks favorable."
I quote again from Major Howell's inclosed letter as follows:
" Holding these views, no army engineer has thrown a straw in the way
of Mr. Eads's jetty work."
This is another misstatement. After the Jetty system was finally adopted
hy the last Congress, Gen. Humphreys published four essays, termed by him
"memorandums," to prove that the jetties would be a failure; these were
published as a part of his official report to the present Congress. They were
at the same time extracted from that voluminous document and illustrated
with maps, were bound in pamphlet form and distributed throughout the
country five months ago. To counteract the injurious effect of these private
opinions of Gen. Humphreys, to which he gave all the weight of his official
titles and position, I deemed it necessary to expose the fallacies upon which
his arguments were founded, by reviewing the United States Levee Commis¬
sion's report, which was based upon the same unsound theories, and to which
report he had given his emphatic approval.
Major Howell endeavors to excuse this conduct of his chief in the closing
words of the following extract :
"Since the passage of the late jetty contract, those opponents of the ex¬
periment who took part in the discussions preceding the passage of the
contract, considered, first, that they were in no way responsible for the experi¬
ment. Second, that further discussion would be useless, except so far as
required to complete that left unfinished by the action of Congress."
Admitting Gen. Humphreys's ability to complete discussions left unfinished
286
THE MISSISSIPPI JETTIES.
by Congress, his justification in this case would have been more satisfactory
had Major Howell informed his readers by what authority an officer of the
United States Engineers presumes to publish his gratuitous opinions at the
public expense, or to indirectly criticise the President and Congress of the
United States for declining to be guided by the judgment of Gen. Humphreys
and Major Howell in this matter.
But few persons inexperienced in the difficulties of raising the large j
amounts of money required in works of great magnitude, can appreciate the
injurious effects of unfavorable arguments or apparently well authenticated
reports against an enterprise, especially when they involve, if correct, the cer¬
tain loss of capital invested. For several weeks past we have, through the
self-acknowledged conduct of Major Howell, been seriously trammeled in the
prosecution of the works we are constructing, by misrepresentations to which
have been given a real or seeming assurance of official truth, while it has been
out of my power to obtain, officially, the real facts to disprove them.
In view of the annoyance and embarrassments already suffered from the
official antagonism of Gen. Humphreys and Major Howell, and of the fact that
their official positions give them the ability to continue their open or insidious
opposition to this work (the one being Chief of the Corps of Engineers, U. S. A.,
and the other stationed in this city in charge of important engineering opera¬
tions in the vicinity), I have to respectfully ask that any further officious or
unauthorized official interference on the part of these officers be interdicted,
and that instructions be issued to the inspecting officer authorized by the act,
and " detailed" by you to make the examinations, to promptly supply me with
any official information he may from time to time acquire respecting these
works and their results, which I may deem important to facilitate us in carry¬
ing out the intent of the grant, or in protecting us from misrepresentation ;
and that his reports hereafter be made directly to the Secretary of War, instead
of through the medium of the Chief of Engineers, U. S. A., as the Secretary of
War alone is, by the words of the grant, "authorized and directed to carry
into effect the provisions of the act."
We are assuming all risks and expending our own money under a grant
which gives us no power to deceive the government, even if we desired to.
Our compensation depends wholly upon results to be achieved, and upon the
good faith of the government. We were entitled to eight months to commence
the work, and thirty months within which to secure twenty feet of depth, yet
before fifteen h^ve elapsed the largest coasting steamers trading to New Or¬
leans have been sent to sea over the bar on which scarcely eight feet of water
could be found last year. We have thus shown an energy and good faith not
only entitling us to the moral support of the government, but to its confidence.
I cannot believe for a moment that the policy of your department will, with
your sanction, be allowed to embarrass me in the prosecution of a work of such
immense importance, when the untrammeled control of it was confided to me
by the almost unanimous action of Congress, and the approval of the Presi¬
dent of the United States.
I have the honor to be, very respectfully.
Your very obedient servant.
Jas. B. Eads. j
ME. EADS TO SECEETAEY OE WAE.
287
"A."
[From the New Orleans Bemccrat, May 6, 18ÎG.]
United States Engineer's Office, )
New Orleans, La., May C, 1876. (
Editor Democrat :—Your editorial of the third instant, elicited by the
lengthy telegram of James B. Eads, which appeared in the New Orleans Times
of April 30th, has provoked Mr. Eads into writing a letter (published in your
issue of the 4th inst.) which is calculated to create a wrong impression on the
minds of the public.
Mr. Eads is mistaken in supposing that because he has a contract to try to
imiirove South Pass, this fact bars me from continuing to completion a series
of surveys made, commenced under orders received two years ago. The series
would have been incomplete without the recent gauging of the passes and re-
connoissance of South Pass bar.
The results, when fully submitted to the public, will greatly interest hy¬
draulic engineers, and go far toward refuting many of the absurd statements
and theories advanced ny Mr. Eads before commencing his jetties, and on
which all his specious plans are based.
Perhaps this is the reason why, in his usual brow-beating manner, with
which the jieople of New Orleans are so familiar, he attempts to choke off in¬
vestigation.
The surveys have been made at government expense, because needed to
aid in solving the great problem presented at the mouth of the Mississippi.
If the results had been available before the passage of the jetty contract, it
is probable that the country would not have been saddled with the adventure.
My charts, observations for velocity of currents, amounts of material car¬
ried in suspension by the river water, and volumes of discharge, have always
been open for the inspection of any courteous gentleman interested in seeing
them. In this there is no impropriety, as Mr. Eads would insinuate.
The insinuation in regard to the St. Louis telegram is one that no just man
would give such publicity to without first satisfying himself as to the facts. I
have not seen a copy of the telegram; do not know what it contained; but I
know this, that if the information on which it was based came from my office,
and was honestly used, instead of being, as styled, a " malicious falsehood,"
it was the unpalatable truth.
The more direct charge, that my assistant endeavored to create among the
guests and passengers of the Grand Repuhlio an impression unfavorable to the
jetties, is equally without foundation.
After investigating the matter, I find these to be the facts : Mr. Collins,
having completed his field work, in accordance with his instructions to return
to New Orleans as soon as possible, took passage on the Grand Republic, paid
his fare, simply answered questions when courtesy required it, and was an in¬
terested observer of the solemn farce entitled " Col. Andrews's examination."
There was no volunteered attempt on his part to influence the minds of
the St. Louis delegation against their "Josh," his work or his teachings.
By implication, the accuracy of the work done by my assistants has been
brought in question.
288
THE MISSISSIPPI JETTIES.
Mr. Collins has been with me over four years. He has worked in the field
with three of my military assistants, who report him to me as an accurate,
rapid, and extremely conscientious engineer. I place full faith in his reports.
The results of dredging at Southwest Pass are very unfairly presented.
The reported mean low tide depth at Southwest Pass is introduced in such
artful connection with a reported high tide depth at South Pass, that the casual
reader would be led to think the depth of channel at the two passes the same;
whereas, the fact is, that on the day of the Orand Republic splurge there
was at South Pass only a channel of twelve feet entitled to be called nav¬
igable, while at Southwest Pass there was a navigable channel of over eighteen
feet.
Now, leime give my understanding of the position held by Mr. Eacls ami
the opponents of his jetty attempt. It may give the public something worth
thinking ever.
I know that - between distances two and a half and seven and a half miles
seaward of the outer end of his jetties the gulf has shoaled at a rate which, if
continued, will in eighteen high-water seasons bring the gulf bottom to the sur¬
face, and necessitate the prolongation of the jetties at least seven and a half miles.
I know that on the day the Orand Republic visited South Pass the nucleus
of a new bar existed one thousand feet in front of the jetties, and that a shoal
had made out from the end of the west jetty, three hundred and eighty feet
toward this and diagonally across the front of the jetties.
I know that since the commencement of the jetty work the low water cross
section of South Pass, one mile below its head, has been diminished one-sixth ;
that the velocity at this point has relatively decreased, and that the volume of
discharge of the pass which, before commencement of the jetties, was found to
be fifteen per cent, of the total discharge of the three passes, is now but eleven
per cent. Mr. Eads has probably discovered, these facts, having such a seri¬
ous bearing on the ultimate success of his work, and knowing that they will
soon be made public through official channels, seeks in advance to break their
force by crying out " malice," " falsehood," etc.
Since the passage of the late jetty contract, those opponents of the experi¬
ment who took part in the discussions preceding the passage of the contract
considered, first, that they were in no way responsible for the experiment.
Second, that further discussion would be useless, except so far as required to
complete that left unfinished by the action of Congress. Third, that as the
experiment had been decided upon, it was every way desirable that it should
be carried to completion, in order that a question which has embarrassed the
mouth of the river problem for forty years, and which might do so for an in¬
definite time to come, should be practically settled one way or the other, beyond
resuscitation.
Holding these views, no army engineer has thrown a straw in the way of
Mr. Eads's jetty work.
His "outside speculations" regarding the closure of the "Jump" and
"Cubit's Gap," and his crude ideas about the improvement of the upper
river, have been criticised, but his jetty adventure has been lot alone. It now
appears that it has been let too much alone to suit his'present purposes.
On my own part, this considerate silence would not have boon broken but
for the recent insidious attacks of Mr. Eads, and after this date I shall feci at
ME. EABS TO SECEETABY OF WAE.
289
liberty to either repel further attack or let the violence of Mr. Eads of itself
gradually disgust the public.
In closing, I offer an opinion, which perhaps I am not alone in holding.
The repeated cries of "success" which we have heard from the very com¬
mencement of the jetties are deceitful. There can be no success except of a
United States Treasury raid until it is ascertained that the jetties are of a per¬
manent character, and afford something more than a temporary outlet to the
commerce of the Mississippi valley.
I am, sir, very respectfully yours,
C. W. Howell,
Capt. of Engineers, United States Army.
"B."
[FromN. 0. Times, 30th April.]
[Special Telegi'am to the Times.]
Poet Eads, April 29, 1876.
Editor New Orleans Times :—In reading your editorial of Friday morn¬
ing, I observe that in alluding to the soundings made through the channel
across the bar of the South Pass, in the presence of Captain Thorwegan and a
number of distinguished passengers on the Orand Republic, you say, "Prom
this it seems plain that a vessel drawing sixteen feet can go to sea through the
jetties at mean low tide any day." ****«■
" All this was very gratifying and encouraging to the visitors. Only one ugly
feature was to be observed, and that was a draft of soundings made by an as¬
sistant of Capt. Howell on the morning of the same day, which draft is said
to be now in Capt. Howell's office." You state in the editorial that this draft
of Capt. Howell's assistant shows soundings four hundred feet out from the
sea end of the jetties, and that the water shoals up there suddenly to sixteen
feet. You add these words, "Assuming these soundings to be official and cor¬
rect, the general impression would be that a new bar is forming, not on the
sea slope of the old one, but on the other side of a narrow sound, across which
the swift current of the river carries its sediment to be suddenly dropped at a
certain distance out. This is a very disagreeable feature of the case, and we
sincerely hope it may be satisfactorily explained away. If it cannot, the
sooner the fact is known the better." It is only two days ago that I author¬
ized the Secretary of the South Pass Jetty Company to state in reply to tele¬
grams sent from New Orleans to St. Louis, and published in the papers of the
latter city, "that the reported shoaling in front of the jetties was a malicious
falsehood." I was justified in thus emphatically expressing these anonymous
misrepresenhations, by recent soundings carefully made by my assistant en¬
gineers, within a thousand feet of the sea end of the jetties and beyond the
bar.
These soundings were carefully located by instruments, and were compared
with those made one year ago by the United States Coast Survey. They prove
conclusively that there has been a general deepening in advance of the bar in
19
290
THE MISSISSIPPI JETTIES.
front of the jetties, precisely where Gen. Humphreys, Major Howell, and
other opposers of the jetty system predicted a reformation of the bar. The
deepening is shown by these soundings to be several feet in depth over an area
of 1,000,000 square feet beyond the outer slope of the bar. At my solicitation,
the Superintendent of the United States Coast Survey, Capt. 0. P. Patterson,
has instructed Assistant Marinden, United States Coast Survey, who made the
survey last year, to run out radial lines of soundings from the sea ends of the
jetties to a distance of three miles, or into about thirty fathoms of water, for
the purpose of ascertaining what deposit has been made within that distance
since we commenced work. This duty Mr. Marinden is to-day performing,
and the results will, I presume, be promptly furnished to the public by the
Superintendent of the Coast Survey, through the proper department. The
steamer employed in this service is furnished by me. The cause of the remark¬
able deepening, which our soundings have discovered immediately in advance
of the bar, is attributed by me to the fact that the river current, now concen¬
trated between the jetties, is a strong, bold stream, from 12 to 16 feet deep,
possessing such momentum and force that the prevailing westerly sea current,
which intersects it nearly at right angles, is forced beneath the river discharge,
and has excavated for its own accommodation an increased depth on the sea
slope of the bar. Before we began work, the river discharge constituted but
a feeble and shallow film of water, several thousand feet wide and only two
or three feet in average depth, and would oppose but little resistance to the sea
current. With this dispatch, I have directed to be handed to you a litho¬
graphic plot of the United States Coast Survey soundings of last May, on
which are shown the jetty lines also ; several hundred copies of these charts
have been sent by me during the past six months to parties interested in the
enterprise, with our own soundings marked thereon, to show them the changes
in depth from time to time. You will see from this chart that about 800 feet
in advance of the jetty line the Coast Survey soundings show a small shoal
spot, on which there was then only twelve feet of water. Upon the shoal
Capt. Howell's assistant, it seems, found 16 feet last Wednesday. As the great¬
est depth across the crest of the bar is only claimed to be 16 feet 4 inches, it
would seem unreasonable that the river current should have scoured off more
than three or four feet of this shoal 800 feet in advance of the bar crest, be¬
cause the river current cannot act outside the jetties at any greater depth
than that at which it flows on over the bar crest, the river water being of
lighter speciflc gravity than that of the sea.
This depth of 16 feet, which really is on this spot to-day, indicates the
very opposite of what you fear, and what the jetty opposers so emphatically
declared would occur. It does not indicate in the slightest degree any refor¬
mation of the bar beyond the jetties, but, on the contrary, it proves that so fast
as the compact current of the river deepens the crest of the bar, it likewise
cuts down this solitary lump, which the Coast Survey sounding of last year
discovered in the deep water of the gulf immediately in advance of the jet¬
ties, which will disappear in due season, and which to-day has from thirty to
forty feet of water all around it. I was informed that Major Howell's steam
Survey launch had come around into South Pass on the day the Grand Repub¬
lic was expected here, and that his assistant had taken some random sound¬
ings through the jetties at that time, and that a draft of these soundings was
ME. EADS TO SECEETAEY OF WAE.
291
exhibited to the passengers of the Grand Republic, which yon say " was the
only ugly feature of the occasion." But as these works are not under the su¬
pervision of Major Howell, it is unjust to him to infer that he has authorized
any of his assistants to make an " official " survey of the South Pass bar at the
government's expense, or that he would countenance on the part of his assist¬
ant any effort to create in the minds of the visitors by the Grand Republic,
or in those of any other persons whatever, the false impression that this bar,
which has thus far been removed by the effect of the jetties, is being reformed
in advance of them, or that he would, as readers of your editorial might pos¬
sibly suppose, permit the draft of such soundings to be exhibited on the
Grand Republic or in his office with any show of " official sanction."
Jas. B. Eads.
"C."
[From New Orleans Democrat, May 3.]
THE JETTIES.
Official Pacts, and Figures about them.—How the Department of United
States Engineers Obtain their Soundings.
Capt. Eads comes out in a communication to the Times, in which he reiter¬
ates his assurances concerning the condition of the jetties, and refutes the
statements of other people; and he takes occasion to say that he has instructed
the Secretary of the South Pass jetties to state in reply to telegrams from New
Orleans to St. Louis, "that the reported shoaling in front of the jetties was a
malicious falsehood." Further on, Capt. Eads says; "But as these works are
not under the supervision of Maj. Howell, it is unjust to infer that he has au¬
thorized any of his assistants to make an official survey of the South Pass bar
at the government's expense, or that he would countenance on the part of his
assistant any effort to create in the minds of the visitors by the Grand Repub¬
lic, or in those of other persons tchatever, (the italics are ours) the false impres¬
sion that this bar, which has thus far been removed by the effect of the jetties,
is being reformed in advance of them, or that he would, as the readers of your
editorial might possibly suppose, permit the draft of such soundings to be ex¬
hibited on the Grand Republic, or in his office, with any show of 'official sanc¬
tion.'" Certainly, in penning the above quotations taken from his communi¬
cation, Capt. Eads was reckoning without his host, as the saying is, and his
deductions in the last paragraph must fall to the ground when he is informed
that the drafts of the soundings of Maj. Howell's assistant, Capt. Collens, are
exhibited in his office with a considerable show of " official sanction." In fact,
the soundings are made "officially " at the government's expense, and are part
of a series of coast surveys which are under Maj. Howell's supervision, al¬
though the jetty works may not bo, and if Capt. Eads doubts the truth of
this statement, he can visit the office of Maj. Howell and satisfy himself. He
will find there charts made from time to time of the South Pass, of so elabo¬
rate a character, that he will confess that by comparison his own lithographed
charts must pale before them. It is useless to refer to the " malicious false-
292
THE MISSISSIPPI JETTIES.
hood " portion of Capt. Eads's communication, in so far as it might afleot
those "other persons -whatever," also spoken of by him. These utterances
■were made under circumstances which exist no longer, since it is now told to
Capt. Eads that the reports, or some of them at least, were based on the "offt-
cial " figures of the Engineer Department. That Capt. Eads is entitled to
belief when he asserts that his soundings are true, nobody will deny, but credit
is also due to Maj. Howell and his assistants in the same relation. If, how¬
ever, the question of correctness is raised on the score of favor or opposition to
the jetty system, Mr. Eads's position becomes delicate, but that of Maj. How¬
ell remains unchanged, whatever may occur in the case of the opppsers of the
system. Capt. Eads is largely interested in the success of the jetties. His
money and that of his friends, to the tune of several hundred thousand dol¬
lars, is jeoparded, and his reputation is involved. He has everything to lose.
Maj. Howell, like all engineers of his ability, may and must have his theory
on the subject, but he has neither money nor reputation involved. He is
simply performing a duty. If, in performing this duty, the results confiiet
with those obtained by Capt. Eads, there can be no impropriety on the part of
the department engineers to give access to their records, when politely re¬
quested to do so.
Now, to facts; they are few but important. During last week, as was stated
in the Democrat, Capt. Coliens was engaged in taking soundings of the Pass,
and yesterday had already compiled and collated a good portion of his work.
This compilation shows that the west end shoal, which a year ago was 800
yards beyond the end of the jetty, was, on the 36th of April last, thrown out
to 1,000 yards, and from the radial soundings taken by the same officers, ex¬
actly 380 feet out of the jetties; the bar has simply been pushed out, slope,
shoal and all, as though it had been bodily removed from one point to another,
showing, however, a difference in favor of Captain Eads, at the crest of the
present bar, of something like a foot in depth of water. But it is shown by
the profiles that the crest of the shoal, as it existed a year ago, was a mei'e
peak, the crest of which has easily ceded to attrition. Again, it is shown by
the same profile that the breadth of the shoal, as it is now, is considerably in¬
creased, and hence will require more force to be removed than previously.
That the soundings have been carefully and elaborately made by the United
States engineers will be understood when it is said that they have been made
in ten longitudinal sections, one hundred yards wide each (the width of the
jetties being one thousand yards), according to the regulation instructions of
the War Department. The profiles are complete, and with their aid, and after
making all due allowances. Major Howell has traced a possible fifteen foot
channel to the west end of the jetties, where the depth on the shoal is about six¬
teen feet. He has, however, been unable to trace a similar channel to the
east end, where the depth of water is far greater.
As to the volume of discharge upon which Captain Eads depended so much
to scour out the channel of the jetties, Major Howell's belief that it had dimin¬
ished in the South Pass and increased in the Southwest Pass has been verified
by actual measurement. The velocity was taken one mile below the head of
South Pass and below Glrand Bayou. In Southwest Pass it was taken at
Scott's, two and a quarter miles below the head of the pass. Major Howell's
assistants have besides discovered, also by accurate measurement, that the in-
J
ME. EADS TO SECEETAET OF WAE. 293
crease in the area of water in Southwest Pass was, on the 20th of April, fifteen
per cent, above last year's measurement, while in South Pass the increase was
only one-tenth, notwithstanding that the Mississippi is much higher at this
period than when the measurements were taken last year.
In connection with the condition of South Pass, the following is given, show¬
ing that of Southwest Pass :
United States Engineer Office,
New Orleans.
memorandum.
During the month of April, 1876, the depth of the channel at Southwest
Pass, at mean low tide, was 16 feet, with a least width for that depth rang¬
ing from 40 to 100 feet.
High tides ranged above mean low tide from 2 to 2 J feet, making the depth
of channel at high tide range from 18 to 184 feet.
The dredge-boat worked on the bar during the month eighty-one
hours and fifty minutes.
The following number of vessels crossed the bar during the month :
Steamers in 27
" out ; 24
Sailing vessels in 41
" " out 92
Total 184
Of these sixteen drew from 18 feet to 18 feet 9 inches. Of this number,
nine, drawing 18 feet and over, were detained an aggregate of seventy-six
hours ; seven, drawing less than 18 feet, were detained an aggregate of one
hundred and thirty-one and a half hours.
"D."
[From the New Orleans Democrat^ May 4.]
LETTER FROM CAPT. EADS.
The Jetties Seventeen Feet on the Bar.—A Permanent Increase'in the
Depth on South Pass Bar.
New Orleans, May 3, 1876.
Editor Democrat :
Dear Sir:—I have read your article in this evening's Democrat, by which
your readers are informed that official soundings of the South Pass bar have
been elaborately made by Major Howell, United States Engineers. You say :
" In fact, the soundings are made officially at the government's expense, and
are a part of a series of coast surveys which are under Major Howell's super¬
vision, although the jetty works may not be."
This is the first declaration I have seen published to the effect that Major
Howell, United States Engineers, is also making official soundings of the
pass, and your editorial seems to go into such details as to leave but little
294
THE MISSISSIPPI JETTIES.
doubt that you have obtained your information from his ofSce, as you say if I
will go there I will find ' ' charts there, made from time to time, of the South
Pass of so elaborate a character that he (I) will confess that, by comparison,
his (my) own lithographed charts must pale before them."
Gen. C. B. Comstock, United States Engineers, was appointed by the Secre¬
tary of War to discharge the same duty which, it seems by your editorial, is
being performed by Major Howell and his assistants. Gen. Comstock's assist¬
ant, Capt. M. R. Brown, United States Engineers, and party were yesterday
engaged at the jetties in making elaborate soundings by order of the War
Department also, and radial soundings, immediately in advance of the jetties,
are likewise being made by the United States Coast Survey.
Elaborate soundings are made at least once a month, and sometimes twice
per month, by ray Chief Assistant Engineer, Mr. E. L. Corthell, assisted by
Mr. Max E. Schmidt and Mr. W. L. Webb, civil engineers, the results of
which have from time to time been promptly published by me. It would
seem, therefore, that between the cost to the government and to myself and
associates, the public are likely to be well informed upon the subject.
There seems to be, however, considerable discrepancy, by your statement,
between the results of Major Howell's and my own soundings on the bar; and
especially respecting the reformation of the bar in advance of the jetties.
On the appearance of anonymous telegrams in the St. Louis papers, sent
recently from this city, stating that the water was shoaling in advance of the
jetties, 1 authorized the emphatic declaration to be made by the South Pass
Jetty Company's Secretary in that city, that this report was a " rhalicious false¬
hood." 1 say so still, although it seems less anonymous than before.
Your editorial leaves but little doubt of the fact that j'ou have been misled
by information derived from Major Howell's office. You say, " This compila¬
tion shows," among other things you mention, " that the bar has simply been
pushed out, slope, shoal and all, as though it had been bodily removed from
one point to another," etc. To this 1 have only to reply that any "com¬
pilations," or charts of soundings, showing any such result as this, are abso¬
lutely false and unreliable.
The contour lines of soundings on the outer slope of the bar embrace
between the width of the jetties 1,000 feet, and these lines have frequently
altered, sometimes receding on the east side of this width and advancing on
the west, and again retreating and advancing on the opposite sides ; and again,
these lines have retreated and advanced in the middle of the jetties, leaving
nearly c(iual depths on each side of a middle ground at their mouth. On the
85th ult. we had a channel of nearly equal depth on each side of such middle
ground, while on this latter, the depth was but two or three feet less than in
these channels. Last Sunday the depth in the east one was sixteen feet,
and in the west sixteen and a half feet, while but thirteen feet was over the
shoal between them. At no time, however, have these contour lines advanced
on one part of the bar front without retreating on some other, and there has
not been, and is not to-day, any average advance all over the front of the bar.
At no time has any part advanced anything like so much as you assert. The
eighteen foot contour line, for instance, is not to-day further seaward than it
was a year ago, while the deeper contour lines have nearly all retreated ; that
is, have come further landward, making the outer slope of the bar steeper
ME. EADS TO SECEETAET OP WAE.
295
than ever before; while beyond the thirty foot contour line the deepening has
been very decided, ranging from one to fifteen feet. I repeat therefore, em¬
phatically, that the reported shoaling in front of the Jetties, or the reformation
of the bar on its sea slope—a phenomenon confidently predicted by Major
Howell and other opposers of the Jetty system—has not occurreä, and that the
effort now being made to create this belief is founded in ignorance or malice.
The cavilers at this improvement declare they have come through the
jetties and found places with but ten or twelve feet on them, when we have
reported fifteen or sixteen. They ignore the fact that the Jetties are 1,000
feet wide, and expect to find the maximum depth from Jetty to Jetty, yet
praise the channel maintained by the dredge-boat at Southwest Pass to a
degree that makes it surprising that any one should want a better one, al¬
though a deviation of thirty feet from its centre ghes but fifteen feet or less,
and within a distance not one-quarter of the width of the jetties there is but
eight or nine feet.
The persistent misrepresentations and hostility shown by a portion of the
citizens and press of this city to this enterprise, is one of the most unexpected
and remarkable features developed by it. I was led to believe that every in¬
telligent citizen of New Orleans wanted deep water at the mouth of the river.
I came here with the authority of Congress to improve the shallowest one of
the passes, and one not at all used for commerce, and having at high tide
scarcely more than eight feet on its bar. I offered to interest the citizens of
New Orleans in such pecuniary profits as I might realize by success. The
plan proposed had been subjected to one of the most thorough discussions, and
was sustained by the opinions of the very ablest engineers in the world. A
very few enterprising citizens hero aided me with their means, and with this
aid and that supplied by myself and parties in St. Louis and New York, we
have been at work less than eleven months, spending our own money, creating
no interruption to the old channels of the river, and in that time we have
obtained a permanent increase in the depth on the South Pass bar, which is
steadily improving, and which is to-day only one foot less than the dredged-out
groove at the Southwest Pass ; and yet one would suppose from the fault-finding
that we were increasing the expenses of the government, or wasting the money
of all these grumblers. "Whereas I have yet to hear one word of doubt or
complaint from the genuine public-spirited men who are spending their own
money under my direction in this important work, and the noble-hearted ones
who are giving it a moral encouragement scarcely less potent and important.
I had not closed the reading of your editorial when I was handed the
accompanying telegram from the jetties. As it is the very latest intelli¬
gence, it may possess some interest to the public. I will merely add that
" average fiood tide," referred to in dispatch, is about six inches below the
level of the recent tides in the Gulf of Mexico.
Very truly, etc.. Jas. B. Eaes.
Port Eads, May 3, 1876—6:15 p. m.
Capt. Jas. B. Eads:—From soundings taken this afternoon, I find seven¬
teen (17) feet over the bar at average flood tide, with channel above deepening
at every point. E. L. Cobthell,
Chief Assistant Engineer.
APPENDIX IX.
(See page 127.)
Estimate of the Detailed Cost of Construction of Dam No. I.—Head
of the Pass.
Piling, two main rows, per lineal loot of piles driven $0.14^
" " " " " " " dike 60
" " " " with bracing, per lineal foot of dike 1.53
Mattresses, foundation, per cord sunken 5.48
" tilted " " in place 4.71
" foundation and tilted, per lineal foot of dike 4.38
Cost per lineal foot of dike 5.91
Note.—General expense account does not enter into the above estimate;
it includes simply materials actually used and labor performed by boats and
men.
296
APPENDIX X.
(See page 142.)
REPORT OF A C0M3ÍISSI0X
CoNSiSTiNa of J. Gr. Barnard, Col. of Engineers and Brevet Maj.-Gen.
U. S. A. ; H. G. Wright, Lt.-Col. of Engineers and Brevet Maj.-Gen.
U. S. A. ; B. S. Alexander, Lt.-Col. of Engineers and Brevet Brig.-
Gen. U. S. A.,
upon the works for the
IMPROVEMENT OF THE SOUTH PASS
of the
MISSISSIPPI KIYER.
[Special Orders No. 229.]
Headquarters of the Army, \
Adjutant-General's Office, V
Washington, November 2, 1876. ;
[Extract.]
1. By direction of the President of the United States, a commission, to
consist of the following-named officers of the Corps of Engineers, is hereby
appointed to meet in New York city on November 6, 1876, or as soon there¬
after as practicable, to report for the information of the Secretary of War an
opinion upon certain subjects connected with the improvement of the South
Pass of the Mississippi River.
Detail for the Commission.—Col. John G. Barnard, Lieut.-Col. H. G.
Wright, Lieut.-Col. B. S. Alexander.
The commission will be governed by instructions to be communicated by
the Secretary of War.
***»««***
By command of Gen. Sherman:
E. D. Townsend,
Adjt.-Oen.
Official: ,
L. H. Pelouze,
Asst. Adjt.-Oen.
297
298
THE MISSISSIPPI JETTIES.
War Department, i
Washington, D. C., November 3, 187C. f
Gentlemen:—I present herewith for your guidance, the instructions re¬
ferred to in the inclosed special order.
The purpose in assembling yeur commission is not to interfere in any way
with the duties of MaJ. C. B. Comstock, the ofBcer of Engineers, who has
faithfully performed the duties assigned to him under the act, viz., "to report
the depth of water and width of channel secured and maintained from time
to time in said channel, together with such other information as the Secretary
of War may direct," but to obtain your professional advice upon certain points
which the law requires the Secretary of War to decide upon.
The questions upon which I desire your opinion are as follows :
First.—Is the shoal at the head of the South Pass a part of that pass, or
of the main Mississippi Hiver ?
If Mr. Eads obtains a channel twenty feet in depth in the South Pass, ex¬
clusive of this shoal, is he entitled under the law to his first payment of half a
million dollars ?
Second.—What depth and width of channel is it desirable to secure per¬
manently through this shoal?
Third.—What is your interpretation of the words "average flood-tide," as
used in the second section of the act ?
It appears from the records that on the 18th May, 1875, Maj. Comstock
propounded this same inquiry to the Chief of Engineers (copy of his letter
herewith), and that that oflicer decided, and the Secretary of War approved
his decision, that "the average flood-tide should be determined by excluding
the effects of variations in the river's discharge."
Mr. Eads now appeals to have this decision set aside for the reason that
"average flood-tide cannot be determined at the head of the pass, if any of
the natural conditions affecting that level are disregarded." ♦
"Neither the moan effect of the winds nor the mean effect of the rise and
fall of the river can be ignored in determining the plane of mean or average
flood-tide even at the mouth of the pass, nor can either one be disregarded in
fixing the plane of 'average flood-tide' at the head of the pass."
In this connection you will please examine the United States Engineer's
gauge, and recommend what point upon it should indicate the plane of "aver¬
age flood-tide " or zero of reference for all measurements of depth.
Fourth.—I desire a full expression of your opinion as to "the materials
used, and the character and permanency with which the jetties are being con¬
structed," and as to whether the work is being constructed according to the
spirit of the act, as mentioned in the tenth section thereof.
Fifth.—I should be glad to receive any general suggestions, in connection
with this very important work, which you think will assist me in performing
the duties required of the Secretary of War by this act.
In order to assist you in forming your opinion, you are authorized to visit
the works at the South Pass, and to proceed to this city, if you consider it
necessary to consult any records here.
The sum of two thousand dollars will be placed to your credit from the
appropriation for contingencies of the Army, and it is hoped that your ex¬
penses may be kept within that sum.
COMMISSION OF 1876.
299
A copy of these instructions has been sent to 3Iaj. Corastock, and he has
been directed to aSord you every facility in his power to aid you in your inves¬
tigations.
Mr. Eads has also been notified of your appointment, and has been informed
that you will be ready to receive any communications he may wish to submit to
you.
The unpublished records on this subject are now in my office, and will be
open to your inspection, or copies will be sent to you, if desired.
The printed documents you are probably familiar with, including the three
reports by Maj. Comstock upon the progress of the works. The fourth report
of that officer, dated September 20, and giving the depth of water on August
17, is now in the hands of the printer, and will be forwarded to you as soon as
received.
Maj. Comstock has also been requested to make another survey during the
present month.
I desire that your investigations be prosecuted with the utmost dispatch
consistent with their great importance.
If it is feasible tb send me your report, or a summary of its conclusions, in
time to be incorporated in my annual report on November 20, I particularly
request that you will do so.
Very respectfully, your obedient servant,
J. D. Cameron,
Secretary of VTar.
Col. John Gr. Barnard,
Corps of Engineers.
Lieut.-Col. H. G. Wright,
Corps of Engineers,
Lieut.-Col. B. S. Alexander,
Corps of Engineers.
EEPORT.
New Orleans, La., November 19, 1876.
Sir :—The commission appointed by virtue of Special Orders No. 229,
dated Headquarters of the Army, Adjutant-General's Office, Washington, No¬
vember 2, 1876, has the honor to report, that its members assembled on the Cth
day of November, in New York, and organized. Your letter of instructions,
dated War Department, Washington, November 2, was received and consid¬
ered, and on the evening of the 7th the officers of the commission started by
railway for New Orleans, arriving there on the afternoon of the 10th ; Maj. C.
B. Comstock, United States Engineers, the officer appointed according to the
act of Congress "to report the depth of water and width of channel secured
and maintained from time to time," joining them at Cincinnati. At New Or¬
leans they met Mr. James B. Eads, and at a preliminary meeting in the even¬
ing of the 10th, listened to suggestions he had to make; and on the following
day examined the maps of recent surveys of works at the South Pass, which
were exhibited to them in his New Orleans office. On the l£th, they pro-
300
THE MISSISSIPPI JETTIES.
ceeded by the reTenue cutter Dix, which had been placed at their disposal for
the performance of their duties, to Port Eads, South Pass. The four fol¬
lowing days, viz., the 13th, 14th, 15th, and 16th, were devoted to examining
the works at the sea entrance to the South Pass, at the head of the pass,
and at Grand Bayou ; likewise the plans of the works and the surveys show¬
ing their present condition, laid before them by Maj. Comstock, and also by
the engineers employed by Mr. Eads, and to discussions ; during which Mr.
Eads and his assistants, as well as Maj. Comstock, were invited freely to im¬
part information and to present their views.
After mature consideration of the information thus obtained, they now
have the honor to report, in response to the live queries propounded to them
in your letter of instructions, as follows :
Query 1. "Is the shoal at the head of the South Pass a part of that pass, or
of the main Mississippi River ? "
" If Mr. Eads obtains a channel twenty feet in depth in the South Pass,
exclusive of this shoal, is he entitled under the law to his flrst payment of
half a million dollars? "
In answer to the flrst paragraph of the foregoing, we would say that this
shoal is not exclusively a part of the South Pass, for it extends entirely across
the river from shore to shore. It is therefore a shoal common to all three
of the passes ; but the channel (or channels) through this shoal, by which ac¬
cess has been had or is to be had in future from the river above into the South
Pass, is a part of that pass. This construction we believe to be in harmony
with the views of the commission of 1874, which estimated the total length of
the " South Pass " at 12.9 miles, thus embracing the entire distance from the
deep water in the river above to deep water in the gulf.
To the second paragraph of this query we answer. Yes; provided the depth
so obtained has a bottom width required by the fifth section of the act of Con¬
gress.
The obligation of the United States to pay half a million of dollars on ob¬
taining a channel twenty feet in depth, and of not less than two hundred
feet in width, is expressed in that section, in terms which apply exclusively to
the "wide and deep channel between the South Pass of the Mississippi River
and the Gulf of Mexico." The obligations of Mr. Eads in reference to the
shoal at the head of the pass are expressed in the second proviso to section 4
of the act, the language of which provides all necessary guaranties, and is
the only language of the law defining depths, etc., which does apply to this
shoal.
Query 2. " What depth and width of channel is it desirable to secure perma¬
nently through this shoal?"
The second proviso to section 4 of the act demands a navigable depth
"through said pass," and of course through this shoal, of "twenty feet"
within thirty months; and "an additional depth of not less than two feet dur¬
ing each succeeding year thereafter, until twenty-six feet shall have been se¬
cured." We deem these depths to be satisfactory; and, considering that an
inland channel requires less depth for equal facility of navigation than a sea-
exposed bar, that they are fairly equivalent to the greater depths demanded by
the act in its fifth section for the " wide and deep channel connecting the pass
with the Gulf of Mexico."
COMMISSION OP 1876.
301
With regard to the width of channel through this shoal, it is probable that
all the necessities of commerce would be satisfied, at least for a time, by a
width sufficient for the passage of a single vessel. One hundred feet would
suffice for this purpose.. We deem it desirable to provide ultimately a channel
wide enough for two large ships to pass each other when under full headway,
without danger of collision. This would require a bottom-width of, say, two
hundred feet. Though this is somewhat greater than is now to be found in
reaches of considerable length in the body of the South Pass itself, below
Grand Bayou, we recommend it as a desirable width to be secured.
Query 3. "What is your interpretation of the words ' average flood-tide '
as used in the second (fifth) section of the act?"
The phrase " average flood-tide " is used in the section referred to only in
reference to the depths prescribed in that section, which depths refer exclu¬
sively to the "wide and deep channel between the South Pass of the Missis¬
sippi River and the Gulf of Mexico," i.e., to the channel to be created by
"jetties and auxiliary works" through the sea-bar of the South Pass. The
expression does not apply to the "navigable depth " to be secured "through
the pass " in the second proviso of the fourth section of the act ; and hence not
to the depth to be secured through the shoal at the " head of the pass." The
matter is left, as is the width, to bo governed by the general prescription of
providing a "navigable depth." This navigable depth ought to be found at
the low as well as at the high stages of the river. We therefore consider the
principle governing the decision of the Chief of Engineers in his indorsement
on the letter of Maj. Comstock, communicated to us with your letter of in¬
structions, to be the correct one for the head of the pass, viz. : that the meas¬
ure of depths prescribed by the second proviso to the fourth section of the act
should be from the level of average high tides " occurring during the stage of
the river when the volume is least; " that is, the mean of the high waters of
the river at this place, taken for one or more lunations when the river is at
what is known as its low stage. Inasmuch, however, as Maj. Comstock found
it necessary to fix provisionally his zero on insufficient data, it is recommended
that it be revised on the principle above stated.
In reference to the prescriptions of the second (fifth) section of the act, the
phrase " average flood-tide " has been universally accepted to mean average
high water of the tide; and, with no qualifications in the language, we under¬
stand this to mean the average of all aaily observed high waters throughout
the full cycle of a year. No complaint has been made as to the zero mark fixed
by the engineer officer for the determination of the depths of water at the gulf
end of the pass. It is possible that, having been established on a series of only
three lunations from August 19th to November 9th, it may vary slightly from
what would be given by such a protracted series of observations. It is, how¬
ever, our opinion that this zero, as established, is so nearly correct, that it need
not be altered, for alteration would involve confusion in the comparison of fu¬
ture soundings with those heretofore made.
Query 4. " I desire a full expression of your opinion as to ' the materials
used and the character and permanency with which the jetties are being con¬
structed,' and as to whether the work is being constructed according to the
spirit of the act, as mentioned in the tenth section thereof."
The several reports of Major Comstock, the United States engineer officer,
302
THE MISSISSIPPI JETTIES.
give a very precise description of the materials used. Maps No. 2 of his re¬
ports of June Ö, 1B7Ö (since printed as Ex. Doc. No. 77, Senate, Forty-fourth
Congress, first session), and of his fourth report of September 20, 1876, repre¬
sent to the eye so clearly the section profiles, the component parts, the dimen¬
sions, and manner of construction o£ the two jetties, that we need add nothing
descriptively. Our opinion thereon is expressed as follows :
The commission of engineers of 1874 gave the project for these works a,
protracted study, and set forth a plan and details, with estimates founded
thereon. While Mr. Eads is, by the language of the act, " untrammeled in
the exercise of his judgment and skill in the location, design, and construction
of said jetties and auxiliary works," yet he is required by the law to construct
" thoroughly substential and permanent works, by which said channel may be
maintained for all time after their conipletion." We find that in general plan
the jetties of Mr. Eads correspond substantially with those designed by the
board. The materials to be used, as recommended by the board, were, after
methods long employed in Holland, to be of layers of mattresses, of willows or
other suitable twigs or saplings, placed in layers, with intervening layers of
quarry-stone. Still this design was in no respect obligatory upon Mr. Eads,
nor should it have been upon an engineer officer of the United States charged
to execute this work. With no experience in this country in the execution of
such a work, in such a lo"ality, and on this scale, it was impossible to foresee
exactly what the work should be. The board expressly states that "it is of
opinion that experience in construction may very probably show that the
cross section of the dikes may be reduced, thus lessening the cost." It was
also an opinion of the board and other engineers that the methods of Holland
would undergo nraterial modification in their actual application in this coun¬
try, and that experience in the work on the locality would also show the cheap¬
est and best methods. Mr. Eads has modified very materially the Holland
model of mattresses, and the mattresses he has used are doubtless much infe¬
rior to those of the Dutch. Again, the amount of stone thus far used has
been very small indeed, barely enough to sink the mattresses. Nevertheless,
the jottio.s so constructed, except at their ends in deep water, where some
damage has been done, have resisted, without material injury, the floods,
storms, and waves, and there has been more than a year's exposure, with its
winter and autumnal storms, for some portions of the existing work.
We do not conceive it to be required of Mr. Eads that each stage of the
progress shall exhibit such " substantial and permanent work " as the law ulti¬
mately contemplates, but rather that each stage of the work shall show an ade¬
quacy to create a channel of the depth and width demanded, and at the same
time such a fair and honest prosecution of the work as shall be, as far as it
has gone, so much really accomplished toward the construction of works
which, in the language of the law, "may be maintained for all time after
their completion."
While we believe that engineer officers, applying moneys appropriated to
meet their estimates by Congress, would have executed the work differently,
cspeeáally in applying freely stone to each layer of mattresses, we are never¬
theless of opinion that the work is being constructed essentially according to
"the spirit of the act as mentioned in the tenth (thirteenth) section thereof."
We would add that the greatest variation from the sectional designs of the
COMMISSION OF 1876.
303
board of 1874 for the jetties, is to be found on their sea sides. That board
recommended that the jetties should have on their sea sides the same slopes as
on the river or channel side. As actually built upon the foundation mattress¬
es, the sea sides are vertical. This construction appears to answer every pur¬
pose throughout most of the length, for the wide shoals on each side afford
great protection, and there is, as had been expected, a great accumulation
of river-sediment and wave-deposit against the exterior of the jetties, by
which that protection is augmented.
The outer ends of the two jetties, and especially the end of the eastern
one, extend beyond their protection, and are greatly exposed ; and we deem
an enlargement of section and a large application of stone to be essential to
security.
Query 5. ' T should be glad to receive any general suggestions in connec¬
tion with this, very important work, which you think will assist me in per¬
forming the duties required of the Secretary of War by this act."
The more important of the duties imposed upon the Secretary of War by
the act are embraced in the thirteenth section ; and of these, the only one on
which we have any suggestions to offer is that which requires him to see that
the works shall be of such substantial and permanent character as shall main¬
tain the channel for all time after their completion.
We have already remarked that we deem not only an enlargement of sec¬
tion, but a large application of stone to be essential to the security of the jet¬
ties, their sea ends especially, and we are of the opinion that this enlargement
of section at the sea ends and consolidation throughout by the application of
stone should be undertaken at once, and a reasonable progress therein be
made the condition of the second and all future payments. The immediate
and full consolidation of the jetties should be neither required nor expected,
as they will continue to settle for some time, both by subsidence of the bot¬
tom upon which they rest, and by the compression of the mattresses of which
they are largely composed. But this settlement and consolidation should be
hastened, as has just been remarked, by the application of stone from time to
time, so that they may be in condition to receive their final finish as soon, at
least, as the expected full depth of water in the channel has been obtained.
The present works at the head of the pass are mostly of a tentative and
temporary character, and as their proper positions are determined, should be
replaced by substantial and permanent structures, to be completed before final
payments arc made.
Respectfully submitted,
J. G. Barnard,
Col. of Eng. and Bvt. Maj.-Oenl.
II. G. Wright,
Li.-Col. of Engrs., Bvt. Maj.-Oenl.
B. S. Alexander,
Lt.-Col. Engrs., Bvt. Brig.-Oen., U. S. A.
Hon. J. D. Cameron,
Secretary of War, Washington, D. C.
APPENDIX XI.
(See page 107.)
LETTER FROM JAMES B. EADS TO THE SECRETARY OF WAR.
New Orleans, Äjiril 19, 1877.
Hon. George W. M'Crary, Secretary of War, Washington, D. C.:
Sir :—On 7th of February, 1877, I addressed a letter to Hon. J. D. Cam¬
eron, Secretary of War, requesting that Capt. Brown, U. S. Engineer,
assistant of Gen. Comstock, stationed here, be instructed to furnish me or my
chief assistant engineer at the jetties the results of his soundings and current
observations in the channel through South Pass. I said that permission for
one of my assistant engineers to copy his charts would be sutficient for my
purpose, and would thus avoid any possible increase of expense in his office.
This letter was written because my chief assistant had been refused a copy
of a survey of the shoal at the head of the pass, just completed by Capt.
Brown, and which I desired him to obtain and send to me in Washington.
Nearly a year ago (23d May, 1876), I requested of the Hon. Alonzo Taft, Sec¬
retary of War, " that instructions be issued to the inspecting officer * * to
promptly supply me with any official information he may from time to time
acquire respecting these works and their results, which I may deem important
to facilitate us in carrying out the intent of the grant, or in protecting us
from misrepresentation. In compliance with this request the Secretary ad¬
dressed Gen. Comstock letters, dated 28th June and 31st July, 1876, which
directed him to forward me a duplicate copy of his official reports simulta¬
neously with the transmission of the originals to him, and to furnish me "the
results of actual soundings that have been or may be hereafter made under
(his) direction, in connection with this improvement." In compliance there¬
with instructions were given, I believe, by Gen. Comstock to Capt. Brown, to
permit me and my assistants to look at the results of his soundings, but not
to permit me to take any copies of them without first referring them to him
at Detroit.
It is scarcely necessary for me to point out the importance of having the
earliest official information respecting any changes which are produced by my
works; and I respectfully submit that there can be no injury to the public by
furnishing me promptly any such information as soon as it is obtained by
Capt. Brown.
I do not ask that he should make surveys or observations, or perform any
work for my benefit or information ; but as these are contemplated by the law,
and are made for your information, and for the benefit of the public, I cannot
301
MB. EADS TO SECEETAEY OP WAE.
305
conceive how it is possible that the public interest can suffer, or the dignity of
the Secretary of War be lessened, by permitting me to know, at the earliest
moment, whatever facts are developed by these surveys, that have relation to
the success of the improvement.
Until the instructions of June and July referred to were issued to the in¬
specting officer, the results of the surveys of his assistant were carefully kept
secret from me and my employees; and it was not until after they were
transmitted by Capt. Brown to Gen. Comstock at Detroit ; and by him to tlie
Chief of Engineers; and by him to the Secretary of War; and by him to
Congress; and by Congress to the public printer; and by him back to Con¬
gress, that they were seen by the public or myself. They were then so old as
to be of little interest or value to any one.
Although the instructions of the Secretary of War were evidently intended
to give me the benefit of this information at the earliest moment, I cannot at
present have a tracing from Capt. Brown's official surveys made, even at my
own expense, until it is sent to Detroit for examination or approval. The
location of an inspecting officer on the northern lakes for works of such im¬
portance at the mouth of the Mississippi, and the difficulty of obtaining a
statement of the simplest facts from him with promptitude, is an injustice to
me and my associates, and an injury to the public.
The depth and width of channel between the jetties last October entitled
me to the first payment of $500,000 on account of this work. The Secretary
of War ordered Gen. Comstock to come to Washington for the purpose of
consulting him with reference to my obligations respecting the shoal in the
Mississippi River at the head of the Pass. Gen. Comstock was emphatic in
the opinion that I was not entitled to the payment, because I had not an equal
width and depth through this shoal. I appealed from this decision, and the
question was referred by the Secretary of War to a commission of officers of
higher rank, viz. : Generals Barnard, Wright, and Alexander. They decided
that I was entitled to this payment whenever the requisite width and depth
were secured through the jetties, without reference to the depth on the shoal;
the depth through the latter being insured by my liability to have the grant
forfeited. This opinion was then submitted to the Attorney-General, who em¬
phatically sustained it, thus proving that General Comstock was wrong. The
result, however, caused me to be delayed several months in receiving the pay¬
ment to which I was entitled in October; and it was not until about the
middle of February that 1 received it.
After suffering the hardship of delay in payment, resulting from the in¬
specting officer misrepi'csenting the law, and awaiting its reversal by the late
Commission and the Attorney-General, I was put to a further delay in pay¬
ment ; because, although this survey, like all others made since Capt. Brown
was stationed here in December, 1875, was not made under the formal super¬
vision of the inspecting officer, yet it had to go to Detroit for examination and
approval by him; and flien, after the chart reached there, some informality in
its certification at the jetties necessitated a further delay, until a duplicate
could be sent from the mouth of the Mississippi to Detroit; after which the
report entitling me to payment was finally sent by the inspecting officer to the
Secretary of War.
Within the last week I have found it necessary to provide an additional
20
306
THE MISSISSIPPI JETTIES.
amount of money to carry on these works; and I submitted the terms of a loan
for two hundred thousand dollars to capitalists in this city, who had previously
supplied a portion of the money expended on them. A meeting of these
gentlemen was called a few days ago, at which the loan was proposed. The
next morning the Associated Press dispatches contained a synopsis of Gen.
Comstock's report of Sth April to you^ in which it is stated that the twenty-
foot channel through the Jetties has been reduced from two hundred feet to
seventy feet in width. The effect of this upon the loan you can readily under¬
stand.
The report Just made to you, dated 5th April, 1877, gives the result of
soundings made a month previously; but it gives neither to you nor to the
public any information as to the present condition of the channel. A subse¬
quent survey or reconnoisance made by Capt. Brown, I am verbally informed
by him, within the last ten days, shows a twenty-foot channel with a least
width of three hundred feet; yet Capt. Brown dare not certify this improve¬
ment to me, because he has no authority or permission from Detroit to do so.
The delay in getting my first payment prevented me from completing and
strengthening the sea ends of the Jetties to resist the storms of winter; and I
have been compelled to rebuild a large amount of the work, the destruction of
which caused the deterioration of channel referred to by Gen. Comstock.
Their improved condition has now again enlarged the channel; but before I
can get the official evidence of it, its certification will be of no value to me.
Last May, when semi-official misrepresentations were published by Capt.
Howell respecting the depth of channel we had then secured through the Jet¬
ties, I asked the Secretary of War, by telegraph (see my letter, 23d May, 1876),
to direct Gen. Comstock, who was then on the spot, to measure the depth be¬
tween the Jetties, and certify the same, so that I could correct this misrepresen¬
tation, which was then seriously embarrassing our enterprise by destroying the
confidence of the public and the faith of capitalists in it. This could have
been done in three hours ; but the request was refused ; and nothing but the
passage of the Cromwell steamers through the Jetties, a few days afterwards,
furnished to the public the evidence that Capt. Howell had officially published
a deliberate and gross misstatement of the depth of the Jetty channel. In con¬
nection with this misstatement, the same officer, at the same time, published
a statement to the effect that, from his own surveys, he knew that a bar was
forming one thousand feet in advance of the Jetties, and that a shoal had
made out three hundred and eighty feet from the west Jetty towards this bar.
This statement was absolutely untrue. It was designed to impress the public
with the belief that these works would prove a failure, as the rapid reforma¬
tion of the bar in advance of the Jetties, predicted by the chief of engineers,
was actually progressing; whereas, I knew from my own surveys, and from
soundings Just then made by the United States Coast Survey in front of the
Jetties, that the very reverse of his statement was the fact. An immediate
official disproof of Capt. Howell's statement regarding the depth of channel
being denied me (see Mr. Secretary Taft's telegram in my letter of 23d May),
I appealed, by telegraph, to the Superintendent of the Coast Survey to instruct
Mr. Marindin to certify to me the results of the survey he had Just made,
and to make which survey I had furnished a steamer. His refusal will be
found in my letter of 23d May. I was, however, determined to have this
ME. EADS TO SECEETAEY OF WAE.
307
official disproof if possible, and therefore requested the Secretary of War to
obtain it. On the 19th of July, he requested the superintendent to furnish
the War Department with a comparative chart of the soundings made May,
1875, and May, 1876, in front of the Jetties. The verbal declaration after re¬
ceipt of this request, made to me by the superintendent, that he would not
supply this information even to the War Department, caused me to appeal by
letter a few days afterwards to Mr. Secretary Morrill, of the Treasury, to
instruct the superintendent to furnish the chart to me, with an official state¬
ment of the results shown by it. Mr. Morrill, on 26th July, refused this re¬
quest, on the plea that the last survey was "unauthorized and informal;"
" while provision is made in the said [Jetty] act for the facts and information
desired through the War Department."
Being thus foiled in getting the official disproof of this misrepresentation
of Captl Howell, I finally appealed to the House of Representatives; anda
resolution, directing the Secretary of the Treasury to furnish the House the
specific information asked for by me, was unanimously passed by that body,
immediately after the Secretary of the Treasury refused to give it to me. In
pursuance of this resolution, the House and the War Department were sup
plied 1st August with the information solicited a fortnight previously by the
Secretary of War; and it proved that, instead of a reformation of the bar,
sixty-eight thousand four hundred cubic yards of material had actually been
scoured away, in a space of two thousand one hundred feet square, immedi¬
ately in front of the Jetties, in excess of all deposits made on that area.
I refer to these facts regretfully, and only to show you that when official
information would be of value to me, or even when absolutely necessary to
right a gross wrong by a government officer, it has been almost impossible for
me to get it. Although the fact was shown by two surveys, and the report of
the Superintendent of the Coast Survey last August, that the predicted bar ad¬
vance had not occurred, but that the water last May was actually deeper im¬
mediately in advance of the Jetties than when they were commenced ; and
although this fact would greatly increase the confidence of the public in the
permanency of this improvement; and although it constitutes a most interest¬
ing fact in the history of the work, it has not yet elicited the notice of the in¬
specting officer in his reports to you. Every temporary advance in the contour
curves of the bar, however, observed during the rapid scour between the Jet¬
ties previously, was reported by him, but his reports have never alluded to the
fact that a decided recession of the outer face of the bar has occurred since the
construction of the Jetties.
I earnestly beg that, in connection with these representations, you will
kindly consider the fact that we are executing a great national work, almost
wholly without aid of the government—for thus far we have received less than
one-tenth part of the price to bo paid for it—while we have already secured
much deeper water than ever existed at the mouth of the river before; and
which now constitutes a safe channel, in no place less than twenty and one-half
feet deep, at average high tide, from New Orleans to the gulf, where there was
previously scarcely eight feet in depth. Our works and our good faith surely
entitle us to such aid as the government can give us without injury to the pub¬
lic interest, and also to such moral support as can be rendered by furnishing
promptly, in an official form, any certification that may be desired respecting
308
THE MISSISSIPPI JETTIES.
the results accomplished. The law constitutes you the agent of the United
States to carry into effect the provisions of the act, and your practical knowl¬
edge will certainly plead my excuse for appealing to you most earnestly to
correct the injustice we are suffering, more especially as it has been continued
so long after a correction has been solicited. If you will kindly consider that
this work is not only the largest, in point of cost, which the United States is
executing, but that it far surpasses, in the importance of its results, all others
in this country, you will, I am sure, pardon me for trespassing upon your
time with a letter of this length.
In conclusion, I respectfully beg:
1st. That the inspecting officer of these works be located at New Or¬
leans, or at the jetties ; and,
Sd. That he be authorized to publish promptly, from time to time, the
depth and width of channel through South Pass ; and,
3d. That he be directed to furnish me or my principal assistant engineer,
ofllcially and promptly, such information respecting the changes in the
channel throughout the pass, the jetties, and the outer slope of the bar,
and such other results of the works in progress as he and his assistants
shall obtain from time to time, by their surveys and observations.
I have the honor to be, your obedient servant.
Jas. B. Eads.
APPENDIX XII.
(See page 168.)
LETTER FROM THE SECRETARY OF WAR,
SuBMiTTraa a Statement fkom James B. Eads Relative to Wokk Exe¬
cuted at the South Pass of the Mississippi River.
May 14, 1878.—Referued to the Select Committee on Transportation Routes to
the Seaboard, and ordered to be printed.
War Department, )
Washington City, 3Iay 14, 1878. S
The Secretary of War has the honor to transmit to the United States Senate
a copy of a communication from James B. Eads, dated the 7th instant, sub¬
mitting a statement relative to the amount of worl5»executed at the South Pass
of the Mississippi River, and asking that certain specified modifications be
made in the conditions imposed by the law known as the jetty act, under which
the works at the South Pass have been prosecuted.
This communication was referred to Gens. J. G. Barnard and H. G.
Wright, of the Corps of Engineers, for examination and report, and a copy of
their report, dated the 13th instant, is herewith transmitted.
It will be seen that while the Board are of the opinion that the widths of
channel proposed by the petitioner may be considered as fairly meeting the
present wants of commerce, they regard the question whether the concessions
asked for should be granted as peculiarly a question for Congress to decide.
The views expressed by Gens. Barnard and Wright are concurred in by
this department.
Geo. W. McCrary,
Secretary of War.
The President,
United States Senate,
Washington, D. C., May 7, 1878.
Sir:—I have reached a point in the construction of the works authorized
by the jetty act at which I deem it absolutely necessary to communicate cer¬
tain matters for your consideration. I respectfully submit, therefore, the rea¬
sons which induce me to ask for such modifications in the times of payment
set forth in the law as are necessary to relieve me and my associates of the
309
310
THE mSSISSIPPI JETTIES.
sorious financial difiiculties with which we are embarrassed, and to enable us
to prosecute the work with greater energy.
The progress of the work has shown that the desire to guard the govern¬
ment against the possibility of bearing any portion of the risk of the jetty sys¬
tem, or of the hazards of construction, has resulted in framing a law which
imposes on us unnecessarily stringent conditions of payment. In consequence
of the very large portion of the work which we have had to execute in order to
secure the tw^ payments already received, and of the stringency of these con¬
ditions, we find ourselves oppressed with such a burden of debt as to almost
completely paralyze, for the present, our ability to push the work with the
energy necessary to insure the largest benefits to the public at the earliest pos¬
sible time.
The provisions of the law were intended to afford a reasonable reimburse¬
ment of our outlays as fast as the work progressed, after certain specified
depths of channel should be secured by permanent works. It was impossible,
however, to tell with any degree of accuracy how much of the whole work
would have to be executed before we could be entitled to the first payments un¬
der the law, and while the total cost of the improvement will not exceed the
original estimates, the proportion of the entire outlay necessarily expended to
secure the present depth has greatly exceeded our expectations.
Experience has shown and custom has sanctioned the wisdom of the govern¬
ment paying ninety per cent, of the contract-price for work as it progresses, by
which those who undertake it may avoid excessive rates of interest and need¬
less financial burdens, which can result in no benefit to the government.
The compensation fixed in the law for the work we are executing is to be
$5,350,000. We have already completed at least eighty per cent, of this en¬
tire work, and have received on it thus far only $1,000,000. If we were com¬
pensated for ninety per cent, of the work done, we would receive $2,826,000
more than has been paid to us. We do not ask for any such liberality, but re¬
fer to this fact to show the hardships under which we are laboring by the
terms of the haw, and the absolute security with which the government can
grant the relief we are compelled to ask.
By the terms of the act, thirty months from its approval were allowed,
within which to secure a depth of twenty feet, and two feet additional are re¬
quired to bo secured each year thereafter. The act was approved March 3,
1875, and by September 3, 1877, we were required to have a channel of twenty
feet, and twenty-two feet by September 3, 1878. These depths have been al¬
ready secured, and the stipulated compensation received. We have, therefore,
by the terms of the law, until September 3, 1879, to secure twenty-four feet,
and to September 8, 1880, to secure the twenty-six feet channel. The interests
of the public will of course be promoted by the attainment of these depths at
an earlier day.
Under the present terms of payment it will be impossible for us to expend
upon the work the large additional sums still necessary to secure the maxi¬
mum channel at the earliest possible period, for the reason that the indebted¬
ness already incurred will absorb so much of the next payments as to leave for
it a totally inadequate provision.
The sum of $1,350,000 of the stipulated compensation becomes due and
payable after certain depths have been maintained for twelve months, and
LETTEB ¿NT) EEPOKT, 1878.
311
these payments bear interest at the rate of five per cent, per annum. By add¬
ing these deferred payments to the cash payments as the latter are earned,
the government will save interest on the respective amounts, and will greatly
relieve us, while an earlier completion of the work will be secured.
The commission of engineers authorized by Congress in 1874, and which
reported in favor of applying the Jetty system to the South Pass, proposed to
secure a channel thirty feet in depth, and the permanent maintenance of only
twenty-five feet, without any specified width. The Jetty act requires a per¬
manent depth of thirty feet with a least width of three hundred and fifty feet.
This great width of thirty feet water will involve a much larger channel than
was contemplated by the commission as proper for the size of the pass. Such
great width cannot probably be secured without a central depth of channel
several feet greater than that recommended by the commission. We do not
ask to have the depth of thirty feet lessened, but observation confirms the
opinion (which I expressed to the committees when the bill was under consid¬
eration), that the width required was injudicious, and might involve injury to
the works.
The payments under the present law are as follows:
On securing—
24 feet deep by 250 feet in width $500,000 ; cash in one year.... $250,000
26 feet deep by 300 feet in width 500,000 ; cash in one year.... 250,000
28 feet deep by 300 feet in width 500,000 ; cash in one year 250,000
80 feet deep by 350 feet in width 500,000 ; cash in one year.... 500,000
Total $2,000,000 Total $1,250,000
The amendments desired are as follows :
On securing a channel through the Jetties—
24 feet deep by a least width of 150 feet $750,000
25 feet deep by a least width of 150 feet 750,000
20 feet deep by a least width of 150 feet 500,000
27 feet deep by a least width of 100 feet 375,000
28 feet deep by a least width of 100 feet 375,000
29 feet deep by a least width of 100 feet 250,000
30 feet deep by a least width of 100 feet 250,000
Total $3,250,000
Provided, that when each of the above depths and widths has been obtained
the survey shall also show through the Jetties a channel of the following depths
and widths, viz.: When twenty-four by one hundred and fifty feet shall
have been obtained, there must also be a channel twenty-two feet deep by a
width of two hundred feet ; when twenty-five by one hundred and- fifty feet
shall have been obtained, there must also be a channel twenty-two feet deep
by two hundred and fifty feet wide ; when twenty-six by one hundred and fifty
feet shall have been obtained, there must also be a channel twenty-two feet
deep by three hundred feet wide ; when twenty-seven by one hundred feet shall
have been obtained, there must also be a channel twenty-four feet deep by two
312
THE MISSISSIPPI JETTIES.
hundred feet wide; when twenty-eight by one hundred feet shall have been
obtained, there must also be a channel twenty-four foet deep by two hundred
and fifty foet wide ; when twenty-nine by one hundred feet shall have been ob¬
tained, there must also be a channel twenty-four feet deep by two hundred and
fifty feet wide; when thirty by one hundred feet shall have been obtained,
there must also be a channel twenty-six feet deep by two hundred feet wide.
By the above arrangement, the first payment of §750,000 will not be made
until a channel is attained large enough for all practical purposes ; and the
fact that no further payments are to be made, except as each additional foot in
depth is gained, insures every effort to maintain and increase the size of the
channel as fully as under the present distribution of payments.
The act provides that after a channel thirty feet deep and three hundred
and fifty foet wide is secured, one hundred thousand dollars per annum shall
be paid for its maintenance during twenty years. This clause should be
amended to apply to the thirty feet channel jvbove described. The one million
dollars reserved by the jetty act to be held in the United States Treasury as
security for the performance of this part of our obligations will remain undis¬
turbed.
We undertook the construction and maintenance of these works for six
hundred and ninety-two thousand one hundred and ten dollars less than the
official estimate of the commission upon whose report the act was framed.
We also assumed the whole risk of their failure to produce the desired chan¬
nel, notwithstanding the confident and reiterated predictions made by official
and other experts that they would be unsuccessful. We likewise took all the
risk of their destruction by storms and treacherous foundations—dangers
which were believed by many to be insurmountable. Besides all this, we were
not permitted to improve the pass of our choice, with its normal depth of fif¬
teen feet, but were given one only a quarter as large, with a depth of but
eight feet. In spite of the natural difficulties which were to be surmounted
during a period of unusual financial prostration, we have carried this enter¬
prise to a point where its complete success is acknowledged even by its op¬
ponents. We have changed the little pass into a grand channel of commerce,
through which the largest shipping that visits the port of New Orleans floats
in safety ; while every prediction of failure and of reformation of the bar in
advance of the jetties is shown by official surveys to have been without founda¬
tion.
We ask no increase in the price of the work, nor do we ask to be relieved
of the obligation to create a permanent channel thirty feet deep through the
jetties, and that shall be fully as wide as the size of the pass will justify. We
ask no legislation to retrieve forfeited privileges or lapsed concessions, nor the
assumption of any risk of outlay for doubtful benefits. We ask simply that
a reasonable portion of moneys actually expended may be repaid to relieve
embarrassments resulting from provisions in the law unusually severe and op¬
pressive, and which cannot now be retained without injuriously reacting upon
the commercial and industrial interests of the country. We have striven to
carry through, by private means and individual hazard, the largest and most
important public work ever undertaken by the government ; and have forborne,
under many discouragements, to ask relief from the stringent conditions of
the law until the official reports of the most eminent engineers of the govern-
LETTEB AXD EEPOET, 1878.
313
ment have confirmed the public faith in our complete success ; and now that
sheer necessity compels us to do so, we only come after the changing tides of
commerce attest the substantial benefits already reached, and after the people
are assured that private enterprise and courage have promptly secured, at
moderate cost, "an open river mouth " for the Mississippi in lieu of the more
costly and dilatory method proposed of a canal with locks. And with this
record we ask no payments on the work that will not leave in the hands of the
government an ample amount of our compensation to insure the entire com¬
pletion of the jetties.
With great respect, I have the honor to be, your obedient servant.
Jas. B. Eads.
Hon. George W. McCrart,
Secretary of ^Var, Washington, D. C.
[ludorscmeni.]
War Department, 3Iay 8, 1878.
Respectfully referred to Gens. J. G. Barnard and II. G. Wright, Corps of
Engineers, for examination and report.
Geo. W. McCrary,
Secretary of War.
Washington, D. C., Hay 18, 1878.
Sir :—We have the honor to acknowledge the reference to us for examina¬
tion and report of the communication of Mr. James B. Eads, dated the 7th
instant, submitting a statement relative to the amount of work executed at
the South Pass of the Mississippi River, and asking that certain specified
modifications be made in the conditions imposed by the law known as the jetty
act, under which the works at the South Pass have been prosecuted, and to
present our views thereon as follows :
In his communication Mr. Eads says :
"We have completed eighty per cent, of the entire work. * * *
" If we were compensated for ninety per cent, of the work actually done, we
would receive $2,825,000 more than has been paid to us."
Referring to the words of the law, we find it stated that "the intent of
this act is not simply to secure the wide and deep channel first above named,
but likewise to provide for the construction of thoroughly substantial and per¬
manent works, by which said channel may be maintained for all time after
their completion."
There is in these words quoted from the law not only an unmistakable ex¬
position of its intent, but a clear distinction implied between constructions
which will " simply secure the wide and deep channel, and the construction of
thoroughly substantial and permanent works," etc.
The works as they now are have served their purpose to the extent of the
requirements of the law to this date, but the ultimate requirements of the act
are thirty feet depth for three hundred and fifty feet width ; whereas only the
second of the six stages of progress defined by the law has been arrived at :
that which gives twenty-two feet depth for two hundred feet width. There is
exhibited, however, a progressive increase of width between the twenty-four feet
curves to justify, to some extent, the assumption that the actual works are
314
THE MISSISSIPPI JETTIES.
fulfllling their function of creating additional depths ; but we are not of
opinion, taking the volume and linear extent alone of the works executed as
measured, that "eighty per cent, of this entire work has been completed." If
we make the requirements of the law a measure, we should hardly feel justified
in accepting the achievement of a channel twenty-two feet deep and two hundred
feet wide as 80 per cent, of the achievement ultimately required, viz., thirty feet
deep and three hundred and fifty wide, even though it could be shown that the
requisite bottom-scouring in cubic yards for the respective channel dimensions
were in that ratio.
Or, if we turn from the question of geometric magnitude of works executed
to the character of the existing works, we shall find that very much more than
twenty per cent, of work, estimated by cost, remains to be done to make them,
in the words of the law, " substantial and permanent works, by which said
channel may bo maintained for all time after their completion."
The commission of officers appointed by direction of the President, Novem¬
ber 3, 1870, in responding to the categorical query "as to the materials used,
and the character and permanency with which the jetties are being constructed,
and as to whether the work is being constructed according to the spirit of the
act as mentioned in the tenth (13th) section thereof," in reporting affirmatively,
prefaced this expression of opinion by the statement :
"We do not conceive it to be required of Mr. Eads that each stage of the
progress shall exhibit such ' substantial and permanent work ' as the law ulti¬
mately contemplates, but rather that each stage of the work shall show an
adequacy to create a channel of the depth and width demanded, and at the
same time such a fair and honest prosecution of the work as shall be, as far as
it has gone, so much really accomplished toward the construction of works
which, in the language of the law, may be maintained for all time after their
completion.
"We have already remarked that we deem not only an enlargement of section
but a large application of stone to be essential to the security of the jetties,
their sea-ends especially ; and we are of the opinion that this enlargement of
sections at the sea-ends and consolidation throughout by the application of
stone should be undertaken at once, and a reasonable progress therein be made
the condition of the second and all future payments."
Moreover, the undersigned, as a commission to decide certain points upon
the becoming due (December 15, 1877) of the second payment, in responding to
the interrogatory, "Are the jetties and auxiliary works constructed or in pro¬
gress of construction permanent, sufficient, and thoroughly substantial, within
the meaning of said act of Congress ? " expressed themselves as follows :
" No part of the jetties are as yet entirely completed, and some portions,
especially the outer ends, will require extension of width and a large amount
of stone before they are brought to that permanent and substantial condition
when completed which the act, in our judgment, requires. This additional
work, we understand, Mr. Eads and associates propose to do from time to time,
as payments are made to them by the United States. * » «
"With regard to the sea-ends, however, a much larger application of stone
will still be necessary; but the defect of vertical sea-sides has not yet been
remedied, nor has the required enlargement of section, to any great extent,
been made. Nevertheless these ends have maintained themselves so as to suffer
LETTER AND REPORT, 1878.
315
only from subsidence of the bottom, compression of the mattresses, and super¬
ficial abrasion by storms. It is understood to be Mr. Eads's intention to
enlarge and strengthen these sea-ends in accordance with the views above
expressed. * * «
"Further observation and longer experience are necessary to a full develop¬
ment of the question involved, i.e., the destruction of the wood of the mat¬
tresses by the teredo ; but it is believed that when the lateral slopes of stone
are fully provided, the penetration of the worm into the interior of the jetties
in these salt-water exposed parts will bo checked, and that, to the extent to
which they may be impaired, the remedy will be found in the increase of the
quantity of stone."
While the commission first referred to conceded that the plan of construc¬
tion devised by the board of 1874, which recommended the jetty system, was
"in no respect obligatory upon Mr. Eads," that "experience in the work on
the locality would sliow the cheapest and best methods," yet it "pointed out
the fact that while the plans of the board contemplated the jetties to be made
up of one-third stone and two-thirds fascines, the amount of stone thus far
used has been very small indeed; barely enough to sink the mattresses." Since
that date about twenty thousand cubic yards of stone have been applied, mainly
to the top surface of the jetties, and, as we are informed by Mr. Eads, about
fourteen thousand cubic yards in addition aro on hand ready for application or
on the way. The total amount, say, thirty-four thousand cubic yards, is still
quite insignificant compared with the more than two hundred thousand cubic
yards required by the plans of the board of 1874. Wc are by no means taking
the latter estimate as an absolute standard, for we have conceded that ex¬
perience justifies a conriderable decrease of section, and perhaps a diminution
of quantity of stone in parts of the work. But experience has not as yet had
time to settle all questions. Stone is the costly element in the construction,
and, as already remarked, a large amount of this material must yet be applied.
If we turn now to the works at the head of the passes, we find them
alluded to by the commission of 1876 as "mostly of a tentative and temporary
character, which, as their proper positions are determined, should be replaced
by substantial and permanent structures," etc. ; a description which without
change applies to these works at the present date.
We by no means depreciate the extent or the value of the works as they
exist; but we cannot concur in the petitioner's statement to the effect that "we
have already completed at least eighty per cent, of this entire work."
We, as members of the Commission of 1876, and as ourselves constituting
the Commission of 1877, have expressed our opinion that the work "is being
constructed according to the spirit of the act." We believe, moreover, that
the work is now so far advanced and the success so far pronounced that it is
for the interest of the government and the country not only to have the con¬
structions carried on, but pushed with the utmost possible vigor to such a
point at least as shall insure their security and utmost efficiency of action in
increasing the capacity of the channel.
The present law fixes times or periods at which specified depths must be
attained, as follows: Thirty months are granted for securing twenty feet ; but
the law (fourth section) says explicitly ; "Said Eads and his associates shall,
after securing twenty feet of water, secure an additional depth of not less than
316
THE MISSISSIPPI JETTIES.
two feet during each succeeding year thereafter." This clearly makes the date
of the securing of twenty feet depth the initial time-point from which to com¬
pute the periods for the subsequent increased depths. Thus December 27,
1876, was this initial date ; hence, twenty-two feet was called for by the law
December 27, 1877, and twenty-four feet deep is demanded December 27, 1878,
instead of September 3, 1879, as the petitioner states the matter.
The foregoing are the main points in the petitioner's letter upon which he
supports his plea for a modification of the terms of the law as regards pay¬
ments. He states these terms, as they affect future payments, in tabular
form, as follows:
Third payment on securing 24
feet depth by 250 feet width, $500,000; one year thereafter *$250,000
Fourth payment on securing 26
feet depth by 800 feet width, 500,000; one year thereafter..., *250,000
Fifth payment on securing 28
feet depth by 800 feet width, 500,000; one year thereafter.... *250,000
Sixth payment on securing 80
feet depth by 850 feet width, 500,000; one year thereafter.... *500,000
Totals $2,000,000 *$1,250,000
To a full understanding of the matter of payments as now prescribed, we
add, that the first payment of $500,000 on securing twenty feet depth by two hun¬
dred feet width, and the second payment of $500,000 on securing twenty-two
feet depth by two hundred feet width, became due December 27, 1876,
and December 15, 1877, respectively, and have been paid; that $1,000,000
"deemed as having been earned by said Eads and his associates" when the
thirty by three hundred and fifty feet channel shall have been obtained (when
the sixth payment becomes due), is to be retained as " security " for the future
maintenance for a term of years of said channel. We have thus the stated
total of $5,250,000. It must be remembered, however, that the items of the
last column (marked *), payable each one year after the respective channel-
dimensions to which they refer have been secured, though bearing interest
from that date, become due only in case " said depth and width shall have
been maintained during twelve consecutive months."
In lieu of the foregoing terms of payment and widths and depths of chan¬
nel prescribed by the law, the petitioner desires that the following be author¬
ized:
Third. On securing a channel through the jetties 24 feet deep by
150 feet wide, provided it shall also be 22 feet deep by 200 feet
wide $750,000
Fourth. On securing a channel through the jetties 25 feet deep by
150 feet wide, provided it shall also be 22 feet deep by 250 feet
wide 750,000
Fifth. On securing a channel through the jetties 26 feet deep
by 150 feet wide, provided it shall also be 22 feet deep by 800
feet wide 500,000
Carried forward $2,000,000
LETTER AND REPORT, 1878.
317
Brought forward $2,000,000
Sixth. On securing a channel through the jetties 27 feet deep
by 100 feet wide, provided it shall also be 24 feet deep by 200
feet wide 375,000
Seventh. On securing a channel through the jetties 28 feet deep
by 100 feet wide, provided it shall also be 24 feet deep by 250
feet wide 375,000
Eighth. On securing a channel through the jetties 29 feet deep
by 100 feet wide, provided it shall also be 24 feet deep by 250
feet wide 250,000
Ninth. On securing a channel through the jetties 30 feet deep
by 100 feet wide, provided it shall also be 26 feet deep by 200
feet wide 250,OCO
Total $3,250,000
Moreover, the act provides that when the thirty by three hundred and fifty
feet channel is secured, $100,000 per annum shall be paid, under certain speci¬
fied conditions, for its maintenance during twenty years. It is asked that this
clause be amended so as to apply to the (as desired) modified thirty feet chan¬
nel; the $1,000,000 to be reserved as security for this maintenance being still
retained under unchanged conditions.
On the above, and the arguments presented in support thereof, we now
make the following comments :
The petitioner is quite right in saying that—
The commission of engineers authorized by Congress in 1874, and which
reported in favor of applying the jetty system to the South Pass, proposed to
secure a channel thirty feet in depth, and the permanent maintenance of only
twenty-five feet, without any specified width.
In fact that commission (or " board," as styled by the organic law and or¬
der) states :
The depth of thirty feet has been chosen, in order that some time may
elapse before the bar which will form at the sea-end of the jetties can have
less than twenty-five feet at mean low water upon it, that being the minimum
depth which it is desired to maintain.
In other words, that board aimed at simply maintaining, under all contin¬
gencies, a navigable depth (of unspecified width) at mean low water of twenty-
five feet, and to this end it aimed at securing, in the first instance, thirty feet
depth, in order that for a long time thereafter, without extension of jetties,
there should be not less than twenty-five feet at mean low water. This depth,
since the law makes mean high water instead of low water the plane of refer¬
ence, corresponds nearly to twenty-six feet depth under the law. It only dif¬
fers, therefore, from the conditions of the petitioner's (desired) fifth payment
by the latter specifying a width of one hundred and fifty feet. It only differs
from the desired ninth (and last) payment in the latter specifying a width of
two hundred feet for a depth of twenty-six feet, and a central depth of thirty
feet for a width of one hundred feet. The petitioner states:
" The jetty act requires a permanent depth of thirty feet, with a least width
of three hundred and fifty feet. This great width of thirty feet water will in-
318
THE MISSISSIPPI JETTIES.
volve a much larger channel than was contemplated by the commission as
proper for the size of the pass. Such width cannot probably be secured with¬
out a central depth of channel several feet greater than that recommended by
the commission."
He states also that he represented repeatedly to the committee, when the
bill was under consideration, that the width required was injudicious, and
might involve injury to the work. We remark that in the pass itself there is
found, for the greater portion of its length, a greater width of thirty feet
depth than three hundred and fifty feet. We have no personal knowledge of
the views of the committee in insisting on the above width. They might have
believed it important to have a channel width over the bar fully equal to that
in the pass itself.
After these quotations and remarks, we proceed to state our views as
follows :
The depths and widths specified, as desired by the petitioner, will fulfill
measurably the needs of commerce. We find the depth prescribed for his
(desired) fifth payment to be about equal to what the Board of 1874 aimed at
permanently maintaining, while the thirty feet depth with one hundred feet
width of the ninth and ultimate payment would enable the greatest draught
ocean-going vessel to enter the pass. A draught of twenty-three feet (and it
must be borne in mind that at the mouths of the Wississippi nearly all the
depth on the bar can be realized in actual draught) will include probably
eighty-five per cent, of the sea-going vessels of the world ; while over the bar
of New York Harbor twenty-six feet is about the maximum for regular traffic,
and twenty-eight feet (and a small fraction) the maximum ever carried over
(the ease of a war vessel, the Spanish Kumancia we believe).
The Board of 1874, to which, as the agent expressly constituted to investi¬
gate the whole question, and the authority which recommended and planned
jetties for the South Pass, states in reference to its choice of passes, "The
greater width (of the Southwest Pass) is more favorable to navigation, but in
our opinion the South Pass, when improved, will be adequate to the present
and prospective wants of commerce."
The petitioner, we think, has no good ground for the complaint that he
was not permitted to improve the pass of his choice. The difficulties, we deem,
would have been far greater there ; at any rate. Congress was fully justified in
legislating for the much less costly improvement for a navigation deemed fully
adequate.
We find that under the desired modification to get the fifth payment, the
contractor must have secured a navigation capacity probably equal to that
contemplated for permanent maintenance by the Board of 1874, while he will
at this stage of progress be entitled to but $3.000,000 of the $5,350,000 of his
ultimate total. As the law now stands, he would be entitled to $3,350,000, in¬
cluding the sum of $350,000 for keeping open the twenty-four feet channel for
twelve consecutive months.
We are of the opinion, as before stated, that the widths of channel pro¬
posed by the petitioner may be considered as fairly meeting the present wants
of commerce, but the widths proposed by the law as it now stands are obvi¬
ously desirable; and the question whether the large concession asked for in
those widths should be granted, and the compensation for the depths between
LETTER AND REPORT, 1878.
319
twenty-four and twenty-eight feet increasfed at the expense of the deeper ones,
seems to be one on which we can hardly be considered the proper exponents.
Respectfully submitted,
J. G. Barnard,
Col. of Engineers, and Brevet Maj.-Oen.
H. G. "Wright,
Lieiit.-Col. of Engineers, and Brevet Maj.-Oen.
Hon. George W. McCrary,
Secretary of War, Washington, D. C.
APPENDIX XIII.
(See page 171.)
LETTER OF GEN. A. A. HUMPHREYS, CHIEF OF ENGINEERS,
U. S. A.
Washington, D. C., May 1, 1878.
To the Hon. E. W. Robertson,
Chairman Committee on Levees and Improvement of the Mississippi River,
House of Representatives ;
Dear Sir :—A bill has been introduced in Congress for the appointment of
a commission of five engineers to survey the Mississippi River from St. Louis
to the Gulf of Mexico ; prepare plans for the improvement of its navigation
and protection of the alluvial region against overfiow, and carry on the works
for these objects as moneys are appropriated by Congress for them. Provision
is made for four of these engineers to be taken from the Corps of Engineers,
the fifth to be appointed from civil life, and it is indicated, though not ex¬
pressly stated, that the engineer from civil life is to be the president of the
commission and is to control its decisions, and no project, plan, or estimate of
cost is even to be submitted to the Secretary of War or President of the
United States unless approved by the president of the commission. Such
power as this has never been conferred upon any presiding officer of a board,
commission, or court. This project of a commission of survey and construction
is brought forward, notwithstanding that a detailed survey under the En¬
gineer Department is already in progress with a view to low water improve¬
ment, and to protection against fioods, carried on in accordance with the
recommendation of the commission organized by act of Congress of June 23,
1874, to devise a plan of protection against overfiow, and with the general
project for the improvement of the low water navigation of the Missis¬
sippi below Cairo, which was submitted by Major Suter of the Engineers, after
the reconnoissance made by him of the bars and obstructions to navigation in
that section of the river, under appropriations for surveys for routes of cheap
transportation to the seaboard.
It is generally understood that the peculiar features of this bill have their
origin, first, in the scheme recently proposed by Mr. Eads to deepen the low
water channel of the Mississippi River to twenty feet, claiming that by thus
improving the low water navigation of the river, its surface will be lowered in
floods to the level of the natural banks, and that in this way levees will be
330
LETTER, HUMPHREYS TO ROBERTSON.
321
dispens3d with ; and second, in the statements made in the public press that
Mr. Eads has succeeded in the permanent improvement of the South Pass of
the Mississippi River by jetties, while the Engineer Department had opposed
the use of jetties for that purpose, and maintained that it was not practicable
to improve the pass by them.
It may be well to examine into these grounds of action.
First, as the views of the Engineer Department upon the application of
jetties to the improvement of the mouth of the Mississippi River. They are
to be found in reports to the Engineer Department, as far back as 1853, and
in various official documents readily accessible to the public, notably in the
Physics and Hydraulics of the Mississippi River, pages 443 to 456, where the
manner of delta bar-formation is described in connection with an account of
measurements and experiments made at the mouth of the Mississippi, and
where it is demonstrated that by the use of jetties the channels at the mouths
of the river may be deepened to the full depth of the pass to which they are
applied.
This subject is further treated in still more detail in Ex. Doc. 330, House
of Representatives, Forty-third Congress, first session, and an estimate of the
first cost of applying jetties to deepen the Southwest Pass to twenty-eight
feet is given, as well as the first cost of the same for the South Pass, the cost
of permanent works for the former being $7,000,000, and for the latler loss
than $5,000,000. For less permanent v/orks the cost in each case, it is
stated, would be one-half the sums named.
The first cost of these works was not the objection to this method of im¬
provement ; but the cost of maintaining the channel depths permanently with¬
out fiuctuation, which could only be certainly effected by the extension of the
jetties constantly in the deep water of the sea, formed the objection to their
use, and induced a preference for a canal ; though the first cost of a canal
would materially exceed the first cost of the jetties at either pass, yet the cost
of its maintenance would be small, and there would be no variation in the
depth at either the river or sea end of the canal.
During the session of Congress that this subject was discussed, bill after
bill was introduced into Congress proposing to pay Mr. Eads $10,000,000 for
deepening any pass he might select to twenty-eight or thirty feet at flood tide.
These bills were referred to the Engineer Department for its views, and were
returned with their defects pointed out, showing that they gave no security to
the United States for the permanent maintenance of the deep water desired.
This class of bills was advocated on the ground that the jetties once built the
channel would bo deepened, without the assistance of dredging, even, and that
the earthy material borne along by the river would be taken so far seaward by
the increased velocity of the current produced by the jetties that no bar would
be formed in front of the jetties, and no extension of the jetties seaward would
be needed.
It was pointed out by the Chief of Engineers that if it were so, then
$7,000,000 for the Southwest Pass and not exceeding $5,000,000 for the South
Pass, would be the greatest sums that should be paid for the work, and not
$10,000,000. None of these bills were enacted into law.
At the succeeding session of Congress a Board of Engineers, organized un¬
der an act of Congress, and composed of three officers of the Corps of En-
31
322
THE MISSISSIPPI JETTIES.
gineers, one assistant United States Coast Survey, and three civil engineers,
recommended the application of jetties to the South Pass as less costly than
the building and maintenance of a canal. The application of jetties to the
Southwest Pass they reported would be more costly than the canal. Under
this recommendation a contract with Mr. Eads was entered into by act of
Congress of March 3, 1875, the total sum to be paid him for obtaining through
the South Pass a channel depth of thirty feet at mean flood tide being
$5,350,000 ; and for maintaining it twenty years the sum of $100,000 annually
—one million to be retained as security. The works of construction were
begun late in the year 1875, at which time the depth on the crest of the bar
of the South Pass at low tide was about eight feet ; at high tide about nine feet.
The river began to rise about the first of January, 1876, and reached its
highest point that year at New Orleans in the early part of May, when the
Carrollton gauge read 18.7 feet, the average flood reading of the river at that
point for 1876 being twelve feet.
The usual flood reading of the river at Carrollton is above fifteen feet.
The Jump and Cubitt's Gap crevasse below New Orleans, but above the head of
the passes, discharged a large volume of water into the gulf, so that the maxi¬
mum discharge into the sea through the passes that year did not largely exceed
the volume of the river when half way between low and high water stages.
The river at New Orleans went down in August, 1876, fluctuating some¬
what until November, when it reached the extreme low stage, remaining in
that condition until the latter part of January, 1877, when a brief rise took
place which subsided in February, the river being low until the latter part of
March, when the flood rise began, its greatest height, attained in May and
June, being eleven feet on the Carrollton gauge. The discharge through Cu¬
bitt's Gap and the Jump at the high-water stage was about the same as the
preceding year, and again we have, during the high-water period of 1877, a
volume of discharge into the sea through the passes not largely exceeding one-
half the flood volume of the river. The river began to fall in July, and reached
the low-water stage by the last of August.
It is to be borne in mind that it is an established fact, ascertained by re¬
peated examination, which no person accustomed to the investigation of
physical phenomena can or does question, that when the Mississippi River is
in the flood condition, and the rising river gets above nine feet on the Carroll¬
ton gauge, there is a broad, thick sheet of earthy matter moving along the
bottom of the passes, which is carried over the bar crests and dumped on the
outer slope of the bars. This process continues during the flood stage, and
constitutes the bar growth. During the low stage of the river the fresh water
of the river does not touch the bottom of, the passes, nor of the river for some
distance above the head of the passes, the lower part of the channel being occu¬
pied by salt water, whose chief movements are independent of the fresh-water
current. At this low-water period there is an accumulation of soft earthy mat¬
ter on the bed, and the bar growth does not go on. Or. the contrary, the waves
of the gulf and its sait-water currents modify the new bar growth of the pre¬
vious flood stage, the crest usually receding, and the depth on it increasing.
It will be perceived from this statement, and that which precedes it, con¬
cerning the 'highest reading of the gauge at Carrollton, and the volume of
discharge into the sea through the passes, that during the high-water stage of
LETTER, HUMPHREYS TO ROBERTSON.
323
the Mississippi in 1876 and 1877 there was comparatively little bar growth at
the mouths ol the passes in those years.
Before the construction of the Jetties, the annual extension into the sea of
the bar of the South Pass did not exceed one hundred feet a year.
The construction of the jetties at the South Pass was begun in the fall of
1875. The report and map of Gen. Comstock (the inspecting oificer), of the
0th June, 1876, show that its bar had extended seaward four or five hundred
feet (soundings early in May), the depth on the bar growth being between
twelve and fifteen feet flood tide, and its outer line or crest resting in water
that was about forty feet deep in November, 1875.
The next report of Gen. Comstock, September 30, 1876 (soundings between ,
last of July and first half of August), shows the bar growth in about the same
position, the average depth on it being from eighteen to twenty feet flood tide.
The next report of Gen. Comstock, December 6, 1876, shows the condition
of the work in November, 1876. The depth on the bar growth had increased
about two feet.
The next report of Gen. Comstock, April 5, 1877, shows the condition of
the work March 16,1877.* The depth on the east side of the bar had increased.
By the next report, that of Capt. Brown, August 1, 1877, showing the con¬
dition of the work July 34, 1877, we find the total extension of the bar up to
that date to have been six hundred feet, the depth on the greater part of the
bar varying from fifteen to twenty feet flood tide; on the inner eastern side
the depth being about twenty-one feet.*
The next report of Capt. Brown, December 23, 1877, was made after a
powerful, newly-constructed dredge had been working on the bar seaward of
the jetties for a month, by which means the depth on the bar had been in¬
creased, and a channel twenty-two feet deep at flood tide and two hundred feet
wide had been secured.* This dredge was designed to work on the newly-
grown bar seaward of the jetties, where, from exposure to the sea, the ordinary
dredge cannot be used to advantage.
The river at New Orleans began to rise about the 1st January, 1878, and
during February and March was in condition to cause some bar growth, the
Carrollton gauge reading between nine and ten in February, and between ten
and eleven in March. Accordingly, we find Capt. Brown reporting on the 4th
and 8th March that the channel of twenty-two feet depth at flood-tide was but
one hundred and ten feet wide for a portion of its length " over the bar's crest "
(through the new bar seaward of the jetties), and on the 3d Aprii reporting
that the least width of this channel (on this bar-growth) "between South Pass
jetties" and "deeper water in the Gulf of Mexico" was seventy feet. This
decrease of the channel width had taken place notwithstanding that the
dredging on the bar growth had been going on with the new dredge designed
for sea dredging. Capt. Brown's report of the 3d April also states: "At the
head of passes a least depth of twenty-one feet at average flood-tide was found
on the 18th of March."
It will bo noticed that Mr. Eads obtained the channel two hundred feet
wide and twenty feet deep December 37, 1876; that is, when the river had been
in the low-water stage for several months. The channel two hundred feet
* See tlic maps accompanying these and previous reports.
324
THE MISSISSIPPI JETTIES.
wide and twenty-two feet deep was obtained December 17, 1877, at which time
also the river had been in the low-water stage for several months. In fact,
these depths were obtained at the end of the low-water stage of the river.
It may be needless to recur again to the results of careful investigation at
the mouth of the Mississippi Hiver, one of which is that during the low-water
stage of the river there is no bar growth.
Notwithstanding the discharge of the river through the passes in the flood
stages of 1870 and 1877 was so much reduced by crevasses that comparatively
little bar-forming process at their mouths went on in those years, yet the facts
exhibited by the reports of the officers inspecting the South Pass show that the
views expressed by many engineer officers, the Chief of Engineers among them,
that a new bar would form at the sea end of the jetties, and that it would ex¬
tend into the sea more rapidly than the old bar, are correct even during the
changes going on under the scouring power of the jetties, aided by dredging be¬
tween and seaward of them ; and it is also evident that the only method of per¬
manently maintaining a deep channel to the sea is to constantly extend the
jetties into the sea in advance of the bar. It is evident that this has not been
done in the present case, and undoubtedly because of the great difficulty and
expense of extending the jetties into the deep water of the sea. It was precisely
this objection to the jetty system which the Chief of Engineers and other
engineer officers made. This new bar growth beyond the jetties has been formed
under the action of the jetties. To make a channel through it, and to endeavor
to maintain the channel, dredging has been resorted to, precisely as was done
on the Southwest Pass bar, a process which it ivas designed by Congress to
dispense with in entering into a contract for deepening the South Pass channel
by the construction of jetties and auxiliary ivorks, for that contract declares its
intent to be "not simply to secure the wide and deep channel first above named,
but likewise to provide for the construction of thoroughly substantial and per¬
manent works by which said channel may be maintained for all time after
their completion."
The foregoino historical summary sufficiently proves that the re¬
sults actually attained at the SoUTH PaSS disprove the views ad¬
vanced by Mr. Eads and confirm those op the Engineer Department.
Hence any claim that he should be intrusted with the control of the
Mississippi River, in so far as it rests upon the results thus far
achieved by him, has no proper basis. * * *
Very respectfully.
Your obedient servant,
A. A. Humphreys.
APPENDIX XIV.
(See page 173.)
EEVIEW BY JAS. B. EADS
of the letter of
Geî7. a. a. humpheeys,
Chief of U. s. Engineers, May 1, 1878,
to
Hok. e. w. eobeetson,
Chairman House Committee on Levees and Improvement of the Mississippi.
National Hotel, )
Washington, D. C., June 1, 1878. )
To the Hon. E. W. Robertson,
Chairman Committee on Levees and Impr-ovement of the Mississippi River,
House of Representatives ;
Dear Sir :—I have just read with astonishment a letter addressed to you,
dated Washington, D. C., May 1, 1878, and signed by A. A. Humphreys. As
the writer holds the office of Chief of Engineers, U. S. A., he is in a position
to have at hand reliable official facts which emphatically refute many of the
statements contained in his letter respecting the jetties at the South Pass.
The letter seems ostensibly intended as a protest against the improvement of
the Mississippi River being in any wise intrusted to me. He assumes that
the bill providing for a commission of five engineers to prepare plans for the
improvement of the river is designed to place its whole control in my hands,
whereas the only bill reported from your Committee to the House six weeks
ago, provides that three of the five engineers shall be taken from the army, and
that one of these three shall be president of the commission. So far from my
expecting to have the presidency of it, the bill prevents the possibility of such
a thing. Nor have I ever expressed to a single member of the Senate or House
a wish to have its provisions altered, nor have I authorized or requested any
one to secure the presidency of the commission for me.
I shall reserve the discussion of the views entertained by General Hum¬
phreys and myself, respecting the improvement of the river, until a more con¬
venient season. It is sufficient to say here that they are totally different. I
335
326
THE MISSISSIPPI JETTIES.
cannot, however, permit some of the statements in his letter respecting the
jetties to go unchallenged.
General Humphreys says the views of the Engineer Department are to be
found in its reports as far back as 1853 ; " notably in the Physics and Hydrau¬
lics of the Mississippi River, pages 442 to 456, * * * . ^vhere it is demon¬
strated that, by the use of jetties, the channels at the mouths of the river may
be deepened to the full depth or the pass to which they are applied."
It is encouraging to see that General Humphreys desires to be recognized
as one of the earliest to suggest jetties for the improvement of the mouth of the
Mississippi ; and, as the South Pass has a depth through it of thirty feet, this
testimony will probably remove from the minds of those who consider him an
authority upon the jetty question all doubt as to the ability of the jetties, to
produce the maximum depth I have undertaken to secure.
General Humphreys, in his letter, refers to the earlier reports on the jetties
by General Comstock, to prove that the bar had advanced four or five hundred
feet in May, 1876. The answer to this absurdity will be found in a compara¬
tive chart of surveys of the outer crest of the bar, made by the United States
Coast Survey, in May, 1875, before the jetties were begun, and in May, 1876,
accompanied with a statement from the Superintendent of the Coast Survey,
Hon. C. P. Patterson. They were furnished, in compliance with a resolution of
the House of Representatives, and duplicates were at the same time, August 1,
1876, sent to the War Department. Reference to them will show that, instead
of there being an advance of the bar, there had been excavated by the current
from a space two thousand one hundred feet square in front of the jetties,
sixty-eight thousand four hundred cubic yards of material in excess of deposits
made in that area during the year.
General Humphreys says ;
"By the next report of Captain Brown, August 1, 1877, showing the con¬
dition of the work July 24, 1877, we find the total extension of the bar up to
that date to have been six hundred feet. The depth on the greater part of the
bar varying from fifteen to twenty feet flood tide ; on the inner eastern side
the depth being about twenty-one feet." A foot-note says, "See the maps
accompanying these and previous reports."
The report of Captain Brown, August 1, 1877, shows no such extension,
nor do any of his maps. On the contrary, he says on page 26 :
"On sheet No. 4will be found the results of a suiwey on June 80 to June
22. 1877, of a mile or more beyond the ends of the jetties, and for a consider¬
able space on either side. A comparison of this chart with that of the sur¬
vey of Juno 20 to 24, 1876, reveals the following regarding various curves of
equal depth : Averaging, the twenty-feet curve has receded about two hun¬
dred feet, the thirty-feet curve about three hundred feet ; the forty-feet curve
has remained nearly stationary on the whole." »*****-
The curves referred to indicate the form or contour of the outer slope of
the bar between the depths of twenty and forty feet.
By reference to Captain Brown's chart. No. 4, it will be seen that an area
of about one square mile in front of the jetties is embraced in this survey, and
this has been subdivided by him on the chart into twenty-one sections, the
whole forming a fan-shaped area in front of the jetties. A portion of this
, area—sections No. 1, 7, 13, and 21—lay to the right and left of the end of
EADS KEVIEWS HUMPHBEYS.
327
the jetties, and out of the track of the river's discharge. Referring to this chart,
Captain Brown, on page 28, says :
"Taking into account all the divisions, except 1, 7, 13, and 21, we find
that the scour in the year was one million one hundred and forty-five thousand
nine hundred and seventy-six cubic yards, equivalent to a scour of 1.8109 feet,
or one foot and three and seven-tenths inches, over this latter area."
By a glance at the table on page 80 of the report, it will be seen that sec¬
tion 17, containing about thirty-eight acres, had an average depth of 29.28 feet
in 1870, and in 1877 this depth had increased almost four feet, viz., to 33.25
feet.
It is thus shown that General Humphreys' statement is not only directly
refuted by Captain Brown's report, to which he refers, but that the bar, during
the twelve months, had actually receded two hundred or three hundred feet ;
that the bottom for a mile in advance of the jetties had deepened one foot and
three-tenths, and that the portion immediately in front of the jetties, thirty-
eight acres in extent, and precisely where General Humphreys predicted the
reformation of the bar would occur, had actually deepened in one year nearly
four feet.
General Humphreys says :
"The next report of Captain Brown, December 23, 1877, was made after
a powerful newly-constructed dredge had been working on the bar seaward of
the jetties for a month, by which means the depth on the bar had been in¬
creased, and a channel twenty-two feet deep at flood tide and two hundred feet
wide had been secured."
On page 17 of this report Captain Brown says :
" When the new dredge began its experimental work, the interruption to
the twenty-two-feet channel, i.e., from twenty-two feet inside 'on the bar to
twenty-two feet outside, was fifty feet only."
On page 19, he says :
" In obtaining the channel twenty-two feet deep for a width of two hun¬
dred feet, the dredge Bayley has worked about twenty days, of ten hours
each."
Soon after the channel referred to was obtained, entitling me to the second
paymentof $500,000, the Secretary of War directed a Commission of Hngineers,
composed of Gens. Barnard and Wright, United States Engineers, to visit the
works, and among other subjects they were required to report upon the follow¬
ing interrogatory, viz. :
" Have such depth and width of channel been obtained by the action of
such jetties and auxiliary works as are contemplated by the terms of the act of
Congress aforesaid ? "
The report of this commission will bo found in Ex. Doc. 37, Forty-fifth
Congress. Second Session, House of Representatives.
In answering this interrogatory the commission says, on page 5:
"If we look at the actual facts presented by the prosecution of this work,
we find that where two and a half years ago there was a bar at the mouth of
the South Pass of over two miles in extent, measured from twenty-two feet
water inside to the same depth outside, over about half a mile of which there
was but eight feet of water, ' a wide and deep channel ' of twenty-two feet
depth now exists, and a result inferior in physical magnitude, but no less in im-
328
THE MISSISSIPPI JETTIES.
portanee, at the head of the passes has been obtained. And these results are
so exclusively due to the jetties and auxiliary works, that the auxiliary aid of
' appliances,' if in such we include dredging machines, is utterly insignificant,
consisting mainly, indeed, in a slight widening at two points, and widening
and deepening at a third."
Gen. Humphreys says, in italics :
" Yet the facts exhibited by the reports of the officers inspecting the South
Pass show that the views expressed by many engineer officers, the Chief of En¬
gineers among them, that a new bar would form at the sea-end of the jdties,
and that it would extend into the sea more rapidly than the old bar, are correct,
even during the changes going on under the scouring power of the jetties, aided
by dredging between and seaward of them."
Gen. Humphreys predicted (see page 677, last edition Physics and Hydrau¬
lics) that the bar, under the action of jetties, would advance six hundred and
seventy feet annually. Instead of this bar advance, as predicted, there is shown
to have been no advance at all, but an actual recession. He, however, pro¬
ceeds to say :
" And it is also evident that the only method of permanently maintaining a
deep channel to the sea is to constantly extend the jetties into the sea in advance
of the bar. ^ » Jt mas precisely this objection to the jetty system
which the Chief of Engineers and other engineer officers made."
\ Capt. Brown, oa_pago 26 of his seventh report, August 1, 1877, says :
"It must be noted in regard to the recession of the twenty-feet and thirty-
feet curves that the present end of the east jetty is three hundred and thirty
feet north of what I have always called the old end of the east jetty, and the
present end of the west jetty is two hundred and sixty-three feet northerly of
the point formerly considered to be the end of the west jetty."
The meaning of this is that, instead of having to advance the jetties six
hundred and seventy feet every year, as predicted, at a cost of $670,000(seo
page 677, last edition Physics and Hydraulics), they are actually more than
two hundred feet shorter to-day than they were originally intended to be. The
deepening has been so marked at the sea-ends of the jetties, where the predicted
bar growth was to occur, that I have not found it necessary to completo them as
far out as they were located and partly built two years ago.
This notable difference between his declarations and the official reports I
have quoted, proves that on the subject of the jetties Gen. Humphreys is not
a trustworthy authority.
Gen. Humphreys says :
" To make a channel through it [fh^ 'bar growth,' as he calls if], and to
endeavor to maintain the channel, dredging has been resorted to precisely as
was done on the Southwest Pass bar, a process which it ivas designed by Con¬
gress to dispense with in entering into a contract for deepening the South Pass
channel by the construction of jetties and auxiliary works."
The commission, from whose report I have before quoted with reference to
dredging, states on page 4 ;
"If, however, we refer to autlioritative statements of the methods of apply¬
ing that principle, we find it stated in the Physics and Hydraulics [page 4S9,
reprint], in treating of the 'plan of jetties,' that 'the erosive action should be
aided at first by dragging and scraping the hard portion of the bar.' "
EADS KEVIEWS HUMPHEEÏS.
329
Having himself pointed out in the Physics and Hydraulics the importance
of " dragging and scraping " as an auxiliary of the jetty system, his objection
to my use of a dredge at the South Pass is without force. But that it was
clearly my right to hasten the development of the channel by dredging is
shown by the commission to whom this question was referred. It says, page
4, after referring to an item of $250,000 estimated for dredging by the previous
Commission of 1874, in connection with the jetties :
"We conceive, therefore, that the true intent of the proviso does not pro¬
hibit the auxiliary aid of dredging; that its spirit is as above defined, and that,
indeed, in the authorizing of the employment of such boats, rafts, and appli¬
ances as he may in the 'prosecution of said works deem necessary,' allows
dredging, and should not prohibit payment for channel widths and depths
which the jetties and auxiliary works have to all intents and purposes really
created, and to which dredging has been slightly auxiliary."
Of the cost of the jetties. Gen. Humphreys says in his letter :
" This subject is further treated in still more detail in Ex. Doc. 220, House
of Representatives, Forty-third Congress, first session, and an estimate of the
first cost of applying jetties to deepen the Southwest Pass to twenty-eight feet
is given, as well as the first cost of the same for the South Pass ; the cost of
permanent works for the former being $7,000,000, and for the latter less than
$5,000,000. For less permanent works the costs in each case, it is stated,
would be one'-half the sums named."
Gen. Humphreys evidently intends to create the impression that he showed
to Congress in 1874 that the jetties could be built for less than the price to be
paid to me.
In Appendix M, page 677, "Physics .and Hydraulics," last edition, the cost
of applying the jetty system to the Southwest Pass is stated as $28,000,000, and
the cost of applying it to South Pass, after adding $670,000 per annum for ex¬
tension, and $100,000 per annum for dredging, is thus expressed :
"The total cost to the government of securing permanently a depth of
twenty-seven feet at low water by this pass will then be about $17,000,000."
Thus, to defeat the jetty bill in 1874, and secure the construction of the
Fort St. Philip canal, the cost of which is stated on the same page to be but
$13,000,000, the official assurance was given that the jetties at South Pass
would cost $17,000,000 ; and now the same eminent authority who made that
statement, wishing to depreciate the value of my works, leads you to believe
that he only estimated the cost of jetties in 1874 at less than $5,000,000.
I have shown conclusively, from official reports on the jetties, that there has
been no advance of the bar ; th.at it has not been necessary to extend the jetties,
and that there has been no shoaling in front of them. These three facts are
precisely the opposHe of the results predicted by Gen. Humphreys. It is evident
from these extracts, that the conviction which Gen. Humphreys entertained in
1874, that the jetty system, if applied to the Mississippi River, would prove a
failure, has become so fixed in his mind that he is unable to realize the em¬
phatic official declarations of the officers of his own corps, which testify to
their complete success.
The act of Congress of March 3, 1875, provided :
"Said Eadsshall be untrammeled in the exercise of his judgment and skill
in the location, design, and construction of said jetties and auxiliary works."
330
THE MISSISSIPPI JETTIES.
This meant that, having undertaken an important vork at the risk oí my¬
self and associates, I should have no hostile interference on the part of the
government so long as I should faithfully carry on the work. In contempt of
this provision of the law, the Chief of Engineers, U. S. A., in the summer of
1875, when I had just begun the jetties, set himself assiduously at work to im¬
peach my judgment and skill, and to show that the enterprise would be a
failure. Not only was his time given to this effort to defeat the purpose of Con¬
gress, but the public money was used to print his " memorandums " against
the South Pass jetties. These were issued in pamphlet form for circulation,
to lessen the public confidence in my undertaking. They were then put in his
annual report for 1875 ; and in 1876 they were reproduced with added matter
in the last edition of the " Physios and Hydraulics of the Mississippi."
This was not only an injury to me, but was a ñagrant disrespect to Con¬
gress, whose act had provided that 1 should be free from such interference.
The fact that Congress, in passing the jetty act, had disregarded the un¬
sound views of General Humphreys, would fairly excuse his loss of temper,
but could not justify this reproduction at the public cost of his repudiated
theories.
Although the jetty act was purposely framed to exclude General Hum¬
phreys from all connection with the work (because of his hostility to it), by
providing that the inspecting officer should be detailed to report to the Secre¬
tary of War, General Humphreys gave the officer his instructions, and the
reports were made to him during the first year, when his interference and hos¬
tility became so pronounced that 1 appealed successfully to the Secretary of
War, in an open letter, May 23, 1876, to have him absolutely excluded from
any further connection with the work, and to have the inspecting officer re¬
port directly to the Secretary of War, as the law provided. And noiv, on the
very day when a measure to secure the more vigorous prosecution of the work
is reported to the Senate from the appropriate committee. General Humphreys
presents the letter 1 am reviewing, evidently with the intent to defeat this
measure ; and as a pretext for presenting it, asserts that a bill has been intro¬
duced in Congress to give me the control of the further improvement of the
Mississippi River, when he must have known, or could easily have ascertained,
that no such bill has been reported by your committee, or any other.
And, in absolute defiance of the plainest official evidence to the contrary.
Gen. Humphreys makes the astonishing statement that "the results actually
attaimd at the South Pass disprove the views of Mr. Pads and confirm those
of the Engineer Department while the safety and ease with which the
heaviest draught ships already use the jetty channel, and the immense benefits
resulting to commerce, should convince even him of the wisdom of the gov¬
ernment in rejecting the advice of the Chief of Engineers when deciding on
the problem of improving the mouth of the Mississippi River.
Very respectfully,
Jas. B. Eabs.
APPENDIX XV,
(See page 177.)
ESTIMATE OF THE DETAILED COST OP THE CONSTEUCTION
OP THE SILL ACROSS PASS 1 LOUTRE.
Total number of cords of mattresses 8230.63.
" " lineal feet of sill 2950.00.
Kinds of Material or Work.
Anchorages
Guide Piles (rear)
" (side)
Mattresses, Material
" Construction..
Towing and Placing
Stone
Sinking
Superintendence and )
General Expense acc. )
Total Quantity.
20
63-8394 lin. feet,
84-4364 "
3230.63 cords.
Detailed
Cost.
Total.
157.56
0.200
0.221
2.578
.65
903.04 cub. yds.
3.80
Amount to
One Corel
Mattre&s.
1.02
1.35
0.28
Cost per .
one cord i
of Mat¬
tress
Work.
10.356
0.219
0.30
2.578
0.65
0.706
1.059
0.413
0.479
S.660
Cost per cubic yard $1.418.
Cost per cubic yard to Mr. Eads 5.360.
331
APPENDIX XVI.
(See pages 183 and 209.)
Final Estimate of Materials Used on Jetties and Auxiliary "Works,
June, 1875-Junb, 1880.
MVhat work.
Bast Jetty
West Jetty
Kipp Dam
Wing dams
Rubble wall
Picayune Bayou
Grand Bayou
East Dike
Dam No. I
Island Dike
Lighthouse Dike
Island Dam
Cross Dike
Southwest Pass sill....
Pass à Loutre sill
Upper Dam
Lost and no record....
Total
Willows
Cords.
3,
7.
3;
11,
10.
2.
1,
10,
3
5,
3
718.03
812.61
099.53
621.95
' 56.00
887.96
592.00
547.86
462.58
566.21
928.41
864.19
057.94
230.62
335.07
896.05
126,697.01
Stone.
Cubic yards.
43,400.36
23,429.31
2,237.32
2,411.10
463.00
20.41
1,258.00
2,742.80
1,260.00
3,077.69
3.669.35
1,451.25
437.00
2.809.36
903.04
1,674.43
1,255.53
92,499.95
Concrete.
Cubic yards.
5,106.00
2,220.00
7,326.00
Crib timber.
Lineal feet.
34,201.
33,549.
67,750.
Total amount of all works, 702,973 cubic yards.
332
APPENDIX XVII.
(See pages 192 and 212.)
Depths op Channel, each 2,000 Feet, from Report op Capt. M. R. Brown,
June 30, 1879.
Date.
June —,
May —,
Aug. -,
Nov. —,
Mar. 16,
Apr. 2,
Apr. 22,
May 10,
May 24,
June 28,
July 3,
July 7,
July 8,
J uly 28,
Aug. 80,
Sept. 28,
Oct. 25,
Oct, 31,
Nov. 3,
Nov. 13,
Dec. 1,
Dec. 7,
Dec. 14,
Jan. 1,
Feb. 2,
Mar. 4,
Mar. 13,
Mar. 24,
Mar. 25,
Mar. 26,
Mar. 27,
Apr. 3,
May 9,
May 23,
June 3,
June 19,
July 2,
Dec. 2,
Dec. 3,
1875.
1876.
1876.
1876.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1877.
1878.
1878.
1878.
1878.
1878.
187».
1878.
1878.
1878.
1878.
1878.
1878.
1878.
1878.
1878.
1878.
Distances in feet from East Point.
0 to 2,000.
2,000 to
4,000.
4,000 to
0,000.
6.000 to
8,Out).
8.000 to
10,000.
10,000 to
12,000,
22.5
23.3
23.5
22.0
24.1
18.7
20.3
19.6
20.3
21.1
16.7
22.0
21.0
21.1
23.2
10.2
21.0
23.5
21.2
22.0
9.7
17.1
23.0
21.1
21.2
9.2
"15.0
19.8
20.3
20.5
21.3
20.5
19.5
17.8
18.0
22.1
21.4
24.9
240
23.5
23.8
26.0
20.3
20.8
20.7
24.4
21.0
26.3
28.5
24.2
21.3
"23.7"
23.0
22.8
23.2
20.5
23.0
26.0
25.9
35.5
25.4
24.8
23.0
23.2
22.3
22.2
22.0
21.9
28.4
26.4
35.7
27.1
25.3
334 the rassissippi jetties.
APPENDIX XVII. —[continued. )
Date.
Distances in feet from East Point.
0 to 2,000.
2,000 to
4,000.
4.000 to
0,000.
6.000 to
8,000.
8.000 to
10,000.
10,000 to
20,000.
Dec. 6, 1878
23.0
23.0
23.9
22.2
24.8
Dec. 23, 1878
Jan. 20, 1879
Feb. 13, 1879
Mar. 14, 1879
Mar. 19, 1879
28.6
27.5
43.4
Mar. 24, 1879
27.0
27.0
Mar. 27, 1879
27.0
27.0
Apr. 8, 1879
May 13, 1879
June 11, 1879
27.5
June 12, 1879
47.7
29.2
29.2
23.0
June 18, 1879
28.4
30.7
July 8, 1879
30.5
81.0
30.7
30.5
APPENDIX XVIII.
(See page 191.)
LETTER FROM THE SECRETARY OP WAR,
Communicating, in obedience to Law, the Report of the Board of Offi¬
cers appointed to Examine the Works in Progress of Construction
by James B. Eads, at the Mouth of the Mississippi -River.
January 27, -1879.—Referred to the Committee on Commerce, and ordered to
be printed.
War Department, )
Washington City, January 27, 1879. (
The Secretary of War has the" honor to transmit to the United States Sen¬
ate the report of the Board of Officers, constituted by direction of the Presi¬
dent, to examine the works in progress of construction by James B. Eads, at
the South Pass of the Mississippi River, and report thereon, as required by
section 4 of the act of Congress approved June 19, 1878.
G. W. McCrary,
Secretary of War.
The President
of the United States Senate.
Army Building, )
New York, January 23, 1879. )
Sir :—I have the honor to transmit to you herewith the report of the Board
constituted by direction of the President, by Special Orders No. 228, Head¬
quarters Army, Adjutant-General's Office, Washington, D. C., October 22,
1878.
Very respectfully, your most obedient,
J. G. Barnard,
Col. of Engineers and Brevet Maj.-Oen., President of the Board.
Hon. Geo. W. McCrary,
Secretary of War, Washington, D. C.
835
336
THE MISSISSIPPI JETTIES.
1.
[Special Orders No. 228.]
Headquarters of the Army, ^
Adjutant-General's Office, y
Washington, October 22, 1878. \
The following order has been received from the Secretary of War:
By direction of the President of the United States, a board to consist of
the following-named officers of the Corps of Engineers is hereby appointed in
accordance with the provisions of Section 4 of the act of Congress approved
June 19, 1878.
Detail for the Board: Col. John G. Barnard, Col. John N. Macomb, Col.
Z. B. Tower, Lieut.-Col. H. G. Wright, Maj. William E. Merrill.
The board, which will be governed by the provisions of the section of the
act above referred to, will assemble in New York City on the 11th of Decem¬
ber, 1878, and adjourn to meet at the mouth of the South Pass of the Missis¬
sippi before the end of that month.
After completing its examinations, the board is authorized to adjourn to
such place as it may designate for the preparation of its report.
By command of Gen. Sherman.
E. D. Townsend,
Adjutani-Cren.
Official :
K. C. Drum,
Assistant Adjutant-Gen.
A.
Port Eads, January 2, 1879.
Mr. James B. Eads :
The fourth section of the act of Congress, approved June 19, 1878, which
authorized and directed the President oí the United States to convene a board
of five engineers of the army to visit the works "in process of construction
* * * at the South Pass of the Mississippi River," requires, after examina¬
tion of the same, that a "full report" be made, embracing the following
points, viz. :
1. Progress made in the construction of the works.
2. The probable cost of completion.
3. The results produced.
4. The results that may probably be produced by them.
5. Their probable permanency.
6. "The advisability of any modification of the terms of the act under
which said Eads is constructing the said works, so far as regards dimensions of
channel through the jetties, and of the terms of payment for the same."
On the second of these points it is obvious that the board cannot report
EEPOET OF BOAED, 1879.
337
without first having from you a statement of your plans for ' ' completion, "ac¬
companied with such details as to proposed modes of construction as will en¬
able the board to estimate the probable cost. Should you choose to accompany
such statement of your plans with your own estimates of their probable cost,
it will be acceptable ; understanding, however, that they wül be regarded as
only furnishing toward enabling the board to prepare its own estimate.
It is obvious, too, that on the fifth point, that of "permanency," a knowl¬
edge of your plans for completion is likewise an essential.
If, in addition to what you are requested to furnish, in what precedes, you
should desire to present your views on the "results that may probably be
produced " by the works as you design to complete them, or to suggest any
modification of the terms of the act under which you are constructing the
works, as regards dimensions of channel and terms of payment, you are invited
so to do.
I am, very respectfully, etc.,
J. &. Barnard,
President of the Board.
B.
Port Eads, January 4, 1879.
Sir :—I have the honor to acknowledge receipt of your letter of 2d instant
suggesting the propriety of my supplying the board with such information re¬
specting my plans for completing the jetties as will enable the board to esti¬
mate the probable cost of such completion. I am also invited to present to
the board my views as to the probable results that will be produced by the
works when completed, and likewise to suggest such modification of the law
under which I am building them as I may desire.
Availing myself of the courtesy of the board, I herewith submit drawings
of the cross-sections of the jetties, in different stations in their length, which
represent the dimensions of the work and the plan of construction. I also
present herewith drawings of the plan of construction at the head of the pass.
I have made large contracts for the prompt delivery of stone, gravel, ce¬
ment, willows, machinery, and piles, for the purpose of completing these
works in accordance with the drawings herewith submitted, and have com¬
menced the construction of a mixing-house and railway on each jetty, about
one thousand five hundred feet from its sea end, for the purpose of pre¬
paring and transporting the material to form the blocks of concrete with
which jetties are to be consolidated and finished. Each house will contain
suitable machinery for the purpose, driven by a steam-engine, to hasten the
completion of this part of the work.
I do not anticipate any necessity for modifying these plans in any manner
whatever, but intend completing the works in accordance with them. If,
however, in the progress of the work I find they can be modified with advan¬
tage, I shall avail myself of the right to do so, as provided in the act.
With the plans I present an estimate of the cost of completing the works,
which estimate is based upon the prices I am paying for the different kinds of
materials, with an additional allowance amply sufficient to cover the cost of
putting them in place. Mr. Wright, my book-keeper, will be instructed to
23
338
THE MISSISSIPPI JETTIES.
show receipted bills to the board for these various materials, by which the
board can learn the prices that I am and have been paying for them. The
amount of the estimate is $362,110.67.
With respect to a modiflcation of the dimensions of the channel described
in the act, I earnestly hope the board will state the probable size which the
normal discharge of the pass is capable of maintaining between the jetties
when they are fully consolidated and completed, and that it will also express
its views as to the advisability of undertaking to maintain one of greater di¬
mensions, by forcing an increased volume through it. The results which have
been developed thus far by the works seem to me to correspond in a remarkable
degree with the effects which were anticipated by the commission of 1874, and
to indicate that the maximum capacity of the pass was correctly assumed by
the commission. To produce the maximum channel described in the act will,
I think, involve the necessity of a central depth throughout the jetties of not
less than from thirty-five to forty feet.
The natural volume of the pass cannot, I am confident, create so great a
depth through the jetties, and if it be insisted upon by the United States, it
can only be produced by forcing more water through the pass. This will in¬
volve, in my opinion, danger to the jetties, and a disturbance of the regimen
of the three passes to an extent that can only be known after it is probably too
late to remedy the evil.
I deem it unnecessary to point out in detail to engineers who are so familiar
with the hydraulics of the river, the various objections that can properly be
urged against the attempt to produce a channel through the jetties by a method
which involves the enlargement of the pass itself through its entire length,
and which method (directing more water into the pass) is the only one which
can permanently maintain such a channel.
One effect of the works thus far completed seems, according to Captain
Brown's observations, to have resulted in a diminution of the size of the pass
probably equal to about five per cent, of its former capacity, which is, I think,
a certain evidence that the quantity of water now discharged by it is propor¬
tionately less than it was before the work was begun. To restore the orig¬
inal capacity of the pass, and thus re-establish the disturbed conditions, or
equilibrium of the three passes, I am now increasing the thickness of the sill
across the head of the Southwest Pass, by which the discharge of the South
Pass will be restored to its former volume. When this is accomplished, I
shall sill the entrance into South Pass, if it shall appear to be necessary to
prevent too great an inflow into this pass. If the maximum channel de¬
manded by the act be insisted upon, I shall have no alternajtive but to dimin¬
ish the discharges of the Southwest Pass and Pass â Loutre, by increasing the
height of the sills which now control their discharges, until South Pass shall
discharge the volume necessary to create and maintain such channel. I be¬
lieve the natural discharge of South Pass is sufficient to create and maintain a
channel through the jetties that shall have a central depth of thirty feet when
the jetties are fully consolidated and all leakage through them is prevented;
but I do not believe such volume will produce a channel of greater magnitude.
The cost of raising the Southwest Pass and the Pass à Loutre sills suf¬
ficiently to produce a thirty by three hundred and fifty foot channel through
the jetties has not been included in the estimate herewith submitted. This
REPORT OF BOARD, 1879.
339
■would involve an outlay of about |50,000, and would require the present depth
over them to be diminished two feet, exclusive of the work now being executed
on Southwest Pass sill. This would reduce the cross-section of the volume
entering those passes about twelve thousand square feet, and would propor¬
tionately increase the cross-section of .South Pass.
With reference to the question of modifying the terms of payment for the
work, I desire to call the attention of the board to the fact that they were ar¬
ranged by the Congressional committees when perfecting the bill so as to pro¬
tect the government against the possible expenditure of a dollar of money
until after the experiment of the jetty system should have produced valuable
results for commerce. Experience has shown that these payments were wholly
disproportioned to the amount of work necessary to obtain the stipulated
depths. The attempt to deepen the mouth of the river by jetties is no longer
an experiment, so far as the attainment of a permanent channel deep enough
to give an immense relief to commerce is concerned, even if it be admitted
that the present depth cannot be increased. There is, therefore, I think, no
equitable reason why I and my associates should not be paid for the work al¬
ready done, with the same degree of liberality which the government shows
to others who undertake the execution of works for it, where no such risks are
assumed as we have encountered. We think we should not now be less liber¬
ally dealt with, since the results obtained have demonstrated the great practi¬
cal value of the works we have executed. If we are allowed ninety per cent,
on the amount of work already executed, the account between us and the
government would stand thus :
Agreed price of the whole work $5,250,000
Estimated cost of completing it 362,110
4,887,890
Less ten per cent, reservation 475,000
4,412,890
Amount paid by the government (about) 1,000,000
2,812,890
Additional reservation for the million to be retained for 10 and 20
years 525,000
2,287,890
Leaving $2,287,890 as the amount actually earned but unpaid for construct¬
ing the works, with $1,000,000 in reserve. If it be urged against this state¬
ment that the creation of certain dimensions of channel is as much an obliga¬
tion on our part under the law as that of building the works, I will admit it ;
but the reason for enforcing this obligation no longer exists, or is at least so
greatly modified that to insist upon it now, when the public interest cannot be
promoted by its enforcement, seems to us as unnecessary and oppressive as it
would have been to insist on the original conditions of payment which Congress
modified by the act of June 18, 1878, after being satisfied such modification was
just. Its disposition to release us from these oppressive conditions now, so far
as the public interest will justify, may be safely inferred, I think, from the
340
THE MISSISSIPPI JETTIES.
clause in the act which requires the board to report upon the propriety of
modifying the size of the channel and terras of payment. But if the progress
made by us in producing stipulated depths of channel be alone taken as the
only basis for determining the proportion ot the work that has thus far been
completed (although such method of estimating it would seem manifestly
unfair), it can be shown that the pay thus far received falls much below what
it should be even under such ruling.
For instance, we were to deepen the bar from eight feet to thirty feet, be¬
ing a total deepening of twenty-two feet, of whieh twenty-two feet we. have
already accomplished fifteen feet, having at present a channel depth of twenty-
three feet. This is equal to fifteen twenty-seconds, or nearly sixty-eight per
cent, of the total depth.
Sixty-eight per cent, of the price for the completed works is $3,570,000
Paid by the government 1,600,000
If this sum were authorized to be paid at once by the government, it would
still retain $1,877,000, or $877,000 to complete the works, and $1,000,000 re¬
served to be paid in ten and twenty years. I will add that if this total sum were
at once paid me it would not suffice to discharge all of the debts created by me
in the construction of the works.
It may be advanced against this computation on the basis of depth alone,
that sixty-eight per cent, is an overestimate for what has been accomplished,
as it will probably be more difficult to secure the next seven feet than it
was to obtain the last seven. This is clearly an error, if the cost alone be con¬
sidered, because the works are already so near completion. It may possibly
take more time to secure this seven feet, but certainly less money will have to
be expended. In this connection it may be said that when twenty-five feet
shall have been obtained, by far the most valuable part of the depth will have
been secured, as all over twenty five feet could be dispensed with without injury
to commerce (except possibly on very rare occasions), and, on this view, sixty-
eight per cent, is not a high estimate of the commercial value of the proportion
of the thirty feet maximum yet to be obtained.
I hope the board will, after due consideration, determine the maximum
amount which may be paid to us at this time with safety to the public interest,
and will recommend such modification in the terms of payment of the re¬
mainder as will provide for its distribution pro rata upon each additional one
foot of depth that may be hereafter secured, without regard to any specific
widths for such depths, inasmuch as each increment of depth must necessarily
bring with it a corresponding improvement in the width of channel.
In reporting upon ' ' the results produced "by the works, I respectfully sug¬
gest that changes in the depth of the sea-bottom immediately in front of the
jetties, and the ability of the works to maintain the channel without the auxil¬
iary aid of dredging, are two questions of such general public interest as to
make an expression upon them by the board of great value and importance.
Less ten per cent, reservation
Leaving unpaid and already earned.
1,970,000
197,000
1,773,000
EEPOBT OF BOARD, 1879. 341
especially as there seems to be still some doubt in the public mind upon
them.
I have the honor to be, very respectfully, your obedient servant.
Jas. B. Eads.
Gen. J. G. Barnard,
United States Engineers, President of the Board, etc.
Army Building, )
New York, January 33, 1879. )
Sir !—The board constituted by Special Orders No. 338, Headquarters of the
Army, Adjutant-General's OfBce, Washington, D. C., October 33, 1878 (of
which a copy is annexed, marked 1), assembled at New York on the 11th of
December, 1878, and after examination and discussion of the section of the act
of Congress by which its proceedings are to bè governed, and of other docu¬
ments referring to their prescribed duties, adjourned to meet at the mouth of
the South Pass of the Mississippi on the 30th of December.
The section of the act (section 4, act approved June 19,1878) requires that—
The board shall visit the works in process of construction by said James B.
Eads, at the South Pass of the Mississippi River, and make an examination of
the same, and make a full report of the progress made in the construction of
the works, the probable cost of their completion, and the results produced, or
that may properly [probably?] be produced by them, their probable perma¬
nency, and of the advisability of any modification of the terms of the act under
which said Eads is constructing said works, so far as regards dimensions of
channel through the Jetties, and of the terms of payment for the same ; which
said report shall be submitted to the Secretary of War, to be presented at the
next séssion of Congress.
The subjects upon which the board is required to make a full report are
these :
1. Progress.
3. Probable cost of completion.
3. The results produced.
4. The results that may probably be produced.
5. Their probable permanency.
6. The advisability of any modification of the act, etc.
To discuss these subjects in the order named:
1. Progress made in the Construction op the Works.
This requires reference to the original design, which was to construct,
starting at marginal points on its banks above where the normal channel depth
(thirty feet) of the pass itself begins to diminish, dikes or parallel piers (as they
are commonly designated) extending thence to the deep water of the Gulf, thus
confining the outflowing water in a channel of the same width (nearly) as that
of the pass itself until it reaches the deep water of the Gulf, and thereby pro¬
longing through the " bar" and to the Gulf the normal depth (nearly) which
the pass maintains between its natural banks. These parallel piers or dikes.
342
THE MISSISSIPPI JETTIES.
technically called "jetties," ave essentially, then, an artificial prolongation of
the natural " banks " to deep water in the Gulf. From the land's end (East
Point) of eastern shore to thirty-five feet depth in the Gulf (which was about
three hundred feet beyond the crest of the bar) was a distance of eleven thou¬
sand nine hundred and forty-one feet, which figures define the length of the
east jetty as originally designed and marked out by piles.
The natural bank on the west side of the South Pass extended seaward four
thousand feet farther than the natural eastern bank ; the initial point of the
west jetty was, therefore, taken about that distance below the origin of the
eastern one ; hence the required length of the west jetty was eight thousand
feet nearly.
The average width between banks of the pass itself is about seven hundred
feet; which width, by the act of March 4, 1875, is fixed as the minimum be¬
tween the authorized jetties.
The origin of the west jetty was established some distance (about six hun¬
dred feet) from the west bank ; hence it became necessary to connect this point
with the natural west bank by a dam of this length, built at right angles to
the jetty, to which the name of the Kipp dam was given.
The original design therefore consisted of "east jetty," eleven thousand
nine hundred and forty-one feet in length (two and a half miles, nearly), a
" west jetty " eight thousand and fifty feet in length, and the "Kipp dam."
The plan of "construction" w.as, in its main features, essentially that de¬
veloped by long experience in Holland for dikes, dams, and jetties, on like
yielding substrata, viz., a broad foundation stratum of willows or other suit¬
able brush, formed into " mattresses " (technically so called), on top of which
was built a superstructure of tapering section, of alternate strata of mattresses
and stone or gravel.
If we except three hundred and thirty feet in length of extreme end of the
originally designed east jetty, and two hundred and eighty feet in length of the
west jetty (reducing the total lengths of these jetties to eleven thousand six
hundred and seven thousand seven hundred and seventy feet respectively), the
jetties, throughout the lengths just mentioned, and the dam have been actually
huilt up to the level of average high-water, or somewhat above that level, and,
owing to subsidence, supplementary elevations of willows and stone have from
time to time been added. At present the seaward ends for about one thousand
five hundred feet are overflowed at high tide, and even at low water through a
portion of less extent.
Pages eight and nine of the annual report upon the improvement of the
South Pass, give for east and west jetty the actual height (July 1, 1878) above
" average flood tide " throughout their whole length. It will be seen that the
outer ends and a few points higher up are now at various depths below high
tide. The extreme end of the east jetty is reported by Capt. Brown to be
eleven feet below ; at the date of our visit the lower ends of both jetties for
one thousand feet or more were more or less submerged at flood tide. Higher
up the two jetties were found to be from three-tenths to one foot or one and a
half feet above high tide.
Page ten gives the same particulars for the " Kipp " dam, which is through¬
out from one-half to one foot above flood tide.
After the mention just made of " supplementary elevations " added from
BEPOET CE BOAED, 1879.
343
time to time to the jetties, to compensate for subsidence, it is proper to say a
few words on this point.
Owing to the well-known character of the formation at the mouth of the
Mississippi, much subsidence was expected. We have no accurate record of the
total settlement of the various parts from the commencement. But on page
19 of the annual report already cited, Capt. Brown has given them for the year
ending July 1, 1878. The amount of depression, superficial destruction by
storms being eliminated, due to actual settlement and compression of willows
is, beginning at East Point, one-half foot, gradually increasing to three and
one-third feet at the extreme end of the east jetty.
It is impossible to eliminate the compression of willows, to show how much
of the above is due to pure settlement ; but, from the corresponding depression
of the heads of the piles along the center portions of the jetties, it would seem
probable that it is mainly due to " settlement." On pg.ge 3 of the fifth report,
Major Comstock gives the settlement of certain piles along the last one thou¬
sand feet of the east jetty, counting from the old end, and therefore covering
the outer six or seven hundred feet of this jetty as it is at present. Between
July 18 and October 31, 1876, three months, the outermost pile had settled 3.55
feet, the innermost 0.67, the gradation being progressive.
On the west jetty the observations began about two hundred and seventy
feet within the present end, and extended back along two hundred and fifty
running feet of the jetty, the observed settlements graduating from l.GOtoO.BO
feet. Owing, however, to the great subsidence of mattresses and piles at the
outer ends at first fixed, the terminal points were (as before stated) withdrawn
three hundred and thirty and two hundred and eighty feet respectively, by
which withdrawal the jetties now terminate inside the crest of the old bar—the
eastern on the very edge, the western at two hundred feet inside of it.
Inasmuch as a full statement of the "progress" of the construction can
scarcely be made without reference to the repeated partial reconstructions on
account of subsidence, we have been led to develop that subject so fully. For
details of actual construction, we refer to the third report of Major Comstock,
and to map of No. 3 of the same report, which exhibits various sections of the
jetties as built, and makes it unnecessary that we should swell this report by
further description.
Up to November 1, 1878, there had been consumed in the construction of
the two jetties and of the Kipp dam, as stated by the engineers employed by
Mr. Eads, three hundred and ten thousand eight hundred and thirty cubic
yards of mattresses and willows, and fifty-four thousand five hundred and sixty-
five cubic yards of stone, mostly small stone.
By decision of the Attorney-General, January 17, 1877 (Ex. Doc. 38, Part 1,
H. R., Forty-fourth Congress, second session), the channel through the shoal
at the "head of the pass" is made a part of the "South Pass," through which
a "navigable depth " is exacted by the act of March 3, 1875. The work at this
locality had, however, been undertaken by Mr. Eads simultaneously with that
on the jetties. A deflecting dike or "catchwater" was designed and com¬
menced, running from the eastern margin of the entrance to the pass, a distance
of about throe thousand feet, in a course starting northerly, curving to the
westward ; but a channel into the west entrance developing itself, which vessels
began to use, the plan was abandoned, and the channel cast of the island was
Sü THE MISSISSIPPI JETTIES.
closed by a dam. Dikes (called " T-head dams " on charts) were run out from
the island and from the west bank, and they now define the present channel or
entrance. The island or eastern T-head, about one thousand sis hundred feet
long (originally eight hundred feet longer), running northwest by north from
the head of the island, consists at present only of a row of piles and a single
layer of mattresses on the bottom.
The west T-head, eight hundred feet distant from the eastern one, starts
from a point about one thousand two hundred feet above the origin of the latter,
and four hundred feet distant from the west shore, with which it is connected
by a dam. Except the last three hundred and fifty feet, this T-head is built
up above flood tide with five or six tiers of mattresses loaded with stone on a
double foundation layer of two mattresses side by side. The extension of
three hundred and fifty feet has at present its foundation layer only. The
dam above mentioned has been built up above high-water level and loaded with
stone.
The permanent dam, five hundred and fifty feet long, extending from the
lower part of the island to the east shore and stopping the old east channel, has
been built up above high water and well loaded with stone.
The foregoing described constitute the system of " works " properly belong¬
ing to the head of the pass. Auxiliary thereto, mattress "sills," so called,
have been laid on the bottom across the two great passes. The one across
Southwest Pass runs from the west shore (from which a spur-dam about four
hundred feet long is first thrown out) to a point near the upper end of the
west T-head. The entire length, including spur-dam, is about three thousand
two hundred feet. The one across the Northeast Pass runs from the end of
the old east dike to the opposite shore ; length, about three thousand feet.
They consist of a single mattress layer seventy feet wide and about thirty
inches thick, weighted with stone.
In these various works at the head of the pass have been consumed one
hundred and forty-one thousand one hundred cubic yards of mattresses and
willows, and ten thousand seven hundred and fifty-five cubic yards of stone,
as stated by Mr. Eads's engineer.
The foregoing is deemed a sufficiently full report of the " progress made
in the construction of the works."
In what precedes we have made no mention of the wing-dams which have
been constructed at various times. Their maintenance not being contem¬
plated as permanent works, it is understood they have already subserved the
purpose intended, of accelerating the process of channel formation.
2. Pkobable Cost op Completion.
Inasmuch as the act of Congress by which the contract was made with
James B. Bads for improving the South Pass of the Mississippi River ex¬
pressly stipulates that the contractor should have perfect freedom as to the
means to be used in obtaining the depths and widths of channel named in the
act, estimates of the cost of completing the works could only be made after
the board had been officially informed by the contractor of the methods which
he purposed using. An official letter requesting this information was sent to
the contractor (copy attached and marked A) as soon as the Imard arrived at
Port Eads, His reply (copy attached and marked B), with the accompanying
EEPOET OF BOAED, 1879.
345
drawings, fully sets forth his present plans and methods of completing the
works. These plans are necessarily subjeot to modification should experience
in carrying them into efl:ect indicate a necessity therefor. Whether such a
necessity will arise cannot be foreseen, and therefore estimates must be based
on the plans as they now stand.
The following is a brief statement of the work proposed :
1. The top of the east jetty is to be raised to the height which the contractor
deems desirable, which varies from one and a half feet above average flood-
tide at East Point to seven feet nine inches above the same plane at the sea
end. The upper part of this jetty, from the point five hundred feet below its
origin (to which point the jetty may be considered as finished) to a point nine
thousand two hundred feet below, is to be raised to the level of one and a half
feet above average flood-tide, and flnished by a rounded paving of riprap stone.
The next thousand feet in length is to be capped by a low wall of rubble
masonry. The remaining portion of this jetty to its sea end, a distance of one
thousand flve hundred and fifty feet, is to be capped with large blocks of con¬
crete built in place, on which at a later date a continuous parapet of concrete
is to be built. The river and sea slopes of this jetty and its sea end are to be
protected by mattresses covered with stone, additionally strengthened at the
sea ends for some distance back by crib-works of palmetto logs filled with
stone.
3. The west jetty is to be treated in a similar manner, the changes in the
method of finish being made at points opposite those at which the changes are
made on the east jetty. The protections designed for the sea end and for the
slopes of the west jetty are not so extensive as those for the east jetty, the
latter being apparently considered as more exposed to injury.
3. The training-walls at the head of the South Pass (called on the maps
"T-head dams") are to be improved. The eastern training-wall, on which
but little work had been done, is to be raised above the surface of the water.
The portion at the head of the western training-wall, now consisting of piles
and one layer of mattresses, is to be completed.
4. The obstruction now in the Southwest Pass is to be increased by the
superposition of other mattresses until the cross-section of this pass is made
about twelve thousand square feet less than it was after the original sill had
been laid.
5. The dam closing Grand Bayou is to be maintained by such additional
work as may from time to time become necessary.
Mr. Eads estimates the cost of doing the work thus summarily indicated at
three hundred and forty-nine thousand six hundred and forty-one dollars.
The board have carefully gone over the details of this estimate, and believe
that it is substantially correct. They differ from Mr. Eads in some minor
items of cost, but these differences are amply covered by the fifty-eight thou¬
sand two hundred and seventy-three dollars allowed for contingencies. The
board is, therefore, of the opinion that the work indicated by Mr. Eads can
probably be done for his estimate, provided no extraordinary contingencies
intervene.
This at once brings up the question whether the completion of the indi¬
cated works is a substantial completion of the original project, and may bo so
considered in questions of compensation.
346
THE MISSISSIPPI JETTIES.
When may the works at the South Pass be considered as completed ?
A careful study of the act of Congress under whose authority the original
contract was made with Mr. Eads shows that there is no mention of any spe¬
cific woi'k to be done by the contractor. The act authorizes him to construct
" such walls, jetties, dikes, levees, and other structures, » » * as he may
in the prosecution of said work deem necessary." It also expressly states that
"said Eads shall be untrammeled in the exercise of his judgment and skill in
the location, design, and construction of said jetties and auxiliary works." The
only limitation on the contractor is the provision that the jetties "shall not be
less than seven hundred feet apart."
The whole contract is based on results. Certain specified sums were to be
given to the contractor for certain depths of channel obtained by him. It
was only required that the jetties should be "permanent and sufficient" "to
create and permanently maintain " these various depths, the test of the per¬
manent completion of the work being the creation and maintenance for twenty
years of a channel thirty feet deep and three hundred and fifty feet wide. This
is the standard of completion established by law, and there is no power short
of the power that made the law, that can change the standard.
With this view of the law and the duty of the board under the same, it is
unable to make any other statement of the progress that Mr. Eads has made
toward the completion of the jetties than the fact that he has obtained a depth
of twenty-three feet on the bar, and that there yet remains to be obtained seven
more feet of depth, and a very considerable increase in width.
While the board adopts the estimate of Mr. Eads for the work which he
still proposes to execute, it does not consent to his claim that that amount of
work will even complete his project. The yielding character of the bottom un¬
derlying the jetties for the last two thousand feet, and especially at the ex¬
treme outer ends, is such that the works have been constantly sinking into it,
requiring frequent additions of brush and stone to bring them above the water
surface, and it seems very certain that the final subsidence has not been
reached, and that the works now proposed will require, from time to time, simi¬
lar additions, the cost of which must be added to his estimate. What the cost
of such additions will be cannot be foreseen. And further, even if the project
as now proposed by Mr. Eads were completed, it does not follow that the works
would satisfy the conditions of the law by producing a channel of thirty by
three hundred and fifty feet. The opinion of the board on this point will be
found farther on.
, 3. Tue Results Produced.
The average width of the South Pass, between banks, is about seven hun¬
dred feet; the depth, so long as that width is maintained, is about thirty feet.
At East Point, where the eastern bank terminates, and where the width was
already increased to eight hundred and fifty feet, the oank confinement ceased ;
thence to the crest of the bar, two and one-quarter miles distant, the depth grad¬
ually diminished to about nine feet (average flood tide), the last half mile
before reaching the outer crest having, nearly uniformly, only this small
depth.
The results produced by the works may be well exhibited by the following
table, giving the depth of water in feet and tenths that could be carried through
EEPOET OF BOAED, 1879.
347
each section of two thousand feet below East Point at different dates, com¬
mencing June, 1875 (the date of the commencement of the works), to December
28, 1878. By following with the eye each column downward, the progressive
increase in depth of the particular two thousand feet section of the channel
indicated at the head will be readily observed. (See Appendix XVII.)
The last column is more especially a test one, since it gives the bar-depth or
shoalest part of the channel. The maximum bar-depth that has been obtained
prevailed December 14, 1877, when it was 23.7 feet. At the date of the latest
survey, December 28, 1878, it was twenty-three feet. This slightly diminished
bar-depth by nomeahs indicates actual retrogression in the progress of "re¬
sults." On the contrary, there has been constant progressive general improve¬
ment In the jettied channel, at no time more evident than at the present.
At the date last named a depth of twenty-four feet, with a channel width
of three hundred feet, extended down to within two thousand feet of the jetty
ends; and the same depth, with a channel width of two hundred feet, almost
to the very ends. Thence to the same depth outside was a distance of but
sixty feet, with a navigable channel of twenty-three feet intervening.
The twenty-five foot channel has nearly the extent of, and not much less
width than, the twenty-four foot channel. From its terminus inside to the
same depth outside of the bar there is but an interval of one hundred and sixty
feet.
The twenty-six foot channel extends (with a break of only one hundred and
fifty feet) down to within one thousand feet of the jetty ends. Above the sin¬
gle interruption mentioned, which is three thousand feet from the ends, the
twenty-six foot channel has in its narrowest parts one hundred and one hun¬
dred and fifty feet width ; in the widest three hundred and fifty and seven
hundred feet, the latter at the site of the so-called " deep hole."
The depth of twenty-seven feet is found at various points in the channel
down to very near t|ie jetty ends.
If we compare the above with the chart of a year's earlier date (December
5, 1877), we find a general improvement of navigable channel through the
lower six thousand feet. There is twenty-four feet where there then was
twenty-two feet ; that is to say, a general increment of the channel depth by
two feet, accompanied by rectification and widening of areas of lesser naviga¬
ble depths; there being for the twenty-two foot depth two hundred and thirty
feet width at the bar, and a general width within of over four hundred feet.
While the abnormally "deep hole" itself has filled from extreme depth of
eighty feet to sixty-five feet, the channel for one thousand feet below the hole
has deepened by an average of ten feet (i.e., from depihs of twenty-eight feet
and thirty-eight feet to depths of thirty-eight feet and forty-eight feet). (The
deep hole, so called, above began to form two yeai-s ago, commencing near the
origin of the west jetty and extending about two thousand feet down the jet-
tied channel. Various causes have been assigned, eddies being the most prom¬
inent. Depths of over one hundred feet have been exhibited.) As to the
channel from Kipp Dam (at upper limit of the hole) up to the beginning of the
jetty works at East Point, we find for two thousand five hundred feet upwards
an average deepening of from six to seven feet (extreme twelve feet), above
which to East Point the depth of about thirty feet has remained pretty con¬
stant.
348
THE MISSISSIPPI JETTIES.
At the head of the passes the result of the works has been the procuring of
a channel depth of twenty-two feet where there was, over the shoal, but four¬
teen or fifteen feet. If we compare the present condition with the chart of De¬
cember, 1877, we find that while the actually navigable depth is not much
changed, the distance between the twenty-four foot curves at T-heads and
above the same respectively has increased from three hundred and fifty to
eight hundred feet ; this augmentation of the 5ftr-width faking place both in¬
wardly and outwardly, but in much the greater proportion outwardly {i.e., on
the Southwest Pass margin). Between the training walls the channel may
have somewhat improved, not by increase of maximum depths, but by the dif¬
fusion of the current more equally over the intervening space.
4. Results that may Probably be Produced.
It is a difficult matter to respond satisfactorily to this requirement of the
law, inasmuch as the efRcient causes cannot be precisely defined or measured.
Reference to opinions of engineers who have recommended the resort to jetties,
and developed their views as to depths which should be obtained by the means
proposed, furnishes one basis of judgment. Reference to the actual results,
combined with the progress and present condition of the works, furnishes
another. The trial of the jetty system at the South Pass, or at least a further
study of the subject, before undertaking the construction of a ship canal, was
first recommended in the minority report of the Board of Engineers of 1873,
with the expression of opinion that twenty-five feet at low water might be at¬
tained; the practicability of terminating the jetties inside the bar crest (instead
of encountering the great expense and doubtful practicability of prolongation
to deep water) being assumed or supposed probable.
The Board of Engineers constituted by act of June 23, 1874, " to determine
the best method of obtaining and maintaining a depth of water sufficient for
the purposes of commerce, either by a canal from said river to the waters of
the gulf, or by deepening one or more of the natural outlets of said river,"
proposed, by the extension of jetties, nine hundred feet apart, to the depth
of thirty feet outside, to obtain provisionally a channel depth which would,
as was estimated, gradually shoal by bar advance in about ten years to
twenty-five feet depth, when the jetties must be extended one thousand feet
seaward to reach thirty feet depth again. The present jetties are about
nine hundred and fifty feet apart, and terminate, the eastern almost on the
outer edge of the bar, where there was originally but fifteen or sixteen feet
of water ; the western, about two hundred feet within the outer edge,
where there was but seven or eight feet of water. The conditions, therefore,
by which the engineers of the Board of 1874 expected to get, provisionally,
thirty feet depth, do not, in the existing arrangement, fully obtain.
Mr. Eads, in his letter to this board, herewith appended, states :
" I believe the natural pass is sufficient to create and maintain a channel
through the jetties that shall have a central depth of thirty feet when the
jetties are fully consolidated and all leakage through them is prevented; but I
do not believe such volume will produce a channel of greater magnitude."
Though the ground for this belief is not here stated by Mr. Eads, it is
understood that he relies on the fact that the pass in its natural condition
KEPOET OF BOAED, 1879.
349
maintains a depth of thirty feet in its channel. He believes that the jet¬
ties will carry out that depth, undiminished, to the sea. This, too, was ad¬
mitted or assumed by the Board of 1874, provided always, the jetties, nine
hundred feet apart or less, be extended to or beyond that natural depth in
the gulf. This proviso is not fulfilled, as we have seen, by the existing
jetties.
The foregoing refers to à priori opinions. Turning now to the results actu¬
ally and progressively obtained, coupled with the stage of construction and
present condition of the jetties, the facts of the case have been stated under
the proper head.
The jetties since their commencement have produced an increase of bar
(or minimum navigable) depth from nine to twenty-three feet; and if the
last twelve months have shown no actual increment of that particular ele¬
ment, yet there has been (as already fully set forth) a most decided im¬
provement throughout the whole jettied channel length. There is ground to
look for further improvement, coupled with increase of bar depth, which,
to twenty-five feet, requires the cutting through of a bar of only one hun¬
dred and sixty feet width. But the jetties have not yet (as seen in our
statements on "progress, etc."), acquired their full action. The outer ends,
though more than once raised, are still submerged. According to Capt.
Brown, Eighth Report, p. 31, "at least twenty per cent, of the water passing
land's end at East Point escapes over the jetties and through the meshes of
the mattresses at average flood-tide." Mr. Corthell, resident engineer under
Mr. Eads, estimates the escape at twenty-five per cent. By far the greater
portion of this escape takes place along the lower one thousand or one thou¬
sand five hundred feet of length. Moreover, the temporary effect of the opera¬
tions at the jetties at Grand Bayou, and at the head of the passes, has been to
diminish the discharge of the pass by ten or twelve per cent. The raising
and consolidating the jetties at their outer ends will in great measure pre¬
vent the loss attributed to imperfect confinement; the volume originally en¬
tering the pass at the head may probably be restored.
The foregoing considerations, and the facts already stated under the head
of " results actually observed in the progress of channel development during
the last twelve months," induce us to think that if the jetties were well con¬
solidated and raised sufficiently high to prevent leakage and overflow, a con¬
siderable increase of navigable depth would result. We cannot state that in
our opinion it is a "probable result" that the depth of thirty feet will be
attained, as assumed by Mr. Eads. What the limit will be cannot be posi¬
tively announced. That it may attain twenty-five or twenty-six feet is all
we can venture to expect as a depth which shall permanently maintain it¬
self; and as past experience shows annual fluctuations amounting to about
two feet, a permanent channel of twenty-five or twenty-six feet will require an
occasional channel of twenty-seven or twenty-eight feet.
With regard to the head of the passes, the considerable widening of the
bar or shoal between twenty-four feet inside and twenty-four feet outside dur¬
ing the last twelve months is an unfavorable result. The work designed by
Ml'. Eads, and embraced in.his estimate for "completion," and now com¬
menced, consisting mainly in the raising by additional mattresses the sill of
the Southwest Pass, with the view of restoring the lost inflow to the South
350
THE MISSISSIPPI JETTIES.
Pass, and deepening the entrance, may accomplish the result expected. We
have not full confidence, however, that that measure alone will do so.
In connection with the "probable results" of jetty construction upon
which we are directed to report, there is one to which pre-eminent importance has
been attributed, and which should not be here overlooked—that of bar advance.
The Board of Engineers of 1874, in recommending the jetty construction at the
South Pass, assumed that the normal rate (supposed to be one hundred feet per
annum) would be maintained after the pass was jettied, and hence that to main¬
tain a depth of at least twenty-five feet, the jetties must be prolonged every
ten years. One of the main arguments used against the resort to the jetty
system has always been that a greatly increased rate of bar advance will ensue.
On this point we refer to the Seventh and Eighth Reports of Captain Brown,
and to his Annual Report of June 30, 1878. By the Seventh Report, page 30,
it is shown that over a fan-shaped area of one and one-quarter square miles
immediately seaward of the ends of the jetties, there had been between June
20, 1876, and June 22, 1877, a mean "fill" of four-tenths of a foot. Parts
of this area had scoured {i.e., had become deeper) ; in four of the twenty-one
sections there had been, on the contrary, a large "fill the average total
result having been, as just stated, a slight shoaling of 0.4 foot. Over this
same area (page 15, Annual Report) there had been in the subsequent twelve
months from June, 1877, to July, 1878, a scour {i.e., increase of depth) averag¬
ing 1.8 feet.
By the table, p. 83, of the Eighth Report, it is shown that in that portion
of the thirty-foot curve lying seaward, between the prolongations of the jet¬
ties, an advance of one hundred and thirty-two feet had taken place so early
as October, 1875, soon after the jetties were commenced, and before any impres¬
sion had been made on the bar. During the subsequent period of two years
there had been fluctuations, the advance reaching (July 28, 1877) the magni¬
tude of two hundred and forty-two feet, followed by a retrogression to one
hundred and eight feet, December 15, 1877. This last was followed by another
retrogression (table, page 18, Annual Report) to sixty feet in the early summer
of 1878, succeeded by an advance, July 15, to one hundred and forty feet.
The foregoing, referring to the portions of the thirty-foot curve included
between the prolongations of the jetties, affords no proof of progressive ad¬
vance. If, in this connection, we take into account the position of the thirty-
foot curve outside the jetties (and this is evidently a better testl, there is
shown, instead of advance, an absolute retrogression. Or, again. If we have
reference to deeper curves. Captain Brown's surveys (Annual Report, table,
page 15) show that from June, 1877, to July, 1878, the forty, fifty, sixty,
eighty, ninety, and one hundred foot curves had drawn in towards the ends of
the jetties the respective distances of one hundred and seventeen, two hundred
and twenty-eight, one hundred and ninety, sixty-flve, seventy-one, and one
hundred and eighty-three feet ; the seventy-foot curve alone showing advance
into the gulf (forty-six feet). The actual results, therefore, so far as we know
them, do not justify the predictions of accelerated bar advance. On the con¬
trary, they show a disap-'carance of bar material from the front of the jetties.
5. Probable Permanency.
"WOfVe (or storm) action of the sea and decay or destruction hy tlic teredo of
EEPOET OF BOAED, 1879.
351
the willo'w mattresses are the principal destructive elements to be mentioned.
An additional element of deterioration, not peculiar to the location, but sup¬
posed to be so prominent as to involve the question of permanence, must also
be noticed. The jetties, except the extreme ends and contiguous portions for
about fifteen hundred feet inward, are so well sheltered by shoals that wave
action, except on those portions, has little effect. On the sea-ends the effect
has been considerable, but mainly superficial, destroying more than once the
upper course or courses of mattresses, and washing off and scattering the
stones (mostly small) which have been repeatedly applied to the top surface.
Wave action is by no means as violent here as in similar exposures on the
Atlantic coast. We see no reason to doubt that the thick concrete capping
Mr. Eads is now commencing to apply (work having already begun on the
upper portions), fianked by enrockments of heavy stones on palmetto-log gril¬
lages overlying the original marginal mattresses, will resist sea action.
Wood of all kinds considerably submerged is sufiiciently secure against decay.
Experience here shows that for about seventeen hundred feet inwards from
the jetty ends the teredo destroys rapidly all exposed wood (inchiding in this
term the willows of the mattresses) lying more than four or five feet below the
surface of the water. Evidence enough of its attacks upon piles and willows
exists. But the teredo does not attack wood where the free access of sea-water
is impeded. Those portions of a stick buried in mud or sand, or packed
around with mud or sand, are secure. We have no reason to believe that the
teredo has penetrated or can penetrate far into the interior of the mattress
courses ; we have pretty good reason to believe that the foundation mattresses
are and will remain secure ; and probably also the bulk of the interior of the
masses of willow-work.
In what we have said under the head of " progress," we have given suffi¬
ciently full details concerning settlement. It is still very great at the outer
ends, though very much less in all those portions more than two or three thou¬
sand feet from those ends. That additional superficial applicatiops of stone or
concrete will be necessary to the structures we must expect.
In the ordinary sense of the word permanency, i.e., capability of endur¬
ance of destructive forces, the works may be said to possess the attribute, to a
reasonable degree, for work of the kind thus situated. As regards the outer
ends, it is yet early to predict to what extent or how long renewals of height
to compensate the still progressing settlement must be resorted to.
6. Advisability of any Modification op the Act as Regards Terms op
Payment and Dimensions op Channel.
As the United States has not suggested or desired any modifications of the
terms of the act in these or other particulars, it follows that any change must
be for the benefit of the contractor, and it equally follows that no change
should be made unless justice to the contractor should demand it. This leads to
an examination of the claims advanced by him for a modification of the terms
of the act of 1875, by which the contract was awarded to him for improving
the South Pass of the Mississippi River, so as to give a channel of twenty-six
feet depth at its head, and a channel of thirty by three hundred and fifty feet
at its outlet into the gulf.
352
THE MISSISSIPPI JETTIES.
The Board of 1874, instituted by act of Congress to determine the best
method to secure an outlet from the Mississippi River to the gulf, either by a
canal or by the improvement of one of its natural outlets, reported in favor of
improvement of the South Pass at an estimated cost of $5,343,110, declaring
that while its estimate was designed to cover every possible contingency of cost,
it was believed the work could be done for a much less sum. No reason is
known why Congress, which adopted this recommendation, should not have left
the execution of the work to its own agents, except that the present contractor,
Mr. James B. Eads, offered to accomplish the results contemplated by the board
without payment unless those results were secured. It would seem, therefore,
that this proposition of payments for results only influenced Congress to
award the contract to Mr. Eads, instead of leaving the execution of the work
to its usual agents. Taking this principle of no payments except for results,
as the motive which governed Congress in awarding the contract to Mr. Eads,
we are prepared to consider his claims to aid beyond what the original contract
gives him, and what the supplementary act of June 19, 1878, advances to him.
His claims are based, first, on the assumption that the work already exe¬
cuted and the results attained are greatly disproportionate to the payments he
has received; and, second, on the financial embarrassment under which he
labors, in consequence of his large expenditures in excess of his receipts.
In regard to the results accomplished, Sir. Eads claims that as he was to
provide a channel of thirty feet where there was only eight feet originally,
and as he obtained a channel of twenty-three feet, he has accomplished fifteen
twenty-seconds of the result promised, and that he should be paid in that pro¬
portion. But it should be remarked that a channel of less depth than eighteen
feet at South Pass was not necessary, and it is clear from the contract and
other evidence that Congress did not design to pay for any channel of a less
depth than this. The useful result accomplished is, therefore, a channetfrom
eighteen feet to twenty-three feet, and the proportion to the whole depth of
thirty feet is five-twelfths. If the required widths of the prescribed channels
and the failure to maintain the above full depths during twelve months be
also taken into consideration, this proportion of five-twelfths will be largely in
excess of the truth. But the contractor has been paid for results obtained,
and had advances made to him up to date, aggregating $1,686,066, or about
five-twelfths of the amount to which he will be entitled on securing a thirty-
foot channel, leaving out of consideration the sum of $1,000,000, to be retained
for a series of years as security for the maintenance of the channel. On the
other hand, neither the results of our own examinations nor the records and
estimates of the inspecting engineer ofiicer warrant us to believe that the
amounts already paid are disproportioned to the amount of work actually done.
Einancial embarrassment on the part of a contractor is not usually con¬
sidered by the government as a sufficient reason for an advance of money be¬
yond the provisions of the contract; but as Congress has already authorized
the advancing to Mr. Eads of $1,000,000, and as that sum may not be sufficient
for the work still to bo executed according to Mr. Eads's present project,
we would recommend the advance of a further amount, not to exceed the
$350,000 remaining of the $500,000 due on the attainment of a channel twenty-
six by three hundred feet: the money to be expended under conditions similar
to those imposed by the third section of the act of June 19, 1878.
BEPOBT OF BOABD, 1879.
353
As every additional foot in depth of channel is of substantial benefit to
commerce, wo would suggest the advisability of a change in the terms of pay¬
ment in the original act, so as to allow of payments for each additional foot
gained, instead of for every two feet, the channels and payments to be as shown
in the following table:
Present
system.
System recommended.
Channel.
Payments.
Payments for twelve
months' maintenance.
Channel.
Payments
Payments for twelve
months' maintenance.
Feet.
28 by 350
30 by 350
$500,000
500,000
$250,000 with 6
per cent. int.
$500,000 with 5
per cent. int.
Feet.
27 by 825
28 by 350
29 by 850
80 by 850
$250,000
250,000
250,000
250,000
$125,000 with 6
per cent. int.
$125,000 with 0
per cent. int.
$250,000 with 5
per cent. int.
$250,000 with 5
per cent. int.
In view of our recommendation that Mr. Eads be provided with sufficient
funds to complete his work according to his own programme as explained to
us, and of his expressed ability to obtain virtually the depths and widths of
channels prescribed; and further, as but a short time need elapse before results
of completing his plans will be made manifest, this board think it premature
to recommend at this time any changes in channel dimensions as required by
the contract.
Summakt.
The opinions which the board have given in the above report may bo con¬
densed into the following summary:
Progress.—The east jetty has been built to a distance from East Point of
about two and a quarter miles. The west jetty terminates opposite the east jetty,
but its total length is only about one and a half miles ; the difference being
duo to the greater extension of the natural banks on the west side of the pass.
The distance in the clear between the jetties is about nine hundred and fifty
feet. Both jetties, to within one thousand five hundred feet from their sea-
ends, are well advanced toward completion, but it is desirable that they should
be in some portions raised and compacted to prevent the current passing so
freely through them. The outer one thousand five hundred feet of each jetty
is quite deficient in height and compactness, allowing the escape of a large
percentage of the water of the pass, and require, therefore, to be raised and
ccusolidatcd quite materially, and especially so at the sea-ends. Much mate¬
rial has been expended on these ends, but they continue to settle. The outer
three hundred and thirty feet of the east jetty as originally built and the outer
two hundred and eighty feet of the west jetty have altogether disappeared,
and the contractor has decided not to attempt to rebuild the lengths thus lost.
Kipp's Dam, which connects the starting-point of the west jetty with the
natural west bank, is in good condition.
23
354
THE MISSISSIPPI JETTIES.
The dam across Grand Bayou has settled, and -will require some building
up from time to time in consequence of subsidence.
The works at the head of the pass, where built above water, are in good
condition, but some portions remain to be completed, and some additions are
contemplated.
Probahle cost of completion.—It is impossible to state definitely the cost of
completing a work that by its nature is indefinite. Mr. Eads, in his estimate,
proposes to make certain repairs and additions for the sum of about $350,000.
The board agrees with him that the sum named will do the work estimated
for: but it is of opinion that, on account of settlement and other causes, the in¬
dicated work will not complete his project. It is unable to predict what will
be the resulting depth on the bar, and as the only standard of completion is
the attainment of a channel over the bar thirty feet deep and three hundred
and fifty feet wide, it follows that an estimate of the probable cost for works
necessary to produce such channel, if it ever can be produced, cannot now be
made.
Results produced.—On the 28th of December, 1878, there was twenty-three
feet depth over the bar at the mouth of South Pass. Although the depth over
the bar is eight inches less than it was a year ago, the bar is naiTower, and
there has been a marked general improvement in the channel within the jet¬
ties. It is much more regular in form, and there has been an average increase
in depth of two feet in the lower part of the jettied channel, and of from six
to ten feet in the upper part. Outside of the jetties there is no present appear¬
ance of bar advance, and though during the past year soundings indicated
variable conditions during different months, at the end of the year a scour of
twenty-two inches is shown in the one and one-quarter square miles just sea¬
ward of the jetties, where during the preceding year there had been a resultant
average fill of five inches.
The channel at the head of the pass has somewhat deteriorated during the
past year. The depth over the shoal at this place is about the same that it wcs
a year ago (twenty-two feet), but the bar, which was then three hundred and
fifty feet wide, is now eight hundred and fifty feet wide.
Results that may probably be produced.—The board is of the opinion that if
the jetties are raised and consolidated, so as to confine to the channel-way the
greater part of the water now escaping by kateral waste, it may be possible to
procure a depth of twenty-five or twenty-six feet over the bar, without regard
to width, which corresponds to occasional depths of twenty-seven or twenty-
eight feet. At the head of the pass Mr. Eads expects to procure the depth of
twenty-six feet required by the contract by still further diminishing the cross-
section of the Southwest Pass and Pass à Loutre, if necessary. The board is
not fully confident that that alone will suffice.
Probable permanency.—The jetties may be considered as fairly permanent,
except the outer ends, for a distance of about fifteen hundred feet. Here the
chief difficulty is due to the softness of the bottom on which the jetties l'est.
Experience indicates that they will continue to settle, and will therefore re¬
quire to be raised from time to time. When this subsidence will cease it is
now impossible to predict. All the other works may be considered as fairly
permanent, or can be made so. What repairs will be needed on them from time
to time will be moderate in amount and easily made.
EEPOET OF BOAED, 1879.
355
Advisability of any change in the contract in regard to terms of payment
and dimensions of channel.—As the gain of each foot in depth of channel is
of much importance to commerce, the board recommends that the act of 1815
be so amended as to authorize the payments for each foot instead of two feet,
the aggregate to be paid remaining the same, and, as the contractor represents
himself as laboring under serious financial embari-assments, occasioned by
large outlays beyond what he has received, which will prevent his prosecution
of the works toward completion, beyond what can be done with the advances
to him already authorized by Congress, the board further recommends an
additional advance, if needed, to complete his project, of not exceeding two
hundred and fifty thousand dollars, the expenditures to be made according to
the conditions prescribed by section 3 of the act of June 19, 1878.
In view of the various considerations presented in the report, and of the
confidence expressed by Mr. Eads of his ability to secure the ultimately re¬
quired channel of thirty by three hundred and fifty feet by works the cost of
which will be amply covered, according to his estimates, by the additional two
hundred and fifty thousand dollars which we have advised to be advanced to
him, the board does not recommend any further changes in the terms of pay¬
ment or dimensions of channel required by the contract.
Respectfully submitted.
J. G. Barnard,
Colonel of Engineers and Brevet Major-General,
J. N. Macomb,
Colonel of Engineers, United Slates Army.
Z. B. Tower,
Colonel of Engineers, Brevet Major-Oeneral.
H. G. Wright,
Lieutenant-Colonel of Engineers, Brevet Major-Oeneral.
Wm. E. Merrill, *
Major of Engineers and Brevet Colonel.
Hon. Geo. W. McCrary,
Secretary of War, Washington, LK C.
APPENDIX XIX.
(See page 194.)
EEVIEW
by
JAMES B. EADS,
of the
EEPOET
op the
Board op U. S. Engineers appointed under the Act op Congress
approved June 19, a.d. 1878.
This report, although in some respects objectionable (as will hereafter be
shown), effectually settles several important questions, which have been much
controverted. These will be first considered.
results in front of the jetties.
Prominent among the evils which were prophesied by the enemies of the
jetties, was that of the formation of a bar at their mouth. It was declared
that if a deep channel could be obtained it would have no permanent exist¬
ence, but would soon be rendered valueless by an advance of the bar. So per¬
sistent has been the cry of bar advance, in official and unofficial publications,
and so widely has it been circulated through the medium of the press of the
country, that these predictions have given rise to grave doubts upon the sub¬
ject, in the minds of many of those who were deeply interested in, and who
sympathized with this effort to give relief to the commerce of the Mississippi
River. Facts are not wanting to dispel these doubts. The reports from time
to time of the government officer in charge of the work (Captain Brown), the
charts which he submitted from official surveys made by himself, conclusively
demonstrated the utter falsity of all allegations in regard to a "bar advance ; "
but, in the face of these reports and accompanying charts, the enemies of the
work have persisted in repeating their assertions to the contrary. The report
of the Board of Engineers, which we are now considering, certainly puts for-
356
EADS REVIEWS BOARD, 1879.
357
ever at rest this much-vexed question, and dispels all doubt upon the subject.
In considering this question of " bar advance," the board unanimously says :
"In connection with the 'probable results' of jetty construction, upon
which we are directed to report, there is one to which pre-eminent importance
has been attributed, and which should not be here overlooked—that of bar ad¬
vance. * * * * If, in this connection, we take into account the position
of the thirty-foot curve outside the jetties (and this is evidently a better test),
there is shown, instead of advance, an absolute retrogression. Or, again, if we
have reference to deeper curves. Captain Brown's surveys (Annual Report, table,
p. 15) show that, from June, 1877, to July, 1878, the 40, 50, 60, 80, 90, and 100
feet curves had drawn in toward the ends of the jetties the respective distances
of 117, 228, 190, 65, 71, and 183 feet, the seventy-foot curve alone showing ad¬
vance into the gulf (forty-six feet). The actual results, therefore, so far as we
know them, io not justify the predictions of oteee lerated bar advance. On the con¬
trary, they show a disappearance of bar material from the front of the jetties."
RESULTS WITHIN THE JETTIES.
The next important matter settled by the Board is that relating to results
produced within the jettied channel. The opponents of the jetties, as we have
seen, started with the prediction that no reliable results would be achieved, and
sought to induce the belief that the improvement from time to time in the
channel was not a general one, but that a deepening in one place involved a
shoaling in another. The report of the present Board disposes very summarily
of all such assertions. After quite an elaborate detail of the results produced,
the Board says :
" The maximum bar depth that has been obtained prevailed December
14, 1877, when it was 23.7 feet. At the date of the latest survey, December
28th, 1878, it was twenty-three feet. This slightly decreased bar depth by no
means indicates actual retrogression in the progress of results. On the con¬
trary, there has been constant progressive general improvement in the jettied
channel, at no time more evident than at present.
" At the date last named a depth of twenty-four feet, with a channel width
of three hundred feet, extended down to within two thousand feet of the jetty
ends; and the same depth with a channel width of two hundred feet, almost to
the very ends. Thence to the same depth outside was a distance of but sixty
feet, with a navigable channel of twenty-three feet intervening.
" The twenty-five foot channel has nearly the extent of, and not much less
width than the twenty-four foot channel. From its terminus int-ide to the
same depth outside of the bar, there is but an interval of one hundred and
sixty feet."
PERMANENCY OF THE WORKS.
. Another question of interest and importance settled by the Board is that
relating to the " permanency of the works." This is of course a matter of
great moment, as it involves the question whether the good results produced
can be permanently maintained.
In reference to this matter the Board says;
" Wave (or storm) action of the sea and decay or destruction by the teredo of
358
THE MISSISSIPPI JETTIES.
the willow mattresses are the principal destructive elements to be mentioned;
an additional element of deterioration, not peculiar to the location, but sup¬
posed to be so prominent as to involve the question of permanence, must also
be noticed. The jetties, except the extreme ends and contiguous portions, for
about one thousand five hundred feet inwardr, are so well sheltered by shoals
that wave action, except on those portions, has little effect. On the sea ends
the effect has been considerable, but mainly superficial, destroying more than
once the upper course or courses of mattresses, and washing off and scatter¬
ing the stones (mostiy small) which have been repeatedly applied to the top
surface. Wave action is by no means as violent here as in similar exposures on
the Atlantic coast. We see no reason to doubt that the thick concrete capping
Mr. Eads is now commencing to apply (work having already begun on the
upper portions), flanked by enrockments of heavy stones on palmetto-log gril¬
lages, overlying the original marginal mattresses, will resist sea action.
"Wood of all kinds, considerably submerged, is sufficiently secure against
decay.
" Experience here shows that for about one thousand seven hundred feet
inwards from the jetty ends the teredo destroys rapidly all exposed wood (in¬
cluding in this term the willows of the mattresses) lying more than four or five
feet below the surface of the water. Evidence enough of its attacks upon piles
and willows exists. But the teredo does not attack .wood where the free ac¬
cess of sea water is impeded. Those portions of a stick buried in mud or sand,
or packed around with mud or sand, are secure. We have no reason to be¬
lieve that the teredo has penetrated, or can penetrate, far into the interior of
the mattress courses; we have pretty good reason to believe that the foundation
mattresses are and will remain secure ; and probably also the bulk of the in¬
terior of the masses of willow-work.
" In what we have said under the head of ' progress ' we have given suffi¬
ciently full details concerning settlement. It is still very great at the outer
ends, though very much less in all those portions more than two or three
thousand feet from these ends. That additional superficial applications of
stone or concrete will be necessary to the structures we must expect.
" In the ordinary sense of the word permanency, i. e., capability of endur¬
ance of destructive forces, the works may be said to possess the attribute to a
reasonable degree, for work of the kind thus situated. As regards the outer
ends, it is yet early to predict to what extent or how long renewals of height to
compensate the still progressing settlement must be resorted to."
MODIFICATION OF THE SPECIFIED DIMENSIONS OF CHANNEL.
Having thus emphatically certified to the complete success of the jetties, the
Board proceeds to consider the advisability of modifying the jetty act as re¬
gards dimensions of channel and terms of payment. These matters we will no¬
tice in their order; and first, as to " dimensions of channel."
An official letter which I addressed to the Board under date of January
4th, A.D. 1879, contained the following urgent request, which is here put in
italics :
"With respect to a modification of the dimensions of the channel described
in the act, I earnestly hope the Board will state the probable size which the
normal discharge of the pass is capable of maintaining between the jetties when
EADS KETIEWS BOAED, 1878.
359
they are fully consolidated and completed, and that it will also express its views
as to the advisability of undertaking to maintain one of greater dimensions, by
forcing an increased volume through it. The results which have been developed
thus far by the works seem to me to correspond in a remarkable degree with
the eifects which were anticipated by the commission of 1874, and to indicate
that the maximum capacity of the pass was correctly assumed by the commis¬
sion. To produce the maximum channel described in the act will, I think, in¬
volve the necessity of a central depth throughout the jetties of not less than
from thirty-five to forty feet.
" The natural volume of the pass cannot, I am confident, create so great a
depth through the jetties, and if it be insisted upon by the United States, it
can only be produced by forcing more water through the pass. This will in¬
volve, in my opinion, danger to the jetties, and a disturbance of the regimen
of the three passes to an extent that can only be known after it is probably too
late to remedy the evil."
Having submitted this request for an expression of opinion upon a matter
so manifestly important, and so clearly embraced within the duties imposed
upon the Board by the act of 1878, I confidently expected a response.
It will be at once apparent to even the casual reader that the question sub¬
mitted was a vital one. If the safety of the works be endangered, and the de¬
struction of the good resuits achieved be possible, from forcing an unnatural
quantity of water through the pass, thus again placing fetters upon the now
free commerce of the river, and if the works now erected are likely to produce
a channel suificient for the prosent and prospective wants of commerce, it
would seem plain that the question is one which should hav^e commended itself
to the most careful attention and consideration of the commission. That a
twenty-six foot channel is entirely adequate would appear from the fact that
the commission of A.D. 1874, instituted by act of Congress, to determine the
best method of securing an outlet from the Mississippi River to the Gulf, rec¬
ommended in its report a resort to the jetty system, claiming that by that
system a channel twenty-five or twenty-six feet could be secured.
In this connection it may also be noticed that the president of the present
Board (Gen. Barnard), in a minority report on the Port St. Philip Canal pro¬
ject, dated January 39, 1874,* gave expression to the following opinion ;
" With twenty feet at extreme low tide, vessels drawing twenty-two and a
half feet could, owing to the softness of the bar, frequent the port of New
Orleans, and for mere commercial purposes probably twenty feet draft would
be adequate. A draft of twenty-three feet will include eighty-five per cent,
of the shipping of the world ; and with a draft of but eighteen feet vessels
(steamers) can be built of five thousand tons, carrying seventy thousand bushels
of corn, or about eleven thousand bales of cotton. It is clear, then, that for
commercial purposes a depth of twenty feet on the bars of the passes will
suifice to furnish a navigable outlet, and relievo the commerce of the valley
from enhanced charges arising from insufficient tonnage in the transports."
A perusal of the report of the present Board will show that it utterly ignores
the important question submitted to it by me, and that its recommendations
are entirely uninfluenced thereby. It says :
* See Report of the Secretary of War, 1874-'75, vol, ii. part 1, p. 844.
360
THE MISSISSIPPI JEITIES.
" In view of our recommendation that Mr. Eads bo provided with sufficient
funds to complete his work according to his own programme, as explained to us,
and of his expressed ability to obtain virtually the depths and widths of chan¬
nel prescribed ; and further, as but a short time need elapse before results of
completing his plans will be made manifest, this Board thinks it premature to
recommend at this time any changes in channel dimensions as required by the
contract."
The "expressed ability to obtain the depths and widths of channel pre¬
scribed," attributed to me by the Board, may have some light thrown upon it
by a reference to a portion of my official letter before quoted. I say in it ;
"The natural volume of the pass cannot, I am confident, create so great a
depth through the jetties, and if it be insisted upon by the United States, it
can only be produced by forcing more water through the pass. This will in¬
volve, in my opinion, danger to the jetties, and a disturbance of the regimen
of the three passes, to an extent that can only be known after it is probably too
late to remedy the evil."
It is passing strange that I should have been so misunderstood by the Board.
A Board composed, as this one was, of several of the most distinguished
members of the corps, could not have failed to appreciate the vital importance
of a question which not only Involves the stability of the jetties, but the regi¬
men, or sensitive adjustment, which nature has established between the dif¬
ferent inclinations of the surfaces of the main river and its three chief outlets,
and their respective volumes of water, by which adjustment the velocity of
current in each channel is so tempered that the floods of the parent stream are
discharged through it year after year, without rapid or important alterations
in its size, although each fl.ows through a bed formed by the most recent and
sensitive deposits of the delta—deposits which are swept away or added to with
every abnormal increase or diminution of velocity. The slope or fall per mile
of each pass and of the main river is different in each channel, and if the vol¬
ume flowing in either be increased or diminished, the current velocity must be
altered, and it is then no longer adjusted to carry the sediment with which it
is charged through such channel without deposit or scour occurring. The re¬
sult of such disturbance of regimen, therefore, tends at once to produce results
which, if unchecked, may lead to the extinction or filling up of the pass with
deposits on the one hand, or its continual enlargement on the other, until it may
at last discharge the entire volume of the river, and thus destroy the other passes.
That two members of the Board, at least, had settled convictions upon this
important question, and that the entire Commission of 1874 fully agreed with
them, is evident from the testimony given by these two members (Generals
Barnard and 'Wright^, before a committee of the Senate in 1878.
General Barnard, in his testimony, said :
"Question. Suppose the scouring force between the jetties should deepen it
from seven to from twenty-three to twenty-four feet ; now suppose the scouring
force with the present water in it is exhausted at twenty-four feet, would it be
safe to turn in any water from the Southwest Pass and Pass à Loutre from the
main river, through this South Pass, to add to the scouring, to make it thirty?
—Answer. I have no confidence in it ; nor was that ever recommended by the
Board of 1874. I do not say it cannot be done, but to be safe, I would say it
should be a slow process. It would require much labor and great expense. It
EADS EEVIEWS BOAED, 1878.
361
would create an additional ' head,' and the results in the ease of that kind are
not easily foreseen. If done at all, I would advise it to be done very carefully
and slowly, and in that way probably more water would be directed in the
pass. It would have to increase its own section all the way down in order to
carry that water."
General Wright, in answer to the question as to the advisability of forcing
more water into South Pass, in his testimony, said :
"The Commission of 1874, which got up the original plan of the Jetties,
discussed that matter at great length, and it was, I think I may say, the unani¬
mous opinion of the members that the size of the pass could not be interfered
with ; that what we wanted was that the regimen of the pass should not be
disturbed ; and to that end there is put into the estimates a certain amount,
I don't remember whether specifically or not, though I think it was, to prevent
any enlargement of the pass at all."
In the face of this record further comment is unnecessary.
modification of terms of payment.
We next come to consider the recommendations of the Board as to the
advisability of a modification of the act of a.d. 1875, as regards "terms of
payment." In its consideration of this question, the Commission does not
exhibit that breadth of view whiqh would be expected from officers of such
high rank and character. The Board approaches the matter from a most
unfortunate standpoint. It adverts to the fact that Congress did not leave
" the execution of the work to its own agents." It will be unnecessary now to
discuss the question as to whether government engineers should have a mo¬
nopoly of government work, and the civil engineers of the country be excluded
from all participation therein, and this regardless of all considerations, whether
in the saving of money to the Government or otherwise. This matter seems
evidently to have presented itself to the mind of the Board, and no doubt un¬
consciously warped its judgment and contracted its views. How far it did so,
can only be determined by a careful consideration of the report. Now, what
facts do the board find ? 1. That the works are permanent ; 2. That great
and good results have been produced thereby ; 3. That $350,000 will substan¬
tially complete the works ; and, 4. That the works, when completed, will
probably produce a channel which can be maintained of at least twenty-five or
twenty-six feet in depth. In regard to the amount which will be necessary to
complete the works, the Board says :
" Mr. Eads estimates the cost of doing the work thus summarily indicated
at $349,641.
"The Board have carefully gone over the details of this estimate, and be¬
lieve that it is substantially correct. They differ from Mr. Eads in some minor
items of cost, but these differences are amply covered by the $58,273 allowed
for contingencies.
" The Board is therefore of the opinion that the work indicated by Mr.
Eads can probably be done for his estimate, provided no extraordinary contin¬
gencies intervene."
The Commission of 1874 estimated the cost of the works at the sum of
$5,342,110. I agreed, however, to do the work for $5,250,000, thus saving to the
362
THE MISSISSIPPI JETTIES.
Government $93,110 in construction. And I agreed to maintain the works for
twenty years for $100,000 per annum (which maintenance the Commission had
estimated at $180,000 per annum), thus saving $600,000 more. It appears,
then, that $5,350,000 was a low estimate for the cost of the work. The Board
(as we have seen) says $350,000 will complete the work ; and it admits that
only $1,686,066 has been paid on it up to this time.
The account, therefore, from the Board's own showing, stands thus :
Price to be paid for the works $5,250,000
Paid on account to date 1,686,063
Amount unpaid 8,563,934
Required to complete the works 350,000
Surplus in the hands of the United States $3,213,934
Reference might here again bo made to my lettor to the Board, from which
I quote the following :
"But if the progress made by us in producing stipulated depths of channel
be alone taken as the only basis for determining the proportion of the work
that has thus far been completed (although such method of estimating it would
seem manifestly unfair), it can be shown that the pay received falls much
bolow what it should be, even under such ruling.
"For instance, we were to deepen the bar from eight feet to thirty feet,
being a total deepening of twenty-two feet, of which twenty-two feet we have
already accomplished fifteen feet, having at present a channel depth of twenty-
three feet. This is equal to fifteen twenty-seconds, or nearly sixty-eight per
cent, of the total depth.
Sixty-eight per cent, of the price for the completed work is $3,570,000
Paid by the Government (to Jan. 1st) 1,600,000
"If this sum were authorized to be paid at once by the Government, it
would still retain $1,877,000, or $877,000 to complete the works, and $1,000,000
reserved to be paid in ten and twenty years. I will add that, if this total sum
were at once paid me, it would not suffice to discharge all the debts created by
me in the construction of the works."
Surely the retention by the Government of the sum of $1,877,000 would
afford it ample security to cover any exigency which might arise. The con¬
clusions of the Board upon this subject we will notice hereafter. Reference
may here be made, however, to a suggestion of the Board touching the matter
of future expenditures upon work at the sea ends of the jetties. It says :
" The jetties may be considered as fairly permanent, except the outer ends
for a distance of about one thousand five hundred feet. Here the chief diffi¬
culty is due to the softness of the bottom on which the jetties rest. Experience
Less ten per cent, reservation
Leaving unpaid and already earned.
1,970,000
197,000
$1,773,000
EADS BETIEWS BOABD, 1878.
363
indicates that they will continue to settle, and will therefore require to be raised
from time to time. "When this subsidence will cease it is now impossible to
predict. All the other works may be considered as fairly permanent, or can be
made so. What repairs will oe needed on them from time to time will be
moderate in amount and easily made."
If, indeed, it be true that the sea ends of the jetties will settle, and it will
become necessary to raise them from time to time, such work can readily be
done without reference to the sum of $5,250,000 to be paid for the work. The
act of a.d. 1875 (jetty act) reserves one million of the price, and $100,000 per
annum as an independent fund for maintenance, which is sufficiently ample to
cover aU such contingencies.
probable results.
We now come to consider the question " what depths of channel will the
works produce ? " In regard to this the Board says :
" The foregoing considerations and the facts already stated under the head
of results actually observed in the progress of channel development during the
last twelve months, induce us to think that if the jetties were well consolidated
and raised sufficiently high to prevent leakage and overflow, a considerable in¬
crease of navigable depth would result. We cannot state that, in our opinion
it is a ' probable result ' that the depth of thirty feet will be attained, as as¬
sumed by Mr. Eads. What the limit will be cannot be positively announced.
That it may attain a depth of twenty-five or twenty-six feet is all we can ven¬
ture to expect as a depth which shall permanently maintain itself ; and as past
experience shows annual fluctuations amounting to about two feet, a perma¬
nent channel of twenty-five or twenty-six feet will require an occasional chan¬
nel of twenty-seven or twenty-eight feet."
recomííendations of the board.
Having thus given the facts found and submitted by the Board, we come to
consider its recommendations. These are, in brief, as follows : 1, That $250,000
of the twenty-six foot payment be advanced to me, to be expended under con¬
ditions similar to those imposed by the third section of the act of June 19, a.d.
1878 ; and 2 (in the language of the Board), " As every additional foot in
depth of channel is a benefit to commerce, we would suggest the advisability
of a change in the terms of payment in the original act, so as to allow of pay¬
ments for each additional foot gained instead of for every two feet, the chan¬
nels and payments to be as shown in the following table :
364
THE MISSISSIPPI JETTIES.
Present System. System Recommended.
Cliannel.
Pay'ts.
Payments for 12 months' ,
maintenance. Channel. Pay ts.
Payments for 12 montlis'
maintenance.
28x350'
80x350'
500,000
500,000
250,000 with 6 per
cent, interest.
500,000 with 5 per
cent, interest.
27x335'
28'x350'
29x350
30'x850'
250,000
250,000
250,000
250,000
125,000 with 6 per
cent, interest.
125.000 with 6 per
cent, interest.
250,000 with 5 per
cent, interest.
250,000 with 5 per
cent, interest."
In the face of the great results accomplished and about to be accomplished,
and with less than one-third of the price of the works paid, the Board recom¬
mends no action whatever by Congress which would really afford me the relief
which my necessities demand. The report is rich in expressions of approval of
the work—poor only in its recommendations. Of what avail to me would be
the advance of $250,000, hampered by the condition that it be expended only
on the works ? Would it serve to relieve me from the mountain of debt which
I bear ? Would it pay, even to a small extent, the contractors whom I have
employed, and who have devoted their whole fortunes and years of labor to
this great work ? The liberality of this recommendation of the Board is only
equaled by that of its second recommendation, which, in plain English, may
bo stated thus : " The works will not, we believe, produce a greater depth of
channel than twenty-six feet. We recommend that for every additional foot
over twenty-six feet secured, Mr. Eads be paid the following sums of money."
Again I call attention to the fact that the Board of a.d. 1874 (of which
one of the present Board was the president), recommended the improvement
of the South Pass. They said in substance : This work will cost $5,342,110 ;
it rvill secure a channel twenty-flve or twenty-six feet in depth. This is a suflS-
cient channel to accommodate the present and prospective wants of commerce,
and the work should be done. The present Board (in effect) says : Mr. Eads
has done the work contemplated by the Board of a.d. 1874 ; he has secured
twenty-three feet of channel depth ; the completion of the works, which are
of a permanent character, will cost $350,000, and a channel will then be pro¬
duced of twenty-six feet, which can be maintained; for this work Mr. Eads has
only thus far received from the Government $1,680,063, and, with $3,583,084
of the agreed price still unpaid in the hands of the Government, we are only
willing to recommend that $250,000 more, hampered with the condition that
every dollar shall be expended on the work, shall be appropriated by Congress,
and provision be made that he shall receive further payments when he obtains
depths which we do not believe he ever can secure.
The Board, in its report, uses the following language:
"But it should be remarked that a channel of less depth than eighteen
EAl)S KETIEWS BOAED, 1878.
365
feet at South Pass was not necessary. * * * * The useful result accom¬
plished is, therefore, a channel from eighteen feet to twenty-three feet." In this
connection the Board might have added that a permanent channel eighteen
feet in depth was worth to the Government $350,000 per annum, as it cost about
that amount to maintain the uncertain channel at Southwest Pass.
Particular attention is called to the following paragraph in the report :
" The Board of 1874, instituted by act of Congress to determine the best
method to secure an outlet from the Mississippi River to the gulf, either by a
canal or by the improvement of one of its natural outlets, reported in favor of
improvement of the South Pass at an estimated cost of $5,343,110, declaring
that while its estimate was designed to cover every possible contingency of
cost, it was believed the work could be done for a much less sum. No reason
is known why Congress, which adopted this recommendation, should not have
left the execution of the work to its own agents, except that the present con¬
tractor, Mr. James B. Eads, offered to accomplish the results contemplated by
the Board without payment unless those results were secured. It would seem,
therefore, that this proposition of payments for results only influenced Con¬
gress to award the contract to Mr. Eads, instead of leaving the execution of
the work to its usual agents. Taking this principle of no payments except
for results as the motive which governed Congress in awarding the contract to
Mr. Eads, we are prepared to consider his claims to aid beyond what the origi¬
nal contract gives him, and what the supplemental act of June 19, 1878, ad¬
vances to him."
This paragraph conveys the plain inference that I have been simply execut¬
ing a system of improvements originally designed and recommended by the
Commission of 1874, and that the construction of the works was not put in
the hands of the Engineer Corps of the Army by Congress simply because I
promised certain specified results on pain of non-payment. This inference is
fully sustained by the conclusions of the Board and its recommendations. I
am thus not only denied the right to pecuniary relief by the deductions which
the Board has drawn from its premises, but the premises themselves deprive
mo of any consideration in connection with my appeal, of the important fact,
that it was I, and not the engineers of the army, who initiated and planned
the improvement which has proved so successful.
This statement of the Board and its unfair conclusions therefore compel
me, in self-defense, to state that I urged this plan of improvement as the only
proper one, upon the attention of a large number of the members of the Forty-
third Congress, in May of 1873, during their visit to the mouth of the river,
and that in the winter following I made a formal proposition to Congress to
deepen the mouth of the Southwest Pass by the jetty system, and offered to
guarantee its complete success, before any member of the Corps of Engineers (so
far as I can learn) had ever expressed officially or publicly any preference what¬
ever for this method of improving the mouth of the Mississippi over that of a
canal, and long before the Commission of 1874 was oven thought of.* In-
* The first appropriation for improving the mouth of the river was made 42 years ago. The
plan of dredging with buckets was recommended, and the plan was approved by a Board of
United States Engineers. In 1852. another appropriation was made, and a Board composed of
Captain Latimer, of the Navy, and Major Chase, General Barnard, and General Beauregard
was appointed. This Board recommended,the process of stirring up the bottom should
363
THE MISSISSIPPI JETTIES.
deed, the very creation of the Commission was the result of my proposal, and
the opposition it evoked from some of the prominent engineers of the army.
General Barnard afterwards,* and the Commission after him, recommended
its application to the South Pass, which location required the reduction of a
shoal at the head of the pass, that has since been admitted by engineers gen¬
erally to have been a problem of greater difficulty than that at the mouth.
General Barnard and the Commission simply differed with me in the selection
of the pass for the application of the jetty system, and there has been nothing
in the results produced, or in my studies of the subject, to alter my belief that
a larger and deeper channel could have been secured at an earlier date at the
Southwest Pass, and one no less permanent, than the one which has been ob¬
tained at the South Pass.
So far as the plans of construction and location of the various works are
concerned at South Pass, they are my own, and were not furnished or planned
by the Commission. The report of the Commission and the lesser cost of im¬
proving South Pass caused the Senate to disagree with the House, which, not¬
withstanding the report, had voted almost unanimously to apply the proposed
system to the larger pass.
The unusual severity of those provisions of the jetty act, by which an
almost entire completion of the work was really required for a total payment
of less than one-third of the agreed price, can only be attributed to the hos¬
tility evinced by some of the members of the Engineer Corps of the army.
Their arguments against the plan and their determination that this great work
should not be intrusted to me, gave birth to all kinds of predictions of evil
and failure. Their antagonism naturally enough alarmed Congress, and re¬
sulted, first, in the enactment of the severe provisions referred to; and, second,
in requiring me to accept the South instead of the Southwest Pass. The bill
as it passed the House provided for the improvement of the Southwest Pass.
In the closing hours of the session, however, the Senate Committee, as advised
by the Commission, substituted the South Pass ; but, against my ownprotesta-
tion and without the advice of experts, it insisted on my agreeing to produce
at this little pass, depths and widths of channel similar to those I had pro¬
posed for a pass four times as large, or else see the execution of my project
put into the hands of its opposers.
be tried ; second, if this failed, dredging by buckets should be tried ; third, if both those
modes failed, parallel jetties should be constructed *'at the mouth of Southwest Pass, to be
extended into the gulf annually, as experience should show necessary ; " foarih, should it
tlien be needed, lateral outlets should be closed. FinaPy, should all these methods fail, a
ship canM might be resorted to. See Humphreys and Abbott's Report, page 486.
* General Barnard, in his minority report on the Fort St. Philip Canal, dated 29th Jan-
uarj', 1874, discusses, Jirat, tlie method of dredging or stirring up the bottom, anà, second,
that of jetties. With respect to dredging, and as a reason for further consideration and study
of the means to be finally selected for surmounting the difficulties at the mouth of the river,
he says : " By reference to the best authority, I have proved the adequacy of dredging opera¬
tions on the bar by well-tested means ; but I think there is yet room for improvement, and
especially in diminishing cost." He further says of dredging, that the attainment of 20 feet
depth on the bar has by no means been established to be the maximum, and adds : "As to
that depth, liowever, we have the strongest assurances." He discusses the jetty method of
improvement with great ability, but says : "The question submitted, however, is not so much
to recommend its trial (of the jetty system) as to recommend its consideration and that scru¬
tiny and survey on which alone estimates can be based."
EADS REVIEWS BOARD, 1878.
367
In March, 1871, the Secretary of War was requested to cause an examina¬
tion and survey, with plans and estimates of cost, to be made for a ship canal
to connect the river with the gulf, and to report upon the feasibility of the
same. About three years later (February 4, 1874) a Board consisting of seven
army engineer oflBcers reported in favor of its construction, General Barnard,
its president, alone dissenting. The majority of that Board and the Chief of
Engineers took strong ground against the jetties, and the energy with which
their opinions were maintained resulted in the passage of a bill in the House
of Representatives in June, 1874, appropriating $8,000,000 with which to com¬
mence the construction of the canal, the cost of which was estimated at
$13,000,000.* The Senate Committee rejected the canal bill, and introduced
a bill to create the Commission referred Jto by the Board as the Commission of
1874, which Commission did not report in favor of applying the jetty system
to the South Pass until January 13th, 1875.
I think the members of the Forty-third Congress will dissent from the
inference sought to be created by the Board, namely, that the method of im¬
provement adopted by that Congress was originated by the Commission of
1874, and that but for my proposal the engineers of the army would have been
intrusted with the building of the jetties ; for the facts show that the Commis¬
sion of 1874 would not have been created but for my proposal, and that if I
had not made it, and urged the jetty system with all the ability I could com¬
mand, the "usual agents of the government," instead of being intrusted with
this work, would, in all probability, now be digging in the sickly marshes of
Louisiana the canal recommended by a prior Commission.
Of that stupendous project. General Barnard, when advocating "an open
river mouth," said, "It would be a rash confidence that would anticipate a
completed Fort St. Philip Canal earlier than 1884."
From these facts it is evident that if it had not been for my proposition to
deepen the mouth of the Mississippi River by the jetty system, the commerce
of the vast empire which constitutes its valley, would to-day, and for yeais to
come, be fretted and hampered by the bars at the mouth of the river, or be
compelled to seek expensive and unnatural routes to the seaboard. Further
comment is unnecessary.
It remains to be seen whether an American Congress is prepared to put
the stamp of condemnation upon individual enterprise, and decline to act with
justice and liberality toward one, who, in the face of unprecedented difficul¬
ties, has secured to the Valley of the Mississippi, and to the whole country, a
deep and permanent outlet from the river to the sea.
♦ See report of the Secretary of War, 1874,1875, vol. li, part 1, page 866.
APPEXDIX XX.
(See page 202.)
ACT OF CONGRESS,
Approved March 3, 1879.
BEING PART OF THE
RIVER HAlRBOR BILE
OP THAT DATE.
That the fourth and succeeding sections of an act entitled " An act mak¬
ing appropriations for the repair, preservation, and completion of certain pub¬
lic works on rivers and harbors, and for other purposes," approved March 3d,
anno Domini eighteen hundred and seventy-flve, authorizing James B. Eads
and his associates to create and permanently maintain a wide and deep channel
between the South Pass of the Mississippi River and the Gulf of Mexico, be
and they are hereby amended so as to provide, in lieu of the payments therein
provided, that payments to said Eads or his legal representatives shall be made
as follows, namely:
The Secretary of War is hereby authorized and directed to draw his war¬
rant upon the Secretary of the Treasury of the United States, in favor of said
James B. Bads or his legal representatives, for the sum of seven hundred and
fifty thousand dollars, which said sum is hereby appropriated; and the Secre¬
tary of the Treasury is hereby authorized and directed to pay to said Eads or
his legal representatives, out of any money in the treasury not otherwise appro¬
priated, the sum for which said warrant is drawn.
When a channel shall have been obtained by the action of the jetties and
auxiliary works authorized by said act, twenty-five feet in depth, and not less
than two hundred feet in width at the bottom, through the said jetties, there
shall be paid five hundred thousand dollars.
When a channel shall have been obtained through the jetties twenty-six
368
AMENDATOBY ACT—MARCH, 1879.
369
feet in depth, and not less than two hundred feet in width at the bottom, there
shall be paid five hundred thousand dollars.
When a channel thirty feet in depth, without regard to width, shall have
been obtained through the jetties, there shall be paid five hundred thousand
dollars; and the one million dollars provided by the hereinbefore-recited act to
be paid by the United States in ten and twenty years shall be earned by said
Eads and his associates, and the same, with interest, shall be paid to said Eads
or his legal representatives, at the times and in the manner provided by said
act.
The one hundred thousand dollars per annum provided by said recited act
to be paid to said Eads and his associates during a period of twenty years,
shall be paid at the times and in the manner therein provided, upon the main¬
tenance by said Eads and his associates of a channel through the jetties twenty-
six feet in depth, not less than two hundred feet in width at the bottom, and
having through it a central depth of thirty feet, without regard to width.
Nothing herein contained shall be so construed as to repeal or in any wise
affect the provisions of the amendatory act, approved June 19, anno Domini
eighteen hundred and seventy-eight, by which said Eads is entitled to receive
certain moneys to pay for materials furnished, labor done, and expenditures
incurred in the construction of the work at the mouth of the Mississippi
River; and the whole of the hereinbefore-iecited act, approved March 3d, anno
Domini eighteen hundred and seventy-five, except as the same is hereby ex¬
pressly modified or amended, or has by act heretofore passed been modified or
amended, shall be and remain in full force, and have the same effect as if this
act had not been passed.
24
APPENDIX XXI.
(See page 220.)
TABLE OP COMPARISON
Ol" Scour and Deposit in 37 Subdivisions, containing about 0.278 Square
Miles, o"r 178.38 Acres, immediately seaward op the end of the
SOUTH PASS JETTIES,
(See Plate 23, facing page 220,)
Between the dates of May, 1875, and December, 1879, to accompany
Comparative Chart, Plate 23.
Number
of sub¬
divi¬
sions.
Area of subdi¬
visions in square
feet.
Mean depths in sub¬
divisions in feet.
Scour in subdi-
vision.s in
cub. yds.
1875 to 1879.
Deposit in sub¬
divisions in
cub. yds.
1875 to 1879.
Number of
soundings in
subdivisions.
1875.
1879.
1875.
1879.
1
500,000
21.5
26.1
85,185
35
80
2
500,000
33.2
31.6
29,629
26
70
3
500,000
33.9
37.6
68,519
24
64
4
500,000
41.1
42.0
16,667
19
64
5
500,000
47.8
45.7
38,889
10
62
6
50,000
18.3
17.8
926
5
14
7
100,000
36.9
30.7
22,963
4
18
8
150,000
31.2
37.2
33,333
7
22
9
200,000
39.0
35.0
29,629
6
30
10
250,000
48.3
48.2
926
8
34
11
50,000
24.6
24.9
556
7
17
12
100,000
30.3
34.9
17,037
4
30
13
150,000
33.2
40.2
38,889
5
37
14
200,000
38.9
39.8
6,667
8
34
15
250,000
52.3
46.8
50,926
3
36
16
100,000
15.4
14.7
2,592
10
16
17
100,000
36.6
30.1
24,074
5
18
18
200,000
36.0
37.4
10,370
6
26
19
250,000
37.6
37.5
926
10
32
20
100,000
23.6
27.1
12,963
7
24
21
100,000
28.8
35.1
23,333
6
22
22
200,000
32.7
38.5
42,963
14
34
23
250,000
45.7
40.4
49,074
8
41
24
100,000
16.0
13.0
11,111
4
18
5,400,000
356,482
261,665
241
843
APPENDIX.
371
APPENDIX XXI.—(continued).
Number
of sub¬
divi¬
sions.
Area of subdi¬
visions in square
feet.
Mean depths in sub¬
divisions m feet.
Scour in subdi-
vi.«ions in
cub. yds.
1875 to 1879.
Deposit in sub¬
divisions in
cub. yds.
1875 to 1879.
Number of
soundings in
subdivisions.
1875.
1879.
1875
1879.
25
36
37
28
29
30
31
33
33
34
35
36
37
Totals
5,400,000
300,000
350,000
60,000
100,000
300,000
350,000
60,000
135,000
250.000
350,000
135,000
350,000
350,000
34.6
87.7
31.3
38.0
31.5
38.9
41.3
33.0
38.7
38.5
31.3
39.9
44.6
2è.8
36.3
34.0
80.4
36.9
41.0
43.3
15.6
33.5
33.3
34.1
39.5
43.6
856,483
6,000
8,889
40,600
19.444
3,333
44.445
13,963
361,665
43,963
13,963
è4.259
57,407
3,704
18,519
241
10
10
3
4
7
11
3
7
7
14
10
8
4
843
34
38
14
18
34
36
10
36
30
35
17
26
35
7,770,000
490,445
431,480
337
1136
Excess of scour over deposit over whole area of 7,770,000 square feet, 58,963
cubic yards.
KEY TO COMBINATIONS.
Combination A contains subdivisions 1-5 inclusive.
" B " 1-15 "
C " 1-23
" D " 1-31 "
" E " 1-37 "
Letters
of
combi¬
nations.
Area of combi¬
nations
in square feet.
A
3,500,000
B
4,000,000
C
5,300,000
D
6,520,000
E
7,770,000
Mean gain in
depth on
combinationfi
from 1875
to 1879,
in feet.
1.10
0.03
0.54
0.53
0.20
Mean loss in
depth on
combinations
from 1875
to 1879,
In feet.
Hcour in Deposit in
combinations combinations
from 1875
to 1879,
in cnb. yds.
101,853
93.963
105,936
135,444
58,965
from Í8T5
to 1879,
in cub. 3'ds.
APPENDIX XXII.
(See page 221.)
No. 1.—TABLE SnOWINa CHANGES IN GULP BOTTOM BEYOND
THE JETTIES.
(See Plate 24, facing page 220.)
CoMPARiiíG Subdivisions of Pan-shaped Area surveyed by Capt. M. E.
Brown, U. S. Inspecting Officer, in 1876 and 1879. Subdivisions 7
to 19 inclusive.
No. of
subdi¬
vision.
9
10
11
12
13
14
15
16
17
18
19
Mean depths,
feet.
isrG.
68.63
58.40
53.78
47.93
52.48
50.56
36.80
31.46
35.20
33.37
29.23
31.44
37.08
1879.
62.66
58.30
56.58
47.70
54.54
51.05
40.35
34.73
40.26
39.01
33.16
35.92
39.47
Totals.
Area,
iqnare feet.
3,146,568
1,177,965
1,911,590
1,804,280
1,910,900
1,177,965
2,664,385
354,931
196,900
305,820
1,658,310
390,600
195,900
16,895,674
Cubic yards of water
^ overlying subdivisions.
1876.
7,415,403
2,547,905
3,807,800
3,203,170
3,714,389
2,205,950
8,631,752
413,612
256,699
488,689
1,798,376
454,959
269,090
30,207,794
1879.
7,303,062
2,543,532
4,005,839
8,187,621
3,860,303
2,227,400
3,982,775
456,546
293,599
271,281
2,036,957
519,838
286,413
30,875,166
Scour,
cub. yds.
Fill,
cub. yds.
198,039
Í45,'9Í4
■ 21,450
351,023
42,934
36,900
238,581
64,879
17,323
1,117,043
112,341
4,373
' Í5,'549
217,408
19
15 33
46 30
59 35
56 48
40 33
66 72
14 13
15 10
53 11
271 55
86 14
12 4
349,671
30,207,794 cubic yards
16,895,674 square feet
30,975,166 cuoic yaras
16,895,674 square feet
= 48.27, mean depth in 1S«70.
= 49.49, moan depth in 1879.
Average increase of depth over whole area.... 1.02 feet.
Excess of scour over deposit " " 770,037 cub. yds.
372
APPENDIX XXII.
No. 3.—Table compaking U. S. Coast Survey op 1875 -with Survey of
U. S. Engineers op 1879, using Subdivisions of Capt. Brown's Fan-
shaped Area.
No. of
subdi¬
vision.
Mean depths,
feet.
Area,
square feet.
Cubic yards of water.
icour, rill,
CTii). yds. cub. yds.
'é , "é .
5S sE
C»
y. X
'i? X 's cc
® ® tc
O-5 o-S
Zi %
1815.
isro.
isrs.
1819.
15
16
17
18
19
36.53
35.36
34.33
34.36
34.65
40.36
39.01
33.16
85.93
39.47
196,900
395,330
1,658,310
390,660
195,900
366,658
517,733
3,108,044
497,151
351,405
393,599
571,381
3,036,957
519,838
386,413
36,941
53,559
33,087
85,008
71,087
17
15
58
15
7-
10
11
55
14
4
Totals
3,837,090 3,640,980
8,768,088
138,195
71,087
3,640,980 cubic yards
o QQ-7 noA S—r = 34. Go, mean depth m 187o.
3,837,090 square feet '■
8,708,088 cubic yards
a oor, nnr,— ï"T = 3o.38, mean depth m 1879.
3,837,090 square feet
Average increase of depth over whole area.... 0.63 feet.
Excess of scour over deposit 67,108 cub. yds.
APPENDIX XXTII.
(See page 228.)
Rate of Subsidence of Concrete Blocks. Expressed in Decimals of a
Foot.
EAST JETTY.
Subsidence in 5
Subiidonce in next
Total subsidence in
Station.
months after 1st month.
5 months.
10 months.
104
.107
.090
.197
105
.110
.116
.282
106
.196
.096
.292
107
.338
.201
.539
108
.193
.313
.506
109
.200
.233
.433
110
.283
.312
.595
111
.261
.206
.467
112
.281
.226
.507
113
.283
.330
.613
114
.256
.278
.534
115
.228
.241
.469
116
.410
.227
.637
Average. ..
243
.220
.463
WEST
JETTY.
Subsidence in 4 months,
Subsidence in next
Total subsidence in
Station.
after Ist month.
5 months.
9 months.
113
.165
.028
.193
.04
.090
.058
.148
105
.171
.023
.199
106
.256
.045
.301
107
.247
.041
.288
108
.190
.040
.230
109
.340
.180
.520
110
.437
.191
.628
111
.371
.102
.473
112
.314
.108
.422
Average ..
258
.082
.340
Average subsidence on both jetties 401
Rate of subsidence per month 0.042 feet, or I inch.
374
APPENDIX XXIV.
(See page 235.)
RECORD OF NAVKÎATION.
Sailinq Vessels in and out over South Pass Bar.
Draft in feet.
May, 1875. to
July, 1876.
July, I876.to
July, 1877.
July, 1877, to
July, 1878.
July.1878, to
July, 1879.
July,1879. to
May 18, 80.
Total.
10 to 18
18 " 20
20 " 22
22 " 24
19
307
20
922
109
32
923
89
15
4
955
130
40
5
3126
348
87
9
Total Number.. 19
327
1063
1031
1130
3570
Steamships in and out over South Pass Bar.
10 to 20
20 " 24
24 " 25
29
153
10
576
11
653
81
704
134
2
2115
236
2
Total Number.. 29
103
587
734
840
2853
Total steamships and sailing vessels in five years 5923
375
APPENDIX XXV.
(See page 340.)
EMPLOYEES DESERVING HONORABLE MENTION.
R. S. Elliott, Private Secretary and Secretary South Pass Jetty Co.
Wm. S. Nelson,* Captain of dredge-boat Cf. W. H. Bayley.
W. L. Wright, Chief Clerk and Paymaster at Port Eads.
W. J. Kamer, Cashier and Purchasing Agent in charge of New Orleans
office and Secretary in compilation of History of Jetties.
Henry Cory, Superintendent of mattress work.
Thomas T. Rubey, Captain of steamer Ornfion.
James Keefe, Master Mechanic and Superintendent of Construction.
Chauncey Hoadley, Foreman of Mattress Placing and Sinking.
Wm. Tinsley,* Foreman of Mattress Construction.
John Holland,* " "
H. C. Blanchard,* " "
Geo. L. Mitchell, Pile-driver and Concrete Foreman.
Joseph Greppin, Master Machinist.
M. C. Tully, Foreman and Mate of dredge-boat Bayley.
Peter McGee, Pile-driver Foreman.
John McGee, " "
Wm. Faber, Blacksmith.
J. T. Houston, Leadsman.
John Frasier, Captain of Tug Brearly.
. Geo. W. Adams, Captain of Tug Ella Andrews ^nd dredge-boat Bayley.
Spencer P. Rous,* Chief Engineer of steamer Grafton.
F. C. Welschhans, Telegraph Operator.
W. J. Mathews, " "
A. W. Wire, "
J. H. Stockley, Resident Physician.
» Deceased.
376
APPEXDIX XXVI.
GEOGRAPHICAL, HYDROMBTKICAL, METEOROLOGICAL,
I. Geographical.
Location of Jetties.
Longitude 89 deg. 9 min. west from Greenwich.
Latitude 29 deg. 0 min. north.
II. Hydrometrical.
a. Fluvial.
Location of Gauge.
Distance from Gulf.
Range of River.
Carrollton
115 miles.
17.40 feet.
Prom - 1.70
on gauge to
15.70.
Head of Passes..
12i "
2.50 "
S. Pass Light¬
house
2i "
0.40 "
J. Tidal.
Character of tides, diurnal (single day type). Mean rise and fall,
14 inches. Extreme range (from storms and other causes), 5 feet.
Tidal current approaching delta, maximum velocity, 1.5 feet per
second. Reverse currents in South Pass at Port Eads, with Car-
rollton gauge at + 0.70, tide rising during observations 1.43 feet,
and at a depth below surface of 18 feet, average velocity, 0.82 feet
per sec. ; maximum velocity, 1.06 feet per second. " Average
flood-tide " of U. S. Engineers at South Pass Lighthouse (da¬
tum plane for measurements of channel depth), 1.8 feet above
mean low water of U. S. Coast Survey, and 0.2 feet below datum
plane at head of pass.
III. Meteorological.
a. Winda.
Direction, chiefly between N. E. and S. E. Maximum velocity
observed, 61 miles per hour. Average velocity in seven storms
377
THE MISSISSIPPI JETTIES.
at Southwest Pass, 35J miles per hour ; raised tides above normal
level, an average height of 2.34 feet.
Thermometrical.
Average range during the year, from 35 degrees Fahrenheit to
93 degrees. Average height in summer, 85 degrees. Average
height in winter, 65 degrees.
Rainfall. (1877-1879) Average, 54.45 inches per annum.
INDEX.
Accretions on leeward bank, 73.
Acres, number of, in Miss. Valle}', 2.
Act of concession, anniversary of, 9C ; text
of, 261-265 ; amendatory, text of, March
3. 1879, 368, 369.
Adams, Capt, Geo. W., placed in charge, 188.
Agriculture, wealth of, land-locked, 6 ; bene»
fits to, 236.
Alexander, Oen. B. S., member of Advisory
Board. 92 ; on Commission of 1876, 142.
Alignment, curve of, 74 ; East Jetty, 75.
Andrews. Janus, conditions of contract of,
67 ; biographical, 72 ; jetties indebted to,
241.
Aprons, wooden, 87.
AppropHations, Congress must make, for pay¬
ments, 265.
Ai^kansas, The, description of, 4.
Associates, Eads's, in concession, 67.
Atwood, matfie, schooner, 96.
Average flood /¿if«," discussion of, at head
of passes, 301.
Axes, neutral, head of passes, 113.
Ballast, discharged at Port Eads, 210 ; where
obtained. 210.
Bxnquet at St. Louis to E-ids, 63.
Bar. blockaded in 1859, 7 ; rate of advance,
13 ; normal depths on, 13; slopes of, 13;
dimensions of, 15 ; will not reform soon,
35 ; theory of formation by Gen. Humph¬
reys, 42 ; formed by same process as at
other delta rivers, 45 ; cannot be deepened
over 20 feet by stirrinï process, 60 ; ad¬
vance of, discussed by Commission of 1875,
61 ; at South Pass, least depth on, lb75,
72; reformation hastened by delay, 81;
advance of, prophesied by (opponents, 198;
report of inspecting officer disproves ad¬
vance of, 198; difference between S. and
S. W. Pass, 231 ; formation of, described
by Board 1875,255 ; advance of, calculated,
257 ; solidity of, shown by pile-driving.
2T3 ; advance of, dis'-ussed "by Board 1879,
356 ; retrogression of, proved. 357.
Bar, outer sloite of, changes in, 102 ; Schmidt's
survey of, 103 ; report on, by Boanl of 1878,
192 ; results of jetties upon, 216 ; changes
in, illustrated by curves, 217,218 ; changes
in, illustrated by movement of material,
220; results on, shown by fan-shaped
area, 22 ) ; shoals and lumps on, reduced
by current, 234 ; changes in, shown by
tables. 370-373.
Bornard, Gen. J. G., president of Board of
1874, 21 ; makes minority report, 22 ;
member of Advisory Board, 92 ; on Com¬
mission of 1876, 142; on Commission of
1877, 165 ; letter of Eads referred to by,
170 : on Board of 1878,191 ; his relations to
jetty project <liscussed, 197 ; explains
reaj'ons for minority report, 198 ; state¬
ment of, before Senaie Committee 1878,
200 ; president Board 1874, 243 ; minority
report of, 247 249 ; reports on Eads's let¬
ter, May 13, 1878, 813; president Board
of 18T9, 335.
Barges, size of, 77 ; to sink mattres-ses, 79 ;
capacity for stone, 209 ; fleets of, for grain,
237.
Basin, caused by wing dams, 152.
Basins, drainage, description of, 3.
Bay, Garden Island, 70.
Baylty, G. W. Ji., early advocate of jetty
system, 54 ; journal of, 74 ; general direc¬
tion of affairs given to, 81 ; death and
memoir of, 1-16 ; concurs in Corthell's
statement, 282.
Beatiregaid, Gen. G. T'., member of Board of
1852, 20 ; opinion of, on jetties and canal,
247.
Beton, Mocks of, for consolidating jetties,
188.
Bill for improvement of S. Pass passed by
Congress, 66.
Board of 1852, recommendations of, 17-20 ; of
1874, majority favors ship canal, 21 ; ad¬
visor}', meets, 92 ; opinion of, 93 ; of 1878,
191: report of, 192-194; report reviewea
by Eads, 194-200; of 1874, 243-2.50; of
1875, 251-260 : advisory, report of, 266-274 ;
report of, Jan. 23, 1879, 335-355 ; reviewed
by Kads, 357-367.
Bonds or money in payment. 265.
Bridge, St. Louis, constructed by Andrews,
Bridge rope for mattress, 78.
Briquettes f(tr testing cement described, 204.
Brown. Capt. B., surveys channel. May,
1876, 100; his fan-shaped area, 220; com¬
plimentary, 240.
Buisson, henj.. plans ship canal, 1832,19.
Bu8<(y, Gen. Corns, extracts from letter of, on
commercial benefits, 236.
Cameron, J. T).. Secretary of War, complies
with requests of Eads. 104-106 ; instructs
Commission, 1876, 143. 299.
Canot, Fort St. Philip, history of project of,
19-2Î5 : bill of. passed House of Hep.. 47 ;
bill of, did not pas« Senate, 48; Commis¬
sion discuss location of. and give estimare,
60 ; report of Board, 1874, 243 ; locations
discn«sed by Board, 1875, 253 ; estimate
of. 254.
Car, dumping, for concrete, 190.
379
380
INDEX.
Carrollton gauge, record of, 172, cnrve of,
217 ; range of river on, 377.
Caving of banks explained, 30.
Cement, specifications for, 204 ; Saylor'.«
American Portland, described, 204; light
weight, strength of, 205 ; strength tnd
hardness of. 206.
Certificates used for pay-rolls, 156.
Chan\l>er of Com7nerc€, N. O .eo<.rmmend
ship canal, 20 ; favors cai.ai and opposes
jetties, 37.
Channels, necessary to be obtained quickly,
81 : development of, 94; illustrated, 94 :
table of depths of, 95 ; materials removed
from, 95 ; development of, 1876, 142 : 2d
feel by 200 feet, 142 ; jetty, contracted,
146: 20 feet reported Dec. 27. 1876, 146 ;
Î>ayment of, delayed, 146 ; remarkable en-
argement of, 150 ; condition of, July, 1877,
158 ; 22 feet by 200 feet obtained, 165 ;
changes in head of pas.s, 179 ; results pro¬
duced, 192; dimensions of, .«hoiild have
been considered by Board, 199 ; S. Pass
and S. W. Pass, in cost compared by Eads.
1878, 202 ; results in, 211 ; 25 feet by 200
feel o])tained, 211 ; 3i) leet obtained, 212 ;
changes in, illustrated in Appendix 6,
and 17, 212 ; fluctuations of, reasons for,
212; relation of, to coiistiiictloii work.
213 ; total amount of material removed
from, 213 ; artificial deepening of, not per¬
manent, 214 ; material removed from,
plotted, 217 : at head of pass, 30 feet. 223 ;
general results in, 223 ; process of forma¬
tion of, 226 ; full section of, not yet ob¬
tained, 229 : oi)inion of maximum size by
Eads and Hartlej', 229 ; greater dimeitf-ions
probable, 230; results in, shown by models,
234 ; terms and payments of in grant,
262 ; natural causes of formation given,
27'3; table of depths In, 276: coiitruir
lines of. 277 ; table of depths of. 333. 334 :
results in, stated by Board, 1879, 346 348 ;
lirobable, 348, 350 ; progressive improve¬
ment of, 357; dimensions of, discussed,
358,361.
Chase, Moj. TK H, plan of, for ship canal, 19.
ChU-f of Engineers, V. S. A., instructed by
Secretary of War to ilisconilnue surveys,
100.
Coast Sin^^ey, V. S., just preceded us, 71;
Suiit. of," instructed by act to make survey,
71, 264.
Commerce released by jettie-». 1 ; of Miss.
Valley, 3; benefits to, 235, 2-36, 237.
Commis,^ion of January 14, 1875, names of,
49 ; decide to visit rivers of Europe, 49 :
report of, 1875. 60 ; on head of passes,
1876, 143 145 : of 1877, 165 ; advisory, re¬
port of, 2G0. 274 ; of 1876, repoit of, 29? ;
of May 13, 1878, 313-319.
Cwnmitfee. V. S. Senate, unwilling to improve
S. W. Pass. 65.
Cowpamj, S. Pass Jetty, formed to furnish
additional means, 68 : relation to enter¬
prise. 68 ; commended, 239.
Comstocl\ Gen. C. B., declines to give infor¬
mation. 100: opinion of, on head of pass
channel, 142.
Concrete, preparations for, 188 : described,
189; proportions of ingredients, 190: ex¬
tent of, and size of blocks, 202 ; materials
for, described, 2a3 : generated wave forces,
^6 ; record of levels on, 228 ; rate of sub¬
sidence of. 228 ; estimate of, 332.
Conger. Hon. 0. T)., speaks in favor of Eads's
proposition. 64.
Congress, bill passed by, to appoint Commis¬
sion 1874, 48 ; bill parsed by, to improve
S. Pass, 66; appropriations voted by,
^78, 171 ; relief to Eads appropriated by,
CohcVitions changed by jetties at mouth of 8.
Pass, 2:^3.
Constrnciion, cheaper methods devised by
Eads, 67 ; rapid, demanded, 81; progress
of, discussed by, 1879. 341-344.
Continent, half, embraced by river and trib¬
utaries 2.
Cwthell, E. L., details of instruction intrusted
to, 82 ; ctrntroverts Howell's statements,
99 ; promoted, 147; letter of, for Advisory
Boam, 270 ; letter of, refuting HoweH's
statement, *<81, 282.
Craigr c£' Eightor, contract of, 18.
Craighitl, Col. ^^7ll. P., board, 1874, 21, 247.
Crn-asse, Cubitt's. 15 ; Bonnet Carré, 31.
Cribs, spur, 207 ; palmetto, 207 ; described,
207.
Crcmwell S. S. Line uses jetty channel, 116 ;
passage of jetties by, necessary, 117.
C7CSS'¿>écíion, area of, ¿realer in jetties than
in pass, 13
Cuirent, littoral, velocity of, 43, 44 ; fluvi-1,
diiected against littoral, 74; changed by
jetties, 214 : velocity of, in pass, 217 ; cross,
affects lead line. 222 ; littoral, dii-cussed
and facts staled. 233.
Curves, various, 217 : dependence of, on Car¬
rollton gauge, 218.
Bam, Aim recommendations about, by Ad-
visorj' Board, 268.
Bam, hland, length and description of, 135.
Dam Eo. I., de.scription of, 124-126 ; effects of,
126 ; estimate of cost of, 296.
Bam Eo. 11.. description of, 127.
Bam, I'pjer. description of, 182.
Banvbe, sediment of, compared with Missis-
sip] i. 45 ; sediment of, prcportional to
volume, 46 ; delta, bars and jetties of, de¬
scribed and discussed by Sir Charles A.
Harth y, 52-55; compared with Mississippi,
55 5^ ;'uoiks on. successful, 2 .2 ; delta of,
similar to Mississippi, 272; dipth at¬
tained at, 272.
Belfa of Misfissij'pi, history, growth, regimen,
8; proce.'^s c f formation en, described, 11 ;
compared with highlands, 69 ; more fa^or-
rble to impiovcment than Danube, 2?2.
Den.ocroi, E. C.. Howell's and Eads's letters
published by, 278-281 ; editorial of, 291-
293.
Be2 osits, in 1875, 95 ; in 1876, 95 ; on seaside
of jetties. 157; in channel, during its for¬
mation, 226.
Bipiold & McDonald, stone furnished by, 209.
Imcom ü(,emerds stated in Eads's letter, 170.
Donovan '. C., complimented, 240.
Brede,eboaf, uecessitj' for, 158 ; " G. W. R. Bay-
ley " described, 159-165.
Bredgeboofs, G(,vefhment. 18 ; depth obtained
by» 1^9 ; " Macaelester " and "Essayons"
described, 159; opposed to correct princi¬
ples, 159. ^
Dredging, at head of S. Pass, 136 ; Commis¬
sion on. 1877, 166; material removed at
jetties by, 214 : by chains, harrows, and
ploughs, 214 ; Grant's machine described,
215.
Driver, sheet pile, described, 84.
Brina, river aud jetties, 50.
Byhe, Cross, length and location of, 123 ;
causes of disaster to, 123.
Dyke, East, advisea by Advisory Board, 113 ;
location of, described, 114 ; abandoned,
114 ; effects of, 114.
Dyke. Island, description of, 128 ; destroyed,
178, 179 ; rebuilt, 1879, 181 ; down-stream
extension of, 182.
INDEX.
381
Dyke^ Liyhlhome. extension of, 133 ; damaged
by current, 134 ; rebuilt, 187T, 177.
Eads, James B., address of, before Merchants'
Exchange, 1 ; biography of, 23 ; declarefi in
favor or jetties, m May. 1873, 24 ; oilers
extraordinary' inducements on account of
hostility of Government engineers. 25 ;
makes formal proposition to deepen S. W.
Pass, 25 ; contends alone against opposi¬
tion, 28 ; addresses letter to VVindoni, 28 ;
states jetties not been tried, 37 ; reviews
Humphreys, May 29, 18T4, 43 ; makes
proposition to deepen S. W. Pass, 62 ;
speech of, at banquet, 1875, 66 ; absence
of, from jetties, 1875, 81 ; letter to Patter¬
son, March 7, 18T6, 98 ; letter to Taft,
May 23, 1876, 103 ; his requests, 105 ; de- ,
cides plan for head of passes. 113 ; letter
to Secretary of War, May 7, 1878, 168; let¬
ter to Robertson, reviewing Humphreys'
letter, 172 ; submits drawings and esti¬
mates to Board, 1878, 191 ; reviews report,
194-196 ; theories of, proven hy results,
219 ; tribute to, 241; authorized^ to build
jetties, 2iil; letter to Secretary of War,
May 23, 1876, 278 ; letters to Patterson.
279 280 ; ra ikes requests of Secretary of
War, 283 ; letters in N. O. papers, 289-291,
293 295 ; letter of, to Secretary of War,
April, 19, 1877, 304 308 ; May 7," 1878, 809-
313 ; answer of, to Humphreys' letter,
June 1, 1878, 325-^30 ; letter of, to Board
1879, 337-841 ; reviews report of Board
1879, 357-367.
East Point, zero for all distances, 84.
Edwards, Joseph, constructs pumps for "Bay-
ley," 161.
E'evator, steam, for concrete, 189.
Emharrassments, work hampered by, 1.55.
Employees work for certificares, 156 ; list of,
deserving mention. 376.
Enghx'-er-in-charge, daily work of, 82.
Eagimers, Civil, national work-» in Europe
intrusted to, 23; suoport Eads's views,
47 ; favor jetty plan, 239 ; American Soci¬
ety vi-it jetties, 239.
Engineer Corp^, jetty, efflcienov and faithful¬
ness of, 296.
Engineers, Military^ national works in their
charge, 25 ; oppose Eads's proposition,
1874, 26 ; oppose giving improvement to
an ont-»ider, 47; none favor jetty plan
fully, 197 ; hostility of, compelled severe
provisions in act. 366.
Erosion of banks not dependent on friction, 29.
Estuary, ancient, of Mississippi, 10.
Eà'ixo tation of products increased by jetties,
255.
Forskey, C. G., opposes jetties before Con¬
gress, 38-40.
Francis, Capt. i?., pilots S. S. Hudson through
jetties, 108
Francis, St., The, description of, 5.
Freights reduced by jetties, 236.
Gager, Capt. E. V., commanding S. S. Hud¬
son, enters jetties, 108.
Geographical location of jetties, 377.
Gillmore, Gen. Ç. A., on Board, 1874.21, 247.
Grafton, steamboat, arrived at Porr Eads, 75.
Grain not heated since construciion of jet¬
ties, 237.
Grand Bayou, half way np the pas«, 70 ; Eads
intended to close, 73 ; closure of, and
effects. 119 ; dam at, described, 139 ; re¬
sults of dam, 141.
Grant from U. 8. to Eads, authorizing jetties,
text of, 201.
Grant, Capt. John, constructs machine^ for
deepening ctianiiel at head S. Pass, 215.
Gravel for concrete, 203 ; worked into mat¬
tresses. 208.
Gulf, depth of, 10 ; inland sea of salt water,
14 ; no barrier to current, 34 (.¡-e • bar,
O'lter slope of, ior changes made by jetties) ;
changes in greater depths of, 221 ; sur¬
vey of, 212 ; results in, di.-cussed, 231.
Hartley, Sir Charles A., abstract of his two
papers on Danube jetties and discussion,
53-58 ; member of Advisory Board, 92.
Head gf Passes, problem of, 110 ; conditions
of. described, 112 ; extent of works given,
119: principle of works stated, 120 122;
results of works, 1877.137, 138 ; résumé of
works given, new works described, 175;
final results of work-«, 183 ; economy ana
extraordinary effects of works, 184, 185 ;
genei-al results given, 223 ; works at,
enumerated by Board, 1879. 343, 344.
Head of South Pass, bar of, described, 112 ;
development of cliaimel, 137 ; work' de¬
layed by finances. 156 ; attempt to deepen
by current machine, 215 ; bar at, wearing
away, 258 ; shoal at, discussed by Board
1876, 300.
Head of Water at Kipp Dam. 88 : current cre¬
ated by, through west jetty, 89.
Hebert, P. O., opposed jetties before Con¬
gress, 38 40.
Hilgard, E. TP., classified silts to find law of
deposit, 34.
History of jetties, reasons for writing, given, 3.
Hostility ot Government engineers compelled
Eads to raise additional means, 68.
Howell, Mnj. C. W., on Board of 1873, 21 ;
states that conditions for succos< by jet-
tie.s do not exist, 36 ; assistant of.
makes survey, 97 ; writes letter for iV. 0.
Democrat, 99 ; on Board, 1874, 247 ; pub¬
lishes letter about jetties, 278-287.
Hudson, S. S., entered jetties, 108.
Humphreys, Gen. A. A , approves report of
Board, 1874 , 21 ; replies to Eads, May 22,
1874,36; takes issue withEad-'s views, 41;
opposes Eads's proposition, February,
1875, 63 ; ptiblished meinonandiims. 104 ;
interdicted from further interference, 106;
writes letter to Robertson, 1878, 171 ; bis
predictions not fulfilled, 234 ; memoran¬
dums of, 285 ; interference with jetties,
286 ; letter of, to Robertson, 320-324.
HydromelHcal table of data, 377.
Imperviovs,y^Xi\e% are not, t.57.
Injury to jetties, penalty of. 264.
Insp'cting officer instructed by Secretary oi
War," 106.
Instructions of Eads to assistants, 81.
Jetties, Mississippi, world affected by, 1 ; will
not back up water, 34 ; should be parallel,
' 34 ; European, 50-59 ; Commission of 1875
give reason for application of, 61 ; also
prefer them to ship canal, 62 ; location of,
at South Pass, 73 ; width between, 73 ;
first effects of, 93 ; general problem of,
111 ; described, 147-149; height of, 208;
iiupervious by deposits, grav<'l, etc., 230 ;
commercial benefits of, 23.5-238 ; principle
of. maintained forever, 241 ; desigtied hy
Board, 1874. 244 ; estimate of, by Howell,
245 ; difficulties of. enumerated, 246 ; ad¬
vantages of, stated by Barnard, 248 ; Euro¬
pean. 252. 2.53 ; principle of, explained by
Board, 1875, 255 ; specifications of, 257 ;
e'^timates of, 258 ; compared with canal,
259 ; width between, 2i;6 ; less difficult to
382
KDEX.
conftnict than European, 271 ; progress
of, 342 ; results in front of, 35ö.
Jetty, East, alignment of, 75 ; depth of water
on line of, bH : aliifnrnent of, recommended
by Advisory Board, 206, 267.
Jetty Sy>tt€ni, economy of, dependent upon
rapidity of construction, 81.
Jetty, Went, guMe piling of, commenced, 86 ;
work on, suspended, 80 ; alignment of, 87 :
length of guide piling, 87 ; mattresses,
width of, 89; depth of water on line of.
89 : when raised to surface, 89 ; alignment
of, recommended by Advisory Board. 267.
Johuftoii cuiJ WiUoii furnished cement, 204.
Jumi^ described, 76 ; mattress ways at, 77.
Keg. experiments with, by Forsln*y, 44.
Kimball, <S. N., contract given to*, to dredge
head of pass, 136.
JCipp Dam commenced, 87 ; damaged by cur¬
rent, 88 ; reconstructed, 89.
Land made by deposits of sediment, 213.
Leakage through jetties, and eflects of, 90.
Light/iOifse, view from, 69.
Lineft, head and bridle, in mattresses, 78, 79.
Loan aided by S. S. Hudson, 109.
Losse-^, U. S. not to be liable for. 265.
Lnmber, total amount used, 209 ; where ob¬
tained, 209.
Maas, river, jetties at, described, 50.
Macadam, described, 203.
Maclay, W. W., report of, on cement tests,
204.
Maco7nb, Gen. J. N., on Board 1878,191.
Maintenance, conditions and payments, 14,
262.
Maiindin, H. L., surveying party in charge
of, 71 ; makes survey, 1876, 98.
Marsh, material of soft, 71.
Massachvsetts, Miss, valley compared with in
size, 2.
Materials, total estimate of, 332.
Mattress, described, 76-80 ; patented, 80.
Mattresses, willow, most important part of
jetties, 75; bow plotted, 84 ; size of, 84 ;
Used to prevent scour at sheet pi'ing, 86 ;
west jetty. 89 ; built on barges, 148 ; built
in place, *148 ; built on .«kids, 149.
Mattr'ss ivork at ^faas, estimate of Commis¬
sion, 1875, based on, 67 ; essentially the
same as the Maas, 267 ; derail cost of,
275.
McCrn^y, G. W.. Secretary of War, transmits
report of Board of 1879, 335.
McDonald, J. Sha7p éb Co., furnished stone,
209.
Means embarked by Eads's associates, 67.
Mernll, Col. W7n. E., on Board, 1878, 191.
Meteo7'ologfcat. 377, 378.
Mississippi River Improtement Commission,
pretext for attack on jetties by Humphreys,
171.
Mississippi, description of, 6 ; ancient map
of. 8 ; early discoveries of, 9 ; origin of
name, 9 ; changes in, 0; volume of, 13;
lower, range of between high and low
water, 14 ; upper, identity preserved in
main river, 35 ; compared by Hartley with
Danube, 56, 57.
Ms^otni, the description of, 4.
Misstatejnenfs b.v iMaj. Howell refuted, 108.
Mitclicll, Prof. Ue)mj. member Advisory Board,
92 ; member of Board of 1875, 49.
Mia^er, coitcrefc, described, 189.
Models of jetty channel. 234.
Montaiqa R., plan of, for ship canal, 20.
Mud lump blockade, placard of Hebert and
Forshey, 40 ; analysis cf material in, 154.
Kaxxgation. record of. 2.35 ; table of, 375.
Nelsoxi, Capt, TiWi. ;iS., death of, and memoir
of. 187.
Kew Orleans!, business men of, oppose jetties,
37 : ^entiment of, changed, 63.
Kew^^Orleans S, S. pa^ses through jetties,
Newton, Gen.^ John, on Board of 1874, 21. 247.
Newton, •'Vena Contracta" of, illustrated,
151.
Obstrxictions, natural, commerce imprisoned
by. 3 : history of attempts to remove, 17.
Oder, jetties of, 50.
Ohio river, de-cription of, 4 ; obstructed by
mountain ranges, 10.
Opposition, effects of, by government officials,
118.
Originality, claim of. by Board, 1878,194 ; dis¬
cussed by Eads, 195, 365.
Outlet, created and maintained by jetties. 1 ;
necessity for, 6, 7 ; permanent plans for
improving, 19; natural deepening of, ad¬
vised by Board, lb7'5, 255.
Palmetto-logs, used for cribs, 207.
Parapet on conciete blocks, 203.
Parinely, 0. D., death of, by yellow fever,
187.
Passes, dimensions of, 15 ; phenomena of, ex¬
plained, 32.
Pass à Lmdre selected by Board. 1874, 244 ;
less advantageous than S. Pass, 256.
Pass, South, estimate of jetties at, by Commis¬
sion, 61; Eads objects to, before Commis¬
sion. 63 ; course of, described, 70 ; width
of land on each side of, 70 ; bar of, de¬
scribed from U. S. Coast Survey, 72 ;
changes in, and materials scoured from,
229 ; selected by Board, 1875, 256 ; fitness
of. for navigation, 271, 272.
Pass, Southwest, bill for improvement of, re¬
ported favorably by House Committee,64 ;
channel of. nniintaiued by dredgeboais,
117 ; cost of maintaining channel, 202.
Patterson, C. P.. Supt. U. S. Coa4 Survey,
refuses to order survey. 98 ; refuses to
give result of survey seaward of jetiies,
lOl ; gives result by instructions from
House of Representatives. 102 ; letters lo
and replies by. 279, 280, 283, 284.
Payment of twenty-foot channel d<'layed,
146 ; of bills extended. 155 ; modification
in terms of, 193, 201 ; recommendations
of, by Board 1878 objected to by Eads, 201 ;
specified in grant, 262, 265 ; modification
of terms of, discussed by Board of 1879,
and Ead«, 339, 351 35:3, 361-363 : terms of,
amended by act March 3,1879, 368, 369.
Pay-rolls, overâue. 155.
Permanency, report on, bj'Commission, 1877,
168 ; 1876, 301 ; probable, 193, 350, 351,
357, 358.
Pier Head, east jetty. 208 ; plan for, advised
by Advison' Board, 269.
Physics and Hiidraulics, authority for state¬
ments, 15; objections of, to jetties dis¬
cussed by Barnard, 248.
Piles, distances between, 75 ; simply guides,
75 : jettj'. finished driving. 84; sheet, de¬
scribed, 84 ; washed ont, 85 ; length of,
on west jetty, 87 ; record of driving, 154.
Piling, alignment of, established, 75* on
river side of jetiies, 149.
Pilots opposed to jetties. 117.
Pi'ottown, residence of pilots, 117.
Pins, hickory. 78.
Poitevent <& Favre furnished lumber, 209.
Port Eads. Grafton arrived at, 75 ; vie'.,* of,
210 ; advantages of, 211.
INDEX.
383
President U. S. appoints Commission, 1876,
143.
Pi^ess, New Orleans, opposes Eads, 37.
Pi ices of James Andrews & Co."s contract
high, 67.
Publia lands., materials on, to be used, 264.
Ra'droad, construction of lines of, 6.
Jiainfall, average per annum, 378.
Becommendafions by Board of 1878, 193 ; of
Board 1879 reviewed by Eads, 363-367.
Peeds, dense growth of, on banks of pass, 70 ;
cut down for store-room, 82.
Beference, plane of, 71.
Äe/ie/* asked by Eads, May, 1878, 169.
Beprei^enfatiV'S, House of, directs Secretary
of Treasury to furnish result«, 101.
Bepnblic, Grand., steamer, 96 ; soundings ex¬
hibited on, 280, 291.
Besearch., schooner, arrived at South Pass,
1875, 71.
BesuUs kept secret by ofñcials, 107 ; at head
of passes, 183 ; permanency of, at jetties
discussed, 224.
Bhone, dykes of, described and their failure
discussed. 51, 52 ; dykes oUj 252.
Biver, MUsissippi, one of suidimest wonders
of Creator, 1 ; the great, only natural out¬
let to commercct, 3 ; uniforiu section of,
below Red River, 30 ; conditions of, below
New Orleans, 111.
Biver, Bed., description of. 5.
Bob^rfs, W. Miliior, member of Board 1875,
49 ; member of Advisory Board, 92.
Bdberfson, Hon. E. HI, leiter addressed to, by
Humphreys, May, 1878, 171.
Bubble-stone on crown of jetty, 208.
Bubble-wall on concrete blocks, 2j3.
Sand, size of particles of, 153 ; washed into
channel, 188 ; for concrete, 203 ; ratio to
water, 207.
Scantli'i'j, strips of, for mattresses, 77.
Schnillf, Max E, survey of, beyond jetties,
1876, 103 ; promoted, 147 ; concrete de¬
scribed by, 188 ; cribs described by, 203 ;
indorses Corthell's statement, 283.
Schurz, Hon. Carl, speech of, on composition
of commission or civil and military engi¬
neers, 2J.
Secretary of War, requests made of, by Eads,
105 ; appealed to by Ead-i, 116 ; payments
authorized by, 263 ; to report to Congress,
261.
Sediment, relation to velocity, 11 ; other laws
governing it, 12 ; amount transported by
Mississippi River, 13 ; total amount dis-
chaiged, 15 ; ratio of, suspended. 29 ; rela¬
tion to velocity stated by Humphreys, 43 ;
Eads's experience with, 45; relation to
depth of stream, 46 ; how carried by lit¬
toral current. 73 ; ratio to water, 217 ;
continuation of deposits of, 226.
Skipment-i, foreign, taole of. 235.
Sick^efi, T. E., member of Board 1875, 49;
member of Advisory Board, 92.
Sill, Pa-18 à Loutre, described, 176 ; detailed
cost of, 333.
Sill, S. W. reasons for construction of,
129 ; description of, 1.30-133 ; raised, 180.
Silts, classification of, proves law of depos-it,
34.
Spec'fications of act suited to S. \V. Pass, 168 ;
for cement, 204.
Spikes used in mattress strip«, 79.
Stanard, Gov., speech of, in favor of Eads's
bill, 1875, 64.
Steamers, increase of, 235.
Stirring, bar deepened by, 1853, 18 ; process
of, not sati.«factory, 255.
Stone thrown from jetty by waves, 188 : total
amount used, 209 ; where obtained, 209 ;
tt) be placed in store, 270 ; total amount
used, 332.
Storms, violent, described. 224, 225.
Strarißcation of bar ascertained, 152.
Stfipk mattress, 78.
Subsidence, jetties secured against, by loca¬
tion, 73 ; record and probability of, 227.
228 ; causes of, 228 ; discussed by Board
1879, 343 ; table of, 374.
compared with S. Pa«s by Humphreys.
41 : described and compared with S. Pa^s
by Hartley, 54-58.
System, Mis^issippi River, 1.
Taft, Alj)honso, legal opinion of, on head of
pass question. 145; letter to, and reply by
Ead.«, 278. 284.
Teredo navalis, effect of, 226 : effects of, dis¬
cussed by Board 1879» 351-358.
Tests, cement, 204.
ThertnometriCid, 378.
Tides, range of, 14 ; descril^ed, 85 ; plotted, 217.
Times, A. 0., publishes Eads's letter. 289.
Tow-boats, oppo-ition »»f, to jetties, 117.
Tower, Gen. Z. B.. on Board of 1878,191.
Tributary, each, of Mississippi, described, 3.
Tug, steam, used for towing mattresses, 79.
Xlndeimining, no danger of, 225.
Valley, Mississippi, compaiison of, with Euro¬
pean, 2 ; wonderful productions of, 2.
Vessels, drafts of, increased by jetties, 237.
View, bird's-eye, of Port Eads and jetties, 210.
Volume of water lost through jetties. 157 ;
normal, ïiearly restored, 184; increasing
in S. Pass not advisable, 200 ; norma!, can¬
not create maximum depth, 359 ; in S.
Pass should not be increased, 359.
Warren, Gen. G. K., on Board 1874, 21 ; mi¬
nority report of, 1874, 249.
W'lve, tidal, velocity of, 15.
Waves, force of, 206 ; effects of, upon works,
225 ; heiglit of, 225.,
Ways, mattress, shown in plate, 77 ; construc¬
tion of. hastened, 82 ; extent of, 82 ; con¬
struction of, at li< ad of passes, 179.
Wedges, oak, for nuittiesses. 78.
Weitzel, Gen. O , on Board 1874, 21, 243.
West, Hon. J. R., reported bill In Senate, au¬
thorizing Commission, 48.
Wharf Î01 concrete work described. 189.
Whitcomb, H. D., member of Board 1874, 49 ;
member Advisory Board, 92.
WUhivs, described, 76 ; carried in bundles,
77 ; total amount used, 209. 3"^2.
^Vindoln, Hon. William, letter addressed to by
Eads, 1874, 28.
Winds, influence of, on currents, 15 ; influence
of, on l)ank formation. 7'4 ; direction, ve¬
locity, and effects of, 377.
Wing dams, object of, 90; progress of con¬
struction, 90; description of, 99; raised
to surface, 149 ; extraordinary effects of,
149 , effect of, upon channel aevelopment,
157, 226.
Wotks, completion of, prepared for, 189 ; esti¬
mate for completion of, 191, 337. 344 346.
Wright, Gen. H. G., minority report of, 1875,
62 ; on Board 1876, 142 ; on Board 1877,
165 ; refers to Eads's letter, 170 ; on Board
1878,191 ; examined by Senate Committee,
1878. 200 ; favors canal. 260 ; reports on
Eads's letter, March 13, 1878, 313-319 ;
opinion of, discussed by Kads, 300, 361.
Yaiol, crew of, handled mattrc^ses, 79.
Yazoo, the description of, 5.
Yellow fever, epidemic of, at Port Ead«, 186.
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