THE
LOCOMOTIVE ENGINE:
INCLUDING
A DESCRIPTION OF ITS STRUCTURE,
RULES FOR ESTIMATING ITS CAPABILITIES,
ANI
PRACTICAL OBSERVATIONS ON ITS CONSTRUCTION
AND 5MAN'AGEMIENT.
BY ZERAII COLBURN.
BOSTON:
REDDIN-G AND COMIPANY, -NO. 8 STATE STI'EET.
1851.




Entered according to Act of Congress, in the year 181,
BY REDDING AND COMPA NY,
InL the Clerk's Office of the District Court of the District of IMassachusetts.




INTRODUCTORY NOTICE.
THE absence of any purely practical work on American Locomotives has induced the preparation of the
following pages devoted to that subject.  It is believed
the book will afford to the student a clear idea of the
nature and mode of application of steam power, while
to those engaged in the manufacture and operation of
engines it will afford much useful matter connected
with their construction and management.
MIuch care has been bestowed to render plain and
distinct those parts of the book which are devoted to
the principles of locomotive science, and the rules and
illustrations have been adapted to the wants of those
who have but little time or taste for the pursuit of abstract investigations. While this feature will constitute a chief merit of the work in the hands of such
persons, it will make it none the less definite and exact
for the purposes of the designer and engineer.




4              INTRODUCTORY'NOTICE.
The particulars of many recent eng(ines, and improvements connected therewith, have been presented,
embracing the patterns of a majority of all the builders
in the United States.  For many of these we are indebted to the manufacturers of engines, while others
have been procured for the purpose from the engines
themselves; those machines being selected which presentecl some new or favorable features in the proportions of their parts or in the arrangement of their machinery.
It is therefore hoped that the book may impart some
benefit to those who read it, and that it may serve to
this purpose until the appearance of a better one from
those whose opportunities for information would enable
them to treat the subject in a mauner more suited to
the various requirements of its nature.




T It E
LOCOMOTIVE ENGINE.
SECTION  I.
The Properties of Steam and the Phenomena connected with
its Generation.
THE most prominent of the properties possessed by
steam  are, its high, expansive force, its property of
condensation by an abstraction of its temperature, its
concealed or undeveloped heat, and the inverted ratio
of its pressure to the space which it occupies.
Steam is the result of a combination of water with
a certain amount of heat; and the expansive force of
steam arises from the absence of cohesion between and
among the particles of water.  Heat universally expands all matter within its influence, whether solid or
fluid; but in a solid body it has the cohesion of the
particles to overcome, and this so circumscribes its
effects that in cast iron, for instance, a rate of temperature above the freezing point sufficient to melt it,
causes an extension of only about one-eighth of an inch
in a foot.  With water, however, a temperature of 212~,
or 180~ above the freezing point, (and which is far
from a red heat,) converts it into steam of 1700 times
its original bulk or volume.




6            TIHE LOCOM OTIVE ENGINE.
All bodies may exist in either one or all of three
different states, viz.: the solid state, the liquid state,
and the aeriform state, or state of vapor.  Water, for
example, may exist as ice, liquid, and steam; and the
condition which it assumes depends on its pervading
temperature.
Steam cannot mix with air while its pressure exceeds
that of the atmosphere, and it is this property, with
that which makes the condition of a body dependent on
its temperature, that explains the condensing property
of steam.  In a cylinder once filled with steam of a
pressure of 15 lbs. or more to the square inch, all air
is excluded.  Now as the existence of the steam depends on its temperature, by abstracting that temperature (which may be done by immersing the cylinder in
cold water or in cold air,) the contained steam assumes
the state due to the reduced temperature, and this state
will be water.  And, as the water cannot occupy the
volume which it did under its former temperature, it
follows that its reduction in volume must remain a vacuum.  A  cylinder, therefore, filled with hot steam,
may be condensed by an abstraction of its heat, and a
vacuum will be produced in the cylinder with a few
drops of water at the bottom, which may be pumped
out by an air-tight pump, leaving the vacuum perfect.
When this principle is employed in removing the atmospheric pressure opposed to the back of the piston in
a steam engine, such an engine is termed a condensing
engine; and in such engines more work may be done
with the same pressure of steam, than by a non-condensing engine, as the absence of the weight of the air,
or the negative pressure on the back of the piston is
equivalent to a positive pressure on the other side, and
contributes by so much to the useful effect of the engine.  Locomotive engines, however, and most American stationary engines, discharge their steam without




TIHE LOCOMOTIVE ENGINE.
condensing, and to overcome the atmospheric resistance
they carry higher steam; they are therefore called high
pressure engines.
The next property of steam which we have mentioned,
is that of its latent or concealed heat.  An unknown
amount of latent heat exists in every element in
nature: thus iron becomes hot by merely hammering
it on an anvil; air gives off heat enough to light
fire by being compressed into a syringe, and so on.
The beating of the iron does not create the heat which
it excites, neither does the compressing of the air; they
both merely develop the heat, which must have a previous existence. In these examples the heat which is
excited is freed by the motion communicated, - and
we have no means of knowing its amount; — but the
latent heat of steam, though showing no effects on the
thermometer, may be as easily known as the sensible or
perceivable heat. To show this property of steam by
experiment, place an indefinite amount of water in a
closed vessel, and let a pipe, proceeding from its upper
part, communicate with another vessel, which should
be open, and, for convenience of illustration, shall contain just 5} lbs. of water at 32%, or just freezing. The
pipe from the closed vessel must reach nearly to the
bottom of the open one.  By boiling the water contained in the first vessel until steam enough has passed
through the pipe to raise the water in the open vessel to
the boiling point, (212",) we shall find the weight of
the water contained by the latter to be 6, lbs.  Now
this addition of one pound to its weight has resulted
solely from the admission of steam to it; and this pound
of steam, therefore, retaining its own temperature of
212~, has raised 5~ lbs. of water, 180~, or an equivalent to 990; and including its own temperature we
have 1202', which it must have possessed at first.
The sum of the latent and sensible heat of steam is




8             THE LOCOMOTIVE ENGINE.
in all cases nearly constant, and does not vary much
from 1200G.  It is from this property of steam  that it
becomes of such essential service in heating buildings;
one square foot of superficial surface of cast iron steam
pipe will keep 200 cubic feet of air at a congenial summer heat; but a square foot of the surface of a bar of
iron, of the same perceivable temperature, would scarcely
start the frost on the windows in a cold morning.
If a known volume of steam of a certain pressure be
made to occupy but one-half that volume, its elastic
force will be doubled; or, in other words, the same
pressure is exerted within one-half the original capacity.
By pressure we mean the initial elastic force of the
steam, which is always the same in equal weights of
steam, and which can only act with greater intensity of
pressure by restricting the area exposed to its action.
In fact, it is an established law of steam, and of all
elastic fluids generally, that the pressure which they
exert is inversely as the space oecupied; or, to be
more precise, it is very nearly so.  At the end of the
present section we shall give a table of the temperature
and elastic force of steam, which will show the exact
increase of pressure corresponding with any diminution
in bulk.
The elasticity of steam increases with an increase in
the temperature applied, but not in the same ratio.  If
steam is generating from water at a temperature which
gives it the same pressure as the atmosphere, an additional temperature of 38~ will give it the pressure of
two atmospheres; a still further addition of 42~ gives
it the tension of four atmospheres, and with each suecessive addition of temperature, of between 40~ and
50~, the pressure becomes doubled.  It is well for the
student of the steamn engine to know the reason of this
effect, and we will endeavor to explain it.  We have
already said that there is no cohesion among the parti



THE'LOCOMOTIYE ENGINE.             9
cles of fluids, but there is, however, an attraction
between all matter in nature. The action of heat in
generating steam has to overcome this attraction among
the particles of the water; and likewise the gravity of
the water itself. As the water becomes rarified by heat,
and either in its natural state, or as steam, occupies a
greater volume, this attraction is diminished, and also
the weight or gravity of the water; hence an additional
rate of temperature does not have to contend with the
same resistance as the temperature which preceded it,
and is, therefore, enabled to produce greater effects in
the generation of steam.
Among a variety of facts and notes relative to the
nature of steam, we select the following:If water be boiled in an open vessel, no temperature
greater than that for the boiling point (which for fresh
water is 212~,) can be produced in it. All the surplus heat which may be applied passes off in the steam.
If the vessel be closed, and the steam as it is formed
be retained within it, the temperature may be raised,
and retained in the steam.
If the steam, as it is formed, is allowed to accumulate in the boiler, its pressure on the water level makes
an increased temperature necessary to continue its production.
Steam, in itself, is invisible, and becomes visible
only upon condensation, as when a jet is discharged
into the open air; — its loss of temperature causes it to
condense, and we see it in the form of a vapory cloud.
In treating with steam, the term heat is understood
as expressing its sensible heat, while the term caloric
provides for the expression of every conceivable existence of temperature.
To explain the theory of ebullition, or boiling liquids,
we will observe that in metals, heat is communicated
by the conducting property they possess; but in liquids




10           THE LOCOMOTIVE ENGINE.
it is communicated by a circulation of particles. If
heat be applied to the bottom and sides of a vessel containing water, that portion of the water in contact with
the heated metal becomes heated and rarified, and consequently lighter than the rest, whereby it ascends to
the surface, gives off its vapor, becomes cooled, and in
consequence becoming heavier, descends, again to be.
come heated, rise, and descend as before, and to maintain these operations in a constant succession so long as
the heat is applied. This action is performed in vertical planes, and if the heat be applied above the bottom
of the vessel, the water below that point will receive
but little heat, and can never be made to boil.
An established relation must exist between the temperature and elasticity of steam; in other words, water
at 212~ must be under the pressure of the steam naturally resulting from that temperature, and so at any
other temperature.
If this natural pressure on the surface of the water
be removed without a corresponding reduction in the
temperature, a violent ebullition at the water-level is
the immediate result. Thus, suppose the entire steam
room in a boiler to be six cubic feet, and the contents of
the cylinder which it supplies to be two cubic feet; at
each stroke of the piston one-third of all the steam in the
boiler is discharged, and the surface of the water is consequently relieved from one-third of the pressure upon
it before that stroke.  The temperature remains the
same, but as it does not bear the natural relation to
this diminished pressure, it causes the water to boil
violently, and producesfoaming.  Foaming is a cause
of which priming (or working water along with the
steam into the cylinders,) is the effect. Provision must
therefore be made in all boilers, that they may have a
large extent of steam room"compared with the cylinders
which they supply.




THE LOCOMOTIVE ENGINE.               11
Another result attending the formation of steam is,
that when an engine is in operation and working off a
proper supply of steam, the water-level in the boiler
artificially rises, and shows by the gauge-cocks a supply
greater than that which really exists. This is owing
to the steam forming in the water and rising in bubbles
to the surface, and displacing by its bulk the amount
of water indicated by the rise at the gauge-cocks.  As
the production of steam  under the same temperature
cannot continue under an increased pressure, it follows
that when the discharge of steam is stopped, and its entire pressure is thrown on the surface of the water,
steam is no longer generated, and the water takes its
natural level.
At whatever point in a boiler steam be taken, there
is a determination of water to that point, which is occasioned by the sudden reduction in the pressure, owing
to the withdrawal of the steam.  This is the case with
all boilers having steam domes with throttles in the
same; and it was for this reason that on a new engine
lately constructed at the Eastern Rail Road Shop, at
East Boston, the steam dome was omitted, and in its
stead a steam  pipe, perforated on its upper side, was
extended the whole length of the boiler, occupying the
position usually given to the steam-pipe in ordinary locomotives.  The object of this was to take the steam
alike from all parts of the steam room of the boiler, so
that no rise of water should result at any one point.
NAotes. —One cubic foot of atmospheimc air weighs 527.04 Troy
grains, while an equal bulk of steam at 212~ weighs 258.3
grains; the specific gravity, therefore, of steam at the pressure of the atmosphere, and taking that of the atmosphere at
1, is.490.
The force of steam is the same at the boiling point of every
fluid.
27.104 cubic feet of steam at the pressure of the atmosphere,
equal 1 lb. avoirdupois.




12             THIE LOCOMOTIVE ENGINE
TABLE OF TIlE TEBIPERATURE AND  ELASTIC  FORCE OF
STEAM; ALSO  TIlE VOLUME  OF STEAM  GENERATED,
COMPARED  WITII THE  QUANTITY  OF  WATER  FROM
WIHICI IT IS RAISED AT DIFFERENT PRESSURES.
[Note.-Steam, raised from water at 212~, has no pressure
above that of the atmosphere, and can produce no useful eff'eet
except in obtaining a vacuum in a condensing engine. If admitted to one end of a cvylinder it would expel the air, ande
would there remain without producing any motion, unless the
pressure of the atmosphere on the back of the piston was removed. In this table we have therefore given the temperature
corresponding with the steam  at pressures (bove that of the
atmosphere. We would also here remark that the pressure in
a locomotive or other boiler, as indicated by the safety -dalve,
is the real pressure above the atmosphere, as the air presses
upon the top of the valve with the same force as a corresponding
pressure of steam within.  In a boiler showing,50 lbs. pressure
per square inch, by the safety valve, there is a pressure of 65
lbs. - 15 lbs. of which are expended in overcoming the pr essur e
of the air on the top of the valve. Therefore, the remaiqning
50 lbs., indicated by the valve, is the effective pressure for a
non-condensing engine, although a condensing engine would
realize nearly the full efIect of 65 lbs.]
Pressure in lbs. above   Temperature  Volume of steam comparthe atmosphere, and al-    in deg.    ed with that of the water
so including the same.   Fahrenheit.    from Twhich it is raised.
30 lbs. 45 lbs.    276.4                     610
40   "   55   "       289.3                  508
50   "   65   "       301.3                  437
60   "   75   "       311.2                  383
70   "   85   "       320.1                  34:2
80   "   95   "       328 2                  310
90   " 105   "        335.5                  282
100   " 115   "        342 5                  2,0(
110   " 125   "        349 0'24
120   " 135            355.1,25
130   " 145   "        360.7                  211
140   " 155   "        366.2                  198








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SECTION II.
A General Description of the Construction of the Locomotive
Engine.
HAVING illustrated the prominent properties of
steam, it remains to show in what manner its useful effect may be realized in the production of power for
locomotive purposes.   Any reader would be aware
that a locomotive must combine within itself the means
for the generation of steam, its application to produce
motion within the machine itself, and also the propulsion of the whole upon the road. A complete locomotive steam engine, therefore, combines three distinct
arrangements for realizing these  conditions.  The
source of power lies in the boiler and fire-box; the cylinders, valves, piston, and the connections, are the
means by which it is applied to produce motion within
the machine; and the wheels, by their tractive force or
adhesion to the rails, secure the locomotion of the machinery which impels them, and also, from their surplus
power above what is necessary to move the engine
alone, the draught of a great load upon the rails.  It
is therefore necessary to understand the construction of
each of these parts, and also the general arrangement by
which they are combined in the production of power.
A reference to the figure on the opposite page will
serve to show the construction of an ordinary eightwheeled engine, as divided in the direction of the
length of the boiler so as to show the entire machinery
for generating and applying the power.
The boiler, A, in which the steam is first produced,




16           TIHE LOCOMOTIVE ENGINE.
is of a cylindrical form, having a furnace or fire-box, B,
at one end, surrounded by a water casing, a, a, communicating with the boiler, and which is to prevent the
destruction of the plates of which the fire-box is formed
by the intense heat of the fire.  The plates which form
the outside of this water casing are united to the cylindrical part of the boiler, and form what is called the
outside fire-box.  This outside fire-box supports the
furnace or fire-box proper by a number of stay bolts,
seen at b, b; these bolts being screwed at their ends
into the sides of both fire-boxes.  C is the grate, the
bottom of the fire-box being open to admit the air necessary for the combustion of the fuel, and D is the door
through which the fuel is admitted. At c, c, are shown
a number of small copper tubes, their purpose being to
*convey the heated air through the boiler, from the firebox to the smoke-box, E.  The arrangement of these
tubes may be better understood by an inspection of Fig.
2, which shows the fire-box and boiler divided transversely across its diameter. They are very small, and
are placed so as to be but A of an inch apart in any
direction.  They are also very thin, so as to communicate the heat passing through them to the water
which surrounds them, and which generally stands four
or five inches above their upper or top row.  It is the
surface of the fire-box and the exterior surfaces of these
tubes that constitute the heating surface of the boiler.
That portion of the boiler above the water-level, (which
is shown by the dotted line,) is the steam room of the
boiler, and is occupied by the steam generated from the
water above and among the tubes and in the water
space around the fire-box. The forward compartment
of the boiler, or smoke-box, at E, receives the surplus
of heated air not communicated to the water, and the
gaseous products of the combustion of the fuel in the
fire-box; and the chimney, F, provides for their escape




THE LOCOMOTIVE ENGINE.            17
Fig. 2.
into the open air.  The draught of the fire through the
tubes is excited artificially by the escape of the steam
from the cylinders of the engine, the arrangement and
operation of which we shall explain hereafter.  This,
then, is the arrangement by which the power applied
to produce locomotion is first generated.  The peculiar
form given to the boiler, the contact of water with the
sides and top of the fire-box, and the great extent of
heating surface afforded by the disposition of the tubes,
secure the rapid production of a vast volume of steam
within very restricted limits. In future pages we shall
explain numerous details and appendages belonging to
the boiler, and shall give its best proportions, as, likewise, of every other part connected with the engine.
The second division of the entire arrangement of the
engine is that in which the power already generated is
applied to produce motion within the machine. Upon
2




18           THE LOCOMOTIVE ENGINE.
the top of the boiler a cylindrical chamber or dome, G,
is formed, and the pipe which conveys the steam from
the boiler, penetrates it as seen at H.   The object of
elevating the mouth of the steam feed-pipe is to prevent
the motion of the engine from throwing particles of
water into it, to be carried into the cylinders and to oppose a load to the motion of the engine.  The mouth of
this pipe is covered by a valve, provided with ports or
openings to admit steam within it, and the admission of
steam is governed by the motion communicated to the
valve, through its lever, g, rod, h, and starting lever, i,
without the boiler and accessible from  the footboard,
where the engineer or driver stands.  In the figure
this valve is represented open, and the steam is descending through the pipe, in which it passes along through
the partition between the boiler and smoke-box and down
through the branch-pipe, I, into the steam chest, J. This
steam chest communicates with each end of the cylinder,
M, by the passages seen in the figure, and steam  is
admitted through these passages' alternately to each
end of the cylinder by a sliding valve, seen at K. Within
the cylinder is a piston, L, against which the pressure
of the steam  is exerted to produce motion.  In the
position given to the valve, K, in the figure, the left
hand passage is open and is admitting steam to that
end of the cylinder, to press the piston in the direction
of the arrow. There is also a quantity of steam on the
right hand of the piston, which was employed in the
preceding stroke to force the piston to the left hand of
the cylinder; and its work being now done, it is escaping through the right hand passage, and turning in a
cavity in the under side of the valve into a third passage on the face of the cylinder, and which is situated
between the two induction  passages, already mentioned. The exhaust steam is carried in this last pas* Described as induction ports.




THE LOCOMOTIVE ENGINE.             19
sage a short distance around the cylinder, and passes
through an opening on the side of the same, into
the bottom of a vertical pipe, part of which is seen at N.
The mouth of this pipe is considerably contracted, as
seen in the figure, and the resistance given by this
contraction to the exit of the steam, makes it discharge
in a very forcible blast.  This powerful draught at the
mouth of the tubes excites the passage of the heated air
through them, and causes a great intensity in the fire.
Without this artificial draught the boiler could not,
from its proportions of fire surface, generate sufficient
steam to supply the cylinders.
We have seen the steam  entering by the left hand
passage within the cylinder, and impelling the piston
towards the opposite end of the same.  As the piston
approaches the right hand termination of its stroke, the
valve K is made to shift its position in the steam chest,
and to close the left hand passage, and likewise, by the
same motion, to open the opposite or right hand one.
The left hand passage is fully closed when the piston is
within three or four inches of the end of the cylinder,
and the right hand passage almost at the same instant
begins t6 open, so that the full pressure of steam is
exerted against the right hand side of the piston before
it actually has completed its stroke in that direction.
This advance of the valve on the piston is termed the
lead of the valve, and when confined within certain
limits is found to increase the speed of the engine, as
it allows the steam to act with a concussive force, like
that of a spring, at the ends of the strokes, so as to
lose no time in changing the motion of the piston.
When the piston has commenced on its return stroke,
and while it is in its motion, the valve moves likewise
in the same direction, uncovering the right hand passage more and more, until, when the piston has returned
to the position shown in the figure, or to the middle of




20           TEIE LOCOMOTIVE ENGINE.
the stroke, this passage is fully open; the same as the
left hand passage shown in the figure to admit steam
for the preceding stroke.  The motion of the valve has
transferred the cavity on its under side to the left hand
passage, and the steam, which during the preceding
stroke was admitted through that passage, will now discharge through it, and pass into the exhaust port and
up the exhaust pipe, N, as already described.  By the
time the piston has reached the middle of its stroke,
the valve will have reached the end of its motion on the
face of the cylinder, and will begin to move the contrary
way, so that during the last half of the stroke of the
piston, the piston and valve move in opposite directions.
The cavity on the under side of the valve, in which
the steam turns from  the induction into the eduction
port, must receive such a width of opening as to allow
the exhaust steam to commence its escape from one end
of the cylinder before steam is admitted to the opposite
end; so that if, for instance, the lead of the valve on the
induction side be ~1 of an inch, the exhaust must have a
lead of about 4 inch. In other words, when one steam
port is taking steam through I of an inch, the other
port must be discharging steam through -4 of an inch.
This is necessary for the free escape of the steam, that
it may oppose no load to the progress of the engine.
We are now to show how the motion of the piston is
communicated to the wheels, and in what manner the
sliding valve, K, is moved within the steam chest, so as
to regulate the admission of steam to the cylinder; and
to guard against any misconception on the part of the
reader, we will say here that there are two steam chests
and two valves and cylinders, together with two entire
but similar arrangements for communicating the power
exerted against the pistons to the wheels. The figure
does not admit of the representation of but one engine,
(the cylinder and its valve and piston being the engine,)




THE LOCOMOTIVE ENGINE.             21
the other being behind the one we have shown. The
steam pipe, H, after passing through the partition between the boiler and smoke-box, is divided into two
smaller pipes, one of which conveys the steam to each
cylinder.
Within the centre of the body of the piston is keyed
the rod, P, which passes through a stuffing-box in the
cover of the cylinder, and is attached at its other end
to a cross-head having a pin or bearing for a connecting rod.  This cross-head is also attached to guides to
ensure the motion of the piston-rod in the line of the
axis of the cylinder.  The connecting rod, r, takes hold
of this pin at one end, and at the other to a wrist or
bearing of the crank axle, s, upon the extremities of
which axle, are keyed the driving wheels of the engine.
As there are two cylinders and connecting rods, there
are necessarily two cranks in this axle, and they are
placed at right angles, one with the other, so that one
piston may be exerting its entire force against it, while
the other is changing the direction of its motion, and is
exerting but comparatively little power.
The alternate motion of the pistons is thus converted into a continuous circular motion, and it is from this
motion that the movement for operating the valves is
derived in the following manner.  Four eccentric pulleys, the action of which is the same as that of short
cranks, are affixed to the axle between the two cranks.
There are two eccentrics for each cylinder; one being
set at such an angle with the crank for that cylinder as
to give the proper motion to the valve for a forward
motion of the engine, and the other to produce a backward or retrograde motion. These eccentrics are encircled each with a brass strap, to which is attached a rod, t,
having a hook at its remote end. At u, is a rocker
shaft provided with arms on its upper and lower sides.
If the hook of the forward eccentric rod be dropped on




22           THIE LOCOMIOTIVE ENGINE.
a pin in the lower arm, the motion of the forward eccen
tric will be communicated to the valve through the
rocker shaft, u, and its upper arm, and the valve stem,
v. And so of the hook in the backward eccentric rod.
Another shaft mounted with arms or camnbs, and governed by a lever within reach of the engineer, is made to
throw out either the forward or backward or all the
hooks in the eccentric rods.  This shaft is laid immediately beneath the hooks, and traverses in the same
direction as the rocker shaft, Ut.
It will now be easy to trace the operation of the steam,
and of the machinery put in motion by its action on the
piston.  The throttle valve at the mouth of the steam
pipe, H, being open by the lever, i, the steam will be
admitted to within the pipe, and will descend through it
and through the branch pipe, I, into the steam chest, J.
From here it will find its way into the cylinder through
whichever passage that may be open, and as that is here
the left hand one, it will be admitted to press against
the left hand side of the piston, and to move it towards
the opposite end of the cylinder, by which time the
right hand passage will have been open to admit steam
to force the piston back again. The motion of the piston
will be communicated to the axle of the driving wheels,
through the piston rod, p,connecting rod, r, and crank, s;
and the motion so transmitted will cause the eccentrics
to turn, and by their motion to operate the valve
through the eccentric rod, t, rocker shaft and arms, tt,
and valve stem, v, so as to maintain the admission of
steam to the cylinder in the manner described.  The
driving wheels, as they are turned, will by their adhesion to the rails move along the engine and its load;
and the constant recurrence of these motions in the
piston, valve, and their subordinate connections, will
maintain the action necessary to produce this required
progressive motion of the machine.




THE LOCOMOTIVE ENGINE.              23
Of the remaining parts of the engine, O shows an additional pair of driving wheels, connected with those fixed
to the crank axle, and turning with them. The object
of this second pair of wheels is to obtain a greater adlhesion to the rails than with only one pair, and also to
relieve the principal pair of drivers friom  the great
weight of the engine, which would otherwise come upon
them-at least, all that portion not supported by the
truck wheels, T. The drivers on the crank axle generally have plain rims, while those on the hind axle
have flanges on their inner sides, as likewise the forward
or truck wheels, in order to keep the engine on the
the rails.  The four forward wheels are combined in a
separate frame which turns around a pintal secured to
the body of the engine, and is to facilitate the passage
of the engine around curves.  There are springs over
the bearings of the wheels to relieve the engine from
shocks arising from inequalities passed over on the
rails.  There are pumps which are not shown in the
figure, for supplying the boiler with water, as it is evaporated in the production of steam.  These are of the
forcing kind and are attached to the cross-head or to
a pin on the outside of the driving wheels.
The boiler is provided with a pair of safety valves to
provide for the escape of steam when it attains an unnecessary pressure, and the engine has also a whistle
and bell for alarms and signals.  Many recent engines
have expansion or cut-off valves, the use of which we
shall hereafter explain.
From what we have said we believe any one may
acquaint himself with the general arrangement and
operation of the locomotive engine.  Our remarks on
future pages will explain various details which would
embarrass the reader on a first introduction to the
machine, but which will serve to extend his acquaintance
after he has mastered the leading principles of its




24           TIHE LOCOMOTIVE ENGINE.
action. The principal features of the engine, including
the construction of the boiler and the operation of the
steam in the cylinders, are universally the same, but
there are various modifications in the arrangement of
the subsidiary machinery, which distinguish the engines
of different builders, without affecting, however, the
purposes for which they are employed.




SECTION III.
Details of the Locomotive Engine. The Boiler and its Appendages.
THERE are several essential requisites which locomotive boilers must possess, among which are strength,
lightness, and efficient qualities for the production of
steam; and these requisites can only be obtained by
giving very particular attention to the material of which
a boiler is made, and of the manner in which it is manufactured.
Owing to the diminished strength of large boilers
compared with small ones, the diameter is very rarely
made greater than 4 feet outside of the iron. The
plates of which the cylindrical part of the boiler and
the fire-box are formed, are from T% inch to A inch
thick. Lowmoor iron is generally preferred; and the
quality of the iron is determined by its general appearance and its established reputation among builders and
others. We have, however, much American iron of a
very excellent quality, which comes to the boiler maker entirely warranted by responsible dealers. Angle
iron is often used to connect the cylindrical part of
the boiler to the outside fire-box, and to the smoke-box.
The selection of this iron requires some skill and experience, as much of it is liable to be reedy in its structure;
and for this reason some builders obtain the proper
flanges for joining the boiler to the fire and smoke
boxes by turning over the edge of the boiler plate of
which the shell is formed. The rivets about locomotive
boilers are from i inch to 3 inch in diameter, and have




26           THE LOCOMOTIVE ENGINE.
a pitch of 1 inches, more or less.  The stay bolts to
secure the inside fire-box are for the most part 3 inch
in diameter, and 4~ inches apart.  These stay bolts
are tapped  into the  inside  and outside fire-boxes
and are then riveted at each end.   Their diameter
and number should depend somewhat on the width of
the water space around the fire-box; for if this be pretty wide, they must necessarily be long in proportion to
their diameter. The usual number of stay rods in a
boiler is 6 or 7 for a 40-inch boiler, and a greater
number as the diameter of the boiler is increased.
These rods are 7 inch to an inch in diameter, and are
tapped through the back sheet or sheet next to the footboard of the fire-box, and through the back sheet also
of the smoke-box, and then have a large nut screwed
tightly up at the smoke-box end, (there being a head at
the fire-box end,) and having a little red lead putty
interposed between the nut and the boiler plate to insure a tight joint.  Some makers employ right and left
nuts in these rods, to draw them up to a proper strain,
but these are hardly necessary.  The bars to stay the
crown of the fire-box are generally 5 or 6 in number,
and are 2 inches thick, and from 2- to 3 inches deep.
These bars must rest upon the top of the fire-box only
at their ends, a space of _ to 3 inch being left all along
their under edges, to prevent the crown sheet of the
fire-box from becoming burnt through, owing to an absence of water at those points. At the points, however, where they are riveted to the crown sheet, washers
or thimbles must be placed in this space for the rivets
to pass through, in order that they may have a bearing
and not spring up the crown sheet.
In all ordinary boilers where wood is used as fuel,
all parts of the boiler, with the exception of the tube
plate at the fire-box end, are formed of iron.  These
tube plates, by many makers, are made of copper.




THE LOCOMOTIVE ENGINE.            27
Hinkley's tube plates are 3- inch thick. In Winans'
Coal Engines, however, the fire-box is made of i inch
copper, and the tube sheet of 1 inch iron.  The tubes
are also of wrought iron.
The tubes in wood engines are made mostly of No.
14 copper, their outside diameter being usually 13 in.
Wrought iron thimbles for tubes are used by most builders, generally at the fire-box end, but in some cases at
both ends of the tubes. We could point to some engines having no thimbles at either end of the tubes,
and which show as tight joints as many engines having
thimbles.  Much, indeed, depends upon the management of a boiler. If an engineman is in the habit of
putting out his fire by throwing two or three buckets of
water into the fire-box on every slight emergency, or
running with the door open to regulate the fire, the contraction produced in such cases by the sudden cooling
of the flue sheets often works nearly every tube loose.
A method of tightening tubes has been used by the
Lowell Machine Shop, which has given good results.
It is to take a short piece, say 2 inches in length, of
No. 14 copper tube, and of such diameter as to allow
of its just sliding into the mouth of the boiler tube; it
is firmly united to the latter by a brazed joint an inch
long.  What remains of the short tube projecting out
is passed through the tube sheet, which is drilled to receive it, and the portion projecting beyond the tube
sheet, is then turned over and headed in the usual manner. This brings the end of the boiler tube up to a
tight bearing with the inside of the tube sheet.
With long copper tubes it is sometimes deemed advisable to give them a middle bearing, for which purpose a sheet is placed midway of their length and passing up high enough to support the top row.  Our
opinion, however, is, that these intermediate flue sheets
intercept the circulation of the water, and in some cases




28            TtIE LOCOMOTIVE ENGINE.
occasion priming.  We have observed this to be the
case in some of Norris's engines, which, having tubes
10 ft. 8 in. long, were provided with these extra supports.
The braces which support the boiler and serve to
connect it to the frame, are made either round or flat.
When made round, they are made about 24 inches in
diameter, and are turned, which adds much to their
appearance.
The angle iron which secures the fire-box to the frame
should extend the whole length of the fire-box, if there
is nothing in the way to prevent it.  It should be screwed tightly to the frame, and the screws to fasten it to
the fire-box should pass through the water space, being
tapped through both sheets.  The heads of these screws
should project outward considerably, as they are difficult to unscrew when it becomes necessary to remove
them. There should be two rows of screws passing
into the fire-box, one above the other; and the distance
between the screws should be just sufficient to enable a
wrench to be readily introduced to turn them.
The grates are always of cast iron, and are generally 4 inches deep at the center.  Their thickness is about
8 of an inch on their upper edge, and 3 inch at the
bottom.  The space between them  is -a inch.  We
know of one or two engines which were found to make
steam -much better by placing a piece of plate iron, six
or eight inches wide, across the fire-box at that end of the
grates next the tube sheet.  By admitting air through
the whole extent of grate surface, a large quantity of
cold air naturally passes up close to the side of the firebox, below the tubes, the draft being strongest there,
and, from not passing directly through the fire, escapes
into the tubes before it is properly heated.  As this
cools the tubes, it consequently checks the formation of
steam; therefore, by not admitting the air beneath the




THE LOCOMOTIVE ENGINE.           29
ends of the tubes, but causing all the air to pass directly through the fire, it was found that more steam could
be produced with the same fuel.
The grate should be a very few inches above the bottom of the water space around the fire-box, in order
that the water below it may remain quiescent and collect any sediment that may deposit itself there.
The junction of the inner and outer fire-box at the
bottom of the water space, is made with a bar of wrought
iron 1 1 inches thick, having rivets passed through it and
headed on the outside of the fire-box sheets.  Some,
however, bend the sheet of the inner fire-box outward,
until it meets that of the outer fire-box, and then rivet
them together.  This method, though cheaper, does not
allow the water spaces to be so readily cleared of mud
and deposit.
Norris and some other southern builders construct
their boilers with the top of the fire-box worked into a
hemispherical form, and having a small cast iron dome
placed upon the top.  This makes a very high dome,
and gives a large amount of steam room, but this form
of fire-box has several disadvantages, among which is
the extra expense of a boiler constructed in this way,
there being work about the fire-box which can be done
only by very skilful workmen, and requiring much
more riveting. Again; the height of the dome is liable to make the engine top-heavy, which, in engines
having large wheels, and having the boiler set pretty
well up, is quite a serious objection. The dome, also,
from exposing so large an extent of heated surface,
makes the interior of the " cab," over the footboard, insufferably hot, which is by no means a trifling matter to
a man who has to stand in its heat for several hours
together.  With all this the size of the dome obstructs
the look-out of the engineman, and the diagonal brace
necessary to steady it, lies directly in his way.  With




30           THE LOCOMOTIVE ENGINE.
all these objections against it, this form of dome can hardly
be said to possess any advantages over the old-fashioned
wagon-top fire-box, having a low cylindrical dome;
although it is generally considered that drier steam can be
worked from a' dome boiler," as these boilers are termed.
Hinkley forms a cylindrical dome, about 22 inches
in diameter and 18 inches in height, about midway on
the boiler between the fire-box and smoke-box.  This
dome has a cast iron cover of sufficient thickness to
withstand the pressure of the steam, and of such size
that the aperture which it closes may admit a man to
the interior of the boiler.  The steam pipe and throttle
are placed on one side of the dome, so as not to obstruct
the passage.  The dome is made of the same iron as the
shell of the boiler, is lagged, and covered with sheet
iron in the same manner, and has a thin cast iron base
and cap.
It is believed by many that a point near the smokebox end of the boiler is the most favorable place from
which to take the steam, as it is considered that the
water is not in so violent a state of ebullition at that
point as at the fire-box end.
Locomotives generally have two safety valves; one
of 21 inches in diameter, next the footboard, and one
of 31 in. diameter, at the forward end of the boiler.
We see no reason for this difference of size, unless the
safety valve next the footboard cannot have a lever long
enough for a larger valve without it projects out in the
way oL the engineman.  The lever could be turned to
one side, and thus admit the use of a larger valve.
Large valves of 3I inches or 4 inches in diameter are
less liable to stick, as their bearing surfaces increase
only directly as their diameters, while the pressures
upon them increase directly as their squares. Thus a
four-inch valve has but twice the bearing surface or
circumference of a two-inch valve, while the pressure




THE LOCOMOTIVE ENGINE.            31
on it would be four times greater. A mitre bevel,
which is the bevel usually given to the safety valves,
seems too sharp. Were the bevel an angle of about
30, that is to say having 4 inch depth to - inch width
of valve seat, there would be no difficulty with the valves
as to sticking.
The whistles used on many locomotives are of very
heavy tone, and are 6 inches in diameter.  These whistles have a valve stem passing down through the centre
and operated by a bent lever outside. The exit passage of the steam from the lower cup, should be about
3h inch in width, while the bottom of the upper cup
should be chamfered on the inside so as to bring it nearly
to a sharp edge. This sharp edge of the upper cup should
be placed directly over the annular opening in the lower cup, that the steam from the latter may impinge directly upon it. A whistle 41 inches in diameter, and
of the composition of which clock bells are made, gives
a very clear and sonorous sound. The upper cup, however, is most commonly made of sheet brass or copper.
The spark arresters in general use on New England
locomotives are the common bonnet sparker, the Patent
sparker of French and Baird of Philadelphia, and
Cutting's sparker. The bonnet sparker is the most
common. A chimney of sheet iron, about 4 feet in
height, is placed over the opening in the smoke-box,
and a curved cast iron disc is placed immediately over
this chimney. The cinders and sparks projected by
the blast pipes against this disc, receive from the form
given to it a change in their motion, which throws them
down between the bottom of the chimney and the outer casing surrounding it. The smoke and steam also
receive this motion, but readily rise, and, passing around
the disc, come out through a wire netting at the top,
This wire netting is to throw down such sparks as might
have been carried with the steam, and would otherwise




32           THE LOCOMOTIVE ENGINE.
have been thrown out upon the track, becoming a source
of danger to bridges and buildings along the line.
A pipe sometimes leads from the bottom of the outer
easing of the sparker to a spark-box on the front or
sides of the smoke-box. This box, we believe, is termed~
the " Sub Treasury."
French and Baird's sparker, and Cutting's sparker,
are not in so general use as the bonnet sparker, and
could not be readily understood without the aid of engravings showing their structure.
The opening made for the chimney in the top of the
smoke-box is about the same size as the diameter of the
cylinder of the engine. The following rule, however,
will be found to apply in all wood engines: Divide
the number of square inches in the grate by 7.5, and the
quotient expresses the area of the chimney in square
inches.
Example.  What should be the diameter of a chimney for a boiler having a grate 34 inches by 35 inches?
34
35
7.5)1190(158.6, Area of chimney.
And by calculation we find the nearest corresponding
diameter to this area to be 141 inches.
The ash pan of a boiler is a plate iron tray, suspended by hooks or latches to the bottom of the fire-box,
and should have a clear depth of 9 inches-the front
side being left open to admit the air to the grates.  The
mouth or open side of the ash pan should be provided
with a wire netting, and a damper of plate iron turning on a hinge should be fixed to draw up at pleasure
by a small chain passing up to the footboard.
The gauge-cocks are three in number, and are on
the hind sheet of the fire-box, within reach of the en



THE LOCOMOTIVE ENGINE.           33
gineman. They must communicate with the boiler at
such a point, that should the water chance to fall a trifle below the lower cock, the upper row of tubes shall
not be uncovered. In ascending a grade of 80 feet per
mile, the water at the fire-box end would stand two
inches higher above the tubes than at the smoke-box
end; the gauge-cocks should therefore communicate with
the boiler at so high a point that neither end of the
tubes could become uncovered under any ordinary circumstances without their giving warning of it.
The English have always used glass gauge-tubes in
addition to the three gauge-cocks, but one tried on an
engine on the Maine road broke in the first trial.  To
stand the action of the steam, the interior of the tube
should be round, not formed like a thermometer tube,
and the bore of the tube should not exceed -6 inch;
the glass should be thick and well annealed, and there
should be an expansion joint at the upper end of it.
If these conditions are observed, glass gauge-tubes can
be used here as well as in England.
The blow-off cocks of locomotives should be on the
back side of the fire-box, to prevent the steam and
water escaping by them from blowing up sand into the
bearings of the engine.
The mud-hole plugs are of brass, and are about 13
inches in diameter, and are tapped into the outer firebox at the bottom of the water space. They should
have stout square heads, as it is very difficult to turn
them out when they have been a short time in use.
Having thus explained the details and uses of the
boiler and its appendages, we will proceed to give the
proportions adopted by different makers.
The table of dimensions given on the next page includes two of Hinkley's patterns, two of the Lowell
Machine Shop engines, and also of Souther's 15 in.
cylinder pattern.
3




PRINCIPAL DIMENSIONS OF FIVE DIFFERENT PATTERNS OF LOCOMOTIVE ENGINES.            c
Builders.      Boston Loc. Wks. fIinkley&Drury. Lowell Machine Lowell Machine  John Souther.
for 6 feet gauge.             Shop.        Shop.    John Souther.
Diameter of Cylinder,     15 in.       132 in.      15~ in.       14 in.     15 in.
Stroke of Piston,         20 "         20  "        18  "         18 "       20 "
Diam. of Drivers,         5 feet.      4-l feet.    51 feet.       5 feet.  5 feet.
Diam. inside of Boiler,    44 in.      37 in.       43 in.        40 in.     42 in.
Length of Tubes,         11 feet,      9- feet.    11 feet.       10 feet.  101- feet.
Number of do.              141            88          140         119          135
Outside diam. of do.       13 in.       2 in.        2  in.       2  in.     1 in.
Length of Grate,          36  "        30 "         31  "        34  "       37  "
Width      do.            40  "        39"          36  "        35  "       37  "
Depth of Fire-box,        50- "        36"          53 " 48  "               53 
Tube Surface, sq. feet,   710.9       437.5       806.3        623          649.42
Fire-box, "               56.74        39.33        56.4        52.67        60.8
Area of Grate, "           9.74         8.12         8            8.25        9.63
Water Room, cub. feet,    69.6         40.6         69.0        56.6
Steam   do     "          41           32.1         41.5        33.2
Size of Steam Ports,  10TN- x 1 i in.             10 x 1 in.  10 x 11 in.   9 x 1
" Exhaust do.   101 x 16 X      "               10x 2-"   10 x 2   "    97 x 1:
Position of Cylinders,    inside.      outside.     inside.     inside.      inside.




THE LOCOMOTIVE ENGINE             35
The 15-inch cylinder machines built at Taunton have
726 sq. ft. of tube surface, 11.23 sq. ft. of grate, and
steam ports 14 by 1 in. The performance of these engines (with blast pipes 23 in. at the mouth) is very
superior. The Taunton Company give the largest proportion of heating surface to a given capacity of cylinder
of any of the engine builders in New England.
In giving the fire-box surface, we have reckoned
every inch of surface above the grate, deducting only
for the tubes and the door. It is of course plain that
all this surface is in contact with the water in the
boiler, although it is customary among engineers not to
include any portion of that side of the fire-box next the
tubes as heating surface.
It will be seen from the table that Hinkley's 15inch cylinder engine has the greatest extent of heating
surface, compared with its capacity of cylinder, of the five
engines given; and as the proportions adopted appear
to answer very well, we will give the multipliers which
will give the same proportions for any other size of
cylinder.
Multiply the square of the diameter of the cylinder
by 3.159, to get the heating surface of the tubes:
by.252, to get the heating surface in the fire-box:
by.0433, to get the area of grate:
by.309, to get the cubic feet of water room in the boiler:
by.182, to get the cubic feet of steam room in the boiler.
All the engines of which proportions are given in
the preceding table, have four driving wheels and
fruck, with the exception of the engine by Hinkley &
Drury, having 133 inch cylinders; — this engine has
four driving wheels, upon which the whole weight of
the engine rests.
An engine lately constructed by Robert Stephenson
& Co., Newcastle upon Tyne, England, may be taken
in comparison with the foregoing.




36           THE LOCOMOTIVE ENGINE.
This engine had two pair of 5-feet drivers, and one
pair of leading wheels:
14-inch cylinder:
21-inch stroke:
50 square feet fire surface in fire-box:
9.91.... "  on grate:
640    "    "  "       "  in tubes:
76.86 cubic feet water in boiler and around fire-box:
43      "   " steam in boiler and dome:
7.5    "   "  steam used at one rev. of drivers.
As a further illustration of English locomotives, we
will give the dimensions of an engine built by Bury,
Curtis and Kennedy, of Liverpool, for the Birmingham
and Shrewsbury (narrow gauge) Railway.
15-inch cylinder; 20-inch stroke; one pair of 5 ft.
7 in. driving wheels; one pair 4 ft. 1 in. leading, and
one pair 3 ft. 7 in. trailing wheels.
Boiler shell 47 inches, smallest inside diameter, and
containing 172 1l-inch tubes, 11 ft. 6 in.l ong. Grate,
501 in. long, by 42 in. wide, and 55 inches from crown
sheet.
Induction ports, 12 by 1 —- in.  Exhaust port, 3-'
in. wide.  Single blast pipe, 41 in. at mouth.  Cylinders, 231 in. between centers.  Bearings of driving
axle, 8 in. long, and 7 in. in diameter.
The heating surface of locomotive boilers has of late
years been considerably increased, not only having been
extended with the enlargement of the cylinders, but in
a much higher ratio. In some recent 17-inch cylinder
engines, constructed at Taunton, for the New York and
Erie Railroad, the fire-box surface included about 90
square feet, while the tube surface fell but little short
of 1000 superficial feet.
We will add a few particulars of an engine for burning bituminous coal, which was constructed for the
Baltimore and Ohio Railroad, by Thacher Perkins,




THE LOCOMOTIVE ENGINE.            37
master of machinery on that road.  The performance of
this engine during the year 1849 was upwards of
23,000 miles, and was higher than that of any other
first class engine on that road for the same time.
The diameter of the cylinder was 17 inches; stroke
of piston 22 inches; four pairs of driving wheels having
chilled tires 43 inches in diameter.  The diameter of
the boiler was 44 inches, and there were 125 wrought
iron tubes, 12 feet 6 inches long, and 2- diameter at
the fire-box end, and 2o diameter at the smoke-box
ends of same. The grate was 37- inches long, by
41 inches wide, and the inside depth from crown sheet
to grate was 50 inches.  Attached to the boiler of this
engine was the patent apparatus for heating the feed
water by the surplus exhaust steam of the engine, which
was invented by Mr. Perkins.  The exhaust steam
from both cylinders enters a square box in the center
of the smoke-box. In this box is a movable valve by
which the steam can be discharged through the ordinary
blast pipes, or turned into a pipe leading to a steam
casing surrounding the smoke-box.  This pipe also
continues along beneath the boiler, and is united to a
steam belt surrounding the same at the fire-box end,
and from which the steam finally escapes through a
pipe for that purpose.  The feed water can be admitted
directly to the boiler, near the fire-box end of this pipe,
or, which is intended in running, it can be pumped
into a casing surrounding this pipe, from whence it
passes into a water casing surrounding the smoke-box,
and within the steam casing already mentioned.  From
here it passes into the boiler a little below the water
level, at the smoke-box end.  In this arrangement the
movable valve in the steam-box can be regulated to
discharge steam enough through the blast pipes for all
ordinary purposes of draught, and also to maintain a
flow of steam through the pipe beneath the boiler,




38            TtIE LOCOMOTIVE ENGINE.
The feed water receives a large portion of the heat of
this steam, from its contact with it in the casing surrounding the pipe, and, retaining the heat so obtained,
it passes into the water casing in the smoke-box, where
it is exposed to the heat of the waste steam on the outside, and to the temperature of the smoke-box within.
It thus, when finally admitted to the boiler, has become
heated quite to the boiling point, as the heat within the
smoke-box of a coal engine is very great, even with long
tubes.  This arrangement operates as a variable exhaust
by allowing any portion of the waste steam to be turned
off from the blast pipes; it effects a considerable economy in fuel by giving the water to the boiler already
heated very hot; and the water casing surrounding the
smoke-box prevents the destruction of the latter by the
heat emitted from the tubes.
In the details of this engine the expansion valve was
worked from the backing eccentric, and one lever sufficed for reversing the engine and throwing on the cutoff.  This was effected by making the cut-off rocker
arm work as a shell on the main valve rocker shaft, the
cambs for throwing out all the hooks being on the same
camb shaft, and that for the forward hook being only a
quarter camb, so as to allow that hook to be on its pin
in the rocker arm in two positions of the reversing lever;
that is to say, going forward with the cut-off on, and
forward with it off.
The patent for the heating apparatus described, is owned by
L. B. Tyng, of Lowell, who has drawings and models showing
the application of the same to coal and to wood engines. For
coal engines some arrangement of this nature seems obviously
necessary, while for wood engines having a large extent of tube
surface, with moderate length of tubes, the application of this
invention appears to promise a considerable economy in fuel.
The apparatus may be simplified in wood engines by pumping
the water directly into a single casing about the smoke-box,
and withdrawing the contact of the exhaust steam by suffering
it to pass entirely up the chimney.




SECTION IV.
Details of the Locomotive Engine continued. Of the Cylinders,
Steam Chests, Valves, and Steam Pipes.
THE casting for a cylinder must be perfectly sound;
and this, indeed, is requisite for all the castings of a
locomotive.  The thickness of a cylinder, after boring,
is from 4 to; inch, and about -y3, inch are taken off
all around by the cutter of the boring bar. No cylinder can be truly and accurately bored in a boring
lathe, unless the latter be strong and steady.  The
thickness of the flange of the cylinder is 11 inch or more.
The flange by which itis secured to the frame is 1 I inches
thick, and as long as the distance between the flanges
to which the cylinder heads are bolted. Four or five
one-inch bolts are sufficient to secure this flange to the
frame.  The cylinders are generally cast separately,
and are united by a bar of iron 4 by 11 inches, bolted
to a projecting flange on each.  In one or two instances
we have seen them cast together, but this method
makes rather an awkward casting to mould, to bore,
and to fit, yet it removes the artificial connection which
is otherwise necessary.
The faces of the cylinder and valve require to be
ground perfectly smooth and flat, which is done by closing the ports with blocks of wood, as also the cavity in
the valve; they are then ground together with fine
sharp sand and water, finishing off with emery and oil.
The stuffing boxes for the piston rods and valve stems
require a brass lining filled with Babbitt metal. The




40           THE LOCOMOTIVE ENGINE.
valves are generally of cast iron, but sometimes of
brass.
The valve stem in Hinkley's engines is laid in a
deep recess in the upper side of the valve, and has nuts
and check nuts screwed against each side of same.
The valve is sometimes encircled by a wrought iron
hoop or spectacle ~ inch in thickness, but increased to
11 inches on one side, and has the valve stem tapped
into it.
The expansion valve is often worked directly on the
top of the port valve. When no expansion is sought,
the cut-off valve rod is placed in connection with the
port valve rod, and, acquiring the motion of the latter,
is relatively at rest with it.  Other makers have the
cut-off valve over the port valve, and in the same chest
with it, but interpose a plate with valve ports between
the two valves.  It is, however, difficult to get at the
valves where they are so placed, unless the engine has
outside cylinders, or has its steam chest covers taken
off from the outside.  Hinkley's latest engines have
covers on the side of the valve chest, which are removed from the outside of the smoke-box.  But the
opening on the side of the chest is no larger than to
allow of taking out the valve, not being large enough
to allow of setting the valves when it becomes necessary to do so, except by taking off the entire chest. In
Hinkley's engines, the cut-off valve, when not required
to be used, is thrown entirely off the ports, to prevent
any obstruction to the passage of the steam. This is
effected by an arm on the reversing eamb shaft, which,
when the cut-off hooks are thrown out, throws the lower
rocker arm, which works the cut-off valve, entirely
over, and carries the valve off its ports.
The valve seat requires to be slightly raised above
the face of the casting on which it is formed, that any
foreign substance received by the steam pipe may be




THE LOCOMOTIVE ENGINE.            41
pushed off by the valve without scratching the valve
face.
Steam chests are generally of a square or oblong form,
and in inside cylinder engines are enclosed within the
smoke-box.  In Souther's engines, however, the steam
chest is round, and projects outward, so that the valve
face is inclined at an angle of about 450,-the smokebox being made round, as a continuation of the boiler.
By this arrangement he secures the advantage of a
ground joint for the steam chest cover, and ready
access to the valves of the engine.  A ground joint is
cheaper than a filed joint, and better than a putty
joint. The cylinders and chests, however, from not
being enclosed in the smoke-box, are exposed to the
cold air, which not unfrequently, especially in winter,
operates to condense the steam to an inconvenient degree.  The steam chests, however, have a jacket or
casing over them, and the cylinders might be lagged
so as to make this a trifling objection.
The steam pipe is made of thick copper, united at
one end to the vertical cast iron pipe entering the
dome, and at the other end to a pipe casting formed to
make a tight joint with the smoke-box sheet.  The
steam passes through this tee piece, and then branches
off to each cylinder.  All the joints about the steam
pipe should be ground turning joints. Hangers of
wrought iron must be made to support the steam pipe
in its place. The area of the steam pipe should equal
the area of two of the induction ports to the cylinder,
and each branch pipe should have half this area. The
exhaust pipes should have nearly the same area as the
exhaust ports, until we come to the copper pipe attached as a mouth or blast pipe.  This pipe at its largest
place should be considerably smaller than the eduction
port, and at its mouth requires to be reduced to
about two inches in diameter.  Mlost of Hinkley's




42           THE LOCOMIOTIVE ENGINE.
15-inch cylinder engines are running with their exhaust
pipes contracted to 17-inch diameter at the mouth. For
16-inch cylinders, the blast pipe is 2 in. to 2l in.
English engineers are of opinion that the fire surface of
an engine should be very much increased,* in order that
a proper natural draft may exist without requiring so
great a reduction in the blast pipe.  The resistance
offered to the progress of the piston at high speeds, arising from the contraction of the blast pipes, has been
stated by Stephenson, of Newcastle, to absorb one half
the power of an engine.  It appears to us that a large
extentof heating surface, with the use of some simple
expedient for regulating the draft, would produce very
favorable results in the performances of locomotives. It
has been proposed, instead of varying the mouth of
the blast pipe, to establish a communication between
the exhaust steam and the feed water of the boiler, by
which means the draft could be regulated by turning off
any part of the exhaust to heat the water.  This plan,
however, involves considerable complication, and cannot be regarded as eminently practical.  We have no
doubt, however, that some simple expedient will be devised for accomplishing so desirable an object.
* Dimensions of engine, by Bury, Curtis, and Kennedy,
on page 36.




SECTION V.
Details of the Locomotive Engine continued. Of the Framing,
Jaws, Wheels, Springs, &c.
THE framing of all the engines now built in this country is between the wheels, and rests on the bearings of
the axles of the same, through the intervention of steel
springs.  The frames of the most recent descriptions of
locomotives are solid, and have the jaws for the bearings
either forged with them, or forged separately and secured
to the frame by bolts.  Many of these solid frames are
extremely light. The most usual kind of frame, however, is the riveted frame.  Two plates of flat iron, say
5 by 4 inch, with a bar 2 inches square, riveted between
them so that one of its sides is flush with the upper
edges of the plates. In Hinkley's engines, and in
most others, the frame passes over the bearings, and is
dropped down immediately in front of the forward driving axle, to the level of the centers of the cylinders,
and continues at that level to the forward end of the
engine. This mode of reducing the height of the frame
at the forward end, gives a ready access to the work of
the machine.  The jaws to this frame are of cast iron,
and are secured by bolts passing up through a stout
rib on the upper side of the jaw, and the 2-inch bar
which is riveted in the frame. Cast iron jaws, to stand,
require to be very heavy.  On the "Baldwin" and
"Whistler," (engines on the Lowell road, built at
Lowell,) the want of strength in theirjaws, which were
of cast iron, and were continually breaking, made it




44           THE LOCOMOTIVE ENGINE.
necessary to replace them with a set of wrought iron jaws.
A stout cast iron thimble is placed between the
back and forward jaws; also short thimbles between
the two cheeks of each jaw, and a 1-inch bolt is
then passed through the whole, and has stout nuts at
each end to secure it. Diagonal braces also pass from
the ends of this bolt up to the frame, thus forming a
complete truss.
Engine wheels with rims cast in sand have solid hubs.
Winans' wheels with chilled rims have the hubs cast
with core prints, leaving three open slots throughout
their thickness. After the rim has cooled, these are
filled tight with blocks of wrought iron, and the whole
hub is then encircled with a strong wrought iron band.
In the rims of his chilled wheels he casts a ring of
wrought iron, to assist the strength of the rim; both to
keep it from breaking, and to hold the rim from flying
apart in case it should crack.  Wrought iron tires have
been exclusively used for drivers until the introduction
of Winans' chilled rims, and the later method of using
chilled cast iron tires, which were first used, we believe,
by Thacher Perkins, now master of machinery on the
Baltimore and Ohio Railroad.  To put on a wrought
tire it is first evenly heated to a moderate heat, then
dropped on the rim of the wheel and quickly cooled by
throwing on cold water.  Seven or eight bolts with riveted heads are then passed through the tire and rim,
to secure the tire from working off.  To remove a tire,
the bolts through the rim must be taken out, or, if rivets are used, they must be drilled out: the wheel is
then laid on a circular mound of earth, a few inches
high and nearly as large as the wheel; a steady but
moderate heat is applied directly to the tire, the body
of the wheel being covered with earth, and in a few
minutes the wheel may be lifted out of the tire, by
means of a crane. In this manner the tires are taken




THE LOCOMOTIVE ENGINE.              45
from a pair of wheels without removing them from the
axle, by turning the axle up on one end so as to bring
one wheel on its side.
The chilled tires, when properly cast, are better for
some reasons than chilled rims; but it has not yet been
satisfactorily ascertained whether either can take the
place of wrought iron tires.  The main difficulty anticipated in their use is an insufficient adhesion to the
rails, especially in winter, when the rails are frosty or
damp.  The milder climate of the Southern States has
prevented this from becoming so serious an objection to
their adoption there. The chilled tires are three inches
thick, and are bolted to the rim of the wheel. The
merits of these tires above those of chilled rims, or
chilled wheels, are, that if a tire breaks, it can be replaced without throwing away the wheel, and they are
also readily renewed when worn out; whereas, with a
chilled wheel, it is useless when the rim becomes much
worn, though the rest of the wheel is perfectly sound
and whole.
Chilled wheels are used almost entirely for trucks,
tenders, and cars.  Engine trucks are generally 30
inches in diameter, and car wheels 33 inches. Some
of the roads running out of Boston have imported sets
of wrought iron wheels from England, and placed them
under their cars for trial. On the Boston and Providence road we have seen a pattern of cast wheel with
wrought tire, and having a ring of hard wood, two
inches thick, between the tire and rim of the wheel.
On the above road they are placing these wheels generally under their passenger cars.
Engine trucks and car wheels are usually secured to
their axles by one stout spline, and the driving wheels
by two one-inch square keys.
The cranked axle is forged from a bar which is kinked
or upset by doubling and bending so as to form the




46           THE LOCOMOTIVE ENGINE.
blocks for the cranks on one side of the axle.  The
axle is then twisted between the cranks till they are at
right angles with each other. The crank wrist is formed
by drilling out a sufficient portion of the block, left in
the manufacture of the axle, and then finished by turning.
The cases for the bearings of Hinkley's engines, have
dowels of a composition of equal parts of copper and
tin, inserted in the case in the direction of the length
of the bearing. The space between these dowels is
filled with Babbitt metal. The dripper or cup has
flanges to hold it in the case, and is kept in position by
a screw pressing against its under side.
There is a stout spring over each driver, having one
end attached by a loop to the frame, and the other to a
bar between the drivers, which turns on a pin beneath
the frame.  The object of this bar is to equalize any
effects arising from inequalities on the rail, by transmitting a portion of the shock to the wheel which is removed from this inequality. The lower end of the loopended rod attached to the spring, should be secured in
the end of the equalizing bar by a pin, as the rod
is apt to break off close to the nuts where these are
used.  The equalizing bar is of wrought iron, and for
strength must be made deeper in the center than at
the ends.
The springs are generally from 27 to 34 inches in
length, and are formed of plates of 1,  od,  or 3 inch
steel, and sometimes plates of each size.  A  spring of
the proper form, 30 inches long, and having 14 plates
of —, and two plates at the back of 3 inch steel, and 3
inches wide, makes a good spring for a driver. A tit
or projection is made in the end of each leaf, to fit in a
punched opening in the leaf below.  This is to prevent
any side motion or displacement among the leaves of
the spring. The end of the upper leaf is turned up to




THE LOCOMOTIVE ENGINE.             47
prevent the loop which passes over the end of the
spring from slipping off.
Rogers, Ketchum  and Grosvenor have used'-inch
iron plates, six or eight inches long, interposed between
the leaves at the middle of the spring.  The leaves of
the spring, when not under pressure, are in contact
only at their ends; but on the application of any weight
acting upon them, are brought into contact for several
inches of their length.  This spring, adapted to any
load, is an English idea.
India-rubber springs have been applied to the driving wheels of light engines, and in many cases to the
truck and tender wheels.  They make, at least, a very
cheap spring, and have proved well.
The iron truck frames in general use have inside
bearings.  They are formed of -y-inch plates, with
wrought iron bars, or thimbles, riveted between them.
The side bars are made to clasp the brass boxes enclosing the bearing of the axle. A large inverted spring
at each side has one end resting over the bearing of
each axle, and supports the frame on its upper side. The
under side of the frame is faced with a plate of steel,
where it rests upon the spring. The construction of
this truck does not admit of any one of the wheels rising,
without raising the whole frame. Norris, and some
other makers, however, make the action of the truck
wheels independent of each other, by making what is
called a live truck frame. In this frame the spring, instead of resting directly on the frame, rests on the bearing by a pintal passing through the frame. Any shock
of the forward wheel is thus divided, and partly transmitted through the spring to the hind wheel. The
Lowell Machine Shop use a truck frame, with outside
bearings, on one of their patterns.
The bearings of the truck axles are from 3{ to 3inches in diameter, and 5~ inches long. The bearings




48           THE LOCOMOTIVE ENGINE.
of the driving axle are from 6 to 7 inches in diameter,
and 6 inches long.  The crank wrists are of the same
diameter as the bearings, and are 31 to 4 inches wide.
The cheeks of the cranks are 5 inches thick.
The pintal bushing for the truck is of cast iron, and
is riveted between the plates forming the truck frame.
The pintal is secured to the boiler behind the cylinders,
or is made fast to the cylinders themselves, by being
passed through the flanges connecting them together,
and secured by a shoulder below and a nut above. The
pintal is about 5 inches in diameter.
There should be a slide and wedge between the footboard and tender, to prevent jarring and jolting. This
wedge is drawn up in the slide by a screw and nut.
There is generally a rail, or outside frame, as it is sometimes termed, outside of the wheels.  This outside
frame makes a convenient support for the pump, and
serves to make a walk or balcony by which to go to the
forward end of the engine when it is running.  This
outside frame, if mounted with jaws and springs, might
give additional support for the driving axle, and would
assist the strength of the inside frame.  The eccentrics
could be placed outside the wheels, and wrought iron
cranks would be keyed to the axle outside of the frame,
to connect the drivers. There is no great practical difficulty, in our opinion, in keeping four bearings in line
on the same axle.
It appears to us that a very light and strong tender
frame could be made of flat bars 3~ by 1i inches, and
which would cost no more than our present heavily timbered wooden ones.




SECTION VI.
Details of the Locomotive Engine continued. Of the Pistons,
Slides, Connecting Rods, Valve Motion, and Pumps.
THE pistons generally have two outside rings, while
some makers, as Norris and others, use three.  These
rings are sometimes of cast iron, and sometimes of composition. The piston rings used on the Boston and
Maine road are made from  a composition of 80 parts
copper and 20 parts tin.  The outside rings are some
times cut in -four pieces, and are sometimes cut open
only on one side.  Cast iron rings, if not set out too
tight against the inside of the cylinder, may be regarded
as not only cheaper, but better than composition rings.
And rings simply cut open, are better, for most reasons,
than those which are cut in three or four pieces.   Tihe
cover is usually secured to the body of the piston by
four screws. The following are the dimensions of
Hinkley's 15-inch  pistons on  the Maine road, and
having the kind of packing-rings described as used
by that road.  Diam. of follower or cover, 14l}3 in.;
diam. of outside rings, before cutting open, 15 3 in.;
thickness of piston, 4- in.; thickness of follower,  in. ~;
thickness of outside rings, - in.; depth of do. 1P9 in.;
inside ring of cast iron, 3 thick.  Four screws to secure
cover, each one inch in diameter, 3 in. under head,
and having heads 11 in. square.  Each screw is 5a;,
in. from  center of piston.  Four springs to set out
packing, each 6 in. long, 3 in. wide, T3 in. thick at
thickest part, and having a bend or deflection of 4 in.
4




50           THE LOCOMOTIVE ENGINE.
Screws to set out packing, X in. diam.  Key to secure
piston rod, 1- by Ad. Thickness of iron around rod,
1-a in.; diam. of body of iron penetrated by screws to
secure cover, is 2 in., and is connected to the hub of
the piston head by a bridge of iron 7 in. thick.
Winans' 17-inch piston has six screws to secure the
cover, and each spring which is set out by the packing
screws, presses at each end against the center of a
smaller spring, thus making 24 bearings against the
packing rings.
All this is unnecessary, and makes the springs liable to
derangement.  Norris' springs are 9 inches long, there
being three in his 14-inch piston.
The best slides are undoubtedly the flat slides first
used in the old Locks and Canals Co.'s Engines.
These are now used by Rogers and others.  The simplest and cheapest form of slide is the round slide used
by Norris, and until recently by Hinkley. The length
of cross-head bearing on the slides is generally 10 or 12
inches.  The diameter of the round slides is 2~ in.
One end of the slides is attached to lugs on the cylinder
cover, the other to a wrought iron loop supported by a
cross girt under the boiler.
The connecting rods have oval or octagonal boxes on
the outward sides of the bearings, and square boxes on
the inner sides, or where they abut against the end of
the rod.  The straps are generally 1 in. to 1~ in. thick,
and in width 2- in. at the crank end, and 21 in. at the
cross-head end. The straps are secured by two 7 in.
bolts to each, and the boxes are set up by a key generally 1a and   inch wide and   thick at the crank end,
and by a somewhat smaller key at the cross-head end.
The most recent method of securing the key in its place
is to have its smaller end pass through a piece of iron,
on the outside of the strap, and an inch thick; this
piece being secured to the strap by one of the bolts




THE LOCOMOTIVE ENGINE.             51
already noticed. A set screw in this piece pinches the
end of the key, while another screw at the center of
the flat face of the irod is turned against the key at that
point. The rod is generally not far from six feet between the centers, and is nearly or quite 3 inches in
diameter at the center.  The cross-head bearing, when
of cast iron, is 2- inches in diameter.
As the boxes in the connecting rod become worn,
the setting them up by the keys tends to lengthen the
rod, as the outside boxes retain their places, while the
inside boxes are moved outward. In the main connecting rod this is no great evil, as there is generally sufficient allowance at the end of the cylinder for the piston to work up a little without hitting the head, and
for this purpose there should be more clearance given
at the forward end of the cylinder than at the hind end;
say, on a new engine, 1 in. allowance at the hind end,
and nearly I inch on the forward end. On the rods,
however, to connect the drivers together, it is essential
that the original length of the rod be constantly preserved; and to do this, the key at one end of the rod
presses the inner box outward, while the other key,
being outside the box at that end of the rod, presses the
outer box inwards. On Winans' and on Perkins' engines, having four pairs of wheels to connect, the bearing
is bored out of the end of the rod, a tight bushing
inserted, and no keys used.
The valve motion generally used is the indirect attachment of the eccentric, through the rocker shaft.
In ordinary inside cylinder engines, a shaft 14 in. in
diam. is secured by stands to the cross girt supporting
the slides. On this shaft there are two wrought iron
tubes or shells, one for receiving and communicating
the motion for each valve.  The thickness of these
tubes is - inch. The rocker arms which support the
hooks are 61 inches between the centers, their hubs 4




52           TIlE LOCOMOTIVE ENGINE.
to 4 inch thick, and the arms are 3 inch thick. The
pins or bolts which support the hooks have thimbles 14
in. diameter, and A-  in. thick.  The rocker shaft,
tubes, arms, and thimbles, are all of wrought iron.
(In some instances cast iron tubes, with the arms cast
therewith, have been used, and when working on a
wrought iron shaft, have less friction than the wrought
iron tubes. The Taunton Co. have used cast iron rocker
tubes on upwards of sixty engines, without breakage.)
The pin for the valve stem is turned with a shoulder,
and is passed through the end of the upper arm, and
secured by a nut on the back side of same. The thickness of the upper arm is 14 to 1 - inches, and is of the
same length as the lower arm. The arms on the rocker
shaft, which receive the motion of the hand hooks, are
10 inches between the centers.  The object of the hand
hooks is to catch the eccentric hooks when the engine
is reversed, and also to assist in starting in difficult situations, as in a drift of snow. The inside of the eccentric hooks, where they wear on the thimbles of the
rocker arms, are faced with a wedge or dowel of hardened steel.  The eccentric rods are 1~ to 1  inches in
diameter, and have right and left nuts to adjust their
length.  The end of the rod is secured to the brass
hoop or eccentric band by bolts, or by being passed
through a hub formed on same, with nuts and check
nuts on each side.  The eccentric band is  1 inches
thick, and is lined with Babbitt metal. The eccentrics
generally have three inches throw, and in inside cylinder engines, must be cast in two pieces to allow of their
being placed between the cranks. The eccentrics are
secured to the axle by set screws turned at their ends
to a blunt point, and entering the axle.  This is to give
a chance for altering the lead of the valve when required, which could not be so readily done were the eccentrics keyed to the axle.  It is for this reason, also,




THE LOCOMOTIVE ENGINE.             53
that the eccentrics are generally cast separately, although some engines have the four eccentrics for forward and backward motion for each valve cast in one
piece, or at least it two pieces, to put together around
the axle.  The strap under the hook is ~ to 8 thick,
and long enough that the hook may traverse, when
thrown out, in either direction, without striking the
thimble in the rocker arms.  The cambs for raising the
hooks are of cast iron, and have a throw of 2 inches or
more.  These cambs are secured to a wrought iron
shaft I - to 1- inches in diameter, having a pinion of 12
or 14 teeth on one end and turned by a segment, which
is worked by the reversing lever on the footboard.
The expansion valve is worked through the medium
of a separate rocker shaft, having also a camb shaft,
with reversing rod to work the same.  As this camb
shaft requires to be turned but one quarter around, a
simple arm attached to it is all that is necessary.
The hooks are sometimes formed with V-shaped
openings, in order that they may readily catch the pins
when reversed.
This general arrangement of operating the valve has
been recently superseded in a measure by the introduction of Stephenson's link motion, although the old establishments still adhere to the use of the rocker shaft.
An open curved link is attached at one extremity to
the forward rod, and at the other to the backing rod
from the eccentrics.  A block attached to the valve
stem is made to fit this link, while the link can be
raised or lowered so as to bring this block within the
action of either rod.  By this method, whenever the
engine is reversed, the ports are ready to take steam,
as the act of raising or lowering the link moves the
valve to its proper position on the face of the cylinder.
As this method of working the valve admits of giving




54           THE LOCOMOTIVE ENGINE.
it a variable throw, advantage is sometimes taken of
this circumstance to work expansively.  Indeed, it was
for this purpose that Stephenson first secured a patent
(in England,) for its use. The valve, however, should
generally have a determinate throw, depending on the
size of the ports which it covers; and any increase or
diminution of this throw is attended with a choking of
the induction and eduction of the steam. This result
may be made evident by making a section of the steam
ports on the side of a small piece of board having its
edges straight, and making a section of the valve on
another straight piece of wood. If the edges of these
boards are applied to each other, it will be seen that
any other travel than between 21 and 3~ inches, would
not readily allow of the proper passage of the steamn.
The travel of the valve, for this reason, is generally
fixed at 3 inches.
A modification of the link motion, without altering,
however, its essential features, was devised by Sharp,
Brothers & Co., of Manchester, England, and applied
to the goods engines constructed by them for the Great
Western Line. The link was curved the opposite way
to Stephenson's, his link being described from the
center of the axle, and was suspended by a straight
link to the boiler or frame.  The eccentric rods thus
retaining one position, the block was attached to the
valve stem by a jointed arm, and was raised or lowered
by a lever for that purpose.  There are more joints
about this arrangement than in Stephenson's, and its
only merit above Stephenson's is that the jointed valve
stein may be raised with less power than the whole
weight of the eccentric rods-and links.  The use of this
motion for obtaining a variable expansion, is of course
liable to the same objections as Stephenson's.
A form of variable cut-off, introduced by Horace




THE LOCOMOTIVE ENGINE.            55
Gray, Esq., of Boston, upon the Fitchburg, New
York and Erie, and other roads, consists in an open
curved link formed as an arm on the upper side of the
cut-off rocker shaft.  The cut-off valve rod being
jointed near the stuffing-box, and attached to a block
in this link, can be raised or lowered to acquire any
throw within the limits of motion of the block. By
this method a variable expansion is obtained without
affecting the induction or eduction of steam in the
cylinder.
To set the valves of a locomotive, the piston is
brought to the end of its stroke, the valve is placed
over the ports so as to have the desired lead or advance
on the piston; the eccentric rods are then adjusted to
such a length as to allow the hooks to catch the pins,
the valve retaining the position previously given.
The engine is now moved either forward or backward,
as may be convenient, until the piston is brought to the
other extreme of its stroke; and if the valve has
the same advance on the second port as on the first, it is
properly set. If, however, the lead is more or less than
that given to the first port to which the valve was set,
the eccentrics require to be turned in the proper direction on the axle, and to such an extent as to give the
desired lead. Before turning the eccentrics, the eccentric
rod must be lengthened or shortened, as the case may
require, so as to divide the difference of lead on the
two ports, in order that it may be equal on each. A
proper adjustment of the length of the rods makes the
lead equal on each extreme of the stroke, while the
position given to the eccentrics determines the amount
of lead.
The eccentrics may be properly fixed to the crank
axle, when it is detached from the wheels and from
the engine.




56            THE LOCOMOTIVE ENGINE.
Cylinder side.
Find the point ca on the side of the axle, and in the
horizontal line, A, B, connecting the centers of the crank.
Then take a piece of tin or sheet iron and describe on it
the circle a, in, n, p, of the size of the axle; from the
same center describe a circle equal to the throw of the
valve.  Then if the valve has an indirect attachment,
as in case of the rocker shaft, lay off on the cylinder
side of the axle, the crank being turned that way, a
distance, k, 1, eclual to the sum of the lap and lead at




THE LOCOMOTIVE ENGINE.             57
one end of the valve; draw c, d, through the point k,
and perpendicular to the line A, B.  Through the
points e and f, where this line intersects the circle
described by the throw of the eccentric, draw the diagonal lines 1, t, and 1, s, passing through the points e and
f, and the center of the axle.  The points e' and f', at
which these diagonals intersect the circumference of the
axle, may be transferred by the compasses to the axle
from the point a already found on its side.  The extremity of the line dividing the forward eccentric in two
equal parts, will fall on e', and the line dividing the
backward eccentric will fall on f', as will be seen by
the diagram.
In setting valves with direct attachment, the distance,
k, 1, is applied to the other side of the center of the axle,
and the diagonal lines tend the other way.
We have already explained the nature of lead, and
we should perhaps have explained the term lap before
entering upon the foregoing instructions for setting
valves.  When the valve is in the middle of its travel
or motion on the face of the cylinder, the distance which
it laps at each end over the induction ports, is called
the lap of the valve.  The effect of this lap is to shut
off the steam before the pistonhas completed its stroke,
and the lap valve thus acts as an expansion valve, to a
greater or less extent as the lap is more or less considerable. Indeed, the main difficulty in the use of a lap
valve for a cut-off, is that of starting, especially with a
heavy load or on a bad grade. Engines having no separate cut-off valves usually have as much lap to the
valves as will admit the steam to the cylinders without
serious difficulty in starting.  The effect of combined
lead and lap, when restricted within proper limits, is to
augment the speed of the engine; the lead, by assisting
the change in the motion of the piston so as to lose no
time, and the lap to act as a cut-off valve, to derive the




58            TIIE LOCOMOTIVE ENGINE.
benefits resulting from an expansion of the steam. These
benefits, as we shall hereafter demonstrate, consist in
being able to do more work with the same steam, from
which result a considerable economy in fuel, and a
diminution in the water carried in the boiler.
The pumps of an engine are either attached directly
to the cross-head, and have the same stroke as the
piston, or they are worked by the same through a lever
proportioned so as to give the pump plunger one-half
or one-third the stroke of the piston.  Many recent
engines, however, including Hinkley's patterns, have
an arm attached to the outside crank pin, which communicates motion to the hind pair of drivers, the
end of this arm being brought up to within 33 inches
from the center of the wheel, and working the pump
plunger, giving it a stroke of 7~ inches.  The pumps,
when this connection is used, are placed at the hind
end of the outside framing, and beneath the footboard.
The feed water enters the boiler on the side of the
fire-box at a point about as high as the lower row of
tubes.  Some contend that the feed water should be
injected at the bottom of the water space about the
fire-box, or at the smoke-box end of the boiler, in order
that the cooling effects of the water may not act directly upon the tube sheets, and by alternately contracting and expanding them, cause the tubes to leak.
Pumps having one-half or one-third stroke are generally better for engines running quick, than full stroke
pumps, as the barrel of the pump is more sure to fill,
while the wear of the valves is not so perceptible.
The pumps on all recent engines are provided with
air vessels of iron or brass.  The form of cup valve
working in a brass cage, used by Souther, appears to
us the simplest form of valve which can be devised.
It requires much less fitting than any other form of
valve which we remember to have seen.




THE LOCOMOTIVE ENGINE.             59
The joints between the pump and the suction and
air chambers, and the joint in the check valve chamber,
are usually ground joints of cast iron. These, however,
when long in use, frequently become leaky, as a cast
iron joint about a pump, or in any place where the
water has access to it, is found not to hold its face
well.  If a composition ring be placed inside the valve
chamber, to make a joint upon, the iron with which it
is in contact becomes subject to a peculiar oxidation,
arising from a kind of galvanic action with the composition ring. The iron about this ring often becomes
eat full of small holes. To remedy this evil the pumps
of Souther's engines have rings of a composition cast
inside the valve chambers, and in every situation about
the pump where a ground joint is required. These rings
are first cast by themselves, and their composition is so
proportioned that when placed in the mould of the
valve chambers, and having the melted iron poured
around them, the iron just melts the surface of the ring,
and thereby becomes firmly cast with it, so that water,
which is necessary for the galvanic action described,
cannot enter between them. We regard this as a very
excellent plan, as it saves much expense in keeping the
pumps in order, and makes no material difference in
the first cost of the pump.
The keys to tighten the bearings about an engine
should not have too much taper, as there is danger of
their becoming set so tight as to cause the melting of
the Babbitt lining of the boxes.  When much tapered,
they are also liable to work out, but this does not prevent them from being set so tight as to create the mnischief referred to.  All the bolts should be turned and
fitted, and for such as pass through the straps of the
connecting rods, and other parts in motion, cheek nuts
are required.  The thread of the screws should not be
too coarse, as in that case the nuts are apt to work off,




60           THE LOCOMOTIVE ENGINE.
while if too fine, the thread is liable to strip. A thread
of eleven to the inch appears to answer very well for
the medium-sized bolts.
Such rubbing surfaces about an engine as are liable
to become rapidly worn, require a lining of the composition usually named Babbitt metal, from the inventor, Mr. Isaac Babbitt; of Boston.  A  space is left
around the inside of the shell of the bearing, which is
filled with this composition, there being ledges around
the sides of the shell to keep the soft metal from coming out.  A common proportion for the ingredients of
this composition is twenty parts tin, two of antimony,
and one of copper.
There should always be oil cups on the cross-heads
and means must be found to oil every rubbing surface
about the engine.
There should be a little chance for end playon the
pins for the connecting rod to connect the drivers, and
also on the pins for the pump rod. This play on the
connecting rod may amount to - inch, and is necessary
to allow the wheels to ride freely around a curve.
We shall have occasion to mention two or three particular patterns of engines, and in so doing shall notice
some peculiar arrangements in the various parts of their
moving machinery, differing from what we have described.  A  disposition is constantly shown among
makers for improvements, and new applications possessing their peculiar advantages and disadvantages are
constantly appearing. Our most recent engines possess
many decided improvements over those constructed but
a very few years ago.




SECTION VII.
Remarks on the Management of Engines.
A well-built engine, having its parts easily accessible,
and possessing good qualities for the production of
steam, may, with careful management, be made to run
for a long time with hut little expense for repairs.
The points to which the careful engineman directs his
attention, are the manner of firing, the supply of feed
water, the proper adaptation of the production of steam
to the features of the road, and various other particulars of a like nature, which are necessary for the
proper performance of a locomotive.  It is, of course,
necessary to fire up oftener when the engine is performing hard work, than when the load is light. The fire
should be maintained at a proper point to make sufficient steam, and should not be suffered to get so low
as to affect the pressure in the boiler.  It is an object,
however, in approaching a terminal station, to have
barely sufficient fire to reach the engine house.  The
supply of feed water to the boiler is regulated very
much by local circumstances on the road. In ascending grades, the injection of cold water would check the
formation of steam, and it is therefore necessary to have
a good supply of water in the boiler before reaching the
foot of an unfavorable grade. On long levels and on
descending grades, one pump may be kept working to
nearly its full extent. It is seldom that both pumps
require to be at work at the same time. There should




62            THE LOCOMOTIVE ENGINE.
also be plenty of water in the boiler before reaching
either roadside or terminal stations.  The fire door
should be kept open as little as possible, as the entrance of the cold air through it contracts the tube
sheets, and is sometimes the cause of their leaking.
If an engine has a variable exhaust, it is a good
plan to open it to nearly its full extent, when firing,
and to immediately contract it very much, so as to recover the fire quickly. The cylinders and valves require to be oiled at every fifteen or twenty miles of the
journey. Melted tallow is used for this purpose. If
the ports of the throttle valve are of the same area as
the steam pipe, it is found best to keep the throttle
partly closed, as when the pressure in the steam pipe
is rather less than in the boilers, the engine is not so
liable to prime.  The proper opening for the throttle
of any engine can soon be determined from observation.
In going through covered bridges and station-houses,
enginernen are generally cautioned to shut their dampers, and to otherwise check the draft of their engines,
so as to guard against fire.
The boiler requires to be blown off at intervals of a
week or more. The times at which this operation
should be performed will depend very much on the
purity of the water used. When a scale deposits on
the tubes, and on the internal shell of the boiler, a
double handful of mahogany sawdust thrown in at the
safety valve will tend to remove it.
There should be as few putty joints about an engine
as possible; but where there are any joints requiring
packing, putty seems to answer better th'an Indiarubber.  It should be mixed to have a very firm and
even consistency, which end is best attained by mixing
the red and white lead of which it is composed by
beating with a heavy hand-hammer.




THE LOCOMOTIVE ENGINE.             63
The hemp for packing the piston rods, valve stems,
and pump plungers, should be soaked in warm water
before  using.  Some engineers soak it in melted
tallow, but this appears to rot it. Hemp simply soaked
in warm water will be found strong after two months'
use. Good hemp is to be preferred to India-rubber
for stuffing boxes.
The frequent use of the sand-box on freight engines has the effect of rapidly wearing out the tires
of the wheels.  Its use should therefore be restricted
to cases where it cannot be dispensed with.
In repainting the wood work about an engine, the
best way of cleaning the work from grease and dirt is
to wet it with spirits of turpentine on a handful of waste.
The steam chimneys are best polished with rotten-stone,
used with oil on a woollen cloth.
Every engine man should know whether the spring
balances of his safety valves are correctly marked.
To test the balances themselves, they can be attached
to a balance known to be correct, and if the weight
indicated on each balance is the same, the spring of
your engine balance is correct.  If you wish to find
whether the spring balance is correctly marked, - say,
for instance, to a pressure of 90 lbs. to the inch, -
find in the -first place the diameter of the valve seat,
or smallest diameter of the valve, and find its corresponding area in square inches. Multiply this area by
90, and you have the entire pressure against the whole
valve. Now from this pressure deduct the weight of
the safety valve lever, with the spring balance attached
and disconnected from the boiler, the lever being
weighed at a point directly over the center of the
safety valve.  What remains is the pressure against
the valve, which is to be overcome by the tension of
the spring balance, unaided by its weight. Multiply
this pressure by the distance in inches from the center




64           THE LOCOMOTIVE ENGINE.
of the joint pin or fulcrum, to the center of the valve
pin, and divide the product by the distance from the
joint pin to the center of the spring balance.  This
quotient shows the tension of the spring balance,
requisite to overcome a pressure of 90 lbs. per square
inch against the valve.  Suppose this quotient to be
81, for instance; then in re-marking the spring balance,
the point showing 90 lbs. per inch should be at 81, as
originally marked by the maker of the spring balance
on his scale.  If the original marks of the spring
balance have been covered or destroyed, then attach a
weight equal to the quotient found in the above calculation, and the point to which it draws down the gauge
or pointer may be marked, and calculated from as
though it were the original mark.
If the balance be screwed down to any point supposed to show a certain pressure in the boiler, a pair
of steelyards can be applied to the end-of the safety
valve lever, when the spring balance is screwed to that
pressure and is attached to the boiler, and the resistance or tension of the balance, or the weight sufficient
to just raise it, may be noted.  This weight may be
multiplied by the distance from the joint pin to the
balance, and the product divided by the distance from
the joint pin to the center of the valve;-the quotient
will be the pressure against the valve, which if divided
by the number of square inclhes in the area of the
valve, will show the pressure per inch. This method,
it will be seen, gives the true result also without
deducting the weight of the lever in the calculation,
as its weight is included in getting the tension of the
spring balance.
No careful engineman puts out his fires by throwing
water in the fire-box, except in cases demanding the
immediate withdrawal of the fire.  It is even then
better to pull out the grate bars by a dart, which can




THE LOCOMOTIVE ENGINE.            65
be done if the fire-box be not full of wood, as the
injury caused by contracting the tube sheets is irreparable. To reverse the steam also when the engine
is in motion brings a very powerful strain upon its
bearings. It should never be done, except to prevent
collision or running off the track. When, to prevent
a collision, it sometimes becomes necessary, however,
to reverse full steam ahead to full steam back, a difficulty is& sometimes found in catching the hooks.  The
hand hooks, too, when dropped on the pins, do not
immediately catch, until they will suddenly become
engaged and put the hand levers in rapid motion, so
as to become a source of danger to the engineman.
It is best, therefore, in reversing in such cases, to
place the reversing lever first midway, with all the
eccentric hooks out, when the hand hooks may be at
once caught and the back hooks immediately thrown
in. We know old engineers who say they always do
this in cases of the most imminent danger, and on the
whole it generally takes less time. Where an engine
has V-hooks, or links, there is never any difficulty in
reversing at once.
In removing and replacing the steam chest and
cylinder covers, care should be taken that no one
screw which secures them shall be up to a tight bearing when the others are loose. In putting them on,
the nuts should be turned loosely up all around, and
then gradually tightened.  Unless these precautions
are observed there is danger of cracking the covers.
There are very few roads where any account is kept
of the work performed by their locomotives, so as to
show the comparative power of each engine on the
road.  Every new engine is, to a certain extent, an
experiment, and its performance will very much depend on some of the details observed in its construction.  An engineman knowing the features of the
5




66           THE LOCOMOTIVE ENGINE.
road over which he runs, as the radii of the curves,
length and height of grades, &c., may keep a very
useful and interesting abstract of the load drawn, or
speed attained, together with the consumption of fuel,
oil, &c., on some of the trips performed by the machine in his charge. These particulars are practically
useful, inasmuch as they show what may be expected
-of a locomotive under ordinary circumstances; and
they also facilitate comparisons of the different patterns of engines. Some of the roads running out of
Boston keep a monthly list posted in their enginehouses, of the number of miles run by each of their
engines, together with the amount of oil and waste
used for the same time.
The following is an estimate which has been furnished us of the expenses for running a first class
passenger engine, 100 miles a day for one year.
Wages of Engineman,       -    -    -    $720.00.".   Fireman,   -    -    -    -      360.00
Wood: 4 cords per day, 280 days     -   5,040.00
1120 cords e $4.50 per cord,
Oil; 280 gallons,    X.80    -    -      224.00
Waste; 840 lbs.,     ".02    -    -       16.80
Repairs; 28000 miles, ".06    -    -   1,680.00
Water in Boston,          -    -    -     100.00
Water and pumping on road,    -    -      150.00
Interest on first cost of engine,   -    -  480.00
Total,                      $8,770.80
This, though but an approximation, serves to show
pretty nearly the general expense of locomotive power.
In our railroad reports generally, no mention is
made of the details of the expenditures on account of
the locomotive department, and while the entire
success of the road depends upon the condition of this




TEE LOCOMOTIVE ENGINE.              67
branch of its fixtures, the subject is passed without the
least notice. Those interested in railroad matters may
regard the locomotive of the present day as practically
perfect; this, however, would be a serious error, and
would very much retard the introduction of beneficial
improvements. On some of the Southern roads, the
Baltimore and Ohio, for instance, a detailed account is
appended to the superintendent's yearly report, containing the number, names, rank, classes, and builders
of all the engines on the road; their performances for
the preceding year in miles run, expense for repairs
on each engine, together with details of the charges
for fuel, wages, oil, waste, and incidental expenses
connected therewith.
The Baltimore and Ohio Railroad* is one of the
largest enterprises of the kind in the country.  Its
entire length from Baltimore to Cumberland, including the branch to the City of Washington, is 220
miles; and there are by the last returns sixty-three
locomotives on the road. The careful attention paid
to the minutae of the running department on that
road presents a model which our engineers might well
follow.
*This Company are now extending their road to Wheeling, making the entire road, when finished, 431 miles long.
The difficult passage over the Alleghany Mountains will present
some of the boldest and most striking works of art to be
seen in this country. The new tunnel to pass through the
mountain ridge will be one mile and one quarter long.
Several iron bridges of 180 feet span; also stone masonry
bridges of that span will be erected to carry the line across
the numerous mountain streams. This extension will greatly
increase the already immense traffic now finding its channel
in the Baltimore and Ohio Road.




SECTION VIII.
Various Patterns of Locomotives.
TI-IE most recent patterns of passenger engines have
15-inch inside cylinders, four 5-feet or 5 ~-feet drivers,
and a truck frame.  This general arrangement is seldom modified to any material extent, although the
diameter of cylinder is made by Norris 13 inches, and
in some instances, by other makers, 16 inches. The
use of two pairs of drivers is necessary to obtain sufficient adhesion to the rails, although an engine having
but one pair of drivers runs much easier, and is to be
preferred for special trains of a few cars, and running
only for short distances over a nearly level track.
For freight transportation the cylinder is generally
16 to 18 inches in diameter, and the driving wheels
from 42 to 54 inches in diameter. Hinkley and Norris have each patterns of ten-wheel engines, with six
drivers connected, and Winans' freight engines have
eight wheels connected and supporting the entire
weight of the engine.
Within a year or two there have been constructed
several engines in various parts of the country, of
novel and peculiar design.  The chief feature, however, in these engines has been an increase in the size
of the driving wheels. Among these engines was one
built by Edward S. Norris, of Schenectady, N. Y., for
the Utica and Schenectady Railroad, of the following
dimensions:




TILE LOCOMOTIVE ENGINE.           69
Sixteen-inch cylinder, 22-inch stroke; boiler 42
inches in diameter; 116 two-inch tubes, 10 ft., 3 in.
long; grate about 14 square feet; one pair of wrought
iron driving wheels behind the fire-box, and 7 feet in
diameter; one pair of wrought iron bearing wheels
just forward of the fire-box, and 4 feet in diameter, and
a truck frame beneath the smoke-box of four 3~-feet
wrought iron wheels.  The cylinders are outside, and
are placed in a horizontal position midway between
the fire and smoke boxes.  A large dome, at a corresponding point on the top of the boiler, supplies
steam to the cylinders through pipes running down
outside the boiler to the steam chests.. The valve
motion is the modified form of Stephenson's link
motion, on which we have remarked on a preceding
page. The frame of the engine is below the axle of
the driving wheels, and above that of the 4-feet bearing wheels, the jaws for the bearings of the driving
axle being formed on the upper side of the frame.
There is also an outside frame having a floating bearing
for the end of the driving axle, the crank and eccentrics being between this bearing and the wheel.
The performance of this engine is represented as
being remarkably good.
The coal-burning engine, built by Ross Winans, of
Baltimore, and placed by him for trial on the Boston
and Maine Railroad, had 17-inch outside cylinders
laid horizontally, 22-inch stroke, and eight drivers,
having chilled rims 43 inches in diameter, all. the
drivers being placed between the fire and smoke boxes.
The connecting rod is applied to the third pair of
wheels from the smoke-box. The distance between the
centers of the extreme axle is 11 ft., 3 in.; between
the centers of the cylinders, 6 ft., 5 in. The boiler
shell is made of Ad% iron, and measures, in its smallest
inside diameter, 41 inches.  There are 101 two-and



70           THE LOCOMOTIVE ENGINE.
one-half-inch, and 2 two-inch wrought iron tubes, 13
feet in length. The upper row of tubes is nearly up to
the top of the cylinder part of the boiler, the waterlevel being in the dome above the waist of the boiler.
The dome is formed a little forward of the middle
point of the boiler, having the same diameter, and
rising 51 inches above it. There is a step on the back
side of the fire-box, making the length of the grate 14
inches more than the length of the crown sheet. The
fire-box is of 2 inch copper, with the exception of the
tube sheet, which is of I inch iron. Length of grate,
564  in.; at crown sheet, 424 in.; mean breadth of
grate, 42- in.; at center of boiler or middle row of tubes,
391 in.; all inside measures. The whole depth from the
crown sheet to grate is 514 inches.  The grate bars are
very heavy, and are cast but two together. Their ends
come through the bottom of the fire-box, on the back
side, and have round holes through which to put a bar
to stir them occasionally, in order to loosen the cinders
and melted coal. The exhaust from both cylinders
comes through a cast iron box or blast pipe having
movable sides, so that the aperture at its mouth may
be varied from  34 to 10 square inches.  There is
a pipe about 9 inches in diameter, passing up through
the smoke-box, from the bottom to the top, and entering the chimney, leaving a few inches all around it for
the smoke to rise through. The exhaust enters this
pipe at its bottom, and the partial vacuum created by
its action supplies the blast, as in ordinary locomotives.
The tube surface of this engine is 860 square feet; of
heating surface in fire-box, 66 square feet; and the
area of grate is 162 square feet.
Messrs. Slade and Currier, civil engineers, were
commissioned to make experiments with this engine, in
order to institute a comparison between it and a firstclass wood engine, but more particularly to test its




THE LOCOMOTIVE ENGINE..          71
actual value as a coal-burning engine. The results of
their experiments have been published, but they neglect to state that the "New Hampshire," (the wood
engine,) was of a materially different pattern from the
" coaler," inasmuch as it had six driving wheels and a
truck frame, thereby losing a considerable per cent. of
the adhesion due to its weight as compared with the
"coaler."  The dimensions of the " New Hampshire"
were as follows: 16-inch cylinder, 20-inch stroke; diameter of drivers, 46 inches; length of tubes, 10 ft., 6
in.; diameter of boiler, 45 inches. This engine was
built by Hinkley & Drury.
The experimental trips were made in the latter part
of January and in the beginning of February, 1850.
The'entire distance from Boston to Great Falls is given
as 74 miles. There was more or less snow on the
track during the time in which the experiments were
made. The highest grades were about 47 feet per
mile.  One point unfavorable for the "coaler" was
the fact that from there being but about 26 miles of
double track, the freight trains were subject to frequent
and protracted delays, in waiting for passenger trains
to pass. In waiting, the fire in the wood engine could
be suffered to go nearly down, the fire-box being filled
with wood when the train came in sight. In the coal
engine, however, it was necessary to keep the furnace
filled with coal, as, if suffered to get down, it would
take considerable time to recover the fire.
With the " coaler," the average of ten trips showed
a consumption of 4786 lbs. anthracite coal to evaporate
3512 gallons in going 74 miles; this being 10.31 lbs.
coal required to evaporate one cubic foot of water.
With the wood engine, 3 cords and  l-~ of a foot of
wood of various qualities and prices were used to evaporate 3734 gallons of water.




72           THE LOCOMOTIVE ENGINE.
The cost of carrying 15000 tons one mile with wood
was found to be,                       - $14.04
With coal,  -                            12.70
Favor of coal,  -    -    -    -    -  $1.34
The wood engine had a sand-box, and had wrought
iron tires: the " coaler " had a sand-box, also, but had
chilled wheels.
The "coaler" took 76 cars, weighing, with freight,
433 tons, up Ward Hill, in Bradford, where there is a
grade of 47 feet per mile, and also a very bad reversed
curve. In going up the hill no sand was used, nor
did the wheels slip, except, as the report states, some
three or four turns where some track repairers had
taken off a hand car and left a little snow on the rails.
The wood engine took 61 cars up the same hill,
weighing, with freight, 391 tons.  Sand was constantly
running from the sand-box, except when, to ascertain
whether the engine was working up to its full power,
the sand was turned off, when the wheels were found to
slip very much.
The average cost of wood used on the through trips
was $3.63 per cord.
The cost of anthracite coal, per ton of 2240 pounds,
was $5.25; 5 of a ton of coal was found to be equal in
effect for evaporation to one cord of wood, or $3.28
worth of coal equal to $3.63 worth of wood.
The average speed of the coaler, although having a
smaller wheel and a longer stroke, was found to be,%
of a mile per hour greater than that of the wood
engine.  Their average speeds being 14-y  and 14 1
miles per hour, respectively.  This was probably
owing to a loss on the wood engine by slipping the
wheels.
In conclusion, the commissioners express their
opinion that, for runinng heavy trains, which are not




THE LOCOMOTIVE ENGINE.             73
obliged to wait for any considerable length of time
along the line, for other trains to pass, they believe
coal to be every way more economical than wood.
They also say that in their remarks they would not
wish to be considered as in any way disparaging the
" New Hampshire," as they consider that a first class
wood engine.
Winans has an express engine on the Worcester
road, having 7-feet drivers. In this engine, however,
the proportions of the boiler, &c., are very much the
same as in the freight engine we have noticed.  These
seven feet drivers were cast with chilled rims, and
were of an extremely light pattern; in fact, they
became broken before they had been used two months.
There were two small steam cylinders placed on the sides
of the boiler over the bearings of the driving axle, by
which the weight on the drivers could be varied from
three to twelve and a half tons. But when under
their utmost adhesion, the drivers were found to slip
very much.
Many attempts have been made to burn anthracite
coal effectually and economically.  Winans' engines
appear the best adapted for the use of this kind of
fuel of any yet constructed.  We regard, however, a
very large extent of grate with a moderate depth of
coal as still more likely to attain to superior results.
For a 17-inch cylinder, let the grate be 6 feet by
31 feet, the depth of fire-box being  3  feet, and
having two or three water bridges 4 inches in thickness traversing its entire length.  We are of opinion
that anthracite might be burned in such a fire-box with
increased effect in the production of steam, and with
a diminished waste in the metal of the fire-box and
grate bars. With such a furnace, a pair of small
wheels would be necessary to support the hind end
of it.




74           THE LOCOMOTIVE ENGINE.
The difficulties encountered in the use of hard coal
arise chiefly from the intense and concentrated heat involved in its combustion, thereby destroying the grate
bars and scaling the inside of the fire-box.   This
rapid burning out of the grate has led to leaving
off the ash pan on the coal engines on some of the
Pennsylvania roads, which appears to remove to some
extent the destructive results attending the use of
the coal. The ashes and cinders falling upon the
track, if they do not immediately cause a fire, which
must be guarded against, soon form an impenetrable
crust along the entire line, which removes all further
danger from that source.  This, though it may appear
somewhat improbable at the first view, accords with
the experience of the roads where it has been tried.
Much difficulty has been met in the use of copper
tubes, as the action of the coal, from being projected in
small pieces by the blast, was found to cut them away
near their mouths. This difficulty suggested the use
of wrought iron tubes, which, however, require much
caution in setting them, as the increased force necessary to head up their ends is apt to spring or bend
the tube sheet. A method has been practised with
much success on the Pennsylvania roads, which is to
turn off an inch or more of the end of the wrought
iron tube in the form of the frustum of a cone,
thereby reducing its thickness one half at its extreme
end. The tube is then placed through the tube sheet,
and a thin thimble of copper, an inch in length, and
previously turned off in the same manner as the
tubes, is driven into the mouth of the tube, with its
sharpest edge foremost. After being driven as far as
it will go, the thick edge projecting outwards is turned
over and headed in the usual manner.
The creation of sufficient blast by the action of the
exhaust steam has also been attended with some diffi



THE LOCOMOTIVE ENGINE.            75
culty. Anthracite requires for its proper combustion
a very steady and quite powerful blast, which the
intermittent and fitful action of the blast pipe of a
locomotive fails of producing. It has been attempted
by many arrangements, however, to render this kind
of blast regular and capable of giving the required
intensity to the fire.
The pipe described as passing up through the
smoke-box of Winans' engine, has this result for its
object. Although the steam enters the bottom of this
pipe by sudden and violent impulses, the pipe must
be filled with steam, which will issue in a very regular
manner from the top of it, where its action is first
employed in causing a draft through the tubes. It
has also been tried to obtain a regular blast by letting
the exhaust steam into a receiver or box a foot in
diameter and a foot high, this box being in the middle
of the smoke-box.  Eighteen one-inch tubes in the
top of this box afforded exit for the steam. This plan,
however, from the resistance caused by the steam on
the reverse side of the piston (being solicited to
escape through so difficult a passage,) has rendered its
operation inefficient.
- If future experience determines the exhaust steam to
be insufficient to give a proper blast for burning
anthracite, it will become necessary to adopt some of
the varieties of bituminous coals, or a mixture of anthracite and bituminous coal. We think, however, the
exhaust steam will be found sufficient for burning the
former, under ordinary circumstances, with a large
extent of fire-box surface.
We will now notice a few other patterns of engines
from which our remarks on burning coal have arrested
our attention.
The " John Stevens," by Norris, Brothers, of Philadelphia, had 13-inch cylinders, 34-inch stroke, and




76             THE LOCOMOTIVE ENGINE.
one pair of eight feet drivers.  This engine was
intended to burn coal. Its operation, however, was
not attended with the anticipated results.
0. W. W. Bayley, of the Amoskeag Machine Shop, at
Manchester, N. H., has lately built an engine with 15inch cylinders, 24-inch stroke, and two pairs of seven
feet drivers.  There were two stout shafts, resting in
bearings beneath the frame, and between the cylinders
and driving axle.  Each of these shafts had two stout
arms keyed to it, the one in a line with the piston rod,
to which its upper extremity was attached by a link;
the other outside the frame, and which, by the connecting rod attached to it, communicated motion to the
driving wheels.  The use of this arrangement was to
obtain the supposed advantages of inside cylinders
with an outside connection.  If the proposed object
was to reduce the height of the boiler from the rails by
avoiding the use of the crank axle, we think it might
have been better attained through the use of outside
cylinders, placed midway on the boiler, and connected
to the hind pair of drivers. It could not be supposed
that the use of inside cylinders would contribute to
give the engine a steady motion on the road, so long
as the power was applied outside the wheels. Had
the cylinders been placed as near as they could set to
the forward pair of wheels and clear them, it would
have been merely necessary to let the valve stems
enter the steam chests on the front side,
G. S. Griggs has lately finished an engine for the
Providence road of the following general particulars - 14 —inch cylinders; 18-inch stroke; about a
44-inch boiler; 9 —feet tubes; six driving wheels,
supporting the entire weight of the engine, and being
48 inches in diameter.  These wheels had chilled
rims, and were all cast with flanges.  One pair of
wheels was behind the fire-box, and the connecting rod




THE LOCOMOTIVE ENGINE.           77
was applied to the middle pair of wheels. From the
center of the hind pair of wheels to the center of the
middle pair, was 5 feet, 3 inches; from the center of
the middle pair to the center of the front pair, was
6 feet, 9 inches; making the entire distance between
the extreme axles 12 feet. There was perhaps - inch
end play on the axle of the back pair of wheels, none
to the middle, or crank axle, and about l inch in the
front axle. The engine had inside cylinders, inclined
so as to allow the cross-heads to clear the forward
axle.  There was an  equalizing bar between the
middle and hind pairs of wheels, and an independent
spring over the forward pair.
The performance of this engine in the transportation of freight is mentioned as extremely good, and it
is stated that the engine travels through a curve with
all the facility of an engine of the usual pattern.
One of Hinkley's ten wheelers on the Northern
road was altered by taking out the truck frame and
putting in another pair of drivers. This could be
done only by setting the new drivers very far forward,
and by springing up the smoke-box end of the engine,
as the cylinders in this pattern, though somewhat
inclined, were not intended to admit another pair of
driving wheels. The distance between the extreme
axles of this engine is 15 ft. 6 in.; the two middle
pairs of wheels have no flanges, and no end play was
allowed in any of the boxes. The engine is said to
draw a much greater load than when running with the
truck frame, and is also said to ride as freely around
a curve as before the alteration was made.
We have never believed the use of extra large
wheels on our narrow gauge roads would afford proper
grounds for their general introduction.  The high
point at which the power of the steam must be applied
to work a seven or eight feet wheel, gives the engine




78          THE LOCOMOTIVE ENGINE.
greater leverage in its action on the rails, and consequently involves an increased expenditure for repairs,
both on the road and on the machine. The use of
large wheels presents a choice of two bad arrangements: the boiler, to get an inside connection, must
set very high, so as to clear the cranks; while the
only means of reducing the height of the boiler is to
carry the cylinders outside, and to subject the whole
engine to an injurious and sometimes dangerous oscillating motion, owing to the comparatively wide distance between the points at which the power is
applied. Whichever plan may be adopted is found
to possess its disadvantages.  True, a pair of large
drivers may be placed behind the fire-box, but one
pair of wheels, and at that point also, does not give
the engine sufficient adhesion to the rails.
On the whole, we do not believe the proposed
advantages supposed to result from the use of a 3-feet
stroke will ever compensate for the injurious effects of
outside cylinders, with large wheels.  The present
speed of railroad travelling is as great as can be
economically maintained, and any attempt to increase
it increases in a higher ratio the expense of repairs
and renewals. In support of our opinion we can confidently assert that no instance can be adduced of a
narrow gauge engine in this country, having a wheel
larger than six feet, where it has been thoroughly
tested and its use approved of.  The high speeds
attained by 5-'-feet wheels, with the express trains on
the Worcester road, prove that a very rapid rate of
travelling may be reached with an ordinary sized
wheel.
Although we regard the only sure means of running quick to be found in perfecting and smoothing
our roads, reducing the grades, easing the curves, and
laying the road with more care for smoothness and




THE LOCOMOTIVE ENGINE.           79
stability, still we do not deny that a large wheel would
be better for light express trains, running chiefly to
transmit important despatches; we do not, however,
think the use of such engines would be advisable in
running our regular and heavy trains.
There are many roads where trains of two or three
cars are run by twenty two-ton engines. The injury
sustained by the permanent way, from the continued
passage of such unnecessarily heavy machines, has
drawn a considerable degree of attention to the subject
by practical, railroad men, both in this country and in
Europe. On the Eastern Counties line, in England, a
steam carriage, having engine, tank, and car, on one
frame, the engine having 8 in. cyl., 12 in. stroke, 5 ft.
wheel, and 255 feet heating surface, and the car capable of seating 84 passengers, was placed upon a branch
road, and was found to require but 11I lbs. of coke per
mile, against 311 lbs., the average amount consumed
by the heavy engines before used. The whole carriage,
in working trim, weighed 15 tons, 7 cwt., and with an
additional car, making accommodation in all for 150
passengers, ran at an average rate of 37 miles per hour.
The use of this mode of traffic, where admissible, is
attended with a great diminution in the working expenses, and in the repairs of the line where it is
employed.
To carry 120 passengers on the present system, the
weight of engine, 22 tons, tender, wood and water,
15 tons, baggage car, 8 tons, and 2 passenger cars, 20
tons, must be included. This gives upwards of 1,200
lbs. dead weight to each passenger carried, or a train
of 75 tons, at an average speed of 30 miles per hour.




SECTION IX.
Tables and Calculations relative to the Locomotive.
IT is a very useful and interesting mental exercise to
calculate the power, capacity, and other particulars of a
locomotive. By an acquaintance with the expressed
values of engines, deduced from natural principles, or
being perhaps the results of experimental research, our
minds become habituated to a better conception of their
properties. At the same time, we require to have the
means of knowing the capabilities of any machine in
order to direct or suggest any improvements in its arrangement; and likewise to know that we are in possession  of all the capabilities in the  engine, which
science can point out.
We therefore commence this section with a table
which we have computed for the lengths of stroke and
diameters of wheels of our American engines, and
which is intended to express the speed of the piston
compared with that of the circumference of the driving
wheel, the speed of the latter being taken as 1.  The
use of this table we shall immediately proceed to show.
DIAM. OF DRIVERS.
Stroke
of   42 in. 43 in. 46 in. 48 in. 54 in. 60 in. 66 in. 72 in. 78 in. 84 in.
Piston.
16in..2425.2369.22.2122.122 1886.1697.1543.1415.1306.1213
18.27281.2665.2491.2387.2122.1910.1736.1591.14691.1364
20.3031.2961.27681.2652.23568.2122.1929/.1768. 16321.1516
22.33356.3257.3045.29181.2594.2334.2122,.1946.1795.1668
24.3639.3554.3321.3183t.2829.2g46.2315.2122.1959.1819




THE LOCOMOTIVE ENGINE.           81
Now to calculate the tractive force of a locomotive:
multiply the sum of the areas of the two pistons by the
effective pressure per square inch, the effective pressure
being understood as the pressure in the boiler minus
the pressure of steam barely sufficient to keep the
engine and tender by themselves just in motion;having the product so obtained, multiply it still further
by the decimal coefficient corresponding to its length of
stroke and diameter of wheel, as found in the preceding
table; this last product expresses the tractive force of
the engine, in pounds.
To illustrate the meaning of traction, we will suppose a deep pit to be sunk in the middle of a level
track; let a weight in the bottom of the pit have a rope
attached to it, the rope passing over a pulley, at the
mouth of the pit, and being secured at its other end to
the draw iron of a locomotive.' The weight which the
engine could raise in this manner, entirely through the
adhesion of its drivers, is equal to the tractive force of
the engine.
Example.  What is the tractive power of a locomotive having 17-inch cylinders, 22-inch stroke, 43-inch
wheels, and effective pressure 80 lbs. per square inch?
The area of a 17-inch piston is 226.98 sq. inches.
" two cylinders, therefore, 453.96"'
And   453.96
80
36316.80.3257 the coefficient of the given wheel and
stroke.
11828.38 lbs., the product, which is the traction of the engine. The traction varies, however,
according to the weight of the engine, for which this
calculation does not provide.
The resistance offered by the friction of one ton on
6




82          RTHE LOCOMOTIVE ENGINE.
a level railroad is the same as that of drawing up
through the pit a weight of 10 pounds.* That is, 10
lbs. weight attached to a load of one ton, and passing
over a pulley so as to act with its full weight on the load,
would keep it in motion. Hence, to find how many
tons the above engine would draw on a level, divide
the traction already found by 10, the amount of traction necessary to overcome the friction of one ton on a
level, and the quotient is the desired answer.
Thus:       10)11828(1182+ tons drawn by the
17-inch cylinder engine on a level.
Another rule for obtaining the traction of an engine,
and deduced from the above, is to multiply the effective pressure per square inch by the square of the
diameter of the cylinder, that product by the length
of stroke, and divide the whole by the diameter of the
wheel in inches.  Thus, the above example would
become,
289 square of 17-inch cylinder.
80 lbs. pressure of steam.
23120
22 length of stroke.
43)508640(11828 lbs., as before.
The application of this rule, it will be seen, does
not require the use of the table of decimal coefficients.
In going up a grade there is a certain tendency to
roll down the hill, occasioned by the force of gravity.
A portion of the tractive power of the engine is to be
expended in overcoming this tendency of gravity, as
well as thefriction of the load.
To obtain the gravity, in pounds, of one ton on any
grade: multiply 2240, the number of pounds in a ton,
* On a smooth road, with cars in good condition, the friction
is 8, and sometimes as low as 7 pounds per ton.




THE LOCOMOTIVE ENGINE.           83
by the height of the grade, and divide the product by the
length of the grade. To obtain the gravity of one ton
on a 47-feet grade, (the grade of Ward Hill, in Bradford, Mass.,) we multiply 2240 by 47, the height of
the grade, and divide the product by 5280, the number of feet in one mile, or the length of the grade; the
quotient is 19.9 lbs., which is the gravity of one ton
on a grade of that pitch. To this must be added the
friction of: one ton, already given as 10 lbs., and the
whole tractive power of the engine is to be divided by
their amount, thus:
29.9)11.832(395.7 tons, answer.
A simpler rule deduced from the above is to multiply
the height of the grade per mile in feet, by the decimal.4242, which gives precisely the same answer; thus,
47 x.4242=19.9 -+ lbs.
N. B.-The weight of the engine and tender is
not included in the above answers.
The friction of the engine and tender absorbs from
4 to 6 lbs. per square inch on the piston, and if the
engine is not in good order, it will take more.
To find the quantity of water evaporated by an
engine in going a certain distance, we can multiply the
area of the piston by the length of stroke, or by that
part of the stroke into which dense steam is admitted,
where a cut-off is used; this gives the capacity of one
cylinder, which, multiplied by four, gives the amount
of steam used at one revolution. Then divide the distance of your journey by the circumference of the
wheel, and make a discretionary allowance for slipping; this gives the number of revolutions made by
the drivers in going the given distance, which, multiplied by the amount of steam used at one revolution,
gives the entire quantity of steam used in going the
entire distance. The question now arises, what part of
this steam is water, or rather, what amount of water




84          THE LOCOMOTIVE ENGINE.
was required to generate this amount or volume of
steam at the given pressure? We can ascertain this
by reference to the table on page 12. Suppose the
given pressure of steam was 110 lbs. per square inch;
opposite this pressure in the table is 241, the number
of cubic inches of steam generated under a pressure
of 110 lbs. per inch from one cubic inch of water.
Divide, therefore, the whole amount of steam of 110
lbs. used in the journey, by 241, and you have the
amount of water evaporated to generate that steam.
Ex. How many gallons of water would an engine
evaporate in running the distance from Boston to
Lowell, 26 miles, the engine being of the following
dimensions: 15-inch cylinder, 18-inch stroke, 5-feet
wheel, pressure 100 lbs. per inch, and cutting off at
half stroke?
176.71 area of 15-inch piston in square inches.
9 - inches of stroke into which dense steam is
admitted.
1590.39 amount of steam used by one cyl. at one stk.
4
6361.56 amount of steam used at one revolution.
Now get the distance in 26 miles by multiplying
by 5280, the number of feet in a mile, thus:
5280
26
15.708)137280(8739 revolutions in going
26 miles, the divisor, 15.708, being the circumference
of the driver in feet and decimals.
The number of revolutions, 8739, being multiplied
by the quantity of steam used at one revolution,
6361.5 cubic inches, the product is 55593148 cubic
inches of steam used in going 26 miles. Now the




THE LOCOMOTIVE ENGINE.            85
pressure is 100 lbs.; and by the table on page 12, one
cubic inch of water makes 260 cubic inches of steam
of that pressure. Now the whole quantity of steam
used, divided by 260, gives the quantity of water
evaporated to generate that steam, which is, we find
by dividing, 213819 cubic inches; and this amount,
divided by 231, the number of cubic inches in a wine
gallon, gives 925.6 gallons used, which corresponds
very nearly with the actual quantity used by an engine
of the given dimensions, and running on the Lowell
road. It will be seen we have made no allowances for
slipping, nor for any loss of steam by blowing off.
We sometimes wish to know the amount of advantage gained by using steam expansively; that is, the
advantage gained by cutting off steam at any fraction
of the stroke. Suppose the induction port to a cylinder to remain open during one stroke of the piston,
thereby admitting steam enough to fill the entire
capacity of the cylinder, and of the same pressure as
within the boiler. We will then suppose the amount
of work done or load raised by that engine to be represented by the number 3.  Take then the same
cylinder, place the piston at the end of the stroke, and
admit steam by the valve until the piston has gone
through one-third the distance of the stroke. Now
the load raised by the engine is either the same load
as when full steam was used, but to only one-third the
distance, or one-third of the former load to the same
distance. In either case the work done is represented
by one-third the number used to represent the former
load, and that number being 3, the work done when
the piston has gone through one-third of its stroke is 1.
But when the piston is at that point of its stroke, onethird of the length of the cylinder is filled with steam
of the same pressure as in the boiler; this steam
therefore acts upon the piston, at first with its full




86           THE LOCOMOTIVE ENGINE.
pressure, but as the piston moves along, thereby increasing the capacity of that end of the cylinder, the
steam expands and presses with a diminished force,
until the piston has arrived at the extreme of its
stroke; when the steam which was admitted until the
piston was at one-third stroke, has now become expanded into three times its original volume, and
thereby has only one-third of its original pressure
remaining. But it has pressed upon the piston with a
constantly diminishing force during the last two-thirds
of the stroke, and has thereby contributed to the
useful effect of the engine.  The steam  originally
admitted, after performing an amount of work represented by the number 1, has performed during the
last two-thirds of the stroke a still further amount of
work, which in reality should be represented by a
number a trifle over 1, making the entire useful effect
derived from one-third of a cylinder full of steam, a
trifle more than two-thirds of what it was when a full
cylinder of steam was used. It is evident that none
of this additional useful effect, derived from the expansive property of steam, could have been obtained
had steam of full pressure been constantly admitted
upon the piston throughout its whole stroke.:  Were
there sufficient steam in a boiler to fill a given cylinder
12 times full, the pressure in the cylinder being the
same as in the boiler, and the work performed by
using this steam  through the whole stroke of the
piston to be represented by 12, it follows that by filling only one-third of the length of the cylinder at
each stroke, there would be sufficient steam for 36
strokes, the effect of each being represented by 2, and
of the whole, 24 or twice the effect obtained by using
the steam at full stroke. And thus it appears that
although you can never obtain the full effect of the
engine except with full steam, still, more work can be




THE LOCOMOTIVE ENGINE.           87
done by expansion, when compared with the amount
of steam used. Hence there is a very great economy in
employing full steam through but a portion of the
stroke, letting the stroke be completed by the expansion of the steam already in the cylinder.
Again, this principle of expanding the steam in the
cylinder, while it reduces the quantity of steam used,
has no effect on the production of steam in the boiler,
other than what results from throwing a surplus pressure, as it accumulates, upon the water level. By
tracing the practical applications of this advantage, we
find a given boiler may supply a larger cylinder, or a
given cylinder may be supplied by a smaller boiler,
and do more work than with the original proportions
before expansion.  With  expansion, therefore, the
same work may be performed with a reduction in the
weight of the engine, which is a very important advantage. The less the resistance of the load, the greater
may be the extent to which expansion is carried in the
cylinder, and for this reason expedients are sometimes
resorted to for adapting the expansion to the resistance
of the train.
Having thus explained the philosophy which dictates the use of expansion or cut-off valves, we will
give a table by which the effect of the engine may be
estimated for any amount of expansion. This table
is called a table of hyperbolic logarithms, and as an
explanation of the manner in which the table is prepared would encroach upon our limits, and at the same
time be foreign to the character of our work, we will
confine ourselves to the manner of employing this
table, for the purpose of calculating the effect due to
the expansion of steam. We will first present the
table.




88         THE LOCOMOTIVE ENGINE.
TABLE OF HYPERBOLIC LOGARITHMS:
No..y' No.  Lyp.  No.  oyp.  No.  Log.
1.05.049 2.05.718  3.05 1.115 4.05 1.399
1.1.095 2.1.742 3.1  1.131  4.1  1.411
1.15.140 2.15.765 3.15 1.147 4.15 1.423
1.2.182 2.2.788  3.2  1.163 4.2  1.435
1.251.223 2.25.811  3.25 1.179  4.25 1.447
1.3.262 2.3.833  3.3  1.194 4.3  1.459
1.35.300 2.35.854 3.35 1.209 4.35 1.470
1.4.336 2.4.875  3.4  1.224 4.4  1.482
1.45.372 2.45.896  3.45 1.238  4.45 1.493
1.5.405 2.5.916  3.5  1.253 4.5  1.504
1.55.438 2.55.936  3.55 1.267  4.55 1.515
1.6.470 2.6.956 3.6  1.281  4.6  1.526
1.65.500 2.65.975 3.65 1.295  4.65 1.537
1.7.531 2.7.993  3.7  1.308 4.7  1.548
1.75.560 2.75 1.012 3.75 1.322  4.75 1.558
1.8.588 2.8  1.030  3.8  1.335 4.8  1.569
1.851.615 2.85 1.047  3.85 1.348  4.85 1.579
1.9.642 2.9  1.065  3.9  1.361  4.9  1.589
1.95.668 2.95 1.082  3.95 1.374  4.95 1.599
2.693 3   1.099 /4   1.386  5    1.609
To use this table in estimating the gain by expansive force:- Divide the whole length of the stroke
by the distance through which the piston travels before the closing of the cut.off valve; find in the table
the hyperbolic logarithm of the quotient, add 1 to it,
and the amount is the ratio of uniform and expansive
force.
Example. Let the stroke of a locomotive be 18
inches, and the steam cut off at 12 inches; what is
the ratio of the gain? 18 divided by 12 gives for the




THE LOCOMOTIVE ENIGNE.              89
quotient 1l. The hyperbolic logarithm corresponding
to this number in the table is.405, (which we must
remember is decimal;) and adding unity to it, it becomes 1.405, the effect by cutting off at 2 stroke as
compared with 1.5 the effect when using full steam, or.937 of the effect of full steam by using but 3 steam.
In getting the heating surface and capacity of a boiler, we require every extent of surface in the parts
which determine the shape and size of the boiler, in.order to arrive at a correct result. To get the contents of the water room in a boiler, we must first find
the diameter of the boiler in inches, and find by calculation, its corresponding sectional area. To obtain the
area of water section, deduct the sectional area of all
the tubes from one-half the sectional area of the boiler;
then find the average between the width of the center
of the boiler, that is, its diameter, and the width of the
water level, and multiply this average by the depth of
water above the center of the boiler.  This, added to
the water section in the lower half of the boiler, gives
the entire water section. Now, multiply this by the
length of the cylindrical part of the boiler; multiply
the width, depth and thickness of the water spaces
together; make the proper deduction in the contents
of the back water space for the door, and in the front
water space for the tubes, which pass through it; multiply the area of the crown sheet by the depth of water
on its surface, and make the proper deduction for
the stay bars; and the entire contents in cubic inches,
divided by 1728 for cubic feet, or by 231 for wine
gallons, will give a pretty accurate result for the capacity of the boiler.
The steam room of the boiler is calculated very much
in the same way. The steam section in the cylindrical
part of the boiler is obtained by deducting the water
section and tube section from the boiler's sectional




90          THE LOCOMOTIVE ENGINE.
area, this being multiplied by the length of the cylindrical part of the boiler, as for the water content.
As the circle of the outside fire-box is generally a little
larger than that of the boiler, a separate calculation
should be made for this part. The content of the
dome must also be found, and a deduction made for the
steam pipe. In getting the extent of heating surface
on the tubes, we must calculate it from the outer
circumference of the tubes; for, although the fire is
only in contact with their inner circumferences, the
whole thickness of the tube becomes heated, so that the
outer circumference has the same temperature to heat
the water as the inner circumference receives from the
fire. The English engineers reckon the tube surface
of a locomotive as but one-third as effective as the firebox surface, so that an engine with 54 square feet of
fire-box surface, and 660 square feet of tube surface,
would be reckoned as having only 54 plus 220, or 274
square feet of heating surface.
In getting the fire-box surface we should reckon
every square inch of heated surface in contact with the
water, which would of course be the four sides and the
crown sheet, deducting only the areas of the outsides of
the tubes, and the space occupied by the door, and the
bar riveted around it. The heating surface of the firebox could not be considered as extending below the
grate.  We have already said that the practice is sometimes to reckon only the back, sides, and top of the
fire-box as heating surface, but we should suppose that
a man having woodland, pasturage and mowing land,
might with as much propriety give the size of his mowing fields for the size of his farm.
The surface of the grate is of course simply the
length and breadth multiplied together.




TEHE LOCOOTIVE ENGINE.            91
We have already given the manner of calculating the
ratios of the safety valve levers, on page 63.
There can properly be no such expression as the
horse power of a locomotive. The difference between
a stationary and a locomotive engine, is such that while
the former raises a load, or overcomes any directly
opposing resistance, with an effect due to its capacity of
cylinder, the load of the locomotive is drawn, and its
resistance must be adapted to the simple adhesion of
the engine, and which may be varied even as the
rims of the wheels are of wrought or cast iron, as the
rails are in good or bad order, as the grades of the
track, the speed of the engine, and various unsettled
circumstances which cannot well be resolved so as
to give an expression of the power of the locomotive in
the term, horses' power.
Stationary steam engines are applied to a vast variety
of purposes, but locomotives are only required for one
kind of work. A cotton manufacturer negotiating for a
steam engine would not care to know how many feet of
lumber were sawed, nor how many bushels of grain
were ground by a certain sized engine, nor would a
miller wish to know the power of an engine for spinning cotton or weaving cloth. The standard of a horse
power serves as a standard of comparison, and its
utility as a unit of reference is not impaired whether it
represent the actual power of one horse, or three, so
long as the standard is universal. But as the work of
a locomotive is all of one character, it becomes an
object to know the actual power of an engine in drawing freight or passengers, in preference to referring it
to any doubtful standard, not expressing its capabilities. This we have illustrated at the commencement
of this section, but for the assistance of such as may
have occasion to estimate the horses' power of a station



92           THE LOCOMOTIVE ENGINE.
ary, or even a locomotive engine, we will give the
usual rule. It is as follows: multiply the area of the
piston, the pressure of steam per square inch, the number of revolutions per minute, and the length of stroke
together, divide the product by 33,000, and take 17O of
the quotient for the effective horses' power of the
engine.
It is a received law in mechanical science, that the
effect of a machine is to be estimated from its weight or
elemental power multiplied into the space through
which the power acts. Our readers will detect that in
the above rule we have directions to employ but onehalf the speed of the piston to get the power of the
engine. For instance, a 16-inch cylinder engine is
usually rated as a 50-horse engine; but if in calculating its power we employ the actual speed of the piston in feet per minute, we shall find our engine to have
100 horses' power.
If a horse raise 150 lbs. through 220 feet in a minute, or, through the application of wheels and axles,
levers, &c., he raise 33,000 lbs. one foot high in a
minute, then what is usually termed a one-horse engine
will raise 66,000 lbs. through the same distance and
in the same time.  We have always supposed that the
reason for taking but one-half the speed of the piston
in estimating the power of an engine, arose from the
fact that the steam engine was employed on its first
introduction in pumping water from mines, and for
raising water for towns, where only one stroke of
the engine was effectual. A horse may raise a constant load of 33,000 lbs. one foot per minute, but in
pumping he could raise but half that sum, for one-half
of his time would be expended in driving the piston of
the pump downwards.  Hence though our present
allowance for a horse's power answers every purpose




THE LOCOMOTIVE ENGINE.           93
for a standard of reference to determine merely the
comparative power of engines, still we shall contend
that our usual manner of getting the power of an
engine gives us but one-half the proper amount of its
capabilities.
We will give an example illustrating the rule we
have given for estimating the horses' power of a steam
engine.
What is the horses' power of an engine, having a 14inch cylinder, 42-inch stroke, the pressure of steam
being 71 lbs. per square inch, and the fly-wheel making
37 revolutions per minute? N. B.-The speed of the
piston to be obtained in the usual manner, by multiplying the number of revolutions into the length of
stroke.
153.94 sq. in. area of a 14-inch piston.
71 lbs. per square inch.
10929.74 lbs. entire pressure on the piston.
Now we wish to ascertain the number of feet the piston travels per minute, or rather half the actual number:
37 number of rev. per min.
31 length of stroke in feet.
129.5 speed of piston in feet per min.
10929.74 pressure on piston.
129.5 speed of piston.
33000)1415401 (42.9 horse power.
And -7O of this quotient is 30 horses' power, the power
of the engine.
To get the capacity of a tender tank, we must first
obtain the extent of surface on the bottom of the tank,
which, multiplied by its height or depth, and reduced
to gallons, gives its capacity. To illustrate this cal



94           THE LOCOMOTIVE ENGINE.
culation, we will give a diagram of Hinkley's tank for
a six-wheeled tender.
Radius of corners a, a, and a', a', 6 inches.
Depth of tank 35 inches.?he part A may be considered as an exact parallelogram, since the surface cut off by the corners a, a,
is again made up by those at a', a'. The sum of the
two semicircular terminations b, b, of the wings B, B,
has of course the area of one entire circle two feet in
diameter; and these semicircles reduce the length of
the straight part of the wings B, B, one foot.  Hence
the area of the surface of the tank is as follows:
85 x 66         5610   area of part A.
66 x 24 x 2     3168      "  " wingsB,B.
452     "  " terminations b, b.
9230 sq. in. surface of tank.
35 depth of tank.
323050 cub. inches in tank.
This last product, expressing the contents of the tank
in cubic inches, may be divided by 231, and we shall
have the capacity of the tank in gallons. This we find
to be 1398p   gallons.




THE LOCOMOTIVE ENGINE.             95
The young machinist will readily perceive there is
no difficulty in making any of these calculations, as
they involve only the simplest rules of arithmetic,
while their solution forms a very useful and interesting
mental exercise. It is an excellent idea for any one
wishing to get thoroughly acquainted with the steam
engine, to measure and preserve the proportions of
every engine;th:at may come in his way; these dimensions sooner orf later assume a high value to the possessor, inasmuch as he finds them convenient for
reference in comparison, estimation, or in designing
new work.  They also serve to bring him in closer
acquaintance with the principles of the mechanical
science involved in the theory and the practical construction of the steam engine.
To get the area of a circle. Square its diameter,
that is to say, multiply the diameter into itself, and
multiply this product by the decimal number.7854;
the last product will be the area of the circle.
Example 1. What is the area of a 17-inch piston?
17
17
289.7854
226.98 square inches area, answer.
Example 2. What is the sectional area of a steam
pipe 4~ inches inside diameter?
4.5
4.5
20.25.7854
15.904 square inches area, answer.




96            THE LOCOMOTIVE ENGINE.
N. B.-In multiplying with decimal numbers, we
must recollect to point off as many places from the
right hand 6f the product for decimals, as there are
places of decimals in the multiplier and multiplicand
taken together.
To get the circumference of a circle, multiply the
diameter by 3.1416, the product is the circumference.
Another method is to multiply the diameter by 355,
and to divide the product by 113. To those accustomed to proportion, this rule might be presented thus:
113: 355:: diameter: circumference.
These two numbers may be readily carried in the
mind from a slight peculiarity in the order of their
arrangement. By setting the two numbers down in
the following manner, it will be seen there are two
ones, two threes, and two fives, thus: 113355.
Examples. What is the circumference of a copper
tube 2 inches in diameter?
3.1416
2
6.2832 inches, answer.
What is the circumference of a driving wheel 66inches in diameter?
66.5
355
113)23607.5(208.9 in., answer.
N. B.-In dividing with decimal numbers, we must
point off as many places for decimals in the quotient,
as, taken with those in the divisor, if any, will equal the
number of decimal places in the dividend. Division is
the reverse of multiplication, and the divisor and quotient are factors, of which the dividend is the product.




THE LOCOMOTIVE ENGINE.          97
What is the circumference of a 5-feet driving wheel?
Five feet reduced to inches, becomes 60 inches.
355
60
113)21300(188.496 inches, answer.
TABLE OF THE AREAS OF PISTONS.
Diam.      Area.       Diam.       Area.
10 in.    78.540       141- in.   165.130
101-      86.590      *14a-      170.873
11        95.033       15        176.715
11:      103.869       15-       188.692
12       113.097       16        201.062
121-     122.718       16 —      213.825
13       132.732       17        226.980
13~-     143.139       171       240.528
14       153.938       18        254.469
TABLE OF THE CIRCUMFERENCES OF DRIVERS..
Diam.    Circumference.    Diam.    Circumference.
42 in.    131.94 in.    60 in.    188.50 in.
43 "     135.08 "      66 "      207.34"
46 "     144.51 "      72 "      226.19"
48 "     150.80 "      78        245.04"
54 "     169.64 "      84 "      263.89 "
* Size of Grigg's cylinders on the Providence Road.
7




SECTION X.
Miscellaneous Notes and Observations.
THE principal locomotive concerns in this country at
the present time, are the following:
Portland Locomotive Works, Portland, Maine,
Horace Felton, Superintendent.
Amoskeag Manufacturing Co., Manchester, N. H.,
Oliver W. Bayley, Superintendent.
Essex Company at Lawrence, Mass.,
Caleb M. Marvell, Superintendent.
Lowell Machine Shop at Lowell. Mass.,
William A. Burke, Superintendent.
Boston Locomotive Works, Boston, Hinkley, Drury,
and others, Proprietors,
D. T. Child, Treasurer.
Union Works, South Boston,
Seth Wilmarth, Proprietor.
Globe Works, South Boston,
John Souther, Proprietor.
Taunton Locomotive Manufacturing Company, Taunton, Mass.,           W. W. Fairbanks, Agent.
Matteawan Machine Works, Fishkill Landing, New
York,                   W. B. Leonard, Agent.
Norris Locomotive Works, Schenectady, N. Y.,
Edward S. Norris, Proprietor.
Rogers, Ketchum, and Grosvenor, Paterson, N. J.
Swinburn and Smith, Paterson, N. J.
Ross Winans, Baltimore, Md.
Baldwin and Whitney, Philadelphia, Pa.
Norris, Brothers, Philadelphia, Pa.
Denmead at Baltimore, a shop at Richmond, Va.,




THE LOCOMOTIVE ENGINE.           99
and an establishment at Cleveland, Ohio, also advertise to build locomotives.
In Boston, the Maine, the Providence, and the
Worcester Railroads have built many engines for themselves.
The Springfield Car and Engine Co., and the Ballardvale Machine Shop at Andover, Mass., have been
nearly closed, and the manufacture of locomotives at
those places has been entirely suspended.
Jabez Coney, of South Boston, built at his shop, in
1847, two locomotives for the Old Colony road.
The price of a first class 21-ton passenger engine,
varies according to the style from 6800 to 8000 dollars.  Freight engines, from being built from heavier
patterns, generally cost more.
Below we give estimates of the weights of some
of the principal parts about a locomotive, and about
the average prices usually charged for such items.
42-inch boiler, 7500 lbs., a 14c.  -    $1050.00
135, 14-inch copper flues, 101 feet long,
2500 lbs., a 30c.                       750 00
Turning and driving thimbles, settino do. &c.   30.00
Solid engine frame, 2500 lbs. a 6c.     - 150.00
Jaws of wrought iron, 1000 lbs. a 10c.    - 100.00
Finishing frame,               - -    -    - 150.00
4 Driving wheels, for 51 ft. di. 6000 lbs. a 3c. 180.00
1 Crank axle, 6- in. finish, 1500 lbs. a 18c.  270.00
1 Straight axle, 650 lbs. a 10c.  -    -   65.00
2 Truck axles, 3- in. journals, 480 lbs. a 6c.   28.80
4 Truck wheels, 30 in. diameter,    -    -   70.00
4 Lowmoor tires, 51 ft. 2850 lbs. a 13c.   - 370.50
Finishing wheels, cranks, and axles,    - 200.00
2 Cylinder castings, 15 inches in diameter,
1600 lbs. a 3c.       -    -    -    -   48.00
Boring cylinders,   -    -    -    -    -   50.00
2 Rough connecting rods, 360 lbs. a 8c,   -   28.80




100          THE LOCOMOTIVE ENGINE.
The prices given are perhaps a fair average, and the
whole table may serve to show about the usual weight
of the heavier and more important parts of a locomotive.
In regard to explosions, we do not believe any well
made boiler ever gave way to do any serious damage,
except through a want of water in it. If the water is
suffered to get below the upper row of tubes, the fire
generally burns them out, the water rushes into the
fire-box and extinguishes the fire, thus preventing all
danger; but enginemen have sometimes found their
water entirely run down, and the flues entirely spoilt
by the fire, but not burnt out. We recollect, and perhaps others who may read this will recollect also, of an
instance on the Lowell and Lawrence road where an
officer of the road undertook the management of an
engine, and succeeded in boiling every drop of water
away, burning the wooden lagging off the boiler, and
burning the tubes so as to make it necessary to replace
every one of them, though they were not burnt through.
When the water is boiled entirely away, and the internal shell of the boiler becomes heated red hot, the
admission of cold water generally produces an explosion.  Some attribute this to the immediate decomposition of the nitrogen, one of the principal gases which
enter into the composition of water, and leaving the
hydrogen to explode by the intense heat. But the
presence of oxygen is necessary for the explosion of
hydrogen gas, and a very distinguished chemist has
averred that there can be no oxygen in a boiler filled
with steam.  A recent theory is that of the spheroidal
state of water when thrown upon a red hot plate. The
water, it is stated, when thrown upon a plate heated to
a very high rate of temperature, assumes the spheroidal
state, rolling over the plate in smooth globules, like a
mass of melted lead; while in this state no steam can
be produced from the water; but when the tempera



THE LOCOMOTIVE ENGINE.          101
ture of the plate falls to a certain extent, the water becomes almost instantaneously converted into steam of
intense and overwhelming elasticity, and the consequence is, the boiler gives way in the weakest part.
We would not wish to revive in this place the question of the explosion on the Providence road, about
which there was so much diversity of op'nion; but we
must say, that in that instance, the report of the commission, notwithstanding its high autho ity, hardly succeeded in satisfying the minds of a large portion of the
public.
A recent act of the Massachusetts Legislature requires that the boiler of every stationary, locomotive
or marine engine, running within the State, shall have
a fusible plug in the crown sheet of the furnace.  To
answer this requirement, a lead plug, inch in diam.
is tapped into the crown sheet of a locomotive furnace,
so that when the top of the fire-box becomes uncovered with water, this plug may melt, and by letting
the steam escape into the fire-box, give notice of the
danger.
At the introduction of railroads, engines were built
with cylinders no larger than 8 inches in diameter. In
1840, we think there were no engines with cylinders
larger than 12 inches.  In 1844, we had 131-inch
cylinders, by'47, 15 inches; and now Perkins, on the
Baltimore and Ohio Road, is building an engine with a
20-inch cylinder. The gauge of our roads remains the
same now as it was a dozen or fifteen years ago,-four
feet eight and one-half inches inside the rails.  In those
days two trains per day, drawn by the light engines,
were all which the business of a road would warrant.
Now we have twenty to thirty trains drawn over our principal roads daily, by engines averaging from twenty to
twenty-five tons in weight.  These facts are sufficient
to show a vast increase of business wherever railroads




102          THE LOCOMOTIVE ENGINE.
are extended. This constantly growing traffic must, at
no distant period, demand the adoption of a wider
gauge for our tracks. Railroad men prefer engines
with inside cylinders to those having the cylinders outside. Every engine requires apparatus for reversing
and for working expansively, and no better means, we
think, have yet been found to effect these objects
than the use of six eccentrics.  Here the insufficiency
of the width of the track becomes evident; it is only by
economizing every inch of room that sufficient space
can be found to arrange the work of an inside cylinder
engine. It would be a matter of very great convenience were the track wider than at present, and we
believe that the experience of a dozen years at most,
will determine it to be a matter of absolute necessity.
The gauge of the Atlantic and St. Lawrence, and the
Androscoggin and Kennebec roads, in Maine, is five
feet six inches inside the rails, and that of the New
York and Erie railroad is six feet. Wherever a break
of gauge is made, it would seem of importance that the
addition in width should be uniform on all roads, as a
difference in tracks disturbs the traffic, inasmuch as no
means exist of forwarding goods by such roads, except
by changing cars.
Every railroad doing any considerable amount of
business should have sufficient and capacious repair
shops of its own. The increased facility and convenience with which they can do their own repairs, and the
saving in the profits which outside shops charge them,
make it a matter of economy to repair their own work.
For a railroad having fifteen to twenty locomotives, a
shop 120 by 60 feet, and one story high, if properly
laid out, makes a very convenient repair shop. For
such a shop there would probably be required for
tools, &c.,




TEE LOCOMOTIVE ENIGNE.          103
One stationary steam engine (25 horse,) say   $1500
Locomotive boiler with wro't iron flues,  - 1800
"Large engine lathe to swing six feet,    - 1500
"14 feet planing machine,    -    -    -  800
"12  " engine lathe with screw feed,    -  350
"12  "   do.  do. without do.          -  300
"10"   do.  do.    do.  do.            -  250
"Hand lathe for iron,             -    -  175'  do.  do. " wood,          -    -    -  125
"Bolt cutting machine,       -    -    -  250
" Wall drill,      -    -    -    -    -  125
"Suspended drill for tires,    -    -    -  125
" Machine for drawing on wheels,       -   50
" Blower for blacksmith's shop,   -    -   50
"Forge hammer,          -    -    -    -  400
Total,        - $7800
We merely give the above estimate to show with
how few tools and at how little expense the repairing
department of a railroad  may be conducted.  In
arranging such a shop, however, the fancy or belief of
many would lead them to have many additional tools,
such as one 16-feet engine lathe, a compound planer,
(the expense of these two being about $1000); and
for an increased business, some would think a spliner
($500,) and some other tools necessary. We know,
however, of some roads having twenty locomotives, and
doing all their repairs with a list of tools such as is
comprised in our original estimate.
We give below the particulars of the weight and performance of some of the heaviest engines on the Fitchburg road, from the Directors' Report for 1849.  The
whole number of engines on the road on the 31st of
December, 1849, was twenty-five.




104             THE LOCOMOTIVE ENGINE.
N. B.-The following engines were built by Hinkley,
with the exception of the " Boston," which was built
by Lyman and Souther, of South Boston.
Athol,   15 in. cyl. 20 in. stroke, four 41 ft. drivers,& truck outside cl.
Concord, 15 " "  20 "       "     41" "     "    " "      "
Shirley,  14" "  18"  "    " 5 "   "  "  "  inside "
Lincoln,  16 " "  20    "         41 ~   
Camb'dge, 15    18    "        " 5 "     " ""  5"  "
Littleton, 15 " "  18"  "        5 
Boston,  16" "  20"   "        " 5.  "   "   "  "   " 
Fitchburg, 16 " "  20"  "   "  5 "   "   "  " 
Ontario, 16 " "  20"   "   six 46 in.   "   "  "  "
X          R S        o g          
lbs.  lbs. ibs. Galls. Cords
wat'r. wood.
Athol,          40,000 30,000 27,000 1,400  1    six. 10,419
Concord,        40,000 30,003i27,000 1,400  1      "   19,348
Shirley,        34,000 24,00' 23,700 1,200  1      "   23,222
Lincoln,        46,600 30,9j1 29,000 1,600  1.J  eight. 19,050
Cambridge,      40,000 28,00 )127,752 1,400  1    six. 25,182
Littleton,      40,000 2S,00 ) 27,700 1,400  1'"  25,474
Boston,         46,000 30,009 30,000 1,500  1A   eight. 29,000
Fitchburg,      46,600 30,900 29,000 1,600  1     "   12,792
Ontario,        47,000 36,000 28,058 1,600  1l     "   9,515
The "' Champlain," an engine of the same dimensions as the " Ontario," ran 24,628 miles in the same
time.
In regard to the strength of boiler iron and the
effects of high temperatures upon it, it was ascertained
from experiments made by a committee of the Franklin Institute, that at a temperature of 32', the freezing
point, the cohesive strength of boiler iron was 1 below
its maximum, and that its strength increased as an
additional temperature was applied, until it had reached 570 degrees Fahrenheit, when the iron was found
to have attained its maximum strength. Above this
point the strength of the iron was diminished; at




THE LOCOMOTIVE ENGINE.          105
720~ it had the same cohesive strength as at 32~, or ~
below its maximum; at 1050~ one-half its greatest
strength; at 1240%, one-third; and at 1317o, nearly
one-seventh. Copper follows a different law, as every
addition of temperature above the freezing point appears to weaken it.  At 529~, it has but three-fourths
its greatest strength; at 812~, but one-half; while a
temperature of 1300~ entirely destroys its cohesive
force.
The adhesion of the wheels of an engine is about
one-fifth the weight when the rails are clean, and either
perfectly wet or perfectly dry, but only from one-tenth
to one-twelfth the weight when the rails are damp or
greasy. Thus, for a rough calculation, a 25-ton engine will have 5 tons adhesion, and as the resistance of
a train on a level is about S-y-q, such an engine should
draw, including its own weight and that of its tender,
1,000 tons on a level. This would be its maximum
load at a slow speed.
We recollect the published report of the performance
of one of Baldwin's six-driver engines, the " Ontario,"
in 1845, on the Philadelphia and Reading road. The
train consisted of 150 cars fully loaded with coal, the
weight of the coal being 759 tons, and of the coal and
cars 1180 tons.  The engine, it was stated, moved
along alone with this extraordinary train at a rapid
rate. A four-wheel engine, having its entire weight on
the drivers, drew from  Lowell to Boston, in July,
1849, a train of one hundred and twenty-nine cars,
mostly loaded. This engine had 13~ inch cylinders.




106             THE LOCOMOTIVE ENGINE.
S  Having completed the original design of our little work.
we would devote a spare page to some particulars of the present state of the railway system, which must prove interesting
to all.
According to the Railroad Journal, there were at the commencement of 1849, 18666 miles of finished railroad in the
world, costing ~368,567,000, or about 1800 millions of dollars;
also 7829 miles of unfinished road, which at the estimate of
~146,750,000, would give in all, 26485 miles of railroad, costing
2400 millions of dollars, all of which has been invested since
1830!
In July, 1850, there were 7742 miles of Railroad in the
United States, 2423 miles of which are in New England.
Whole amount expended on roads in operation since 1834,
$300,000,000.
At the end of 1848 there were in Great Britain and Ireland
5127 miles opened, 2111 miles in progress, and 4795 miles
authorized, but not commenced. On 4253 miles opened, in
United Kingdom, on May 1, 1848, there were 52,688 operatives. On 7388 miles of unopened road, there were 188,177
operatives. The total amount of money and securities paid
into Railroad treasuries on these lines to the commencement of
1849, was one thousand millions of dollars, while the companies
retained power to raise by existing shares, new shares, and
loans, the further sum of ~143,717,773.
In 1850, there were 24 roads in France, of 1722 miles, and
including portions constructing, but not finished, 2996 miles.
Average cost per mile, $128,240. Fare per mile: First class,
$3.07; second class, $2.31; and third class, $1.77.
In 1849, there were 2294 miles of road opened, in Austria,
Prussia, and the German States.
In Belgium, 347 miles, owned by government.
In Holland, about 110 miles.
In the north of Italy, there is a line, partly finished, from
Venice to Turin and Alexandria. When the proposed tunnel beneath the Alps shall be completed, this road will form
a main link in the great direct railroad line from London to
the Adriatic.
There are short roads in nearly all the States of continental
Europe, except in the States of the Church, where the Pope
has opposed their introduction. And Russia, aided by American energy and skill, is opening a vast road between her two
great capitals, Moscow and St. Petersburg.




A GLOSSARY
OF TERMfS APPLIED TO THE MACHINERY, AND TO THE
OPERATION OF THE LOCOMOTIVE ENGINE.
[N. B. Many of the names and terms here used, are explained at
greater length in the body of the book.]
Adlhesion. The measure of the friction between the tires of
the driving wheels and the surfaces of the rails. The adhesion
varies with the weight on the drivers and the state of the rails,
but with a good rail is generally from one-fifth to one-seventh
of the weight on the drivers. The load drawn is no measure
of the adhesion, except the resistance of friction and gravity of
the load be given.
Air Chamber. A tight vessel attached to the pump. The
feed water, entering it at the bottom, is subjected to the pressure of air within it, which forces out the water in a steady
stream. Recent engines have two air chambers to each pump,
one on the suction, and one on the forcing side of the same.
The capacity of air chamber should equal that of the barrel of
the pump.
Angle of Friction. That pitch of grade at which a loaded
car would just stand without descending, being kept at rest by
the friction of its bearings. Allowing the friction to be 7 lbs.
per ton, this grade would be 16A feet per mile; for 10 lbs. friction per ton, 23A feet per mile.
Ash Pan. A box or tray beneath the furnace, to catch the
falling ashes and cinders.
Axle. The revolving shaft to which the wheels are secured.




108                    GLOSSARY.
Blast Pipes. Two pipes, contracted at their mouths to discharge the waste steam from the cylinders. Their action
excites an artificial draft or blast in the furnace.
Blow-off Cock. A cock at the bottom of fire-box, through
which to empty the boiler.
Boiler. The source of power; the vessel in which the steam
is generated.
Bonnet. A wire cap or netting, surmounting the chimney
to keep down the sparks and cinders.
Box. A bearing, enclosing the journal of a revolving shaft.
When made in two parts, the lighter is called the cap. When
made as a single piece, and supporting the end of an upright
shaft, a step; and when turned outside and fitted into a frame,
or stand, a bushing. To reduce friction, boxes are lined with
soft metal.
Brake. A block or strap applied to the rim of a wheel, to
check its motion, and bring it to a stop.
Bunters. Guards projecting from the ends of tenders and
cars, and connected with springs, to prevent shocks from
collisions.
Camb. A plate or pulley, turning on a shaft out of its center. When made round, and encircled by a strap, and employed to work the valves of a steam engine, and for similar
purposes, is called an eccentric.
Case. A casting sliding in the jaw, and to hold the brass
box of an axle. For drivers, the case is lined with Babbitt
metal, and forms the bearing for the axle.
Check Valve. See Valve.
Counterbalance. A large block secured between two arms of
each driving wheel, to balance the momentum of the moving
machinery connected with the axle.
Connecting Rod. Rod to communicate the pressure on the
piston to the crank.
Crank. In inside cylinder engines is forged in the axle, and
for outside cylinders is supplied by a pin in the wheel. The
crank converts the rectilineal motion of the piston to the
rotary motion of the wheels.
Cross Head. A block moving in guides; having the end of




GLOSSARY.                     109
the piston rod secured within it at one side, and a pin to
attach the connecting rod at the other.
Cut-off Valve.  An additional valve, not indispensable, to
shut off the admission of steam to the cylinder, when the piston
has only completed a part of its stroke.
Cylinder. A cylindrical vessel, closed at its ends by covers.
Steam is admitted alternately at each end, to press upon a
block called the piston. The piston is made to fit, steam tight,
to the inner circumference of the cylinder, and the action of
the steam keeps it in motion, from one end of the cylinder to
the other.
Damper. A door, to exclude the air from the furnace.
Dome. An elevated chamber on the top of the boiler, from
which the steam is taken to the cylinders.
Draw Iron. A rigid bar, connecting the engine and tender,
and secured to each by a pin.
Drivers, or Driving Wheels. Those wheels turned directly
by the moving machinery of the engine, and which, by their
adhesion to the rails, propel the engine along.
Eccentrics. See Canzb.
Eduction Port. A passage on side of cylinder to lead away
the waste steam from same, to the blast pipes.
Equalizing Lever. A bar suspended by its center, beneath
the frame, and connected at each end to the springs of the
drivers, to distribute any shock or jolt between both pairs of
wheels.
Expansion Valve. See Cut-off.
Fire-box. The furnace of the boiler.
Foaming. An artificial excitement, or too great ebullition
on the water level, observed when the boiler has become
greasy, or otherwise foul. Generally productive of priming.
Footboard. A plate iron floor, behind the boiler, for the
engineman and fireman to stand upon.
Frame. Made to attach to the boiler, cylinders, axles, and
all cross shafts, and binds the whole fabric together.
Friction, of trains. The friction of the bearings of the carriages, and for every ton drawn, offers a direct resistance of
from seven to ten pounds.




110                   GLOSSARY.
Frost Cocks. Cocks to admit steam to the feed pipes leading
from the tender to the pump; used when the water becomes
frozen.
Gauge Cocks. Cocks at different levels on the side of the
fire-box, and to ascertain the height of water in the boiler.
When opened, water or steam will escape, according as the
level of the water is above or below them.
Gland. A bushing to secure the packing in a stuffing-box.
Grade. The inclination of a road; expressed either by the
number of feet rise per mile, or by naming the distance passed
in rising one foot; thus, a grade of 1 in 330, which is 16 feet
per mile.
Gravity. The tendency which all bodies have to find the
lowest level. The resistance in pounds, occasioned by the:gravity of one ton on any grade, may be found by multiplying
the grade, in feet per mile, by the decimal number.4242.
Grate. The parallel bars supporting the fuel in the fire-box.
Guides. Rods, or bars, lying in the direction of the axis of
the cylinder, and guiding the cross head, to insure a perfectly
parallel motion in the piston rod.
Hand Levers. Levers to work the main valves by hand.
Housing. See Jaw.
Induction Ports. Two passages on side of cylinder, to admit
steam within it,-one port communicating with each end.
Jaw. A stand secured to the frame, to hold the box of an
axle. The' jaw must allow the box to slide up and down
within it.
Journal. The part of a shaft or axle resting in the box.
Lagging. A wooden sheathing around a boiler or cylinder.
Lap. The distance which the valve overlaps on each end
over the induction ports, when in the middle of its travel.
Lead. Distance to which the induction port is opened,
when the piston commences its stroke.
Link Motion. An arrangement for working the valves, described in the body of the book.
Manometer. An instrument for determining accurately the
pressure on a given surface, as a square inch, within the
boiler.




GLOSSARY.                   111
Man Hole. A hole to admit a man within the boiler.
Mud Iole. A small opening at bottom of water space
around fire-box, to clear out deposits of dirt, and other matter
introduced with the water.
Packing. Any substance used to make a joint steam or
water tight.
Pet Cock. A small cock between the check valve and pump,
to see if the latter is working.
Pintal. An upright pin. There is a pintal secured beneath
the forward end of the engine, to connect it with the truck
frame, and to allow of the turning of the truck, independent of
the engine.
Piston. See Cylinder.
Piston Rod. Rod secured at one end within the body of the
piston, and at the other to the cross head. This rod passes
through the cylinder cover, and is made steam tight by packing
secured in a necking, or recess, outside of cover, and called a
stuffing-box.
Plug, Fusible. A lead plug tapped in top sheet of furnace,
to melt and give warning when the water falls below it.
Plunger. The solid piston of a pump, and pressing only by
one end against the water.
Ports. Openings, or passages.
Printing. The passage of water, along with the steam,
into the cylinders, when the engine is working.
Rocker Shaft. A shaft rocking in its bearings.
Reversing Lever. A lever in reach of the engineman, acting
upon the valve motion, and to change the direction of the progress of the engine.
Safety Valve. A valve on the boiler, to discharge the surplus steam generated, above what is required for the engine,
and which by accumulating would endanger the safety of the
machine.
Slide. See Guide.
Smoke-box. A chamber at forward end of boiler, where the
smoke and sparks from the tubes are received and discharged
through the sparker.




112                    GLOSSARY.
Sparker, or Chimney. A pipe to discharge the smoke and
waste steam, and surrounded by a casing to retain the sparks.
Springs. These are required over each wheel to reduce
shocks and jolts.
Steam Chest. Box on top, or side of cylinder, and containing the valve to admit steam on the piston.
Steam Pipe. Pipe entering the dome, and communicating
with the steam chests through two branch steam pipes in the
smoke-box.
Stuffing-box. See Piston Rod. Used in all situations where
a rod or spindle, having any end motion, requires to be made
steam or water tight around same.
Sub-Treasury. A receptacle for sparks. Slightly different
from those at the custom-house, but quite as beneficial.
Stroke. The distance travelled by the piston at each period
of its motion.
Tender. A separate carriage, to carry wood and water.
Thimble. A tube of iron or steel.
Throttle Valve. A valve in the dome, and closing the mouth
of the steam pipe.
Trailing Wheels. A pair of small wheels, placed behind the
drivers, when but one pair of the latter is used.
Traction. Differing from adhesion in this: The adhesion is
the power of the engine derived from the weight on its driving
wheels, and their friction on the rails; while the traction is
also the power of the engine, but derived from the pressure of
the piston applied through the crank and radius of the wheel.
These two elements may not always be the same.
Truck Frame. A separate frame, supporting four or six
wheels, and turning on a pintal, independent of the body of
the engine or car.
Tubes. These are used to conduct the heat from the firebox, through the waist of the boiler, to the smoke-box. aVhen
a tube is so large as to require to be made of plates, riveted
together, it is called a flue.
Valve. Any gate or fixture, other than a cock, to close a
steam or water passage about an engine. The main, or port
valve, which admits steam directly to the cylinders, is a block




GLOSSARY.                    113
with a recess or cavity on its under side. The steam passes by
the ends of the valve into the ports, and the motion of the
valve, derived from the eccentrics, admits the steam at the
proper time.
The uses of the cut-off and safety valves have been described.
The pump valves are either what are calledtball valves,
spindle valves, or cup valves. The check valve is an additional valve on the forcing side of the pump, and is to prevent all
danger of forcing back the water from the boiler into the pump,
by the action of the steam.
Variable Cut-qof. An arrangement to alter the travel of
either the main, or cut-off valve, to use full steam through a
greater or less distance of the stroke.
Variable Exhaust. An arrangement to enlarge or contract
the blast pipes.
V-Hooks. So called from their form of opening; —much
better than the common kind, as they are sure to catch the
pins, and for this reason (though an old idea) are coming into
general use.
Whistle. A hollow cup made to allow the steam to strike its
lower edge, by which a shrill sound is obtained for signals.
8








INDEX.
PAGE.
Adhesion of Drivers,.105
Alteration of a Ten-wheel Engine on the Northern Road,  77
Anthracite, cost of,.                                 72
Fire-box for burning,.73
difficulties met in the use of,             74
Angle Iron,.                       25
Areas of Cylinders,..                                97
of Chimney,.                   32
Ash Pan,.                    32
Axles. Crank, and mode of manufacture,                  45
Truck,.47
Babbitt's Metal,..60
Baltimore and Ohio Railroad,.                67
Bayley, O. W., Engine by,... 76
Blast Pipe, contraction of,.                   42
for Coal Engine,.                  75
Blow-off Cocks,.....         33
Boilers, details of,...            25
Iron for,.......   25
Bolts,.                          59
Camb Shaft,....   53
Calculations, &c., relative to the Locomotive,.     80
Capacity of Boilers,.34, 89
of Tender Tank,.... 94
Chilled Wheels,.... 44




116                       INDEX.
Chilled Tires,                                         45
Chimney, (see Sparker,)
Chests, Steam,.41
Circumferences of Drivers,                              97
Cleaning greasy wood-work,......   63
Coal Engine by Ross Winans,.69
"John Stevens,".75
Experiments on,.70
Connecting Rods,                                        50
Composition for Packing Rings,.49
Copper Tube Sheet,.                                   27
Cross Head,.50
Crank Axle,                                             45
Cylinders,.                                            39
Outside,.78
Cut-off, principle of,.                                85
to estimate amount of advantage of,.           88
manner of working,.                53
Damper,                                                 32
Description of the Locomotive Engine,.                 15
Dome,.29
Draft, shutting off in going through bridges,.         62
Driving WVheels,.                    44, 109
Eccentrics,.109
Engines, details of,.                              25-60
on Baltimore and Ohio Road,.                  67
on Fitchburg Road,.                          104
by Bury, Curtis & Kennedy,.36
by Thacher Perkins,.37
by Taunton Loc. Mfg. Co.,                      35
Equalizing bar,.                                      46
Estimate for Repair Shop,.    3
of cost of Locomotive Power,                  66
Experiments on Coal Engine,.                          70
Explosions,........  100
Evaporation of Water,.83
Fire-box,.16




INDEX.                      1 17
Flues, (see Tubes,)
Frame,....                                             43
Outside,......             48
Freight Engines,.....                                 68
Friction of Trains,...                         82
Fusible Plug,......101
Gauge Cocks,.                         32
Glass Tubes,.....            33
of Tracks,...                                102
Glossary,.                                            107
Grate,.                      28
Covering up,.                                    28
Area of,...   34
Griggs, G. S., Engine by,..76
Gray's Variable Cut-Off,..                       54
Gravity of Trains...                                 82
Hinkley's Engines,.                                   34
Heating Surface,. 34, 90
Hooks,.                                             53
Iron, for boilers,.......   25
strength of,.104
Introduction,.........    3
India Rubber Springs,.......   47
Iron Tender Frame,....                       48
Jaws,.                                            43, 110
"' John Stevens" Passenger Engine,..         76
Joints, about pump,...                 59
Putty and ground,.                          41, 62
Steam Chest,                                    41
Steam Pipe,.                                    41
Keys,.                                                 59
Lap of Valve,..                         57
Latent Heat,.                        7
Large Drivers,.                                       77
Level of Water,.....   16




1 18                     INDEX.
Lead of Valve,.                                       19
Link Motion,.                                          53
Locomotive, details of,....                      25-60
performance of,.104
cost of,.                                 99
cost of power,                             66
Shops in this country,.                   98
Load drawn by Engines,.                              105
Lowell Machine Shop, Engines by,....         34
Mahogany Dust to prevent scales,.              62
Middle Tube Sheet,.                                   27
Mud-hole Plugs,.33
Norris, E. S., Engine b....      68
Oil used on Engines,.66
Open Spring,.47
Outside Frame,.48
Cylinders,.                                    78
Passenger Engines..             68
Packing,.62, 111
Composition for Rings,.49
Pipes,.41
Pistons,.49
Pintal.                                            48, 111
Priming,.10, 111
Properties of Steam,                                    5
Proportions of Boilers,                                34
Power of Engines,. 81, 91
Pumps,..                                             58
Reversing Apparatus,.53
at full speed,                               65
Repair Shops,.                                       102
Rocker Shafts,.                                      51
Running Engines,.61
Safety Valves,.                                      30
Sand-box, use of wears out the wheels,.              63




INDEX.                     119
Sand-box on Coal Engine,...                  72
Setting Valves on Locomotives,...             55
Sharp, Brothers & Co.'s Link Motion,                    54
Slade and Currier's experiments and report,...   70
Slides,.....,..   50
Slipping the Wheels,.......   72
Souther, John, Engine by,...                 34
Engine on Fitchburg Road,.       104
Solid Frame,..... 43
Spheroidal State of Water,...    100
Springs,..... 46
Sparker,..... 31
Steam, properties of,....                           5
Steam Carriage on the Eastern Counties Line,            79
Stephenson's Link Motion,....  53
Engine by,.35
Estimate of power expended in blast pipe,   42
Strength of Boiler Iron,.                  104
Stuffing Boxes, packing for,....     63
"' Sub-Treasury,".32, 112
Tables and Calculations,.                   80
Circumference of Drivers,...    97
Hyperbolic Logarithms,.               88
Coefficients of Speed of Piston,             80
Temperature and Elasticity of Steam,.       12
Proportions and Dimensions of Engines,       34;
Performance of Engines,...    104
Testing Safety Valves,.                   63;
Ten-wheel Engine on the Northern Road,                 77
Throttle, opening for,....  62.
Tractive force of Engines,...81
Truck Frame,....  47
Tubes, setting do.,.                                  27
on Coal Engines,.                   74
Tires, setting and removing do...                44
Chilled,...                      45
Tyng's Heating Apparatus,                              38




1.2{                     INDEX.
Valves,..                                    39, 112
Valve Motion,.                                        51
Stem,.40
Vaidiable Exhaust,.                   62, 113
throw of Valve,..                            54
V-Hooks,..53, 113
Water Room in Boilers,.34
to calculate,.89
Water evaporated,... 83
Bridges,.                                      73
Waste used,.66
Wheels.                                                44
wrought iron,.45
Chilled,.                                      44
Whistle,.       31
WVinans, Ross, Engine by,.69
Coal Engine on Worcester Road,.        73