? j' .'/ai I 'tis /J ^i^y,^^ . mm , ^^ 'iilW0^ Mi'iW Eift i. 1. Hill IGtbrarg ?fiirth (Earoliiia ^tatp CToUpqp .r.r ^v:^.- CHARLES E.WADDEIvL To follow knoufleJye like a sinking star BeijonJthe utmost hounJ of human thought. " it r -■: .t ■ This book should be used in the Library- building. n ;2 3 'I I»A.PKRS 03S^ FRA.CT1CJLJL. ENGHNKKRING. U. S. ENGINEER DEPARTMENT. No. 9. PRACTICAL TEEATISE OK LIMES, HYDRAULIC CEMENTS. MORTARS. CONTAINING REPORTS OF NUMEROUS EXPERIMENTS CONDUCTED m NEW YORK CITY, DURING THE YEARS 1858 TO 1861, INCLUSIVE. BT Q. A. GILLMOEE, A. M., BBIO.-aSNBBAL OV U. 8. VOLUKTEERS, AND MAJOR U. S. CORPS OP ENGINBBB8. rOTTHTH EDITION, REVISED AND ENLARGED. D. VAN NOSTRAND, PUBLISHER, 23 Murray Street and 27 Warben SxREn'. 1872. •".05 15 D Entered according to Act of Congress, in the year 1872, BY D. VAN NOSTRAXD, In the Office of the Librarian of Congress at Washington. ]::TOTE. The experiments and researclies, wliicli fumisli the groundwork for all the original matter contained in the following work, were conducted under the authority of the Engineer Bureau of the War Department, and were completed in the summer of 1861. The manu- script was nearly ready for the publisher at the same time. Since then, active professional duties have rendered it impossible for me to devote even a brief personal superintendence to the publication of the work. I am, therefore, not insensible to the many disadvantages under which its hasty publication is now undertaken. It doubtless contains many defects. For the method of analysis given in Chapter V., I am indebted to Captain E. C. Boynton, U. S. Army, late Professor of Chemistry in the University of Mis- sissippi. Q. A. GILLMOKE, Brig.- General. HaAD-QuABTEBfl, DkPT. OF THK SoUTH, ) PoBT RoTAL, S. C, June 15, 1863. ) PEEFACE TO THE FOURTH EDITI0:N". In preparing the fourth edition of this work for the press, it has been thought proper to give, in an Appendix, brief descrip- tions of the two methods, one by hand and the other by machinery, followed in making the several qualities of Portland cement concrete, applied, for various purposes, in the construction of the fortifications on Staten Island, New York Harbor, of which the author has charge as superintending Engineer. The special information given has been derived from the ex- perience of two working seasons — 1870 and 1871 — and all the data with regard to the cost and proportions of the constituent ingredients — the cement, lime, sand, gravel, and broken stone — as well as the cost of the finished concrete in position, may be relied upon as correct, within reasonable limits. The Appendix also contains a description of the new concrete mixer, in use on the works, a drawing of which serves as a frontispiece to this edition. A new and carefully prepared index has been inserted in place of the old one, and the work has been, in other respects, essentially revised and improved. Q. A. GILLMOKE, Bvt. Major-GeiieraZ, U.S.A. New York, January, 1872. STl^OPSIS OF CONTEl^TS. CHAPTER I. Geographical and geological localities of hydraulic cement in the United States. — Analysis of various specimens from Virginia, New Jcisey, New York, Massachusetts, and Mississippi. Pages 15-27. CHAPTER II. Precautions employed in procuring cements for testing. — Appliances for testing the transverse strength, hardness, and adhesive properties of mortars. Pages 28-35. CHAPTER III. Rosendale cement. — Location and capacity of the manufactories. — Cement worlis at Shepherdstown, Va. — The Round Top cement works near Hancock, Md. — The Cumberland cement works. — The James River cement works. — The works at Utica, La Salle Co., 111. — Sandusky, Ohio. Louisville, Ky. — Kensington, Conn., and Akron, Manlius, and Chitte- nango, N. Y. — The Portland and the Roman cements. Pages 36-66. CHAPTER IV. Common lime, and lime mortars. — Hydraulic limes and cements. — Natural pozzuolana and trass. — ArSnes. — Artificial hydraulic cement and lime. The use of alkaline silicates. — Silicatization. — Endurance of hydraulic mortars and betons in sea-water. — Opinions thereon of Marshal Vaillant, ! Inspector-General Noel, MM. Ravier, Feburier, Vicat, and other French authorities. Pages 67-109. CHAPTER V. Diversified character of limestone beds. — Method of testing the stone ex- perimentally. — Qualitative and quantitative analysis. — Analyses of vari- ous cements, limes, trass and pozzuolana. — Kilns for burning cement and method of burning. — Effect of varying the intensity and duration of the heat. — Preservation and restoration of cements. Pages 110-173. 14 CONTEXTS. CHAPTER YL Mortar defined. — Aggregates. — The use of sand. — Method of slaking lime. — Action of hydrates in air and under water. — Mill-made mortar. — Hand- made mortar. — Composition and cost of mortar used in Forts Rich- mond, Tompkins, and Warren.— Pointing mortar. — Interior and exterior plastering. Pages 174-223. CHAPTER YIL Concrete or beton. — How made and used. — How laid under water. — Com- position and cost of concrete used at Forts Richmond, Tompkins, and Warren. — Use of concrete at Toulon, Algiers, Marseilles, Cherbourg, Dover, Aldemey, etc. — Tables giving strength of various kinds of con- crete. Pages 223-358. CHAPTER Till. 2\eat cement made semi-fluid with excess of water. — Superiority of Portland over the natural quick cements, when so employed.— Comparison of Portland and Roman cements. — Adhesive properties of American ce- ments. — Transverse strength of various mortars. Pages 259-293. CHAPTER IX. Mural efflorescences. — Induration of mortars of fat lime. — Theory of hydrau- lic induration. — The hardening by artificial means of stone, brick, mortar, etc. Pages 293-316. APPE^TDIX. Description and cost of several kinds and qualities of concrete used in the construction of the fortifications on Staten Island, New York Harbor, during the years 1870 and 1871. — Description of new concrete mixer. Page, 317-326. A PKAOTIOAL TREATISE ON LIMES, HYDRAULIC CEMENTS, MD MORTARS. CHAPTEK I. INTKODTICTION. 1. Nature has supplied us with limestones in great profusi m and endless variety. Those suitable for common lime are so widelj diffused, and have such an extensive development in this country, that no attempt will be made, — nor An abundance would it be consistent with the character and stonerin the' scope of a work devoted to the consideration of United states. " mortars," even under the most comprehensive signification of that term, — to particularize the numerous localities where its manufacture is extensively and successfully carried on. 2. Lnpure or compound limestones, possessing the property of hardening under water after being calcined, and reduced by slaking, or by the aid of mechanical means, to Compound lime- the state of paste, although more rare than the fn^numerousX"'^ common limestones, nevertheless occur in numer- calities. ous localities in the United States ; and from the great and peculiar value, as a cementing material for submarine and sub- terranean constructions, of the mortars derived from them, they merit a more detailed notice. 3. The most extensive beds have thus far been discovered in the valleys of the great Appalachian chain of mountains, as they traverse the States of New York, New Jersey, Peunsyl- 16 PEACTICAL TREATISE ON LIMES, vania, Virginia, Tennessee, and tlie norihern portions of Georgia and Alabama. They are, however, by no means con- fined to those States, but have been found to some extent in the northern terminus of this range, as it passes through Massa- chusetts and Yermont, at the forks of the Kennebeck, and other places in Maine, and in the northern counties of Missis- 8ippi. In a westerly direction, and beyond the lateral limits of the great Appalachian Yalley, in the western regions of New York, Pennsylvania, Yirginia, and Tennessee, as well as in Kentucky, Ohio, Indiana, and Illinois, the same kind of stone exists in numerous and extensive deposits. 4. There is no geological formation to which the term " hydraulic lime" or " hydraulic cement" can with propriety be exclusively applied, inasmuch as we find none which, over extensive areas, and in localities widely separated, is capa- „. , , ble of furnishing uniformly either the one or the stone suitable for other of these products. All sedimentary rocks hydraulic lime or i <» i i ■, • • . ■, . cement is very are noted lor the marked variations in their variab e. lithological characters, within very limited areas, owing to the existence of local causes, afiecting the conditions of their deposition. This is specially the case with those impure limestones of which the composition is such as to render them, as an exceptional class, suitable for hydraulic mortars, — a circumstance due to their peculiar geological position. They the usual ingre- usually contain, in widely varying proportions, dients the same, carbonate of lime, carbonate of magnesia, silica, alumina, oxide of iron, and a small amount of alkali, and are generally comprised in the beds of passage between deposits that are purely silicious or argillaceous, and those tliat are purely calcareous or dolomitic. They therefore, in the general case, derive their character from the contiguous underlying and overlying rocks, and approximate more intimately to the one or to the other, in proportion as the causes operathig during the period of formation unduly favored its deposition. If a limestone, for example, was formed upon a sandstone, by the HYDRAULIC CEMENTS, AND MOETARS. 17 gradual and progressive subsidence of calcareous particles, commenced and carried on before the deposition of the silicious matter was completed, the intermediate beds created by this mingling process would be a silicious limestone, with propor- tions depending on the manner of deposition, and the nature and extent of the causes by which it was produced and regu- lated. It could be uniform only while those causes remained fixed and persistent. The intervention of local disturbances of whatever extent or character, tending to hasten, retard, or ren- der intermittent tlie deposition of either of the principal ingre- dients, would of course modify their proportions, and materi- ally affect the cliaracter and properties of the compound rock. 5. Observations show that the argillaceous and argillo- magnesian limestones of the United States are characterized, in an eminent degree, by variations in composition, due to such causes ; and that these variations frequentlj^, and, in fact, generally, occur within very short distances, 6. At the base of the Lower Silurian System we find the Potsdam Sandstone, the lowest known fossiliferous rock, and interesting in this connection from the fact that it, in a mea- sure, imparts hydraulic character (by supplying the silica) to the calcareous deposits resting upon it. In New \r ^ j.\ ' J J. • JL' T 1^6 Potsdam 1 orK, tins sandstone is a tirm quartzose rock ; Sandstone under- while, in some portions of the West, the cohesion caicareoiIsTeds between the particles is so slight that it can be possessing hy- easily crumbled in the hand. It occurs of various shades of yellow, red, and gray, approaching to white, and is most intimately related to the calcareous beds which underlie it. In many places, it gradually passes into easily recognized compact magnesian limestone, sometimes alternating with the calcareous beds above. This sandstone corresponds to Formation I. of Prof. Eogers' classification of the rocks of Pennsylvania and Yirginia. 7. The next rock in the ascending series belongs to Forma- tion II., known as the calcareous " sandrock," or, more com- 2 18 PEACTICAL TKEATISE OX LIlfES, monly, " calciferous group," whicli, in both composition and age, must be regarded as intermediate between the Potsdam "Calciferous Sandstone and the purer limestones above, viz.: Group." ti^g Chazy, Bird's Eye, Black Kiver, and Tren- ton Groups. It is the oldest known fossiliferous limestone, is calcareo-silicious in character, as its name indicates, and is the lowest 'member of the series capable of yielding either hydraulic lime or cement. In many localities, it exhibits the water-lined laminae of deposition in a marked and conspicuous degree. Three distinct masses of this rock are usually observed wherever it pi-esents a fully developed outcrop. 8. The lowest beds are highly silicious, and in the eastern portions of the United States, where it has been most examined, quite compact, being undoubtedly produced by a partial con- tinuation of the Potsdam Sandstone deposit, carried on simul- taneously with that of the calcareous matter, the composition , , , of the rock showing a notable excess of the Its lower, rmddle, ^ and upper subdi- former. 9. The nniddle beds appear to comprise a variable mixture of yellowish sand and carbonate of lime, pre- senting, when newly broken, a gritty and sparkling fracture. They are those to which the term " Calciferous Sandrock" is usually applied. 10. The upper or superior mass more nearly approximates in character to the limestones above, and is very frequently intermixed with argillaceous matter. The appearance of a recent fracture is granular and sparkling, and often exhibits a sub-crystalline structure. This rock, however, assumes at dif- ferent points a remarkable diversity in both its physical appear- ance and its chemical composition. It is synonA'mous with the Barnegat, Newburgh, Warwick, Oolitic, and Slaty lime- stones, the Transition Sandrock of Eaton and the Fucoidal Layers, and with the Magnesian limestones of the "West. 11. The purer calcareous beds which rest immediately upon nTDRAULIC CEMENTS, AND MORTARS. 19 the " Calciferol] s Group" also belong to Formation II. of Prof. Rogers' classification, and are known at different points as the Black Hiver limestone, the base of the Trenton limestone, the Mohawk, Bird's Eye, Bald Mountain, Blue, and Chazj lime- stones, the Transition Limerock of Eaton, Blue limestone of Kittatinny Valley, Pennsylvania ; and, in the West, as the Fos- siliferous limestones, and the Blue limestones and marls. These beds are frequently connected very intimately ' The calcareous with the members ot the group below, and, m beds resting on numerous localities, possess in suitable propor- Group''^s\'iitaWe"^ tions, and in proper combination, those ingre- for hydraulic ' 1 T mortar, dients which confer the hydraulic property. 12. It is unnecessary for our purpose, in a vrork like this, — in which rocks of a particular class, and bearing a close resem- blance to each other in their general features, are discussed Bpecially with reference to their adaptation to a particular use, — that all the technicalities of a strictly geological classification should be kept constantly in view. It will be Between the Buflicient to intimate, in brief terms, that among ftone amU i?e^' those deposits lying above the Potsdam Sand- Utica Slate, many ^ _ , argillo-magnesian stone, and below the Utica Slate or its corre- deposits possess Bponding member, all of which are comprised in ^ ^^ iceneigy. Prof. Rogers' Formation II., are found in numerous places extensive beds of argillo-magnesian limestone, possessing the hydraulic energy in a high degree ; and that these beds occur sometimes higher, and sometimes lower in the series, as deter- mined by causes operating during the period of their forma- tion. They have an extensive development in the United States, particularly along the great Appalachian range. 13. In the State of Xew York, they occupy a narrow belt along the eastern portion of the State, extending from the Ver- mont line in a southerly direction through Williamstown, Leba- non Springs, Pine Plains, Barnegat, and New- Geographical burgh : thence stretchino: in generally parallel localities of the c' ' o & J r principal oiitcropa strips in a southwesterly direction towards the in ^^ew York. 20 PRACTICAL TREATISE 0^• LIMES, New Jersey State line, which it crosses between Unionville and the Long Pond. The same stone is also brought to the surface repeatedly in Xew York, in the counties of Montgom- ery, Herkimer, Oneida, Lewis, "Warren, Clinton, and Jefl'ei-son. In but few of the localities mentioned is the stone manufac- tured into hydraulic cement, and in none, perhaps, have its full capabilities, in this regard been ascertained by adequate experi- mental tests. 14. Within the State of New Jersey this formation continues its course, exhibiting extensive outcrops, lying generally within the limits of a belt or zone from twenty to twenty-five miles in width, which intersects the Delaware Kiver Id !S'6w Jorscy. in the \-icinity of its confluence with the Lehigh. It then crosses into the State of Pennsylvania, and spreads itself over a large tract in the eastern portion of that State, southeast of Kittatinny valley, in Lehigh, Berks, Chester, Lan- caster, and Tork counties, and elsewhere. 15. In Virginia the limestones of this formation also exist in numerous and extensive beds in the counties of Eockingham, Botetourt, Eoanoke, Washington, Kockbridge, Page, Augusta, Giles, and Shenandoah. Cement from the James Eiver and Kanawha Canal has, for several years, been manufactured at Balcony Falls, Kockbridge County. At the present time cement for constructing the Covington and Ohio Eailroad is derived from Dunlop's Creek, a tributary of the James Eiver, a few miles above Covington. There are three cement manufactories on the Potomac Eiver: one at Shepherdstown, Ya., another three miles above Hancock, Md., and another at Cumberland, Md. From the present state of our knowledge, it would be inferred that the beds The Yirginian and , , . "" , . « . . -r^-- • • j Pennsvivaniande- bclongmg to this formation m \ irgmm ana K'S'of s'lSlTfor Pennsylvania are better calculated to furnish a quality to those reliable cement than those found in the more farther North. ^ ,^ , northern parts of the range. In JNew 1 ork, one member of the series — the Black Eiver limestone — was HYDRAULIC CEMENTS, AND MORTARS. 21 formerly made into cement at and near Galesville, Wasliington County, for the Champlain Canal. At Point-aux-Roches, on Lake Champlain, a bed of it five to six feet in thickness exists, which possesses a good degree of hydraulic energy, but haa never been manufactured for the market. The same stratum has been found to yield only hydraulic lime in some localities, and has been used for that purpose at Lowville, Lewis Coun-' ty, N. Y. 16. Among the many analyses that have from time to time been made of specimens from the various deposits of these limestones, those in Table I. have been selected from the most reliable sources of information which were at command. It is proper to remark in this connection, that those given in the table,— having been derived from State Geological Eeports, principally, for the general purposes of which they are doubt- less sufiiciently exact,— ought not, perhaps, to be implicitly relied upon, as the basis of an}'- special or criti- ^ , 1 , . Analysis of the cal research upon the subject of hydraulic above-mentioned mortars and the theory of sub-aqueous iudu- ^^^*«°^^- ration. None of them show the presence of either potash or soda in any form. It is well known, however, that the salts of both these substances exist in some of the quarries exam- ined, and it is fair to infer, from the close resemblance other- wise preserved in the nature and proportion of „ , ,■■ i'i. . J. JT Soda and potash tlie constituent parts, that adequate tests would probably exist in detect a notable quantity in all. The Rosendale ^^ '''''^''^^^■ cements contain them. An easy process for detecting their presence, and measuring their quantity, has yet to be dis- covered, which may account for the fact that ,. . ., , J.1 . . , . , , r*ot easily de- their existence in this class of rocks is so very tected and mea- generally ignored.* ^"''^^ *M. Fred. Kuhlmann, Professor of Chemistry at Lille, and Corresponding Mem- ber of the lustitut de France, submitted a report to the Academy of Sciences of France m 1841, from which the following extract is taken. The subsequent w-i- tings of M. Kuhhnann, down to a period quite recent, sustain the opinions here PRACTICAL TREATISE 0^' LDIES, TAELE L AKALTSIS OF SETERAL OP THE OLDEST FOSSILITEEOrS LIMXSTON'ES OCCrPTINQ POSITIOXS BETWEEX THE POTSDAM SASDSTOXE AXD THE UTICA SLATE. ri > a a > a > _3 = d >- = > » >- ^ - '9 C s o g a S o C3 3 5 e a 5 a' 1 en c' 1 £ [= a !Z3 i e > s 5 1 15 i a S 6 e i c 5-- V. 6 CO .3 •s > = 1 < 5 ■s 3 i 2 a "5 a — 3Q 1 c c aT ■3 s K c i t c c a: 5 = &• X c s 7: a S q n ^ ►5 5^ = !?< 5 93 z Z »! 53.5 3s.& 54.9 34. 5.3.6 41.6 54. 42.5 52. 37.5 46.5 S4.5 50.1 41.5 50.1 35.S 52. 54. 42.5 49.3 52.9 3S.3 44. 53. 41.1 53.3 Carbonate of masmfsia 22.6 Alamica and oxide of iron. . 1.5 1.5 4. .7 2.1 1.2 .7 2.3 .6 1. .1 2.1 1.4 1.7 Silica 1.5 8.5 13. 1 7.4 ii.a 4.7 2.4 9.4 2.2 3.2 6.3 7.5 3.4 20.7 C^bonate of potash and soda 1 .0* Water and loss .5 .5 1. .» .7 .3 .4 .7 .8 1.7 .1 1.5 1.6J Xo cement stone 1 etween the Utica Slate and the Nia- gara Group of the Ontario Division. IT. After passing the argillo-magnesian limestones associated with the " Calciferous Sandrock," and inter- mediate in lithological features between this rock and the purer limestones above, we meet with no calcareous deposit suitable for hydraulic cement until we reach, in the ascending order, the Niagara Group of the Ontario Division, among the beds of passage from the shale to the limestone of that group. Here is found an argillaceous limestone brought to the surface repeatedly in the State of Xew York, in "Wayne County, and in the towns of Rose, Williamson, and Ogden, in Monroe County, This erpressed as to the g:eneral prevalence of the alkaline salts in the hydraulic limes and cements of Europe. Extract. — In speaking of the nature of the efflorescences upon walls, he says : " iles inrestigations sur ce point m'ont permis de constater la presence de la po- tasse ou de la sonde dans la plupart des calcaires de diverses epoques geologiques, et de justtfier I'existenee de ces alcalis dans les vegetaux qui croissent sur un sol cal- caire." M. K. also analyzed the cements of Pouilly, Yassy-les-Avallon, Bou- logne, and the Roman cement from the Septaria, taken from the banks of the Thames, and found potash in all of them, notwithstanding the confirmed opinion of chemists that they contain no alkaline ingredient. American cements contain chlorides of potassium and sodium generally, sometimes as high as 7 per cent HyDKAULIC CEMENTS, AND MORTAES. 23 deposit exposes very good cement stone in Orleans County, at Oak Orchard Creek, town of Shelby, and at Farwell's Mills, town of Clarendon ; also in Niagara Count}", at Lewiston. Among these beds of passage, only those occupying a central position can be relied upon for hydraulic mortar, the layers above being, as a general thing, too highly charged with car- bonate of lime, while those below contain too much clay. 18. Overlj'ing the Niagara Group, we lind, in the Ilelder- berg division, a limestone among the upper beds of the Onon- daga Salt group, sometimes called the Magnesian n Magnesian De- deposit of that group, which furnishes nearly all S'tatllr ^'^' the hydraulic cement manufactured in the group. western part of the State of New York. It appears on the eastern shore of the Cayuga Lake, and further west, in Phelps and Manchester townships, Ontario County, at Williamsville, Grand Island, and Akron, Erie County. At East Yienna it has been used for cement, and at Akron a manufactory of some extent is in operation now. At Morgantown, Genesee County, and at Black Rock, Erie County, the limestones of this group have an extensive devel- opment in connection with those of the Water Lime Group proper. Its full thickness is seen at the Falls of Falkirk. It underlies the village of Caledonia, Livingston County, ex- tending thence easterly towards the Genesee Eiver, and, re- appearing on the other side of that stream, is found at Mendon, Monroe County, and other neiijhborino; localities. 10, Beyond the limits of the State of New York, the layers above mentioned are not found possessing such prominent features as to entitle them to a distinct and separate descrip- tion, but are included in the contiguous groups under a more general classification. 20. Overlying the Onondaga Salt Group, in regular suc- cession, is found, along the great Appalachian range, the Tentaculate, or Water limestone, from which a " Tcntaculate" or very large proportion — perhaps nine-tenths — of " ^\^^'^''''" ^""** ^^' 24 PEACTICAL TREATISE OX LlilES, tlie hjdi-anlic cement manufactured in the United States is de- , . , , rived. It appears to be wanting in the West- Geographical lo -^ -^ " calities of the ern States, or to have been replaced bj the pnncip e s. ^j.g. jj^^ggj-^j^g ^f Ohio. In Xew York, it is found in large quantities in Oneida, Onondaga, Madison, Ul- ster, Sullivan, and Erie Counties. Its principal deposit is in Ulster County, where it furnishes the celebrated Eosendale cement,* so extensively used on the government works on the Atlantic, Gulf, and Pacific coasts, and along the northern frontier. It is quarried for cement at Maulius and Fayette- ville, Onondaga County, and Chittenango, Madison County. The cements from these localities vary very much in quality. A cement manufactory is also carried on at Lockport, Xiagara County, The stone that may be used for cement, occurring frequently along the line of the Erie Canal, occupies, with some local exceptions, two geological positions quite distinct General character from each Other. The lowest layers are mostly stone^bng^the confined to the beds of passage from the shale Erie Canal. of the Kiagara Group to the purer lime- stones above, while the others are similarly situated with refer- ence to the marls and shales of the Onondaga Salt Group and the purer calcareous beds which overlie them. In either po- sition, great care is requisite in selecting the stone for burning, the best cement being generally confined to the middle of these beds of passage — those below being too argillaceous, those above too calcareous. 21. Reserving a more detailed and minute description of the Ulster County deposits for a subsequent part of this work, we will here simply state that they are mostly found within the limits of a narrow belt, scarcely one mile in width, skirting the Principal deposits northwestem base of the Shaw^angunk Moun- of " Rosendaie tains, along the line of the Delaware and Hudson Cement stone. , ^ Canal, in the valley of Rondout Creek, They are * Named from the town of Rosendaie, in which the cement was first discovered and manufactured, during the construction of the Delaware and Hudson Canal, nrDEAULIC CEMENTS, AND MORTARS. 25 not, however, confined to this locality, but can be traced in a Bouthwesterly direction through Ulbter and Sullivan Counties to the State Line at Carpenter's Point, and Jjience, within the State of New Jersey, in a narrow strip along the left bank of the Delaware River, to AYalpack's Bend, where they cross over in- to the State of Pennsylvania. In a northerly direction, this rock has not been distinctly recognized east of the Hudson River. At the mouth of Rondout Creek the belt takes a turn due north, and can be correctly followed along the right bank of the Hudson, a distance of live or six miles, with occasional glimpses of it in detached masses ten or twelve miles higher up. Except in Ulster County, towards the northern terminus of the range, these beds have not been manufactured into cement, and have not, it is believed, been very critically ex- amined with that view. 22. The only limestone in Massachusetts that has ever been employed for hydraulic mortar is that at Paine's Quarry, West Springfield. It is said to be very good hydraulic lime, and contains, by analysis, .93^ of carbonate of lime. Cement stone in .6r% of argillaceous clay, and less than .1 of car- ^^^^sachusetts. bonate of magnesia. Another hydraulic limestone that has been tried, but never worked, is found in the bed of the Chi- copee River, just below the Chicopee Factory. It contains .86xV of carbonate of lime, and .ISy's- of argillaceous clay. Both of the stones just mentioned are fetid and partially bitu- minous. They belong to the new Red Sandstone formation. Nodules of Septaria are found on the Chicopee and at Cabot- ville, and an argillaceous limestone at West Springfield, that are pronounced by Prof. Hitchcock to furnish a cement as energetic as the " Ruman " The following table contains their analysis : 26 PEACTICAL TEEATISE OX LliffiS, TABLE II. Spjitaria froit the ChicoiK-i-. Carbonnte of lime Carbonate of magnesia . . Silica and alumina Oxide of Iron 46.06 20.97 .Vri;illace<>us limcstime, West Spriii;:Iii'ld. >ef>taria from = — Cal>otville. I 1st Sample. 2il Sample. 4.^.69 30.81 39.35 18.33 13.57 3.39 45.33 5.53 26.04 13.45 54.00 6.51 The 2d sample from "West Springfield is but feebly hydraulic. 23. East of Massachusetts, cement stone is found in some localities, but is not used for hydraulic mortar. Deposits exist Cement stone in ^t Machias and at the forks of the Kennebec Maine. Eiver, Me. ; a specimen from the last-named locality, analyzed several years ago by Dr. Charles T. Jackson, contained .54yV of carbonate of lime, .05 of carbonate of masnesia, .028 of carbonate of iron, .024 of silicate of iron and manganese, .27 of silica, .082 of alumina. 24:. 2s ear Kensington, Conn., a good cement stone is found, Cement stone in which is manufactured to a limited extent for noS^Suckv'' ^ocal use. In the West, supplies of this article and Ohio. are derived from Sandusky, Ohio, from Utica, Lasalle County, Illinois, and from near Louisville, Kentucky, at tlie Falls of the Ohio River. 25. The following extract from the forthcoming work of the Cement stone in State Geologist of Mississippi, gives the analysis Mississippi. qj- ^^^.q cement stones found in that State in Tish- amingo County : " Xo. 1 furnishes a cement which sets as rapidly as Plaster of Paris and becomes very hard. Xo. 2 dif- fers from Xo. 1 in requiring more time to harden." See Table III. TABLE in. ■S<,. 1. Silica and insoluble Silica 54.201 Potash 473 Lime 23.247 Magnesia 783 Protoxide of iron .903 Alumina ] . 064 Phosphoric acid Trace Carbonic acid 15. "Water, organic matter, and loss 3 m No. 2. 35.281 .348 32.603 .630 .158 1.914 27.643 HYDEAULIC CEMENTS, AND M0ETAK8. 27 26. No deposits of hydraulic lime or cement stone are found on the Pacific coast, althougli inquiries to a considerable extent have been made. The Rosendale cements are depended upon for hydraulic mortar. 28 CHAPTER II. 27. The method pursued in testing the mortars which fur- nish the basis of all tables introduced into this report, with the exception of those compiled from the labors of others, for the purpose of reference and comparison, is briefly as follows : 28. "With some exceptions that will be pointed out in the proper place, all the samples of hydraulic ce- The cements not ^ ^ j . ^i x- . " • j prepared under meut not prepared at the manuiactories, under the writer's super- ^|^g personal supervision of the writer or an vision were sam- '^ ^ pies from cargoes agent appointed by him, were obtained from in the market. . , , , , , cargoes m the market, by openmg several casks selected at random, and taking two or three pounds from each. This precaution was adopted in order to secure, beyond a ques- tion, samples of an average quality from the respective cargoes, and for the time being, of the respective cements furnished by the several manufactories. 29. Identit}^ in the composition and properties of samples of the same brand, obtained from different cargoes and at differ- ent times, was never assumed. An examination and compari- son of the tables throughout this work, clearly establish the necessity of this precaution. As some manufacturers habitu- ally grind their stone finer than others, and as there is consid- erable difference, in this particular, in cement from the same establishment manufactured at different times, due in part to the difiiculty with which a high degree of pulverization can be secured with newly-dressed millstones, but principally to negli- gence on the part of the miller, it was important that this cause HYDRAULIC CEMENTS, AND MOTITARS. 29 of variation should be eliminated in all the trials, and particu- larly from those which were to furnish the data for a direct comparison of the qualities of the several cements, and of mor- tars of different composition, but particularly those containing large doses of sand. To this end, all the varieties of cement subjected to trial were passed through a fine wire sieve, designated ^o. 80, that is, containing eighty ^cre^sSua fine wires to the lineal inch, each way, or 6,400 '"''■'e sieve No. meshes to the square inch. The sand used for the mortars, when the object was simply to compare the qualities of the several varieties of cementing substance, whether of pure cement, or a mixture of cement and lime, though quite fine, was clean, and tolerably sharp and angular. It is mostly sili- cious, and was obtained from a pit on Governor's Island, New York harbor, between Castle William and Fort Columbus. After being passed through a wnre sieve No. 30, to remove a small per centage of gravel heterogeneously distributed through it, 1,000 parts by weight contained : 1 G3 parts between ■^^j and ^j of an inch in diameter. qi^9 It It _L_ II .L 'I " " 't II •'"•' 4 6 183 " less than ^o Character of tie sand used. CHARACTER OF THE TESTS APPLIED TO THE MORTARS. 30. 1st. Their capacity to resist a transverse strain, which is also a measure of their tenacity. To this end, rectangular prisms were formed in a cast-iron mould, under pressure or otherwise, as specially set forth in each particular case. The base of these prisms was two inches square, their height eight inches. The first that were prepared were formed in a hori- zontal mould, the pressure being applied to the upper side. As it was always necessary to shave off one of the sides of these blocks, in order to reduce the cross-section to a square, the hor- •2ontal mould was soon replaced by a vertical one, measuring 30 PRACTICAL TREATISE OX LDIES, Mortars made in ^ in. by 2 in. by 8 in. in the interior, to one end prisms 2 in. by 2 ^f ^hich the pressure was applied. AVhen the iiL bv 8. and bro- . . ken on supports prisms had attained the requisite age, they were 4 m. apart. broken on supports 4 in. apart, by a pressure applied at the middle point. 31. 2d. Thtir relative hardness. — This was measured by the penetration of a steel point or needle, impelled by the impact of a falling body. The needle, which is shghtly conical, or tapering toward the point, is truncated at right angles to the axis, so as to give a diameter at the lower end of y j of an inch. It protrudes from a socket in the lower extremity of a vertical rod or spindle, to which it is firmly secured by means of a Hardness com- thumb-screw. To the upper extremity of the dfe Vnetrating spindle is attached a diagonal scale of steel, accu- hy impact rately graduated to tenths, hundredths, and thou- sandths of an inch, and provided with a horizontal index firmly fixed to the frame-work of the instrument. The absolute pen- etration of the needle is obtained by taking the difference be- tween the index readings before and after impact. The falling body is a hollow metal cylinder, weighing one pound, of which the exterior diameter is about equal to the length. This cylin HTDRACLIC CEMENTS, AND MOKTARS. 31 dcr, in its descent, passes freely over the spindle, and strikes upon a shoulder attached just above the screw. The mortar used to determine the hardness was that of the broken prisms, and the penetrations were taken the same day, generally but a few hours after they had been broken. As these fragments were 2 in. square in cross-section, and seldom less than 2^ in. long, they admitted of several trials with the needle. An average of not less than four penetrations, and sometimes more, at each end of the prisms, was taken on all occasions, except, when the frag- ment split open at a lower number, which was sometin:ies the case. This instrument will be well understood by referring to Fig. 1. 32. 3d. Their adhesive properties. — This was measured by cementing bricks and blocks of stone together in pairs, and afterwards drawing them apart by a force applied Adhesiveness to at right angles to the plane of the ioint. The '"''^'^ °'" '^"'^^ t' o r J measured. bricks or stone of each pair were arranged at right angles to each other, as seen in Fig. 2, and were kept together under a pressure of 500 lbs., except on occasions specially mentioned, until the mortar had set. 33. The device for applying the pressure to the -tig'- prisms, and to the pairs of bricks or stone, while the mortar was setting, is essentially the same as that heretofore used for simi- lar purposes. It was also used for testing the strength and ad- hesiveness of the mortars, when they had attained '' Device for com- the proper age. The apparatus consists essen- pressing the tially of a bed-piece and two upright posts, about hito moulds, one foot apart, connected by a cross-piece at the ^'">"^'^'"? '>^® ^ ^ ^1 prisms, ^c. top, from the centre of which is suspended a scale- beam, so arranged that it can be elevated or depressed, as oc- casion may require, by means of a screw. The lower hook of this beam is connected with a horizontal lever of equal arms, so that any weight indicated by the beam will be transmitted without loss to th? reverse end of the lever, and will then act 32 PEACTICAL TREATISE 0:S LIMES, as a downward pressure. The application of this pressure to the breaking of prisms is explained bj Fig. 3. It is only- necessary to replace the wedge-shaped piece which acts upon the prisms by another which will diffuse the pressure over a horizontal area of greater or less extent — say about one super- ficial inch — in order to adjust the instrument for applying pres- sure to the mortar in the moulds, and to the pairs of bricks or stoue. Fig. 4 represents a prism under pressure. The lower Fig. 4. Fig. 5. Fig. 3. portion of the mould is inserted into a mortise in the bed-plate. In order to measure the force necessary to separate the bricks or stones, they are placed directly under the hooks of the scale- beam, the lower lever having first been removed. The lower brick or stone is then confined to the bed-pieces by staples, keyed from below, while the upper one is embraced by the ends of a crescent-shaped iron, suspended from the hook of the scale-beam, as shown in Fior. 5. 34. In all cases, the moment of rupture was attained as quickly as possible — care being taken to avoid shocks— by ^ , pouring sand into the pan of a sprinor-balance Instant of rup- a o i r o ture to bo at- suspended from some given point on the beam, aine quic y. ^^ shown in Fig. 3, In setting forth the results HYDRAULIC CEMENTS, AND MOETAES. 33 of these trials in a tabulated form, the actual breaking weight and penetration are, in all cases, entered without reduction except in the case of separating the bricks and stone, when an additional column is inserted in some cases, giving the ad- hesive power per superficial inch. 35. The trial with the needle was adopted as the most ready means of measurinor the relative hardness ^, , '' ... ^\yj the test of the several mixtures containing no sand, "with needle was whether of pure cement or a combination of cement with fiit lime, IS'othing further than this was at first expected from it. M. Yicat at one time entertained the opin- ion, which he subsequently qualified and even abandoned, that " the squares of the numbers which express the penetra- tion of the rod are reciprocally proportional to , 1 /. 1 • " 1 -^^^ deduced by the resistances to the force which tends to break Yicat ; abmi- the mortars." General Treussart not only ^^^^d by him. doubts the existence of this law, as not fully established by M. Ticat's experiments, but advances objections to the use of the needle, which do not appear to be wholly tenable, viz : 1st. That it is diflicult to appreciate exactly ■^^ '' General Treus- itS penetration ; sart's objections 2d. That, if it falls upon a grain of sand or '°'^' ''""^^ ''''■ gravel, or even a grain of lime, incorrect conclusions will be drawn ; 3d. That it is applied to the surface of the mortar, which frequently differs in hardness from the interior. 36. It is submitted that the first of these objections cannot apply to an instrument like that shown in Fisr. .^ J.I The first not ten- 1, it constructed with accuracy and used with able when needle care ; the second is equally without force when '^ ""'"'^ ^'^^' ''^'^• no sand is introduced into the mixtures; and even the efiect of sand of fine grains, in large doses, might be re- „ 1 J ^- n • ' ^ ^ .11 The second ditto, garded as practically inappreciable, provided for mortars with- the weight of the falling body and the distance ^^jlJi'^^^ear passed over in the descent are such as to cause impacts. 3 3-4 PRACTICAL TREATISE OX LIMES, deep penetrations. Moreover, an ordinary degree of precaution would suggest the propriety of taking the average of a h\rge number of trials in preference to the results indicated by a single one, when they can be repeated with such ease and rapidity. It is not contended that penetrations from impact aftbrd reliable data for comparing mortars containing diflerent proportions of sand, or sand in different degrees of fineness." The objection urged against deducing conclusions with regard to the quality of a mass of mortar from the results of trials restricted to its surface, is certainly worthy of consideration when mortars of common lime, either with or without sand, are under trial, but is scarcely applicable to hydraulic mix- Remarks on tures. The absolute strength of a mass of third objection. mortar is not the only good quality we seek. Deterioration from the action of the elements first takes place upon the surface in all cases, and it is upon the surface, with- out regard to interior qualities, that the requisite power of resistance against these agents must be conferred. Experience teaches us that those mortars which attain the greatest degree of superficial hardness, as shown by the penetrations of the needle, absorb the least amount of water, and are consequently the least liable to undergo disintegrations from frost or " weathering." The resistance offered at the surface to the penetration of a point acted upon by an impulsive force, there- fore, aflbrds reliable means of judging of a most important property in mortars, even if we admit that our conclusions must necessarily be restricted to their surface. But this is not BO. It is well known that hydraulic mixtures owe very little of their powers of sub-aqueous induration to the absorption of car- bonic acid gas, or to superficial desiccation ; that harden s^ulte^ the setting is not initiated at the surface, but neousiv through- almost simultaneously throuo;hout the mass : and out the mass. ... that the subsequent induration is not augment- ed, but rather retarded, and in some measure even destroyed, by free contact with the air, and the absence of humidity. HYDRAULIC 0EME:NTS, AND M0ETAE8. 35 37. We may safely assume tliat mortars of hydraulic cement, either with or without sand, if submerged, harden so nearly homogeneously throughout their entire thickness, that there is no perceptible difference in hardness at the centre, and at a depth of J- to | of an inch. At any rate, those disposed to entertain doubts upon tliis point can readily convince them- selves, by reference to the tables, that, with individual excep- The strongest *^^'^^' ^^^® mortars which sustain the greatest prisms gave tlie transverse strain give the smallest penetrations least penetrations. • i i -,■, With tiie needle; and it certainly is not un. reasonable to suppose that there may exist a fixed law or pro- portion between the resistances offered to two kinds of forces — one constant, and the other impulsive,— by an inflexible sub- stance like mortar. 36 PRACTICAL TEEATISE OX LIMES, CHAPTER in. 3S. The celebrated Eosendale cements, — so named from tlie fact that the stone was first discovered in the township of The "Rosendale" Rosendale, Ulster County, Xew York, in opening Cement ^]^q jjj-^g Qf ^be Delaware and Hudson Canal — are derived from the tentaculate or water limestone belonging to the lower Helderberg Group, known as Formation YI. in Pro- fessor H. D. Eogers' classification of the rocks of Pennsylvania. As stated in Chapter I., the deposits are mostly found within ^ , . , the limits of a narrow belt scarcelv one mile Geographical " limits of the beds in width, skirtinoj the northwestern base of the Shawangunk Mountains, along the line of the Delaware and Hudson Canal, in the valley of Eondout Creek. The beds are found occupying every conceivable in- clination to the horizon, being sometimes vertical, seldom on a level, and ordinarily dipping at a greater or less degree either to the northwest or to the southeast. The entire face of the country in this region exhibits unmistakable evidences of hav- ing been subjected to a succession of remarkable upheavings ; some of them have evidently taken place while the limestone deposits were as yet in a plastic form, by which the strata, in The beds are tor- niany localities, were twisted into a variety of tuous. complex and tortuous shapes, while others, trans- piring at subsequent periods more or less remote, have ruptured the beds in a variety of ways, fi'equently producing faults, but ordinarily resulting in a multitude of seams more or less open, running diagonally across the planes of stratification. The HYDRAULIC CEMENTS, AND MORTARS. 37 useful effect of these upheavings has been to develop, into accessible and convenient positions, a vast amount of cement Btone, that would otherwise have been buried beyond the prac- ticable reach of ordinary mechanical skill. 39. The aggregate thickness of the several layers of this deposit averages about forty-six feet. This includes several strata, varying from four to twelve feet in total thickness, which are so changeable in character that they , . . Aggregate thick- are nt tor use only in certain localities. The ness of the eev- whole deposit is subdivided into several distinct ^^ ^^^"' layers, which are widely dissimilar, as a general thing, in the color, grain, and texture of the raw stone, and also in their hydraulic properties after calcination. As seventeen layers many as seventeen of these layers can be traced ^ ^ throughout the entire range in Ulster county. 40. JSTo one manufacturer makes use.of all of these beds, and no two of them of the same beds, in the same Not aU used for proportions. This is due, principally, to those <=f™ent: due to , . . ^ r ./ ' tlie changeable marked variations in the hydraulic character of character of stone, the stone, within comparatively short distances, which con- stitute a characteristic feature of this deposit, already referred to in general terms. 41. In Bome localities, the upper layers of the cement bear- ing series have been removed by abrasion, while upper layers in others, the lower ones have been thrust so sometimes absent, and lower ones much out of place by the interposition of other beyond reach. rocks, or are so far below the general surface level, that they cannot be reached with facility or economy. 42. Few of the manufacturers have rendered themselves familiar with the distinctive and peculiar properties of the several layers which they introduce into their combination, in stances being comparatively rare where they have caused them to be quarried, calcined, and ground separately, even for the purpose of experiment. 43. With few exceptions, all the stone taken from a quarry 38 PRACTICAL TEEATISE ON LIMES, bad, not necessa- rily objectionable in a combination. rJ enters into the cement prepared for market. This includes certain layers, or portions of layers, possessing little or no Some inferior hydraulic energy by themselves, on account of stone is used. ^\^q preponderance of inert silica or alumina which they contain, and the absence of homogeneousness in the composition ; other portions, in which the carbonate of lime is largely in excess, and which may be classed among ordi- nary hydraulic limes ; and still others, which are an exagger- ated type of the dividing limes {chaux limites) of Yicat, setting rapidly in water under the most difficult circumstances, suc- cedeed sooner or later by a gradual softening of the whole mass. 44. Although mortars giving rise to the phenomena last- Stone individually mentioned contain an excess of caustic lime, which becomes liydrated very sluggishly, and indeed not until the hydraulic induration has fully commenced, and which, therefore, is insusceptible of prompt neutralization by the sil- ica, alumina, and magnesia pre- sent, in the formation of those tre- ble hydrosilicates that are prac- tically insoluble in water, it does not necessarily follow that their incorporation in subordinate pro- portions, and under judicious re- strictions, into the aggregate pro- duct of a quarry, is injurious. In certain cases, when care is taken to reduce the cement to a very fine powder, with a view to facilitate the hydration of the lime, and to secure a thorough incorporation of the sev- eral kinds of stone used, they are believed to operate beneficially by furnishing those requisite constituent ingredients of good ce- ment not found in sufficient quantity in the contiguous rocks, 2 Light cement or Upper Series. Middle Series. Dark cement or Lower Series. Fig. 6l HTDRAULIC CEMENTS, AND MORTARS. 39 or existing there in proportions capable of consideraLle in- crease, without producing an injurious excess. The marginal sketch, Figure 6, sliows an actual Section of the ,. ^,1 J ., -n ^ • TIT cement deposits section ot these deposits, verined in several locah- of Ulster Co. N.Y. ties, where the layers occur in regular order.* 45. In some localities, where the beds have been upheaved into a vertical position, or nearly so, and the stone of inferior quality occurs in layers of sufficient thickness to sustain them- selves, they are left intact, supported at appropriate intervals by masses of the stone composing the adjacent layers. 46. Some of the most prominent features of these several layers will now be briefly noticed. They were quarried and calcined separately by an experienced workman. For their burning, " try-kilns''^ 7 to 7^ feet high and 20 to 24 inches in in- terior diameter were used, and the object aimed at in each case was to submit every variety of stone to that degree and duration of heat that would produce the best results. Besides these tests, otliers were made with the stone by submitting it to different degrees of calcination in crucibles. 47. Number One is moderately fine grained, of a dark gray color, and contains rather too much silica. After burning, the cement is of a light-drab color, and sets under water in fifteen * The sections of the cement strata in Ulster County, as given in the Report of the State Geological Survey, are singularly at fault. The one purporting to havo been taken at High Falls, near and just below the bridges (see Report of First District State Geological Survey, p. 353), is as follows : Cement rock 12tol5 feet . Limestone 10 to 30 " Cement rock G to 8 " Pyritous slaty limestone 4 to 10 " Red shale, &c 15 to 20 " Conglomerate and Shawangunk grits unknown thickness. The correct section of the beds in this locality, now constituting Ogdcn k Co.'s quarry, and at the time of the survey owned and worked by Mr. J. L. Hasbrook, is as follows : — the layers above No. 9 do not occur here. Cement rock 15 to 16 feet. Magnesian limestone, unsuitable for cement, and therefore not used. It is dividing lime 2 to 2^ " Cement rock 5 to 6 " Artrillaceous slaty limestone | tc 1 " Pyritous limestone. Shale, kc as before. I 40 PRACTICAL TKEATISE OX LOIES, Number One a minutes to bear the light testing-wire.''^ Tbia cept af Lawrence- stoiie, except in the vicinity of Lawrenceville, ^^®- wliere it possesses, to a limited extent, tbe objec- tionable properties of intermediate limes, furnishes a good cement by itself. 48. 2^u7nher Two resembles the preceding, when in the raw state, but is of a somewhat darker color, and is much quicker setting after calcination. In the vicinity of Lawrenceville it pos- ^, , sesses, to a limited extent, the bad qualities of the Number Two , ' . _ ', , ^ resembles Xum- "intermediate" limes, and is unlit for use, except in combination with the other layers. It is not excluded bA' any of the manufacturers. 49. Nuniber Three is a coarse-grained light-gray magnesian limestone, containing, after calcination, an excess of caustic lime and silica in the form of sand. It belongs to the worst Number Three ^- P^ ^^ intermediate limes, and is incapable of is an " interme- being used alone, except after several months' diate lime." ° , /v ^ . , . exposure to the euects of air and moisture, either in casks or in bulks, and even then is greatly improved by being mixed with ten to fifteen per cent, of an active cement, with a view to restore the energy destroyed during the process of spon- taneous slaking. A fresh sample, mixed to a stiff paste, and Sets in the air formed into a cake, set in the air in eight min- ens^vhen put°in" '^^^^.'^5 ^^^ "^^s then immersed in water at 65° F. "^^^^'■- It soon began to soften, and in one hour allowed the light-testing wire to pass freely through it. Another cake, immersed in water in the condition of paste, began to set in four or five minutes, so far as to lose the plastic form, which was immediately followed by the appearance of a multitude of small cracks, and a rapid and progressive softening from the surface inwards. After fifteen minutes it was worked up under the trowel, dried off with blotting-paper to a stiff" paste, again formed into a cake, and immersed. At the expiration of twenty *For a description of the testiug-wire, see paragraph 121. HYDRAULIC CEMENTS, AND MORTARS. 4l minutes, a close network of cracks again covered the surface, when it was worked up, as before, for the second time. This operation was repeated for the tliird and fourth times before the submerired cake would retain its form nnder water, and indu- rate without cracking. It then required six days to bear the 2V inch wire, loaded to one pound. Some of the powdered cement was heated to redness for half an hour, in order to approximate more nearly to the condition of complete calcina- tion, but its qualities were in no respect improved thereby. Some of the same cement, when fourteen months old, after having been preserved in an ordinary powder-keg, without paper lining, during that period, had entirely lost the dangerous property of disintegrating under water, which it possessed in such an eminent degree when fresh. It had also parted with much of its hydraulic energy, requiring from eight to nine hours, when submerged, to attain the requisite hardness to support the light-testing wire, and twenty hours to support the heavy one. Some of this old cement was heated to redness for half an hour, which, while it fully restored its hydraulic activity, at the same time destroyed its ability to stand up under water. Trials were also made by adding to this cement a soluble alkaline silicate, in order that silica might be Trials with " solu- presented to the lime in a condition favorable to ^^® glass." an immediate combination with it, with a view to anticipate, as it were, the initial induration of the native hydraulic ingredients. The results were entirely satisfactory. The double silicate of potash and soda was employed for this purpose, in the succes- sive proportions of 11, 9 and 5^ per cent., by mixing it with the water used for bringing the cement to the con- Eleven per cent dition of paste. In the first two cases the sue- >,-i,m'beVThree cess appeared to be perfect, and resulted in the * goo'i cement. cakes setting under water in ten minutes to bear the light test- ing-wire, and in twenty-five and thirty minutes respectively to bear the heavy one, without any subsequent appearance of cracks or change of form. With 5^ per cent, of the alkaline 42 PRACTICAL TREATISE ON LIMES silicate, the cracks upon the surface were not entirely avoided, but tliej penetrated but a very little way into the mortar, caused no visible change of forui, and appeared to exercise no influence upon its ultimate strength and hardness, 50. Nuniber Four, in some localities, is solid and compact ^, , „ throughout, and in others is subdivided into two J> umber Pour ° ' subdivided into layers of nearly equal thickness. The upper portion is fine grained, dark blue, burns of a light drab color, and is quick setting; that below is darker after calcination, contains more lime, and does not set readily imder water, if immersed in the state of paste. Between these two subordinate members of this laver, a thin sheet of arcrillo- calcareous slate sometimes occurs, which has to be excluded from the combination. With this exception, the entire layer, ,p, .. , worked together, makes a cement of fair average The entire layer ~ ' c makes good ce- quality, and there is jDcrhaps no member of the deposit in Ulster Co. which preserves, through- out its entire development, a character moi'e uniformly reliable- Immersed in the state of paste, in water at 65° F., it hardens 60 as to support the light testing-wire in fifteen to twenty min- utes, and the heavy one in twenty-five to thirty minutes. 51. Numher Five. This layer, throughout the entire range of the beds as yet opened, except in the quarries belonging to the Newark Lime and Cement Manufacturing Company, at the mouth of the Eondout Creek, is a coarse-grained magnesian limestone, containing so large an excess of car- Number Five , . 1 1 1 1 slakes after cal- bonate of lime that it generally slakes atter cal- mea^re\ue^ and ciuation, like hydraulic or meagre lime. In the is generally re- .quarries of the Iludson River Company, about five miles back from the Hudson, the upper half of the layer is more highly charged with clay and magnesia, and is so far modified in its prevailing character that it is in- cluded in the combination. With these two exceptions, the stone is rejected by manufacturers. 52. Number Six is a limestone of slaty structure, containing HYDRAULIC CEJIENTS, AND SIORTAES. 43 a large amount of clay and lime, particularly of the latter, and possessing, to a certain extent, the objectional)le dumber Six is an properties of Number Three. It varies in thick- intermediate limo. ness from six inches to two feet, and possesses a distinct devel- opment in all the quarries, except those at the mouth of the Kondout Creek, where it has either been omitted in the depo- sition, or has been more or less uniformlv distributed through out the contiguous layers. The latter would appear to be the most probable hypothesis, as those layers (Five and Seven) W'hich in most of the quarries contain a ruinous excess of car- bonate of lime, constitute in this locality the best stone of the deposit. When made into cement, and allowed to set in the air, the influence of water upon it after immersion is moderately slow, so that the mortar is not thrown down completely, like that derived from Kumber Three, but is simply covered with many deep cracks. A prism measuring 2 in. X 2 in, X 7 in. was formed of a paste of the pure cement from ^ . . ^ ' rnsm of pure this layer, as developed at High Falls, and im- cement from " ^ , , . this layer. mersed in water atter supporting in twenty min- utes the light testing-wire in the air. After twenty hours, it began to swell and crack along the longest edges, the cracks being directed toward the axis. After thirty hours, these cracks presented an exterior opening of ^, and after fifty hours, of ^ of an inch. The prism then broke into three pieces trans- versely, and was nearly a week in assuming a ^''S- ''■ stable form. The form of a cross section at that time is shown in Fig. 7. 53. JSfuniber Seven is perhaps the most changeable member of the cement deposit. Near High Falls, on Coxon Cove Creek, it was manufactured into a cement several years ago by Mr. O'Neill, which was considered by the late Col. J. L. Smith, of the Corps of Engineers, superior ^c^v^oi Sn^he^' to any cement brouorht into market at that time. ^?.^I^"~''^'"' ^ . ^e^ll cement In other localities, near High Falls, the stone is 4*4 PRACTICAL TREATISE ON LIMES, in every respect as good as that used by O'Neill, but all at- tempts to turn it to any account elsewhere have failed, except at a point above one mile south of Rosendale Tillage, where it was worked in 1840, and at the mouth of Eondout ^^ , „ Creek, twelve miles distant, where it is of o^ood Is umber Seven, . , not generally quality, and furnishes about 25 per cent, of all the stone used in that neighborhood. In con- nection with the two overlying strata, Five and Six, it con- stitutes the middle rock, a prominent feature, common to all parts of the range (with the exceptions mentioned above) which is not disturbed in quarrying. The prevailing character of T 11 1 fi. Number Seven, to which its bad qualities are Is gene rail)' left ' i undisturbed in chiefly due, is its remarkable and persistent want of homogeneousness. When burnt, it presents an entire absence of any uniformity of color, being generally vari- egated and mottled in appearance, exhibiting almost every grade of neutral tint between pure white, derived from masses of carbonate of lime, and the darkest brown, approach- ing to black. Hence the constituent elements of the stone, although they may be present in suitable proportions, are be- yond the influence of those mutual reactions which take place during the calcination, when the ingredients are in intimate and homogeneous contact, and the lime which should have en- tered into combination with the silica remains free and in ex- cess. Instead of being pure, however, or practically so, a con- dition which would be favorable to its instantaneous slaking when brought into contact with water, it is mixed with a sufii- ciency of foreign matter to render it meagre, technically so called, and consequently sluggish and tardy in assuming the form of hydrate. Number Seven is therefore, with the excep- tions noted, an intermediate lime, and unfit for cement. 54. NiiTinher Eight is unsuitable for cement in any part of the range yet opened. It is much more uniform in appearance. Number Eight and is far less heterogeneous in composition, than forc"emonf "^ Number Seven. In the vicinity of High Falls, HYDHAULIC CEMENTS, AND MORTARS. 45 it is characterized by tlie objectionable proper- ties of Xuniber Three. It will commence to set readily under water, but in a few hours becomes converted -vviunotset into a thin paste. Further cast, it loses all underwater power of indurating under water, and will not retain in that situation a set taken in the air. In some localities it adheres to, or rather forms a part of Number Seven, and is left stand- ing with it, while the underlying and overlying strata are ren)Oved ; in others it becomes separated in blasting, and in' many cases, it is feared, finds its way into the manufactured cement, and injures its quality. 5.5. The layers numbered from Nine to Sixteen^ inclusive, possess no striking individual characteristics, ex- Layers Number cept in two localities. Taken together in the ^o Mrdtffer'^^'' proportion of their development in the beds, Btrikingiy. they furnish a cement of good quality. Its hydraulic activity is somewhat less than that derived from a combination of the " Upper Series" of layers exclusively, but, in ultimate strength and hardness, it will compare favorably with any cements in the country. The two exceptions are as follows, viz. : one at High Falls, where Number Fifteen is an inter- T T Ti -v^ 1 mi 1 -1 -s^ Number Fifteen mediate lime like JN umber iliree, while iNum- at High Faiu is ber Sixteen sets more rapidly under water than ^i^i^'^Tnd Num- any strata in Ulster Co. ; and the other at the ber Sixteen very , quick setting, mouth ot liondout Creek, where the " Lower Series" of strata do not occur at all, or are so changeable in hydraulic character, chemical composition, and lithological features, that their geological identity is a matter of some doubt. 56. Number Seventeen, although differing very materially from Number Sixteen after calcination, is mechanically at- tached to it, and has generally to be taken out with it. It contains a very large proportion of refractory j,.^,^ber Seventeen clay, and is in most localities, and particularly ^^^ '-^ °^^^ ^'*^'^^- at High Falls, very hard, like overburnt bri cks, when cal- 46 PRACTICAL TBEATISE OX LnrES, cined in the same kiln \nth the other lavers. It possesses little hydraulic energy, and should be excluded from the com- bination. As a prominent feature of the entire deposit, the color of the burnt stone is subject to great changes, within short distances. 57, At High Falls, the southwestern terminus of the deposit as now worked, where the manufactories of the Ogden Com- pany, and Delafield & Baxter (formerly Ogden & Del afield) arelocated, all the lavers, and consequently eom- The cement made ... ,. , *, ^ f ^ • ^' at High Fails is omations 01 them adopted tor the articles sent light colored, be- ^ market, are lighter colored after burning than comes darker as - ~ '^ we approach the in anv Other locality. As we approach the Uud- Hudson PJver. * . , .. ' ^ . ,, , , . , , son Kiyer the " Lower benes undergo a decided and sudden change, so much so. indeed, that at Lawrenceville, only two and a half miles from High Falls, although they fur- nish but .60 of the combination used by the Lawrence Com- pany, and although one-half of the remainder is brought from High Falls, and is yery light-colored, the combination is one of the darkest of the Eosendale brands. Between this point and the Hudson, their color remains dark, and that of the " L'pper Series" becomes moderately so. In point of fact, the only fiosendale cements technically termed " lighi''' are the two brands manufactured at High Falls by Delafield & Baxter, and the Ogden Cement Company. 58. The ^eiearlc Linie and Cement ^danvfactunng Com- Xe-wark Lime JJdny is located on the Hudson Eiver, at the MaiScmring "^^^^^^ ^^ Eondout Creek. Its works comprise Company. — Ca- seventeen cylindrical kilns of the pattern shown paciiv of their . _. ' works. in Figure 12. and the mill driven by steam- power, containing five " crackers'' and eleven run of stone of two and a half feet in diameter, and two run of four and a half feet diameter. Four of the crackers, and five run of stone, can grind eight hundred barrels of cement per day. The cement stone occurs in a continuous bed varying in thickness from twenty to thirty feet, and dipping to the northwest nYDKAULIC CEMENTS, AND M0RTAE3. 47 from 45° to 75°, It crops out along the eastern slope of a high hill or bluiF, at an elevation, in places, of from 150 to 170 feet above the level of the Hudson River. This deposit is reached by five horizontal tunnels, which pierce the slope of the hill near its base at five diiFerent points, by means of which the quarried stone is conveyed to the kilns by cars. There is a marked difference in the qualities of the stone in these several quarries, as well as among the several layers of the same quarry, and great care is exercised in distributing the aggregate yield of the entire deposit among the several kilns, in order to secure as great a degree of uniformity in the quality of the cement as possible. 59. None of the Lower Series of cement strata (see para- graph 44) are used by this company. The upper ^ ^ q • .. layers, from Number One to Number Three in- not used by tins elusive, are in some places too highly charged with carbonate of lime to admit of their entering into the combination. No attempt, however, is made (and it probably would not be advisable) to exclude any layer entirely, the skill and experience of the workmen being, in a great measure, depended upon to detect and throw out those portions of the stone which might injure the quality of the cement. These generally occur in patches, varying from a few inches to sev- eral feet in length and breadth, which are recognized by their coarse-grained or crystalline appearance, or some other charac- teristic feature. With the exception of these rejected portions, all the layers from Number One to Number Seven, inclusive, enter into the cement in the proportion of their thickness in the deposit. This company has a branch at Newark, New Jersey, to which place the stone is conveyed in the raw state. 60. The Lawrence Cement Comjpany^ manufacturing the " Hoffmann" brand, have their quarries and kilns above AVhite- port, about seven miles back from Rondout. The Lawrenco Their mill, driven by steam-power, is located on Cement Co mpanj. 48 PRACTICAL TREATISE OX LlilES, the left bank of the Rondout Creek, about two and a lialf miles from its mouth, and below the slack water of the Dela- ware and Hudson Canal. They have twelve kilns of the old pattern (Figure 12), four run of stone two and a half feet in diameter, and two crackers. Their combination comprises stone from three quarries, as follows : the first, eighteen feet in thickness, comprising the layers fi jm. Nine to Sixteen, inclusive ; the second, eight to ten feet in thickness, containing I^umber One to Four, inclusive, rejecting Xumber Three, separated from the first by the "Mid- dle Hock ;" and the thu-d, ten to eleven feet in thickness, com- prising the same strata as the latter (One to Four, rejecting Number Three). After calcination, the stone is carried in waorons to the mill, four miles distant, and is then mixed together in the proportion of 13^ per cent of the first quarry (Xumbers Nine to Sixteen). 26f " " " second quarry (Number One to Four, rejecting Number Three). 60 " " " third quarry ( " " " " " " ). 61. The Keicarh and Hosendale Company have all their "works at "Whiteport, six miles from Rondout, and about three miles from the point of delivery to boats below the locks of the canal. They have fifteen kilns of the old pattern (Figure 12), and one of Page's Patent (Figures 13 to 18). Their grinding apparatus comprises three crackers and four run of five feet stone, driven by steam, and one cracker The Newark ' ' . and Rosendale and three run of four and a half feet stone, driven by water. Their quarries are in the im- mediate vicinity of those belonging to the Lawrence Company, noticed above, and they make use of the same kind of stone, but combined in difi'erent proportions. They have, from time to time, derived their stone from eight different openings, but, at the present time, work three principally. Two of these are parallel to each other, comprising respectively the Upper and the Lower Series of layers, separated by the Middle Rock, SYDEAULIC CEStENTS, AND MORTARS. 49 •wliicli is worthless in this locality ; the third furnishes the Upper strata only, One to Four, inclusive. Their combination is as follows : 50 of the Upper Layers (One to Four) from two quarries, rejecting part of No. Three. 50 of the Lower Layers (Nine to Sixteen). 62. The Rosendale Cement Company, manufacturing the " Lawrence" brand, is located at Lawrenceville, on the line of the DelaM'are and Hudson Canal, six and a half miles from Rondout. They have seven kilns of the old pattern (Fig. 12), and four run of stone, four feet nine inches in diameter. They grind by water power. The J^^ i^osendale •^ o ./ r Cement Company. Stone is procured from three quarries, as follows . The first is near High Falls, two miles above Lawrenceville, and furnishes the Upper Layers (One to Four, inclusive), of which a large proportion of Xumber Three is rejected. This stone, after burning, is conveyed by laud carriage to the mill at Lawrenceville. The second quarry is situated on the east side of llondout Creek, at La^vrenceville, and furnishes the Lower Layers (Nine to Sixteen, inclusive). The third is about a quarter of a mile distant from the latter, on the west side of the creek, and contains the layers One to Four, inclusive, of which Number Three is rejected. This last- mentioned bed overlies in regular order the Middle and Lower Series. Numbers Nine to Sixteen were formerly quarried at this point, and included in the combination, but for some years past have been omitted, on account of the alleged presence of an excess of carbonate of lime, an objection which is presumed to be more imaginary than real, as the strata, having been treated separately with great care, gave results which com- pared favorably with those obtained from the corresponding layers on the opposite side of the creek. The stone from each quarry, after being burned separately, is added to the combination in grinding in the following pro- portions, viz. : 4 50 PRACTICAL TEEATISE 01^ LlilES, .20 of the first, One to Four, inclusive, rejecting most of No. Three. .60 " second, Nine to Sixteen, inchisive. .20 " third. One to Four, inclusive, rejecting No. Three. 63. Delafield i& Baxter^ fonuerly Ogden tfe Delafield, are located at the High Falls of Rondout Creek, twelve miles Delafield & fi'om its moiith, on the Delaware and Hudson Baxter. Canal. Their mill is driven by water-power,* and consists of three crackers, and four run of four and a half feet stone. They have six kilns of the usual form (Fig. 12). Three quarries furnish the stone used in the combination. The tirst comprises the layers from Xine to Sixteen, inclusive, of which parts of Thirteen and Fifteen are too highly cliarged with carbonate of lime, and have to be rejected ; the second comprises the Upper Strata, One to Four, inclusive, of which portions of Number Three are excluded. These two quarries are located near each other ; the third is about half a mile distant, and contains Number Sixteen only, which occurs in a partially disintegrated or slaty form, and is therefore known as the " Slate Quarry." In the combination, the products of these three quarries are mixed together in equal proportions, viz. : 33^ of Nine to Sixteen, inclusive, rejecting portions of Thirteen and Fifteen. 33^ of One to Four, " '• " No. Three. 33^ of No. Sixteen. Layer Number Sixteen in this locality possesses remarkably quick setting properties. It will harden under Layer Number ■ ^^ ^ • t-ti Sixteen very water more rapidly than any cement m Lister quic settmg. County, and is added to the combination with a view simply to increase its hydraulic activity and energy. Delafield & Baxter are also the proprietors of the quarry which some years ago furnished the O'Xeill cement, an article which sustained a high reputation among military engineers. It comprises the middle layers Six and Seven. It is not worked at the present time, but will probably, at no distant period, have to replace their " Slate Quarry" in the combina- tion, as the latter is becoming exhausted. HYDRAULIC CEMENTS, AND MORTARS. 51 64. The Ogden RosendaU Ceinent Company is also lo- cated at High Falls, near Delafield & Baxter's. Their mill is driven by water-power of great capacity, and contains two crackers and four run of four and a half feet Btone ; their kilns, at present four in number, setTdale'cement"' are of the old pattern (Fig. 12). The stone is ^^'"P'^^J^- derived from an opening contiguous to Delafield & Baxter's " Slate quarry," and comprises the Lower Series of layers Xine to Sixteen, inclusive, rejecting Number Fifteen on account of the large excess of carbonate of lime which it contains, and which places it among the intermediate limes. Layers Nine to Thirteen are subject to frequent and peculiar variations in hydraulic energ}-, containing in places so large an excess of caustic lime after calcination, as to render it necessary to reject these portions when detected. The combination adopted by this company is varied from time to time, as circumstances require. Number Sixteen being principally depended upon to compensate for any deficiency in hydraulic activity in the superincumbent layers. The usual proportion is : 50 of layers Nine to Fourteen, Inclusive, rejecting parts of Nine and Tbirteea 50 " No. Sixteen. The color is light, like that of Delafield & Baxter. Layer Number Sixteen of Ogden's quarry appears to possess all the distinct and characteristic properties of Delafield j^^ er Number & Baxter's " Slate" quarry, that is, it has a Sixteen. slaty structure, burns light colored, and is remarkably quick setting under water. It is a noticeable fact, that, in this par- ticular spot, this stratum, although distant but 400 or 500 yards from the other quarries in the neighborhood, possesses local properties so peculiar, that it would be difiicult, in the absence of the most direct and palpable evidence of their geo- logical identit.y, to believe them to be parts of the same layer. It is only at High Falls, and apparently within contracted limits even there— possibly not more than two to three hundred 52 yards in extent — that it possesses any superior liyJraulic ac- tivity. As we descend the valley of the Rondout, it burns dark colored, and becomes comparatively slov7 setting. 65. At Bruceville, half to three-quarters of a mile below High Falls, Mr. iV. Bruce manufactures cement from the Lower Layers, Nine to Sixteen, inclusive, to which is added a stratum about eighteen inches thick, situated twelve feet below ISTumber Sixteen, and separated from it by a conformable bed of arscillaceous shale. It is not certain whether this stratum forms a part of the cement bed as described, or is a separate and independent deposit, formed out of its usual position by the local intervention of the shale. This cement is light colored, like Delafield & Baxter's. Mr. Bruce also works the Lower Layers at the Green kilns, five miles from Rondout, near the line of the Delaware and Hudson Canal. ^^. Martin <& Clearwater have their works on the line of the Delaware and Hudson Canal, seven and a half miles from Rondout. Tliis mill, comprising four run of four feet eight inches stone, and the requisite number of crackers, is driven Martin & ^7 steam-power. They have six kilns of the old Clearwater's. pattern. (Figure 12). Their stone is derived from two parallel beds comprising the Upper and the Lower Series of strata respectively, separated by the Middle Rock, Numbers Five, Six, and Seven, which is here entirely unfit for cement. Their combination is as follows : •50 of the layers One to Pour, inclusive ; rejecting portions of Three and Four. .50 " " Nine to Sixteen, inclusive. 67. The quarries ^of The Hudson Rii^er Cement Company are situated about one and a half miles from the Delaware and Hudson Canal, five miles from Rondout. Their mill, compris- ing four run of four and a half feet, and two run of two and a The Hudson ^^Xi feet stone, as well as their kilns, are in River Company. Jersey city. Their combination comprises equal proportions of the stone from the Upper and fi'om the Lower Layers, including about one half of Number Five, and difiera. HYDRAULIC CEMENTS, AND MOETAllS. &5 from all others into which the Lower Layers enter at all, in including the whole of Number Three. It is therefore as follows : .50 of layers One to Four, inclusive, and one-half of Number Five- .50 •' " Nine to Sixteen, inclusive. 68. Maguirey Crane d& Co. have recently commenced manu- facturing cement near Martin & Clearwater, Their quarries join each other, and are, in every respect, alike Maguire, Crane in the character of the stone and the number and *■ ^'*- thickness of the strata. Their mill is driven by steam-power, and contains four run of four and a half feet stone. Four cylindrical kilns of the old pattern (Figure 12) are used in burning the stone. 69. The Lawrenceville Cement Maimfucturing Company is located at Lawrenceville. Their milling apparatus com- prises six run of four and a half feet stone, four of them driven by steam-power of ample capacity, and two by water- power, provided with the requisite number of The Lawrence- crackers. Their stone is derived principally from J^lJ^^JJacJuring the Lower Series of layers. A portion of Num- Company. ber Seven, which is divided into three layers possessing very different qualities, is also added to the combination. This quarry is but two or three hundred yards distant from the one worked by the Rosendale Cement Company, on the west side of the Rondout Creek, in which the Lower Layers have been regarded — with insufficient cause, it is thought — as too highly charged with carbonate of lime. 70. The Rosendale and Kingston Cement Company are located at Flatbush, on the right bank of the Hudson Eiver, about three miles above Rondout. Their mill is worked by steam-power, and contains four run of four and a half feet stone. Their stone is burned in the old-fashioned kilns (Figure 12), and is derived in part from quarries situated about 300 yards from the mill, which furnish the layers Tliree and Four of the Upper Series, and Nine to Sixteen, inclusive, of the 54 PRACTICAL TREATISE OIT LIMES, ^ jj , , Lower Series ; and in part from an opening ip and Kingston Ce- the Lower Layers on the line of the Canal, neai Martin & Clearwater's works. This stone is transported in the raw state to the kilns, which are located near the mill. Their combination is as follows : .33^ of layers Three and Four, at Flatbush. .33^ " Nine to Sixteen, inclusive, at Flatbusli. .33^ " " •' from near Martin & Clearwater's, ten miles distant. 71. Hydraulic cement is manufactured on the Potomac River, which finds its waj to an eastern market, via the Ches- apeake and Ohio Canal. There are three works, located respectively at Shepherdstown, Ya., at Hancock, Md., and at Cumberland, Md. 72. The Shepherdstown Worl's comprise two run of four and a half French burr stones and the necessary crackers, driven by water-power, and three perpetual kilns of the form given in Figure 11. Cumberland coal is used for burning. The stone is derived from deposits which crop out in several places on the banks of the Potomac, near the mill. Though consider- _ , ably tortuous and irregular, their general posi- Cement Works at -^ . . ShepherdstovsTi, tiou is nearly vertical. The stone is quarried "■ from the top of the hill, is then passed into the kilns, situated on the slope below, and subsequently to flat- boats in the mill-race. These are then floated into the mill, and the burnt stone is discharged through hatchways up to the crackers. 73. The deposit is in two principal layers, one of which furnishes a quick, and the other a slow set- byeffone'^'S^ ting ccment. The two are mixed together in and the other nearly equal proportions, a combination which slow setting. j i j: i is believed to yield a better cement than either of the beds would if used alone. 74. Besides the quarry from which the stone is at present derived, there are several outlying cement strata, or perhaps HYDEAULIC CEJIENTS, AND MORTAllS. 55 other outcrops of tlie same strata, near by, intermixed with layers of nearly pure limestone, which were added to tlie com- oination in former years ; but the extra expense arising from the necessity of quarrying out the common limestone iii con nection with them, and the doubt as to their possessing any superior qualities, led to their iinal exclusion. It is impossible to estimate satisfactorily the extent and capacity of these quarries, and it is believed that no critical examination by experienced geologists has ever been made with that end in View. The peculiar position of the beds would lead to the inference that their development is not only very extensive, but practically available through its entire extent. (See Table No. lY., paragraph 226, for analysis.) 75. The Round Top Cement Works are located about three miles above Hancock, Md., on the Chesapeake and Ohio Canal. The mill, which stands on the tow-path between the Potomac River and the canal, comprises two run of four feet French burrs, driven by a forty-horse water-power, derived from the discharge of the water of the Cemont^orka. canal into the river. The kilns resemble those at Shepherdstown (Figure 11), and Cumberland coal is used for burning. 76. The cement layers at this place crop out on the left bank of the Potomac, and have been cut off for the excavating of the canal. They are exceedingly crooked and _A.„.gregate thick- tortuous, bending up and down, and doubling ^^^^ of deposit. upon each other in a very complex manner. Their aggregate thickness is about 48 to 50 feet, comprising eleven distinct layers, each possessing marked and peculiar properties. — Commencing at the top : Nuvnher One, 8 feet thick, is highly argillaceous, and is very hard and difficult to grind after calcination. It sets slowly, and will not bear immersion, unless iirst allowed to set in the air. Number Two, 4 feet thick, is mostly argillaceous slate, and 56 PRACTICAL TREATISE OlS" LIMES, is rejected. Portions of good cement stone are sometimes found mixed ^vith it. , Number Three, one foot thick, is a good cement when properly treated, and hardens readily under water. Nmnber Four^ 4 feet thick, is too calcareous to be used Characteristic ^*^^ cemcnt alone. "Wiien suitably nnderlurnt features of the jt possesses a moderate deo'ree of hydraulic activi- several layers. , o ./ ty but is rendered almost worthless, ii exposed to heat of sufficient intensity and duration to burn the other layers of the quarry properly. It is therefore rejected. Number Five, 5 feet thick, furnishes a remarkably quick cement, when the calcination is arrested at the point of complete expulsion of the carbonic acid gas. Beyoud this point it will bear immersion in the state of paste, but does not harden so quickly as when in the condition of sub-carbonate. Number /Six, one foot thick, is nearly pure carbonate of lime, and is rejected. Number Seven, 6 feet thick, burns dark colored, like the Rosen dale cements, but is not a quick cement by itself. It is used in the combination. Number Eight, 4 feet thick, resembles Seven, though superior to it. Number Nine, 5 feet, contains an excess of carbonate of lime, and lo, in fact, an energetic hydraulic lime. It is used in the combination. Nuraber Ten, one and a half feet thick, is a slate. Rejected. Number Eleven, 11 feet thick, gives a quick and energetic cement, which hardens readily under water. It is depended upon, in a measure, to confer hydraulic activity on the combination, whenever from bad burning, carelessness in assorting the stone, or any other cause, there is deficiency in this particular. "With the partial exception last mentioned, the layers that are used are combined together in the proportion of their developed thickness in the quarry. HYDEAULIC CE3IENT3, AjS^D MOETAKS. 57 The Eound Top quarries contain a very larf^e amount of dement stone, so situated, on the slope of the river and canal, as to secure to the manufacturer every advantage which positioa can afford. (See Table lY., paragraph 226, for analysis.) 77. The Cumberland Cement Worlcs are located at Cum- berland City, Md., and comprise two run of French burrs, 4^ and 6 feet in diameter, respectively, driven by a 35- m, . . • J 1 Cumberland horse-power engme. ihis power is considered cement Works, sufficient to drive three run of stone. Tliree Icilns, burning Cumberland coal, and resembling those used in Ulster Co., N. Y., are in operation. 78. The cement stone is derived from two quarries, situated in close proximity to each other, on "Will's Creek, near its junction with the Potomac. The principal bed is from 35 to 40 feet thick, of which the lower half furnishes a slow cement, that will not indurate under water unless first allowed to set in the air, and, even then, rather slowly. The upper half vields a cement that will bear immersion in the state of paste. Each of these two layers furnishes one-third of the combination, the remainder being derived from a nine-feet ledge a few yards distant, which is quarried by tunnelling. It is quick- setting. Below this there are other layers of good cement, •which are not at present used on account of the extra expense of quarrying, and one or two thin beds of argillo-magnesian limestone, possessing the properties of intermediate limes. For analysis of Cumberland cement, see Table IV., paragraph 226. 79. The James Biver Cement 'Worlcs are located at Balcony Falls, Rockbridge county, Va., on the James Eiver, and the James Hiver and Kanawha Canal. The mill stands on the tow-path, and contains two crackers and four run of French burr-stones of medium size, driven by water-power derived from a dam across James Iliver, erected by the Canal Company. The power is deemed sufficient to turn six run t, , o- 1 M i. J • TT" James River of stone. &1X kilns, as represented in iMgure Cemeat Works. 11, are located at the mills The quarries, of 58 PEACTICAL TKEATISE ON LI^tES, which there are two opened in the same stratum, jire on the mar- gin of the river, about one mile above the mill, from which point the stone is transported to the kilns in boats, on the slack water of the dam. This deposit is generally known in Virginia as the " Blue Ridge quarry." The writer visited these rocks in the summer of 1858, under ordei-s from the Engineer Bureau of the War Department. The following is an extract from his report, rendered on the 31st of July of that year : " The cement vein or stratum is twelve to thirteen feet thick, and dips to the northwest fifty-live degrees (55*^). It crops out on the summit of an undulating table-land, or, perhaps, more proper!}', a ridge situated at the base of the mountain. The direction of the outcrop is nearly north- Description of ^g^ ^^^ southwest. The upper ridge of the cement deposit. i i o stratum changes its character very materially before it reaches the surface, gradually disappearing in a soft, porous yellow stone, which in turn runs into a hard clay, of various shades of yellow and light orange, and in various stages of decomposition. This becomes perceptibly softer as it approaches the surface ; the upper portion, to the depth of several feet, yielding readily to the pick and shovel. The entire bed is subdivided into layers, varying in thickness from one and a half to four feet." "The color of the raw stone is dark blue, its texture compact, grain moder- ately fine, and fracture slightly conchoidal." For the analy- sis, see Table lY., paragraph 226. The James River Works, driven to their full capacity, will turn off 350 to 400 barrels of cement daily. It is sent to the eastern markets via the James River and Kanawha Canal, and James River. 80. At Utica^ Lasalle county, Illinois, cement is manufac- tured from a bed of stone seven feet thick, which crops out on the margin of Illinois River, just above the level of high water. It is burnt with bituminous coals in intermittent Cement at utica, Lasalle county, kilns of about 200 barrels capacity. It is stated by one of the manufacturers that perpetual kilns HYDRAULIC CEMENTS, AND MORTAES. 59 would not discharge the burnt stone readily, on account of the thin slaty fragments into which it splits in quarrying. Two parties are engaged in its manufacture. One of them has eight kilns and three run of stone (two of four feet and one of four and a half feet diameter) ; the other has three kilns and one run of four feet stone. Steam-power is used for grinding. The full capacity of both works is stated at TOO to 800 barrels per day. (For analysis, see Table IV,, paragraph 226.) 81. The Sandusl:y Cement Works are in Van Kensselaer town- ship, Ottawa county, Ohio, on the point of the peninsula oppo- site Put-in-Bay Island, and near Hat Island. The thickness of the cement deposit is not accurately known. It is nearly hori- zontal, and is quarried in three or four places to a depth vary- ing from live to eight feet, down to the level of the water of Lake Erie. The stone is burnt Sntwo^rkl^' in perpetual kilns with coal, either bituminous or anthracite, in a manner similar in every respect to that pur- sued in Ulster county, New York. The mill is driven by steam-power, and comprises four run of French burrs with the requisite number of crackers, and is capable of grinding 300 barrels per day. (See Table IV., paragraph 226, for analysis.) 82. I^ear Louisville, Kentucky, at the foot of the falls of the Ohio Kiver, there is a deposit of cement stone, which for many years has been extensively used throughout the West, and particularly along the Mississippi River. The deposit is six feet thick ; the stone is burnt Louisville Ky. in the ordinary draw-kilns (Figure 12), anthra- cite coal being used for fuel. The mill contains one pair of four and a half feet French burrs, driven by water-power. As early as the year 1848, Col. Long, of the Corps of Topo- graphical Engineers, who had witnessed the successful appli- cation of the Louisville cement to building purposes in the West, entertained a very high opinion of its q^-^ Long's quality, and pronounced it, when used "in the opinion of the . , Louisvillo cement. formation oi subterraneous and submarine foun- QO' PEACTICAL TEEATISE OIS^ LIMES, dations, and otlier structures in similar situations, a ceineut unsurpassed by any materials of the kind hitherto employed for such purposes in this or any other country." * * The cost of manufacturing cement varies, of course, among the different works, according to local circumstances, such as the kind of motive power used for milling, the proximity of the kilns to the quarries and to the mill, the dip of the strata, and the proportion of quarried stone not suitable for use, the character of the burnt stone with respect to hardness, &c., &c. The Rosendale cements, on account of the superior faciUties, and the brisk com- petition among the manufacturers, are produced at less expense than any in the country. Great pains have been taken to obtain data for a correct estimate of this expense. The following table is based upon a work whose estimated capacity is 300 bar- rels per day, on the supposition that the kilns and mills are in such proximity that the transportation of the raw stone to the kilns, and of tlie manufactured product to the canal, can all be accomplished with five single teams. In some works it is considerably below this estimate. CURRENT ANNUAL EXPENSES OP A CEMENT MANXTFACTORY OF 300 BARRELS DAILY CAPACITY, WORKLNG 200 DAYS IN THE YEAR: Salary of Superintendent $ 800 00 " " 1 Engineer 500.00 " " 1 Fireman $1.00 for 200 days 200.00 " " 1 Smith 1.25 " " " 250.00 " " 13 Quarrymen 1.00 " " " 2,600.00 " " 5 Single Teams 1.75 " " " 1,750.00 " " 1 Head Burner 2.00 " " " 400.00 « " 3 Assistant Burners . . 1.00 " " " 600.00 " " 4 Drawers 1 00 " " " 800.00 " " 1 Miller 1.75 " " " 350.00 " "1 Assistant Miller 1.25 " " " 250.00 " " 5 Packers 1.00 " " " 1,000.00 Powder for blasting 14,049 Tons of Stone 1,200.00 Coal for burning " " " 2,700.00 Coal for engine, $4.00 per day, 200 days 800.00 Papar and nails for packing, l^c. per barrel 900.00 Total Expenditure $15,100.00 Add 15 per cent, for incidental and contingent expenses, accidents, delays, wear and tear 2,235.00 Annual consumption of quarry, based on total consumption in 12 years 1, 000.00 Interest on capital invested, $30,000 at 7 per cent 2,100.00 Insurance on building and machinery, $18,000 at 2 per cent 360.00 60,000 new barrels dehvered at the works, at 28c 16,800.00 Total cost of 60,000 bbls. of cement, ready for delivery at the work. $37,595.00 Cost per barrel at the work, ready for delivery 62f^ IIl^DEAULIC CEMENTS, AND MORTAKS. 61 83. At Kensington, Conn., a cement has been manufactured for many years, which has never found a distant market in large quantities, owing to the expensive hind transportation to which it would be subjected, and which pre- cludes its ever coming in competition with the Kou3iugton,Conn. Rosen dale cements, for general use. A marked Rupcriority for stucco-work in exposed positions is claimed for it by the proprietors, on the authority of the late A. J. Down: ing, Esq., who gave it a preference over all others for that par- ticular purpose. The mill is driven by water-power, and con- tains two run of four feet Esopus Stone (Shawangunk grit). The deposit of cement stone is about three miles from the mill. Its thickness varies from one to eight feet. 84. Cement manufactories also exist at Akron, Erie county, New York, -at Lockport and Eayetteville, New York, and at other points on the line of the Erie Canal. The cements from Manlius and Chittenango, ^.^^,^3 ^^ Akroii New Tork, rank in point of hydraulic activity Manlius, and ' _ '^ •' _ "^ Chitteuango,N.T. between the genuine cements and the eminently hydraulic limes, some portions of the quarries partaking largely of the character of intermediate limes. These two last-named cements require to be used with great care. 85. Besides the foregoing cements, two well-known imported varieties have been introduced to a limited extent into these trials, viz. : the artificial Portland cement of England, and Parker's Koman cement. As these cements are both exten- sively used in Europe, and have been submit- ted to a great many trials, their character and Poniandcements. value are well known among those who have given the subject attention. They therefore furnish us the means of comparing mortars made from our products with those in common use throughout Europe. In Europe, all natural cements are generally denominated Poman cements, to distinguish them from Portland cements, which are artificial combinations of limestone (usually chalk) and clay. 62 PRACTICAL TKEATISE OX LUfES, EOMAN CEMENT. 86. This cement is manufactured in both England and France, by a process essentially similar to that pursued in making ce- ent in this country. It is derived from argillo-calcareous, kid- ney-shaped stones called " Septaria," belonging Source of Roman to the Kimmeridge and London clay, generally gathered on the sea-shore after storms and high tides, though sometimes obtained by digging. The manufac- tured article usually takes its name from the locality which furnishes the stone, as " Boulogne" Eoman cement, " Har- wich" or " Sheppy" Roman cement. The several brands pos- sess almost identically the same composition. ( See Table lY., paragraph 226.) NATURAL PORTLAND CEMENT. 87. A cement is manufactured by MM. Demarle & Co., of Boulogne-sur-mer, from one of the layers of the Kimmeridge clay, situated about 160 feet below the strata Natural " Port- . -, . ^ ^ , -n, ^ 11155 a C i. • )) laud" cement of m wliich the "Boulogne pebbles or beptana Boulogne-sur-mer. ^^.^ ^^^^^^_ j^^^ deposit is argillo-calcareous, and is burned and ground up for cement in its natural state without the addition of lime, furnishing the so-called Natural '' Portland" cement. It was exhibited in Paris at the Palais de rindustrie, in 1S55, and a report thereon by M. Delesse, Engineer of Mines, sent to me by the manufacturers, has sup- plied the following particulars : No locality, except Boulogne, is known to furnish a soft de- posit that can be excavated with pick and shovel, possessing in suitable proportions all the ingredients of good cement. The calcareous clay which is used in making " Port- inferior S^ta- " land" cement is found in the Liferior Cretaceous ceousFormation. p^jj-j^ation. Its paste is nearly homogeneous, and Percentage of contains from nineteen to twenty-five per cent. clay coutamed. ^^ ^|^^_ Yiie pro]3ortions of silica and alumina HYDRAULIC CEMENTS, AND MOETARS. 63 contained in the latter may vary, -without any inconveniences resulting therefrom ; but it is important to avoid sand, as far as possible. Accordingly^ those portions containing more than one-twentieth of sand are rejected. 88. It is known, that in order to obtain artificial "Portland" cement, it is by no means necessary to use exclusiv^ely the ar- gillaceous mud deposited by certain rivers : the limestone may be mixed with either marls or clays, the only necessary condition being to secure a perfectly homogeneous mixture of carbonate of lime and clay, in the above-mentioned propor- tions. It is, moreover, indispensable that the mixture should be quite intimate, otherwise, even with the required propor- tions, it may fail to yield good " Portland" cement. For this reason, M. Dupont, the patentee, has adopted for grinding the original materials for the natural " Portland" Mills for grinding cement, horizontal mill-stones, similar to those the calcareous used for grinding corn. Instead of using a ^'^^' great quantity of water, in order to separate the materials by levigation, as is practised in tlie English process, he adds only enough to form a plastic paste. Immediately after this paste has passed under the mill, it is shaped into small bricks, which are placed in the kiln as soon as they are properly dried. As above intimated, a most essential condition of the paste is that its composition should be quite homogeneous, otherwise the portions richest in silica would fuse and form a silicate, which could not enter into combination with water. 89. Dui-ing the calcination, it is of the utmost importance to have the temperature sufficiently elevated. The ordinary temperature of lime-kilns would be far too low, for that would merely drive off the water and ^ iii'^h heat, carbonic acid. The materials must receive a Producing incipi- ent vitrihcalion. white heat, whereby they can become slightly agglutinated. The state of incipient vitrification appears to be the proper limit of calcination. 90. Moreover, a high heat, however intense, is not ob- &i. PEACTICAL TBEATISE OX LEVIES, jectionable, as only those portions that would have injured the quality of the cement will become completely fused. This fusion will then afford the means of separating and excluding those parts which do not possess the proper composition, and are unfit for use. Assorting the ^1- After the calcination, a selection is neces- burnt clay. sary ; the pulverulent and scorified portions of the mass are picked out and thrown away. 92. Properties. — 'Wlien taken out of the kiln, it is in the shape of fragments warped and cracked by contraction, and of a gray and slightly greenish color. Its powder has a some- what paler shade. The weight of one cubic metre of loose powder is 1,270 kilograms (2,136 pounds to the "Weightoftlie ^ ,, ■,^ , • -, " ... . , . „o- Boulogne "Port- cuDic Tarn), which Will sometimes reach l,38o t'^ir:^^ kilograms (2,329 pounds per cubic yard). The that of artificial Boulogne " Portland" cement, therefore, has a "Portland." ^ . ,',.,' greater specific gravity than the English " Port- land,'" as that from Xewcastle weighs only 916 kilograms to the cubic metre, and that from London 1,057 kilograms (1,541 and 1,778 pounds per cubic yard, respectively). During the mixing with water in forming paste, the Boulogne " Portland" undergoes a diminution in volume of .3, the same as the Bou- logne " Roman" made from " Septaria." The volume of water which combines with it in mixing is ,366, according to M. Dupont. In weight, 1.00 of " Portland" cement, therefore, absorbs .29 of water, which shows that, for an Tlie Boulocme i -r. i ^r -r> i m " Portland' ab- equal wei2:ht, the Boulogne " Portland cement JSnntirBo^'cSe ^^^1^^"'^^ ^^^^^^ ^'^^^^y '^'^'' '^'^ ^^''^'>S^^ "Roman." It is " Bomau" cemeut. This difference is doubt- slower setting. 11.1 1.1-1 less due to the high temperature at which the " Portland" cement is burnt. The same cause also explains its slow setting, which does not take place until after twelve, or even eighteen hours. 93. This property of setting slowly may be an obstacle to the use of the Boulogne " Portland" cement for hydraulic works ntDKAULic c:-:ment3, and moktars. 65 wliicli liave to contend against immediate causes siow-sctting ce- - . /> • ments objectiou- 01 destruction, as, tor instance, sea construe- able, under some tions whicli have to be executed under water circumstances. between tides. It is, however, possible, in the last-mentioned case, to obviate this inconvenience by temporarily covering the '"Portland" with a quick-setting cement. " Moreover, a quick-setting cement is always difficult to be used ; it often requires special workmen, and, at AdvantaTS, AND MOETARS. 69 seldom if ever pure, but iisiially contain, besides the carbonate of lime and the water of crystallization, vari- Limestones are able proportions, seldom exceeding .10 in the ^^^^"""^ P^""^- aggregate, of some if not all of tlie following impurities, vix.: silica, alumina, magnesia, oxide of iron and oxide of mangatiese, and sometimes traces of the alkalies, the presence of Avhicli modifies to a greater or less degree the phenora- phenomenn devcl- ena developed during the process of slaking, as °P°*^ "^ siakmg. noticed in paragraph 96, and renders necessary certain precau- tions in their manipulation and treatment, when emplo_yed, for the purposes of construction, as mortars. 102. The striking and characteristic property of hardening under water, or when excluded from the air, conferred upon a paste of lime by those foreign substances, when their aggregate amount exceeds .10 of the whole, furnishes the basis for a gen- eral arrangement of all natural or artificial products suitable for mortars,into five distinct classes, as follows: 1st. The common or fat limes. Their classifica- , ,^_ tion as sources of 2d. ihe poor or meagre limes. mortar. 3d. The hydraulic limes. 4th. The hydraulic cements. 5th. Tlie natural pozzuolanas, including pozzuolana, properly so called, trass or terras, the arenes, ochreous earths, schists, grau- wacke and basaltic sands, and a variety of similar su!)stances. 103. Tlie com?non, fat^ or rich limes usually contain less than 10 per cent, of the impurities mentioned 1-1/^-1 T 1 ,. 1 1 • Common lime. m paragraph 101. In the process oi siakmg to a paste, their volume is augmented to from two to three and a half times that of the original mass, accom- panied by a hissinor noise, an elevation of tem- ^*^ increase of ^ *' o 5 volume m slaking. perature, and the rapid and progressive reduc- tion of the lime to powder, and finally, if sufficient water be added, to a homogeneous and consistent paste. "With the ex- ception of a portion of the foreign substances mentioned, it is soluble to the last degree in water frequently changed. If ^0 PEACTICAL TBEATISE ON LOIES, made into a stiff paste, it will not harden under water, or even in damp localities excluded from contact with The paste will not _ ^ harden under the air, or under the exhausted receiver of an air-pump. In the air, it hardens bv the gradual formation of carbonate of lime, due to the absorption of car- bonic acid gas, aided by the deposition of crystals of hydrate Theory of its in- <^f li^^6 from the lime-water of mixture, during duration in the air. ^jjg process of desiccatiou. 104. The pastes of fat lime shrink in hardening to such a deo^ree that they cannot be emploved as mor- Use of sand. » . ^ •' , ^ f " ^, tar witJiout a large dose oi sand. vV hen used alone, they are unsuitable for masonry under water, or for Lime mortars u - foundations in damp soils ; but in other situa- suitabie for sub- tious, have an extensive application, possessing, aqueous works; . . , , as they do, great advantages over the other limes on the score of economy, on account of the large aug- , , , mentation of their volume in slaking, their ex- mucn used under °' other circum- tensive distribution over the surface of the globe, and the simplicity of their process of manufacture. Paste of fat lime may be added to a cement mortar, in quantities equal to that of the cement, without ma- terial diminution of strength. 105. The poor or meagre limes generally contain silica (in the shape of sand), alumina, magnesia, oxide ^or or meagre ^^ -j,^^^ sometimes oxide of manganese, and in most cases traces of the alkalies, in relative proportions which vary very considerably in different locali- , . . ties. Tlieir ao-orreo-ate amount is seldom less Amount of impu- ^^ " rities which they than .10 or greater than .25, although, in contain. ... , i • i o-- some varieties, it reaches as high as .oo, and even, though rarely, .39 of the whole. In slaking they proceed sluggishly, as compared with the rich limes, and sel- dom produce a homogeneous and impalpable powder. Tliey exhibit a more moderate elevation of tempera- Phenomena de- ^ Feloped in slaking, ture. evolve Icss hot vapor, and are accompa- HYDKAULIC CEilENTS, AND MOETARS. 71 nied by a much smaller increase of volume than the rich limes. Like the latter, they dissolve in water frequently renewed, though more sparingly, owing to the presence of a larger amount of impurities, and like them will not harden, if placed in the state of paste, under water or in wet soil, or if excluded from contact with the atmosphere, or carbonic acid gas. They should be employed for mortar, only when it is impossible to procure common or hydraulic lime, or cement, , . T ... -I 1 •,> .11 ^ot to be used in wnicli case it is recommended, it practicable, for mortars, ex- to reduce them to powder by grindino;. As a ^ept under pre- i Jo o cautions. fertilizer, they have an extensive application. 106. A very large proportion, frequently .90 of the silica, con- tained in meagre limes, is in the state of inert t „. •,• • '^ ' Inert silica in grains of sand, which accounts for the frequent meagre limes. absence of those peculiar properties of hardening or "setting" under water, which would place them in one of the classes of hydraulic limes, were tlie silica present, or a suitable propor- tion of it, in a more appropriate form. 107. The hydraulic limes, including the three subdivisions of " li7nes slightly hydra^iUc^'' ^^ hydraulic „ , ,. ,. _•'"'■' ' -^ Hydraulic limes. limes^'' and " limes eminently hydraulic^'' sel- Three classes. dom contain an aggregate of silica, alumina, magnesia, oxide of iron, &c., exceeding .35 of the whole. The proportion in the first class ranges generally between .10 and .20 of the whole ; in the second class, between .17 and .24 : . , . . ' _ ' ' Amount of impu- while the eminently hydraulic limes contain rities which they rarely less than .20, or more than ,35 They all slake under proper treatment, though more slowly than the meagre limes, with but a slight elevation of temperature, the disengagement of little or no vapor, and but .,, , o o r •> Phenomena de- a small augmentation of vulume, rarely ex- yeloped in slak- ceeding .30 of the original, — their appearance presenting in this respect a striking contrast -with the phe- nomena exhibited during the slaking of rich limes. If mixed into a stiff paste, after being slaked, tlie^ possess 72 TiieiT ast ■will ^^'^ valuable property of hardening under water, harden uuder in periods varying from fifteen to twenty days water. after immersion, if '* slightly hydraulic ;'' six tc eight daj-s, if " hydraulic ;*' and one to four days, if " eminently hydraulic." As a general fact, these limes undergo, in slaking, an increase of volume, inversely proportional to their hydrau- lic energy and quickness. lOS. The hydraulic limes, in their chemical composition, as well as in those qualities which confer value in ^een^'commo^ ^^1^"" application to the purposes of construc- lime and hydrau- tiou, and, in their o-eolosical position, occupy lie cement. ,' ' . » » r i fJ an intermediate place between the common or fat limes and the hydraulic cements. They are consequently found in the United States in numerous and extensive deposits ; but as they possess no valuable property not present in a pre-emi- Found extensive- ii^nt degree in those limestones which furnish ly in the United hydraulic cement, it has not been found neces- States, but not "^ ^ ^ manufactured for sary, and certainly it would not be remunera- tive, to eno-age in anv extensive manufactnre of them for the trade. 109. The hydraulic cements contain a larger amount of silica, alumina, magn^ia, &c., than any of the preceding va- ■a A V rieties of lime, thouorh the amount rarelv, if Hyorauuc ce- ' , c .- ' ment ever, exceeds .61 of the whole. They do not _ slake at all after calcination, differino^ materi- WiU not slake. ... . ally in this particular from the limes proper. „ , , If pulverized, thev can be formed into a paste Water does not tr •> ^ x causo increaae of with water, without any sensible increase of volume. , , .,,.-.". p -.. volume, and with little, it any disengagement of heat, except in certain instances among those varieties which contain the maximum amount of lime, or border on the " in- termediate limes." They are greatly superior to the best '' emi- nentlv hvdraulic limes," for all the purposes A paste wiU har- ./ - ' x j. ^ den quickly under of hydraulic construction ; some of them being so enerjjetic as to '* set" under water at 65° F.. itYDBAULIC CEMENTS, AND MOETARS. 73 in three or four minutes, although others require as many liours. Thej do not shrink in hardening like the ^^^6^1^^ lad ^ paste of fat lime, and therefore make an excel- may be used with- , , • 1 IT. n -, ^ out sand. lent mortar without any addition of sand ; al- though, for the sake of economy, sand, and frequently both sand and lime, are combined with them. In the United States, they are almost exclusively depended upon for hy^draulic mortar. 110. Lying between the two preceding classes in the amount of foreign substances which they contain, and possessing such characteristic features as to entitle it, perhaps, to a separate notice, if not a separate classification, there is a class of com- pound limestone prominently developed in the Intermediate. argillo-magnesian deposits of this country, pos- limes of the Uni- sessing in a very marked degree all the objec- *^^ States. tionable properties of the argillaceous intermediate limes (c/uiiix limites), noticed by M. Vicat. When com.jpUtely calcined, they set rapidly, both in the air and in water ; but in the latter case are soon thrown down by the slaking of the Their charactoris- meagre caustic lime, which they contain in ex- *^° featrnres. cess. This result is brought about either by the appearance, soon after submersion, of a fine network of cracks, all over the surface of the mortar, which gradually pene- trate into the interior until the whole is reduced paste under to a granulated or lumpy paste, possessing no ^^*®'"' cohesion, or, by the progressive softening of the whole mass, to a fine and homogeneous pulp, frequently accompanied in either case with a considerable enlargement of volume. If, after the action of the water has commenced, as indicated either by the appearance of cracks, or by a general softening upon the surface, the paste be again M'orked up with the trowel, dried off with bibulous paper, formed .re f , . Destruction of into a still cake and immersed, the same phe- hydraulic energy nomena, though in a more moderate form, will ^ ^'^ ^' frequently exhibit themselves again, ai d with some varieties, 74 PRACTICAL TREATISE ON LIMES will not entirely disappear, until four or five repetitions of tliis process. This is particularly the case with some of the layers in Ulster county, N. Y. In all cases, however, whether one or several remixings siifiice, the hydraulic energy is so far im- paired that the substance cannot assume a higher rank than hydraulic lime, requiring from three to ten days to harden sufficiently to support the 2V inch wire loaded to one pound." "When considerably underburnt, these limestones yield a good cement. They ought not, under any circura- Not to be used for ^ • ^ i • n mortar, except Stance, to be mtroduced, even m a small pro- cautioi^'^^^"' P""®* portion, into any combination wliicli is intend- ed to be kept up to the standard of good ce- ment, without being subjected to a calcination by themselves ; and even then it will be found extremely difficult, if not prac- tically impossible, to so regulate the heat that all the stone shall be suitably wnderhurnt. 111. The natural jpozzuolanas comprise pozzuolana properly T,T . 1 so-called, trass or terras, the arenes, some of Natural pozzuo- ' ' ' lanas. the ochreous earths, and the sand of certain grauwackes, psammites, granites, schists, and basalts. Their Principal ingredi- principal ingredients are silica and alumina, ents thereof. with a large preponderance of the former. Most varieties contain small quantities of soda, potash, ox- ides of iron and manganese, and not unfrequently magnesia. !None of them contain more than .10 of lime, when pulverized When finely pulverized without previous cal- and misced with cination, and combined with the paste of fat fat lime. ' lime in suitable proportions, to supply their deficiency in that ingredient, they possess hydraulic energy to a degree that will compare favorably, in some of the varieties, with that of the " eminently hydraulic limes." Those de- . ,. . rived from the disintegration of grauwacke, Some varieties im- ^ ^ proved by calci- psammite, granite, and the other rocks men- tioned, are the least energetic of the class, and a,re somewhat improved by a slight calcination. AND MOETAES. 75 112. Pozziiolana^ which confers the name upon this class of substances, is of volcanic origin, and has therefore been sub- jected to the action of heat, whereby its constituent elements have experienced a chemical change in their primitive mode of combination. It was originally discovered at the foot of Mount Vesuvius, near the village of origin. ' Pozzuoles, whence its name, although it is com- mon to all localities that have been exposed to igneous agency, being found sometimes upon the surface of the earth, though most generally in beds, which frequently extend to considerable depths. It is extensivelj^ disseminated through- out Europe, and large quantities for buildino- Found extensively purposes, have been derived from the vicinity of Home and Civita Yecchia, in Italy, and from the Puy-de- Dome, Upper Yienne, Upper Loire, Cantal and „. . . -r. T . 1 .. 1 . o. ., Localities. Vivarais, m 1^ ranee. It is also found m oicily, in the Isle of France, and in Guadaloupe and Martinique. It sometimes exists in a coherent form, but more frequently is either pulverulent or in coarse grains, sharp, angular, and rude to the touch. Its prevailino- color is brown, • IT?/.,., Color, with many exceptional shades of red, violet, gray, and yellow, and oftentimes approaching white and black. It is highly magnetic, parts with about .09 of , , . . . . , , . , Properties, water by calcination, is entirely solvent in sul- phuric acid, and in concentrated hydrochloric acid at the boil- ing point. As might be inferred, from the character of the agencies which produce pozzuolana, its hydraulic properties differ very much in different localities. Its value for the purposes of construction in combination with rich lime, has been known for many centuries, and Yitru- vius and Pliny both speak of its admirable properties, as exhi- bited in the marine constructions of the Romans, extant in their day. In using pozzuolana, it is clentT* "^ ^ ^^ customary after pulverizing it, to add sand as well as lime ; the relative proportion of the three ingredients t6 PRACTICAL TEEATISE ON LI3IES, depending on the kind of sand employed, and the character of the lime and pozzuolana. For the Italian pozzuolana, there is perhaps no better combination than that recommended by Vitruvius himself, which has been followed, with slight varia- tions, very generally throughout Italy, and at Toulon, and other ancient ports on the French coast. It is as follows, viz, : 12 parts of pozzuolana well pulverized, 6 " " quartzose sand well washed, 9 " " rich lime recently slaked ; to which is added 6 " " fragments of broken stone, porous and angular, when it is intended for a pise or a filling in. The pozzuolanas of this country, if any exist, Not known to be ^ ^ j ) j > native to the have never been used in constructions, and have United States. . i • i i never been exammed with that view. 113. Tj'ass or terras. — In the valley of the Rhine between Mayence and Cologne, and in various localities in Holland, a substance of volcanic origin is found, called Trass or Terras, which has been extensively employed through- out that region, particularly by the Dutch engi- neers, for the production of hydraulic mortar. It is derived from immense pits or quarries, occupying the Its sources. • ^ /. . • , i i • • i Sites 01 extinct volcanoes, and enjoys m nearly every particular the distinguishing properties of Italian poz- zuolana, closely resembling it in its composition, fuokna^^and^Ts' ^^^ "^ ^he details of its manipulation, requiring used in the same ^q ^^ pulverized and combined with rich lime, manner. ' in order to render it fit for use, and to develop any of its hydraulic properties. 114:. The trass used in Holland is obtained principally from Bonn, Andernach, and from the village of Dor- DtTtoh^tras^s dreck, exclusively devoted to its production, and at the confluence of the Rhine and the Meuse. 115. Trass is of a grayish color, has an earthy appearance, and is found in beds that are sometimes co- herent, though usually composed of a hete- HYDRAULIC CEMENTS, AKD MORTARS. 77 rogeneous mass of pulverulent lumps, from the size of a small pea to that of an esrg. Sulphuric, and , 1 . . 3 1 . Properties, even concentrated hydrochloric acid, attacks it with readiness, leaving a residue of insoluble silica. Smeaton regarded it as inferior to the Italian pozzuolana in some essen- tial particulars, and mentions, as one of its objectionable fea- tures, that of throwing out unsightly efflorescences upon the' faces of walls in which it is used, which attain such a degree of hardness, as to render their removal with instruments necessary, specially in positions where smoothness and regularity of sur- face are essential, as in water conduits, navigable sluices, &c. More recent experiments have led to the suspicion that Smea- ton cither made use of a lime ill adapted to the purpose, or what is perhaps more probable, that he unduly augmented its propor- tion, which should rarely exceed the ratio of one to one. 116. Arenes is the name given to a species of ochreous sand, claimed by some to be of fossil origin, and ^ •^ ^ Arenes. found abundantly in France, in the Depart- ment of Dordogne, and in several localities on the tributaries of the Loire and the Somme. On account of the large pro- portion of clay which many of them contain, which often reaches as high as .70, they can be without Ume. formed into a paste with water, without any addition of lime, and are often used in that state for the walls of buildings constructed en pise, as well as for mortar. Mingled with rich lime, they give apparently excellent mortars, which attain great hardness under water ; and, in hydraulic quickness, compare favorably with the most ener- getic hydraulic limes. 117. It is doubtful, from some careful experiments that have been made, whether their properties, as regards the ulti- mate strength and hardness of the mortal's ^^gir hydraulic made from them, are improved by calcination, activity increased or otherwise. Their hj'draulic quickness, how- ever, is greatly increased thereby. Their colors are various, such 73 PEACTICAL TREATISE ON LBIES, as red, broMoi, yellow, and sometimes white. They contain from .10 to .TO of clay, the balance being a Compositiou. . . , „ , .... mixture oi coarse and ime calcareo-silicious sand ; and have hitlierto been principally found upon the sum- mits of small hills, or forming the superior strata of plateaux bordering water-courses, but rarely in the valleys. These beds exhibit the characteristic physical features of alluvial deposits, and are probably accretions of diluvial or tertiary earths, transported from a distance. This conclusion excludes the idea that they have been subjected to the action of vol- canic heat, and leaves us to account by some other hypothesis for their hydraulic properties, and their close resemblance, in other respects, to the Italian pozzuolana. The most reason- able supposition is that they owe their hydraulic energy, when mixed with the paste of fat lime, to the presence of silica, not in the state of quartz, but in a form favorable rhcSfydrSy^ ^^ its free combination with the lime, in the production of an insoluble silicate. To account for the hydraulic energy in crude arenes requires a more lengthy discussion of certain chemical reactions, than can with propriety be introduced here. It will therefore be deferred to the chapter containing the " theory of the subaqueous induration," 118. "When the arenes were first discovered, great attention was paid to their examination, and with such favorable results at the outset, that the}^ immediately took rank among the most valuable sources of hydraulic mortar. Subsequent experi- ments, however, have not fully realized the high expectations originally entertained with regard to them, or verified their claims to any superiority in initial energy over the pozzuolana and trass ; while the effects of time upon the mortars composed of them, have established the fact that, with few exceptions, they should be classed among the most feeble pozzuolanas, that they contain ingredients which exercise a hurtful influence upon mortars in the air, and that immersed in water, they at tain but a medium degree of ultimate hardness. HYDRAULIC CEMENTS, AND MORTARS. 79 119. Properties similar to tliose possessed by Uie arenes have been discovered in grauwacke, psaininite, granite, scliist, basalt, and otlier rocks, when in a state of disintegra- tion. They must, however, be considered as ^*°'" "^^"'"^ •' ' ' pozzuolanas. verj feeble pozzuolanas, in the crude state, and / acquire but a slight increase of hydraulic energy by any degree of calcination. Even their feeble powers, however, confer upon them this advantage, that, for mortars not absolutely immersed in water, when g^reen, and when there is ample time for their properties to develop themselves before submersion, they can be employed in larger proportions than any species of sand, wholly inert, would admit of. 120. It may be said that a mortar has set, when it has at- tained such a degree of induration, that its form cannot be altered without causing a fracture, that is, when it has entirely lost its plasticity. As the rmorUrSnel precise moment when this takes place is some- what difficult to ascertain in practice, it is important that some more rigorous standard of comparison should be established. The common method is to make use of an iron or steel wire point loaded to a giver, weight ; and the mor- tar is assumed to l^avc set, when it lias become K™/seuing. sufficiently stilf ar.d rirm to support the point without depression. 121. Some cements are remarkably quick in exhibiting their hydraulic property, and will lose their plastic state immersed in water at 65° F. in one or two minutes, but afterwards pro- ceed very sluggiGhly in their induration. These, therefore, setting aside the question of their value in other respects, are admirably adapted to constructions under water, or in positions subjected to immediate submersion. There are others, again, which, though comparatively slow in developing the first in- dications of hydraulic energy, yet in a few hours, greatly sur- pass the former in withstanding the wire test, as well as in tlieir ultimate strength and hardness, and are therefore to be 80 PRACTICAL TEEATISE ON LIMES, preferred in all positions where a very quick induration is not "H dr li f specially important. The former are remark- ity" and " hydrau- able for what we propose to term hydraulic lie GDGrcrv." quichiess or activity / the latter, for hydraulic energy or power. In order that we may be able to detect and recognize these somewhat obscure properties, it is necessary to have at least two testing wires, which differ either in their size, or weight, or in both. General Totten, for his experiments, carried on at Fort Adams, R. I., during several years prior to 1830, used a yV i^itr^ wii-e, loaded to weigh J of a pound, and a ^V inch wire, loaded to weigh one pound. We Testing wires. , , ,' . ,i ,. . have used the same m all oui* tests, raakmg lu every instance two cakes of the mortar under consideration, by forming them in a circular mould or ring 1\ inch in diameter, and f inch deep. As soon as these cakes are prepared, whicli is done by pressing the mortar into the ring with a spatula, and smoothing off the upper surface, one of them is immersed immediately in water of an established temperature (65'^ F.), and the periods of time which it requires to be able to bear respect- ively the y'j inch wire, weighing ^ of a pound, and the ^^ inch wire, weighing one pound, are accurately noted by the watcli. The other cake is left in the air (also brought to 65'^ F.), until it supports the yV ^'^ch wire, and is then immersed in water, and the time required to bear the small wire and heavy weight ascertained. 122. The wire test of hydraulic activity, when applied to cement paste without sand, does not furnish Wire test of pure , . , . . „ , , . oemont paste not even an approximate indication of the relative reliable. value of mortars of the same cements when mixed with a full dose of sand ; for a quick cement might contain on&-half or three-fourths of its volume of inert matter ground up with it, and consequently be incapable ol Roasonswhy. ^ . . ' , ^ , mi , • receiving much sand, and still be superior m hydraulic activity to another, although the latter might bo entirely unadulterated and its capacity for sand unimpaired. HYDEAULIC CEMENTS, AND MORT^^JBS, 81 In pronouncing on the value of cements, from a comparison of their relative hydraulic activity, tliey should, therefore, be mixed with two and a half to three sand to be used times their volume of sand. Even with this pre- caution, the result is far less reliable than some simple device for trying the strength of the mortars, when ten or twelve days old. As an evidence of the truth of this remark, it may be stated that, although eminent hydraulic activity or quick- ness is not necessarily accompanied by inferior hardness and strength, and conversely, neither is a slow setting cement necessarily a strong one ; still, within the range of the experi- ments which furnish the tables of this work, it is somewhat remarkable that the quickest cements gave the worst results, and the slowest ones the best. 123. The effects of a variation of temperature upon the hydraulic quickness of mortars, whether derived from hydraulic lime, hydraulic cement, a mixtm*e of common lime and pozzu- olana, or produced by artificial means is very j,^^^^ ^^ change marked: so much so indeed, that in all compar- oftnnperatureon hydraulic acUvity. ative tests of this kind, it is important to adopt gome fixed standard of temperature, not only for the water %vitli which the cement is mixed, as well as that in which the cement is immersed, but for the dry ingredients and the surrounding atmosphere. To illustrate the necessity for these precautions, we will in- stance two kinds of United States cements. With the dry cement and water for mixing at 90°F., one of these cements immersed in the state of paste in water at 90" F., supported the tV inch wire loaded to ^ of a pound in 1^ minutes. The other one required 4 minutes to attain the same set. , . , ^ Examples cited. Lowering the temperatures to 65°, the former required 6 minutes, and the latter, 17 minutes ; while at 35°, the respective periods were lengthened to 39 and 82 minutes, showing for a depression of 55° in the temperature of the paste (viz. : from 90° to 35°), a corresponding prolongation of the 6 82 period required to set, amounting in the one case, to 37^ minutes, and in the other, to one liour and 18 minutes. Hence, all cements are not equally sensitive to a variation of temjperature ; also, those varieties which contain an excess of caustic lime may exhibit a superior deqree of Deductions. -^ ... t • hydraulic acttvity^ due to tJie heat generated m hringing this lime to the state of hydrate. 124. The diagram (Figure 8) is intended to sliow the effect of a variation of temperature upon the time of setting of cements formed into cakes or cylinders of stilt paste, as de- Bcribed, paragraph 121, immersed in that condition in water. The curves are constnicted with abscissas, which diaer^ ^^^ ° represent the temperature of the air, water, and dry cement (these being varied equally and kept together in all cases), and with ordinates, which repre- sent the times of setting, in minutes, that is, the period of time which elapses before the immersed paste can support the loaded wire point without depression. Tiie dotted curves refer to tests with tV inch wire, loaded to J pound, and the full curves to the aV inch wire, loaded to one pound. OBSEKVATIONS ON THE DIAGRAM, FiG. 8. No. 1 is fi'om the Kound Top Cement Works, on the Poto- mac River, near Hancock, Md. (See paragraph 75.) This is a very quick setting cement, whether left in the air, or im- mersed in water. For masonry, or concrete work in running water, when it is necessary to carry on operations in cold weather, the dotted curve indicates that no cement in the country is superior to it in rapidity of first induration. It sus- tains a change of temperature better than any cement tried, except No. 3. No. 2 is from the James Kiver Works, at Balcony Falls, Rock- bridge Co., Ya. For all temperatures above 55°, this cement exceeds in hydraulic activity, all the specimens submitted to trial ; while below 48° it is surpassed by only two, the Round HYDRAULIC CEMENTS, AND MORTARS. 83 Top and the Cumberland (No. 3). At all temperatures it sets in the water almost as quickly as it will in the air. (See para- graph 79.) "° S5° 80° 75° 70° 65° 60° 55 50° 45° 40 Teiiiptruture of water, dry cement, and air. Fig. 8. 84 PRACTICAL TREATISE OX LIMES, Ko. 3 is from the Cumberland cement. (See paragraph 77.) It is less sensitive to a depression of temperature than any ex- hibited in the diacp-am. No. 4 belongs to the Newark and Rosendale brand, from Ulster Co., N. Y., and is a fair type of the dark-colored Rosen- dale cements. (See paragraph 61.) No. 5 is a light-colored Rosendale cement, manufactured at High Falls by Messrs. Delafield & Baxter. (See paragraph 63.) By examining the above-mentioned curves, a marked differ- ence is observed between No. 1, No. 2, and No. 3, as compared with No. 4 and No. 5. At high temperatures, they all begin to harden under water with nearly equal promptness, requirin g less than five minutes to bear the light testing wire ; while at two degrees above the freezing point, the James and Potomac River cements set in periods varying from twenty-seven to thirty-eight minutes, while the Rosendale brands require seventy-two and eighty-four minutes respectively. The latter are therefore more sensitive to a variation of temperature than the former. No. 6 belongs to a ceinent from Sandusky, Ohio. (Para- graph 81.) This cement is characterized by a remarkable want of uniformity in quality, as it is offered in the market. One sample obtained in the summer of 1859, required several hours under water at 65° F., before it could support the light testing wire (yV inch wire and ^ pound weight), and would not support the heavy wire until the second day after immersion. Another specimen, obtained several months later, gave for the light test- ing wire the curve No. 6. The cement hardened so slowly atler the first set, that the curve for the heavy wire does not come within the limits of the diagram. No. 7 belongs to the cement manufactured at Utica, 111 (See paragraph 80.) It closely resembles that from Sandusky, Ohio, although it conducts itself under water rather more satis- factorily. By mixing the Sandusky and Utica cements to- HYilKAULIC CEMENTS, AND MORTAKS. 85 gether, in equal quantities, a combination is obtained, which from experiments carefully repeated on a small scale, appears to be superior to either. It is therefore suggested to Western engineers and architects to use them in this way. Ko. 8 is derived from an artificial cement prepared from a stiff paste of fat lime mixed up with a sufficiency of double al- kaline silicate, of 39° Baume, in solution to bring it to the con- sistency of ordinary mortar. Almost any required degree of hydraulic activity may be conferred upon a paste of fat lime in this way. Limes that have been allowed to remain some days in the state of paste before adding the silicate, are pref- erable to those that have been slaked to a powder and pre- served in that condition. These latter are apt to crack under water, after the silicate has been added. No. 9 was from Eoman cement manufactured from " Sep- taria," or clay nodules found on the coast of Scotland. It is proper to remark, that this cement bore evidences of having suffered from exposure during transportation, and was not therefore so fresh, and of course, not so energetic as an average sample would have been. In hydraulic quickness, fresli Ro- man cement is by no means inferior to the best Rosendale brands, while its subsequent progressive induration probably exceeds that of most American cement. No. 10 is from the cement manufactured at Louisville, Ky. Artificial Hydraulic Cement and Lime. 125. It is possible to make hydraulic mortar by using arti- ficial preparations of hydraulic cement, lime. Artificial hydrau- and pozzuolana, and this course is often pursued, ^"^ mortar. particularly in France, in localities where there are no natural deposits suitable for such purposes. There are ^owr methods of four methods of attaining this object, viz. : making it. Fird, by combining thoroughly slaked common lime with unburnt clay in suitable proportions, burninor ,, . . . r 1 -1 P J First method. the mixture m a lime-kiln or furnace, and 86 PEACTICAL TREATISE ON LIMES, then grinding it, producing what is called twice-kilned " arti- ficial hydraulic lime." Second, by substituting for the quicklime a carbonate of lime that can be pulverized without burning, like chalk, in other respects following the direc- tions of the first process. Third, by making artificial pozzuolana, which is efiected whenever calcareous sand and certain kinds of clay are subjected to a slight calcination. Fourth, by adding silica, in a soluble form, to a paste of Fourth method. common lime. FIEST METHOD. 126. Before the calcination, the clay should be fully dried in the open air, or under sheds prepared for the purpose, after the manner of bricks and pot- tery. The proportion of lime and clay used should be varied Proportion of according to the quality of the clay, the charac- lime and clay. ^^^ ^^^ purity of the lime, and the degree of hydraulic quickness which the resulting product should possess, that is, whether it is intended to imitate hydraulic cement or hydraulic lime. Ten per cent, of clay will confer "moderately hydraulic" energy, while it will never be necessary to exceed 54 per cent, to produce a very active cement. The clays that Kinds of clay have been found most suitable for that purpose most suitable. q^^q those wliich are unctuous to the touch, and are of common use for manufacturing various kinds of earthen- ware. They contain .30 to .50 of alumina, and .04 to .05 of carbonate of lime. It is of the highest importance that the lime and clay should be thoroughly and homogeneously incor- porated with each other by means of a mortar mill, if prac- ticable, previous to the drying process, and that this latter should be continued until no trace of humidity remains. If this last condition be not fulfilled, no good results can be ob- tained, as the silica contained in the clay will not be in a state HYDRAULIC CEMENTS, AND MORTAES. 87 favorable to its combination with the lime in the dry way, and the clay will remain almost entirely inert, from the moment the mixture reaches a dull red heat. These facts, originally promulgated by M. Kancourt, have been amply verilied by repeated experiments conducted by M. Ducreux and othei-s. To prepare the mixture of lime and clay for „ . . '' Preparation of drymg and burning, it is customary to cut mixtme for bum- it up into small cakes, or roll it into balls of two ^^' or three inches diameter. 127. The calcination is effected at a lower temperature than that required by the natural stone; a bright Calcined at a w red heat is sufficient, as water is more easily dis- temperature, engaged from the cakes than carbonic acid would be. It is also necessary that this second calcination should take place un- der the influence of a good draught, or in contact with the air. The material thus obtained is said by M. Vicat to be prefer- able to the best hydraulic limes directly obtained from argil- laceous limestones, but we shall see further on, that this is at least doubtful. A saving of fuel can be effected by burning raw bricks, or common lime, or both, in the same kiln, with the argillo-calcareous balls, and this is practised in majiy countries. It can be done in kilns somewhat higher than the average, say eighteen feet, filling them with carbonate of lime up to nine and a half or ten feet, placing over it bricks to a height of five feet, and over the latter, the small pieces of lime and clay which have to be converted into hydraulic lime. Tlie burnt balls may be pulverized between millstones, or by any other suitable means. SECOJ^D METHOD. 128. "When a soft carbonate of lime, like chalk, or calcareous tufa, is employed for making artificial hydraulic lime or cement, it is not necessary or customary to subject it to ^, „ , I . . . '' '' Chalk and clay calcination, previously to its being mixed with mixeii to^rother the clay. The reduction of both ingredients ^^°'' '"""^- 88 PRACTICAL TEEATISE OX LDIES, to a fine powder bj suitable macliineiy, however, is essential as the first step ; after which they are thoroughly mixed together in proportions ascertained by previous experiments to give the desired results, made into cakes or balls, dried, cal- cined, and ground for use, as in the first case. The " Portland" cement of England and France* is made in this way, the calcination bemg carried to the land"*cement'^'^ verge of vitrification. In its manufacture, chalk is generally depended on to furnish the calcare- ous ingredient. The necessitv of reducing the carbonate to a state of paste, and of incorporating it with tjie clay before any calcination takes place, practically excludes the more compact varieties of limestone. The chalk may be a mill. ^*^™ ^^ ground in any mill suitable for reducing such substances. One consisting of a circular trough of stone or brick work, in which two wheels are made to turn, has been used in England, and found to answer a good pur- pose. The wheels are located on the axis at unequal distances from the centre of motion, so as not to run in the same track. For extensive operations, a steam mortar mill like the one used at Fort Taylor (Figure 34), or some modification of it, would perhaps possess many advantages. 129. Water is added to the chalk before CbaUc CTOund in a • t ii • • j t ^ i surplus of water, gnndmg, generally m considerable surplus. After this preliminary manipulation is com- pleted, the semi-fluid mass is conveyed into bins with grated or perforated bottoms, or made up into heaps and left, until, by drainage and evaporation, it is reduced to the consistency of stiff mortar. It is then in a condition to be mixed with the clay. Pure alluvial clay, or, when this cannot be pro- cured, fine pit clay, free from sand, is next suitable.^ °^^ added to t!ie chalk paste, and the thorough and homogeneous incorporation of the two ingredi- ents is effected by means of a pug-mill. For the English " Port- * The " artificial" Portland is here referred to. ' HYDRAULIC CEMENTS, AND MOETAKS. 89 land," the argillaceous mud deposited by the Tliaraes and Med- way Rivers is used. The chalk is derived from •' ... 'fhe challc used. the middle and upper layers of that formation, as it crops out on the banks of the Thames. These sub- stances are ground up together by millstones, with a sufficiency of water to produce a semi-fluid mass. A process of decanta- tiuii into vats, or hollows scooped out below the surface of the ground then ensues, by which the unground and heaviest par- ticles are left behind. 130. The mixture having attained the consis- . 1 1 • 1 n i> Mixture formed tency ol potters clay, is kneaded into balls or iutobaUs; drying about three inches in diameter, and dried in [JoqJ'""' '^'^^' the air under cover for about forty-eight hours, and then burned in an ordinary lime-kiln. If the kiln be perpetual, the drawing may commence in about three days, provided a white heat has been preserved during the interval. 131. In comparing this process with the one in which slaked lime is used, it will be observed that they differ in two essential particulars, viz. : 1st. The lime mixture must be thoroughly dried before burning, while the chalk mixture r. ^ m^ (. . 1 • J •.! Difference in the need not be. 2d. ihe former is calcined with a burning by first moderate or bright red heat, and the latter at a ^"tj^o^^fg "'^ white heat. The burnt cement is ground in the ordinary way between millstones. The proportions of clay and sand in the "Portland" cement should, of course, vary with the kind and quality of the clay used. M. Yicat analyzed a sample from the manufactory of Messrs. AVhite & Sons, with the following results : Lime 68.11 Silica 20.G7 ^^^^-^f '^ °[,^'"*^-, ficial " Portland Alumina 10.43 cement. Oxide of iron 87 This composition very nearly corresponds to that of the inter- mediate limes. 132. The fullowingis a synopsis of the method of preparing 90 PBACnCAL T2EATISE OX LIMES, artificial cement followed in Enirland, before the Old process. , ^ i . i t , • ^ advantages ot tlie intense beat applied in burn- ing " Portland"' cement were known. Selection of the ingredients of artificial cement. — The chalk. — Tlie wbite or upper chalk of the geologists being a tolerably pure carbonate of lime, is to be preferred to the Chalk. '^ . '. ^ , marly or impure deposits near the surface. By mechanical means it must be reduced to an impalpable powder, or, by the addition of water, to a homogeneous paste. The clay should be the hlue alluvial of lakes or rivers, in a state of minute division, and free of sand. In England, the deposits of the Medway, and in the United States, the compact beds of this unctuous elav, and the clavs used Oar. * ' for pottery, will answer. A long exposure to the air should be avoided, as it has been found to injure the quality of the clay for artificial cement. Proportions of cJay and chalk. — By weight, 100 pounds of pure dry chalk to 137^ pounds of fresh blue SX2d°d^7. ^^^T^ "being equivalent to four of chalk to five and a half of clay. By measure., one cubic foot of stifi" chalk paste to one and a half cubic feet of fresh blue clay. Xinety-six pounds of dry chalk produces one cubic foot of chalk paste. Mode of grinding the chalk. — The chalk is ground with the water necessary to produce a thin paste, in a mortar mill. Colonel Pasley recommends one with two broad vertical iron wheels, on a common axle, carried around by M^ofgroiding ^^^^^^ ^^ ^ vertical shaft connected with the axle, and turning on a pivot in the centre of a cast iron pan. The wheels are placed at unequal distances from the centre of motion. Tlie horizontal axle is attached rather loosely to the shaft, so as to allow the wheels to rise over lumps that may be larger or harder than usual. Scrapers are attached to the vertical shaft, to remove the paste from the circumference and centre of the pan, and thi'ow HYDRAULIC CEMENTS, AND MORTARS. 91 Fig. 9. it in the track of the wheels, while other scrapers, attached to the axle, clean the sides of the wheels, as they rise out of the paste. The wheels may be four and a half to five feet in diameter, and from ten to fifteen inches wide at the rim which grinds the materials, and one of them may be placed at the central distance of eighteen inches, and the other of twenty-four inches from the centre of the pan. The radius of the horse- path may be eleven feet. Figures 9 and 10 will sufliciently explain the general construction of this mill. After grinding, the chalk paste will usually be found in too fluid a state for immediate use, and is generally allowed to stiffen by evaporation. The incorporation with the clay ia Fig- 10. effected by means of a pug mill, and the mixture is then made up into balls about two and a half inches in diameter. These balls are al- lowed to dry under cover about forty-eight ^^^^^ ^^j ^lay. hours, or until sufliciently hard to bear their own weight when piled in the kiln for burning. The burning 92 PRACTICAL TEEATISE OX LDIES, and grinding differ in no essential particular from the process used in tlie '' first method''. (Paragraph 126.) 133. Hydraulic limes and cements are artificiallv manufac- tured in many localities in France. The hydraulic lime of St. Leger may be taken as a type of tlie former. St. Leger It is composed of four measures of chalk and hydraulic lime. ^^g measure of clay, which corresponds, accord- ing to the analysis by Berthier, to eighty-four of carbonate of lime,and sixteen of clay containing ten of silica ; or in other words, one part of clay calcined with five and cliaik°and°day. ^ quarter parts of pure limestone. The chalk bioken np into pieces of the size of three or four inches cube, is placed with the clay in a large vertical mill driven by two horses, and both materials are crushed and mixed together with a plentiful supply of water. The semi fluid mixture is then run off into a series of five troughs placed on different levels, in which it remains until sufiiciently stiff to be made up into balls two to three inches in diameter. When these are sufiiciently dry, they are cal- balk!^ ^^^ *^^ ^ cined in an ordinary lime-kiln, and then ground up between millstones for use. The fuel used in this burning is a mixture of coal and coke, which is mingled with the balls in a perpetual kiln. The degree of heat is consid- erably below that required in burning the " Portland" cement. For producing artificial cement, M. Yicat recommends the proportion of sixty parts of clay for one hundred of chalk, or fil\y-seven of lime. 134. MM. Chatoney and E.ivot, Frojich engineers, recom- mended to the French Academy of Sciences, in 1856, the use of pulverized siHca in combination with fat lime, for the pro- duction of artificial hydraulic limes. Hydraulic lime These gentlemen claim that " excellent arti- composed of ficial hydraulic limes can be obtained, bv sub- pulverized silica . . , . . " and fat lime. mitting to a moderate calcination an intimate mixture of nearly pure lime and very fine sand STDRAULIC CEMENTS, AND MORTAP.S. 93 or ground silica, in tlie proportion of twenty to twenty-five parts of the pulverized silica to eighty to seventy-five of lime. The greater the care t-aken to produce a homogeneous mixture, the better will be the product obtained." In another place, they remark : "pulverized silica burnt with fat lime produces hydraulic lime of excellent quality. In the experiments tried at Havre within the last two years, it has set under water ia thi'ee or tour davs, and acquired a hardness ^ •^ ' i- Js equnl or supe- in twenty-two months equal and sometimes rior in liardnei,a to ,~ •!! i,--r.i 11 Portland cement. superior to that attamed by the ' r^ortland cement in one or tM-o months." The proportions between the silica and lime were various : the weight of the powdered lime never exceeded four times, and was never less than one-half that of the powdered silica. The calcination of the mixture may be conducted according to the directions given for the clay and chalk mixtures. THIRD METHOD. 135. ArtiJiGidl poszvolana is produced whenever clay is sub- jected to a slight calcination. The properties pos- sessed by brick or tile dust, of forminc; with fat ^^'"^'^^'"^ lime a mixture possessing hydraulic energy, were known to the ancient Hon^ans. Many of the feebly natural pozzuolanas have their activity very sensibly in- ^ ,, ^ _ " " ^ i eeble pozzuo- creased by burning, while there are many inert !;inas improved , . ^ ' ^ .^ ^ i mi by caiciuatiou. substances, besides the clays and argillaceous sands that may be converted into artificial pozzuolana by the application of a moderate heat. Forge scales, such as fall from a smith's anvil, the slags from iron foundries, the ashes from under the grates of lime-kilns, containing cinders, coal, and lime, are artificial pozzuolanas. 136. It is a well established fact that nearly, if not all, mag- nesian, argillaceous, or argillo-magnesian lime- stones, of which the composition approximates li^cstoneT. to that of good cements, however destitute thcv 94 PRACTICAL TREATISE ON LIMES, may be of hydraulic energy and quickness, when fully cal- cined, are moderately, if not eminently quick setting, if suitably undcrburnt. (See paragraph 264 and following.) The same is known to be the case with pure carbonate of lime when partially burnt. Some of the coral sand Ke'/wes?/™"' ^'^'^'^ ^^^7 ^^st, calcined for half an hour in a crucible at a bright red heat, and then pulver- ized, yielded a paste which attained a permanent set under water in half an hour. The tests of the strength of the mortars thus formed without sand were not very satisfactorj^, as com- pared with cement mortars. They were, however, stronger than mortai-s of common lime and sand, besides possessing the advantage of sustaining immersion in a short time after being mixed. There seems no reason to doubt that good artificial ^ ^g g _ pozzuolanas may be produced by suitably under- lana when under- burning calcareous sands, and in localities where, or at times when cement cannot be had, this method of obtaining hydraulic mortar might be advan tageously resorted to. 137. It must be admitted as a general fact, that all attempts to utilize the hydraulicity which characterizes underburnt common lime have either signally failed, or, at best, met with but indifi^erent success. Trials with compound limestones and certain mixed earths and sands have been more successful. 138. Some compact dolomitic earths of France have pro- duced excellent artificial pozzuolanas. The earth is quarried by using wooden wedges, inserted and driven into notches or grooves cut in the beds, in such a manner as to favor the splitting out of good sized masses. These are divided into small blocks, dried in the sun or under a shed, and then baked in an ordi- nary lime-kiln. For burning, there is required about one mea- sure of charcoal to sixteen or eighteen measures of the clay. 139. At Calais, France, a good artificial pozzuolana is pro- duced by burning an argillo-calcareous earth taken from the Bea-shore. The earth is produced by admixture, from natural Sydraulic cements, and mortars. 95 causes, of the calcareous washings of the cliffs of the Normandy coast, and the argillaceous mud either brought down by rivers, or formed by the crumblings of the upper bed of the cliffs. The earth is taken from the beach, dried and burned in the same manner as the paste of ordinary clay, in making artificial pozzuolana. At Brest, gneiss sand is found in considerable beds. By submitting it to calcination in a reverberatory fm-nace, a poz- zuolana is obtained, which, although not very energetic, is yet sufficiently so to cause ordinary fat lime mortar to harden in seven days. FOURTH METHOD. 140. The fourth method, not very well understood at pres- ent, of conferring hydraulic properties upon fat lime, is strictly and technically artificial, and gives promise of . *' ,..,,. Fourth method more extensive application in this country than not very well either of those above noticed. It is, besides, ^^'' ^^^ °° subservient to a variety of useful purposes in the indus- trial arts, to which the others could have no possible appli- cation. It consists essentially and briefly in transferring to the lime mortar, or paste, when undergoing the last manipulation at the hands of the workman, a suitable quantity of silica, in such a minute state of subdivision, that it A^-ill enter into combina- tion with the lime, in the formation of insolu- ble hydro-silicate of lime — the compound to featSe™"^°°* which the cements, derived from the argilla- ceous limestones, principally owe the property of hardening under water. 141. The alkalies have been found to constitute a conve- nient and efficacious medium for this transfer. It is known that if pulverized chalk, or, in fact, any liincatone in tlie con- 96 PEACTICAL TEEATISE 01^ LEVIES, dition of fine powder, be made into a paste with an alkaline solution of silica, or what is commonly known aikSe°siIictte3 as "liquor of flints," "soluble quartz," or with powdered " soluble glasB," a chemical decomposition en- sues between the carbonate of lime and the silicate of potash or soda — the carbonic acid being transferred to the alkali, whilst the silicic acid (silica) enters into combina- tion with the lime, producing silicate of lime. These react^ions take place readily under water ; and the paste, underwater ^^"^ immersed, hardens with greater or less rapidity, depending on the amount of silica used, and comports itself, apparently in all respects, like hy- draulic cement. It is, in fact, an artificial stone, which, when prepared in a sufficiently liquid state, and with the proper amount of silica, possesses the property of adhering with con- siderable force to the surface of bodies receiving it, constitut- ing a stony envelope, or covering, as it were, and rendering them, to a great extent, indestructible by fire or water. It is not theoretically or even practically necessary The silicate i: j j need not be in that the alkaline silicate should be in solution, so ution. when added to the lime. If employed solid, however, it must be reduced to an impalpable powder, in or- der to secure its thorough and complete incorporation with the pulverized carbonate, and the mixture may then be formed into a paste. Some attempts to produce artificial hydraulic mortar by this method did not give satisfactory results. 142. If the limestone has been previously calcined, as will be generally the case in all preparations of mortar for mason- ry, whether of brick, stone, or concrete, and is in the condition of dry hydrate, similar results may be ob- Alkaline silicates . i , ,. . ^ • ^ i mi.Ted with tamed by tormmg this hydrate mto a paste, quicklime. with a requisite proportion of silicate of soda or potash, or a mixture of both, which, as in the former case, may be either in solution or dry powder. It is believed that the advantages to be derived from a thorough and homogo- AKD MOET^VES. 9*7 neons paste can be most readily obtained, when the silica is added in solution. 143. By the means just indicated, probably the common or feebly hydraulic limes, and (what in practice will prove of greater importance) the dividing limes {chaux limites oi Yicsit), those which possess the objectionable and dan- gerous property of setting rapidly under water, J^^r^Jj and only to be immediately followed by a gradual intermediate and complete disintegration, due to the slug- gish caustic lime present, may all be transformed into reliable and valuable cements. All the initial energy of the dividing limes may be preserved in this manner. 144. Experience has shown that, if any hydraulic mortar, possessing no matter how hi^h a degree of quickness and energy, be re-pulverized and formed into a paste, after hav- ing once set, it immediately descends to a level, in point of hydraulicity, with the moderately hydraulic limes. A great destruction of the hydraulic principle therefore results from any disturbance of the molecular preakins? the " "set destroys arrangement of the mortar, after the crystalli- hydraulic zation has commenced. This is precisely what ^°®'^^^" takes place in those cements denominated intennediate or di- viding limes, which take the initial set promptly and firmly, but are subsequently thrown down by the slaking of the im- pure caustic lime which they contain. 145. The alkaline silicates supply a specific remedy for the defects just referred to, and when acjded in the proper form, and in sufficient quantity, to cements of this , • i ^ n ,1 • 1 1 T Alkaline silicate type, preserve mtact all their hydraulic power, a remody by presenting to the defective ingredient an ^^*^'"^*°''- efficacious neutralizing agent. Eight to ten per cent, of an alkaline silicate, of the consistency of thin syrup, will confer upon a mortar of fat lime a degree of hydrau- ,..,,, ,.1, , ... - Proportion of licity that will place it in the class of cements alkaline >iiicat© in hydraulic activity, and any inferior grade of ^° ^^ ^^^^ 7 98 PRACTICAL TREATISE OIN" LIMES. energy that may be desired, is secured by proportionally di- minisliing the percentage of silica. To elevate the hydraulic limes to the standard of cements, or to any fixed standard, re- quires, of course, a less amount of silica than is necessary for the common lime, the proportion varying inversely with the active eneriry of the limes acted upon. 146. There is a variety of other important uses to which this* silicifying process, as it may be termed, can be advantageously applied, for our knowledge of which we are chiefly indebted to M. Fred. Kuhlmann, Professor of Chemistry at Lille College, France, and M. Fuchs. We will refer to them very briefly in this connection. 147. "When a solid body, of any degree of porosity, is im- mersed in water or any other fluid, it rapidly absorbs a certain quantity of the latter, until the* point of complete saturation is reached: and if, in addition, the fluid possesses reacting powers, certain chemical changes will ensue within the pores of the solid body. If a porous limestone, like chalk, Action of the „ , . j. . .• -• . t silicate on porous lor example, or a piece oi mortar oi lat lime, limestone or ^^ dipped in a solution of alkaline silicate, a certain portion of the silica in solution, after its absorption, will part with its potash or soda, and enter into combination with the lime, whilst another portion will remain mechanically interposed in the pores of the solid body, and will, in time, if exposed to a current of air, solidify by desicca- tion. The result will be that, with a single immersion, the density and hardness of the chalk or the mortar V^c m harder ^'^^ ^® augmented, and after several alternate immersions and exposures to the air, these properties are attained in a considerable degree. The softest varieties of chalk may be thus hardened, so as to become capa- ble of receiving a high polish. 148. Upon the sulphate of Kme or plaster, the action of the alkaline silicate is essentially the same, though more rapid, and is accompanied by the inconvenience of giving rise to HTDJIAULIC CEMENTS, AND M0KTAE8. 99 an alkaline snlpluite, which, in crystallizing Action of the ■within the pores of the solid body, near the silicate on the . . . sulphate of lime surface, is apt to cause disintegi-ation. It is recommended in this case to use the solution more diluted, with a view to retard or diminish the effects of the crystal- lization of the sulphate, to such a degree that the nidurating Bolid will be able to resist it. l-iO. The process of silicaiization, so named by Mr, Kuhl- mann, which rests upon the principles enunciated above, is of undoubted utility, although, as yet, its practical application is attended with difficulties, and followed, not unfrequently, with uncertain results. It appears destined to meet with a varied and extensive application, in the industrial and fine arts, not only in the conversion, at a moderate cost, of 11 gilicatization" common into hydraulic lime of any required de- applicable to a gree of activity, and with a fair, or at least, I'^^^HJ^ ""'^'^^ encouraging degree of strength, but in the preservation of walls of whatever kind, already constructed imadvisedlj of materials liable to more than ordinarily rapid decay, whether of brick, stone, pise, or concrete; in the restora- tion and conservation of statuary, monuments, architectural ornaments, &c. ; in transforming designs cast in ordinary plas- ter into hard and durable stone, in rendering wood-work, and, to a limited extent, even cloth fabrics indestructible by fire, and in a multitude of other collateral uses, some of which are even now well developed and in practical operation, while others remain still in their infancy, giving more or less encour- aging promises of future utility and value. 150. Within the last ten years, grave doubts have arisen among European engineers, as to the suitability ., ^, .n • ^ 1 , . . Doubts of the ot those artmcial mortars prepared by mixing stability of arfi/i- slightly-burnt clay with common lime, for con- "«' po^znoiana c> -J J ' mortars in tlie sea. structions exposed to the action of sea-water. The French engineers had entertained very favorable opinions of those mortars, and had paid great attention to their use 100 PRACTICAL TREATISE ON" OMES, between the years 1820 and 1840, deriving their opinions mainly from the investigations of MM. Yicat, Authority for Treussart, Rancourt, and others, who thought using then. '. '. . \ ,. themselves justified in deducmg from their re- sults that the clays, when subjected to the proper degree of calcination, would operate in expediting the hardening of lime, in all respects like the natural pozzuolanas. For some years, these mortars exhibited no marks of weakness or instability, but more recently have, according to the opinion of MM. Chatoney and E,ivot, so far yielded to the solvent action of sea- water in some localities, that but few constructors would be justified in using them, until their peculiarities are further developed by experiments and the test of time. The mortars „ ^ , derived from a mixture of natural pozzuolana Natural pozzuo- ^ lana mortars give and fat lime have been found to give better re- better results. , T , 1 . , . Ill 1 suits, although it is conceded by many who have advocated the preparation of hydraulic mortar by this method, that the Romans were more successful in the emplo}^- ment of natural pozzuolana than those engineers who have given attention to this subject during the present century. 151. Marshal Yaillant, member and reporter of a commission of the Academy of Sciences of France, to whom was referred a memoir of MM. Chatoney and Rivot, entitled, " General Considerations upon Hydraulic Materials used for Constructions in the Ocean," submitted to the Academy in the sifiTamant there- jear 1856, says in his report, when speaking of on to the Academy jnortars of lime and pozzuolana: "Natural of Sciences. ^ pozzuolana mortars were used by the Romans for submarine constructions, which are, at the present day, in a perfect state of preservation. The Dutch engineers have likewise used them successfully in their sluice works. But all . , . , recent trials with pozzuolana, natural or artifi- Recent trials with _ -^ _ pozzuolana unsuc- cial, have resulted in failures. According to '^^^^ ' MM. Chatoney and Rivot, these mistakes in the use of pozzuolana could, without doubt, have been avoided if, HYDKAULIC CEMENTS, AND MOETARS. 101 in conformity to the usages of the ancients, they had been pre- viously submitted to a long concoction. Those gentlemen have as yet, no experimental results to furnish in support of this assertion, but it appears very rational. We can comprehend, in fact, that if the previous concoction is advantageous to mor- tars of lime, and even of cement, it is indispensable to the success of mortars of pozzuolana, which differ from the former, in that the combinations of the lime with the silica exist, for the limes and cements, already formed by the calcination, and have only to become hydrated at the time of their use ; whilst, in the fabricationof mortars of pozzuolana, the silica and alum- ina have to free themselves from combinations in wdiich they exist in the pozzuolana, in order to form with the lime, in the wet way, those compositions which form hy- drates under water. We see from this, that it coltiuul?'"' is better to mix pozzuolana with fat lime than W'ith hydraulic lime, since in the latter case, the hydraulic com- positions formed in the dry way {voie secJie) during the calci- nation, will have set a long time before those formed in the wet way {vote liumide) become hydrates, and the setting of these latter might endanger the stability of the mortars by disinte- gration." Moreover, in mortars of natural pozzuolana and hydraulic lime, it is only the excess of caustic lime contained in the latter, which combines advantageously with the silica and alumina of the pozzuolana. The report goes on to say : " The artificial pozzuolanas consist of burnt clay pulverized ; most of them contain lime, and possess the same causes of de- struction as the mortars of natural pozzuolana and hydraulic lime. They have not yet been successful in the ocean, and their employment will always be attended with difficulty, principally on account of the irregularity of the mortars into which they are introduced. " The authors have had in view, in their memoir, only those mortars exposed to the action of sea- water, but they entertain the opinion that most of these observations are applicable to 102 PRACTICAL TEE ATI SE ON LIMES, mortars immersed in fresli water. Scarcely ten years have elapsed since the disintegration of mortars by the action of sea- water became a well-established fact. It was not observed nntil after the time when a too absolute confidence in SniSd "^ hydraulic materials, led to the execution of heton (concrete) masonry in immediate contact with water, without any revetment of cut stone or carpentry, with- out any covering of wood, and M^ithout any of the protections which the ancient works received. It is also but a short time since heton has been placed in contact with currents of fresh water, and although alterations have not, as yet, taken place in that kind of masonry, nevertheless, it may be presumed that they are gradually produced by the dissolving action of the gas, and the salts which the water contains, modified by the tern perature, and the action of the tides." 152. The proposition laid down by MM. Chatoney and Rivot, that the mortars of Italian pozzuolanu^ Chatoney, and recently employed in the Mediterranean^ have ■^'^°*'' given unsatisfactory results, is concurred in substantially by M. Tostain, Inspector-General of Roads and , . , Bridges, who, in his letters written subsequently concurred in by n 7 j i. ^ Inspector-Geu- to his inspections in the years 1857 and 1858, wherein his attention had been specially di- rected to the condition of the mortars and concretes, observes : "I' have said, and shall again say, that I saw in all the porta which I visited on the Mediterranean, in France, Algeria, Cor sica, and on the coast of Italy, pozzuolana mortars attacked by sea-water. I do not say absolutely that all the mortars, with- out exception, were altered. There were, no doubt, good portions on which I saw nothing wrong ; but everywhere, that is, at all the ports, I found partial alterations. On the other hand, I have not examined the walls of Dock No. 3, mentioned by Mr. Noel.* " With regard to the portions exposed to the shock of heavy * The dock referred to is in the harbor of Toulon. HYDRAULIC CEMENTS, AND MOETAr.S. 103 Beas, such as the large blocks of the outside works of the brenk- water, I shall go further, and state that I have not seen a single one that was free from alterations, that is, one whose whole surface was intact and well preserved. Tlie surface be- comes rough at first, and is continuously made more so bj the /waves; the pebbles of the beton are left projecting and after- wards get loose ; the edges of the work get blunt, and the volume of the block gradually decreases." 153. On the, other hand, M. Noel, Inspector-General of Roads and Bridges, who takes the other side of the question, brings to the discussion a ripe ex- S^L^^^-tSen- perience, and a reputation by no means second ^'"''^ ^'°^^- to that of M. Tostain. In reference to the alleged failure of mortars of fat lime and Italian pozzuolana, he says: "This assertion is in contradiction of well-establibhed facts" All the hydraulic works at the port of Toulon, have been executed ex- clusively, eveu of late years, with mortars composed of Italian pozzuolana and lime, either fat or hydraulic (that of Lagoubran), and I affirm with all the authority which a thirty years' resi- dence at this port can confer, that not one of the works has failed on account of defective mortar." M. Noel also refers to the successful use of the same kind of mortar by Colonel Sauli, in the construction of the dry dock at Genoa, where it was used as concrete. A description of this dock in the " Annales des Fonts et Chaussees," for 1853, furnishes the following extract : " If the work is examined more in detail, it is found that the letm, (concrete) which constitutes the bottom of the apron and the exterior surface of the side walls, has acquired a very great liardness in consequence of its composition,(pozzuolana of Rome, ordinary lime, and calcareous gravel), and that it is free from all porosity, in consequence of the care which the skilful di- rector of these works took to clear his beton, by constantly pumping up the washings {laitance) during the operation of immersion." 154. The mole of Algiers was executed in concrete, some 104 PRACTICAL TREATISE 0^^ LOIES, portions of which were composed of artificial blocks, allowed to dry in the air before immersion, and other portions, of concrete immersed fresh. In this connection, therefore, we will briefly refer to certain " observations and experiments upon the mortars Mortars of the employed in the sea at Algiers," made by M. mole of Algiers. Havier, engineer of roads and bridges, and pub- lished in tlie " Annales des Fonts et Chaussees," vol. viii., 1S54. From this we learn that prior to the year 1S52, the mortars immersed, after drying in the air, were composed of fat lime and a mixture of equal parts of sand and Roman pozzuolana, and that the lime was slaked successively by the ordinary process, and by aspersion. In the first case, the mortar contained equal volumes of lime paste, sand, and pozzuolana, in the second 2^ volumes of slaked lime in powder, 1^ of sand, and 1^ of pozzu- olana. Mortars for immediate innnersion were composed of fat lime and Roman pozzuolana in various proportions. Since the beginning of the year 1852, hydraulic lime from Theil, on the right bank of the river Rhone has been used, the stone being calcined at Algiers, and slaked by aspersion, as required for use. For making the mortar for the artificial blocks, it is mixed with sand. In exceptional cases, w^hen the blocks are to be immersed at the age of thirty days, one-half of the sand is replaced by pozzuolana. An analysis of the Theil limestones is given in Table TV. Page 226. 155. Without attempting a connected synopsis of M. Ra- vier's report, referred to in the last paragraph, a few brief extracts are given below : 1st. Page 25 : " It results from the foregoing experiments, that all mortars on trial of fat lime, sand, and Roman pozzuo- lana, after dryino- in the air, or immersion in Extracts from M. ' •' ^ j -i i j • Ravier's report fresli water, are destroyed when placed in sea- thereou. water. This takes place even with a mortar containing by weight about twenty of caustic lime for one hun- dred of pozzuolana, and one hundred and thirty of sand." 2d. Pa"-e 29 : " It follows from these observations that fat HYDRAULIC CEMENTS, AND MORTARS. 105 lime mortars do not sustain immediate immersion (in sea -water) no matter what proportion of pozznolana they con- tain " " The trials were all favorable to mor- tars of hydraulic lime witli or without pozzuolana." 3d. The trials with mortars of fat lime and Grenoble cement allowed to dry in the air, show that the cohesion of these gangs diminishes with age. A mortar composed by volume of 2.15 of fat lime, 1.00 of cement, and 5.40 of sand (correspond- ing with equal weights of dry cement and quicklime) gave a cohesion strength of 2.55 killograms per centi- , ,. , ,1 T c Strenffth of oer- nietre square, at the age ot two months, and ot ^ain mortars. 1.16 killograms at the age of twenty months. Another mortar, with the same proportion of sand, with a gang containing by weight 100 of dry cement and 47 of quicklime, gave at the same ages, breaking weights, 2.82 kilos, and 1.59 kilos, per centunetre square, respectively. 15C. The following is a condensed view of the resume given by M. Eavier himself: 1st. The Roman pozzuolanas used at Algiers are, contrary to the opinion hitherto entertained, incapable of formmg with fiit limes, mortars able to resist the saline action of the sea- water. 2d. The form of the mortars submitted to immersion exerts an important influence upon the action of the sea- water; the sharp edges and curves of small ^ R^^^er's radius assist the destructive action ; plane sur- condei;sed re- , sume. faces, OP the contrary, essentially protect the cohesion of the mortars, and may preserve them unaltered for several years. 3d. The preservation of the works executed at Algiers with fat lime and Roman pozzuolana, is specially due to the deposits of mineral substances secreted by marine animals. 4th. In this respect, the artificial development of beds of oysters upon sea works, appears to promise important results. 5th. Mortars of fat lime and Z^Taples or Rachgoun pozzuo- 106 PRACTICAL TEEATISE OX LIMES, lana, also fail in the sea. Similar failure attaches to the mor tars of sand and St. Chamas hydraulic lime. 6th. All the observations are favorable to the perfect pres- ervation in sea-water of mortars of sand and hydraulic lime from the Theil quarries. 7th. The substitution of an equal volume of Rachgoun or Roman pozzuolana for a part or the whole of tj^iued ' ' ^^® sand, in the mortars of Theil hydraulic lime disposes them unfavorably at first, to re- sist the saline action. The phenomena of disaggregation that uere observed were limited, and furnish no sufiicieut reason, without further proof, for excluding the use of pozzuolana con- currently with hydraulic limes, when it is desirable or neces- sary to obtain a mortar that will indurate rapidly. 8th. The Roman, Rachgoun, and Xaples pozzuolanas used in the trials, are not homogeneous ; the differences afiecting the composition of the silicate of alumina, in each of these materials, vary between somewhat wide limits. 9th. The same want of homogeneousness is established for the limestones of the Theil and Alignol quarries, which both beloncr to the same formation. 10th. The analysis of the limestones of the Theil quarry, and the results obtained in the sea with the limes manufac- tured from them show, that by taking fur the measure of re- sistance to the saline action, the ratio of the clay plus the magnesia to the lime, this ratio, which has been called the indt^x of hydraulkity^ can, on the average fall to yVo, without the mortars being destroyed, whether they were immersed dry or fresh. 11th. Tlie disaggregation of the mortars coincides with the increase in the quantity of the sulphate of lime, Su(S"^' '^^'^ ^°^ ^^^^ ^^ attributed to that salt, produced by the action upon the lime, of the sulphate of magnesia of the sea-water. It was produced in variable pro- portions in all the gangs experimented upon, but destroys HYDEAULIC CEMENTS, AND MORTALS. 107 tliem only in the cases when it is produced in sufficient quan- tities. The surfaces upon which this salt exists abundantly, can acquire and preserve a considerable hardness. 12th. In the mortars of fat lime and Roman pozzuolana, the sea-water attacks not only the free lime, but also that com- bined with the silica. 13th. In the mortars of hydraulic lime preserved intact, after having been kept under water for several years, and also in the gangs of Yassy cement, a notable proportion of free lime is detected. 157. M. Feburier, as the result of numerous experiments at St. Malo upon various limes, pozzuolanas (nat- ^ F^burier's ural and artificial), and trass, arrives at the fol- experiments, lowing conclusions, which, although indorsed by M. Yicat, are by no means coincident with the deductions of other emi- nent French engineers : 1st. " That mortars of fat lime and Dutch trass do not resist the action of sea-water." 2d. " TJiat ordinary artificial hj'draulic limes, or natural feebly hydraulic limes, even when mixed with feebly hydraulic poz- zuolanas, equally do not resist." 3d. "The only limes capable of thus resisting are the ' twice kilned' artificial hvdraulic limes, or the natural " . . « His coaclusions hydraulic limes which approach the limits of cements." These conclusions are irreconcilable with the excellent re- sults obtained by the Dutch engineers with mixtures of rich shell-lime, trass, and sand. 158. There seems no reason to doubt that the natural quick- setting cements, such as the Roman, the Vassy, the Rosendale, and the Boulogne "Portland" brands, and those artificial Portland cements, produced by calcining a mixture of chalk and clay with a heat sufficiently great to produce incipient vitrification, can furnish mortars capable of resisting the sol- vent action of sea-water. 108 PRACTICAL TREATISE OlST LIMES 159. Upon the general question of the destructive effects of Bea-water upon those gangs, natural or artificial, which form the bases of hydraulic mortars, whether derived from hy- draulic lime, cement, or pozzuolana, M. Vicat's researches led him to certain conclusions which may be condensed as follows, Ij-om the "Annales des Fonts et Chaassees" for 1854 : 1st. The double hydro-sihcates of alumina and lime are de- void of stability, and will, without exception, if pulverized and „ „. , . immersed in sea-water, or even pure water, be- Jtt. Vicat 8 views. ,. i , . lore they have been subjected to the action of carbonic acid, and thereby transformed to carbonates, give up to the water an appreciable quantity of lime. 2d. The other conditions remaining the same, a dilute solu- tion of sulphate of magnesia substituted for the pure water, will convert all the lime of these silicates into a sulphate, un- less carbonic acid be present during the reaction, in which case its equivalent of lime will become a carbonate. 3d. All pozzuolanas, irrespective of origin or composition, require for their complete practical saturation a much smaller dose of lime than they generally receive, when made into mortar, owing to imperfect pulverization and manipulation. 4th. The afiiuity of carbonic acid for the lime is sufficiently powerful, in the presence of water, to separate its full equiva- lent of lime from combination with the other Same, continued. . . ingredients oi tliese silicates, leaving the said ingredients, whether combined or not with each other, simply mixed mechanically in the compound. 160. From the foregoing it would appear that sea- water will destroy the gangs of all mortars derived Protecting coat. ' . i •,> • i n , irom the sources indicated, it it be allowed to penetrate the immersed masses ; but as some mortars do prac- tically withstand continuous immersion in sea-water, it fol- lows that the latter meets on the surface something to impede or prevent its yjenetrations. These impediments are : 1st, and principall.v, a coating of carbonate of lime ; the car- HYDRAULIC CEMENTS, AND MORTALS. 109 bonic acid being siijtpb'cd from the atmosphere before immer- sion, and subsequently from tlie water; f. , . , . ' . 1 -1 . , Carbonate of lime. 2a, in certam cases, particularly with gangs derived from the magnesian limestones, the for- Carbonate of mag. mation of carbonate of magnesia. 3d, an incrustation of shells and submarine vegetation. IGl. M. Vicat was subsequently led to recommend mag- nesia as a suitable ingredient of mortars to be ,r => Magnesia re- immersed in sea-water, stating that if it could commendei be obtained at a cost that would permit its application to such purposes, " the problem of making heton (concrete) unaltera- ble by sea-water would be solved." That learned experi- menter also intimates that the Theil hydraulic lime is the only one with which he is acquainted, that could unquestionably furnish a mortar indestructible by sea-water, o f ^ J Suggestion by M. Balard suggests that the mother water of M.'iaiard. salt ponds, applicable to no other useful purpose, might sup- ply magnesia at a moderate cost. 162. In the presence of these conflicting opinions, which are characterized by apparently irreconcilable elements, the American engineer can congratulate himself that the supply of hydraulic cement in this country affords a . •^ American ce- more reliable source of hydraulic mortars than ment mortars, either natural or artificial pozzuolana ; and that this question, therefore, possesses for him no important practical bearino-. 110 PRACTICAL TEEATISE OX LDfiES CHAPTER Y. 163. Our nomenclature of the products derived from the calcinations of the several varieties of limestone, still remains imperfect. 164. These products are as varied and diversified in their character, and require as manv distinct and peculiar modes of tv.- -^ ^ !_ manipulation, in order to satisfv the conditions DiTersified char- i acter of lime- Avhich are indispensable to their advantageous stones. 1 {• 1 • • employment tor mortar, as there are variations in the composition of the limestones themselves. This is more especially the case with those limestones which contain so large an amount of foreign matter, such as silica, alumina, magnesia, etc., usually exceeding ten of the whole, as to disqualify them for ordinary use as fat lime, but which places them in the cate- gory of hydraulic limes or cements. "When we keep in view the multiplicity of causes for such variation in all sedimentary rocks, causes, indeed, that pertain in their fullest force to all calca- reous formations, and more especially to those which, from their compound character, have proved to be best adapted to the production of hydraulic mixtures, we obviously need seek no further for an explanation of that remarkable want of homo- geneousncss which characterizes these deposits, or expect to find any locality in which it does not exhibit itself. 165. The same strata, even within very narrow lateral limits, frequently become so changed in their physical appearance as well as in their chemical composition, as to lose not only the means of verifying their geological identity, but their most prominent lithological features. HYDRAULIC CEMENTS, AND MORTAES. Ill 166. "We might, tlierefore, ex^ject that the best practical rules for converting such heterogenoeus material into use as a gang for mortar, would require to be modified to suit local circura- Btances, It is equally self-evident that such modifications can only be properly determined by adequate pre- t^^^j liminary and local tests. Although the theoret- t'ons and tests ical correctness of these premises will perhaps ^ '^ ^^^' be questioned by very few, their practical observance by manu- facturers and consumers of limes and cements, is greatly neg- lected. 167. The calcareous deposits in the United States, from which the present supplies of lime and cement are derived, if severally classified and arranged according to their composition, as shown by quantitative analyses, would strikingly illustrate the necessity of awarding to each locality such special rules for manipulation as can only be supplied by an extended series of experiments. It is not to the almost endless variety of quarries of dissimilar Btone simply, that the difiiculty is confined, since this, however great, is only coextensive with the extraordinary heterogeneity generally existing among the strata of the same quarry. Al- though this feature does not characterize the beds of common limestone, at least, not to an extent heterogeneity of ' ' cement deposits. that can be regarded as prominent, it is so uni- formly present in the argillo-magnesian deposits, that we may eafely assume that every extensive deposit capable of furnish- ing an energetic cement, will also furnish from among its several layers, every inferior grade of combination, down to slightly hydraulic, meagre, and common lime. 168. Frequently, and perhaps generally, among deposits fur nishing cement stone, the several layers— which vary consider- ably in thickness, though they are seldom less than one foot or more than six — so far preserve the character and relative pro- portion of their constituent parts within the ordinary lateral limits of a single quarry, as to require only an occasional, — it may be a semi-weekly, or weekly, or perhaps, in rare cases, a 112 PRACTICAL TREATISE ON LDIES montlilv, — verification of their respective characters, but in a majority of cases, tlie want of homogeneousness ^Sffatoe!"^" extends to the several layers indiWdually, and attaches to them persistently for miles in ex- tent, rendering it necessary to keep a daily, and even hourly surveillance upon the workmen, to prevent their making use of bad or worthless stone. 1G9. When the stone occurs in distinct and easily recognized layers which, for considerable distances, retain with little vari- ation, a known and specific character, whether good, bad, or doubtful, and which are readily separated from each other along the principal planes of subdivision, the practical difficulties to be overcome in quarrying are comparatively few, and simply require for their removal, the employment of reliable and faith- ful workmen, who will exercise the precaution to reject those strata which are known to be unfit for use. 170. In the general case, however, the problem is far less easy of solution, for we find those materials, whose exclusion from the combination is of the highest importance, disseminated throughout a series of strata, in constantly and widely varying P f ai d^ffi proportions, and frequently in a form present- ties in selecting ing no physical features except to the most practiced eye, to assist in their detection. The calcination sometimes so far alters their appearance, as to ren- der them more easily identified. Tliese materials generally consist of carbonate of lime more or less pure; or a compound stone, in which the preponderating ingredient is inert silicious Band ; or argillaceous slate or limestone, containing an excess of clay and granulated silica. They usually occur in rather thin masses or sheets, varying from two or three inches to sev- eral feet in length and breadth. Tliere is probably not a single quarry in the United States, worked for hydraulic lime or ce- The ordinary pre- ^^nt, entirely free from them. For the detec- cautions neccs- tion and exclusion of these obiectionable por- sary. , *• ^ tions of a quarry, we must, therefore, depend HYDRAULIC CEMENTS, AND MOETAES. 118 conjointly upon the faithfulness of the quarryman, the experi- ence of the burner, and his skill in detecting them after calci- nation. 171. Changes in the character of a cement stone often take place slowly and progressively within the limits of individual beds, in directions both perpendicular and parallel to the planes of stratification, without any perceptible variation in the ap- pearance of the stone, or in its homogeneousness, and simply require for their correction a modification in either \\\q pj'ojxyr- tion of the diflferent layers introduced into the combination, in the degree of calcination to which they are subjected, or in hoth. It might, under such circumstances, become necessary to use separate kilns for layers that had previously been mixed to- gether in burning. Deposits of this character require close and constant attention, in order dissimUar^tone that the proportion of the several dissimilar layers, and the intensity and duration of the heat employed in burning them, may be so regulated as to give results that shall be uniform, or at least approximately so. 172. It is therefore important that some practical method of ascertaining the absolute as well as the relative value of these several kinds of stone, should be pointed out, and it is equally important that such a method Preliminary trials ^ ■' t: recommended. should be simple, inexpensive, and easy of ap- plication. It is not necessary, though it might be advanta- geous in some cases, that it should comprise any essay upon the composition of the stone, or the proportion of its constituent parts. Indeed, any practical method would be much better without any accessory requiring the exercise of any theoretical knowledge, not within the ready comprehension of that class of men to whom manufacturers, with few exceptions, confide the details of their work, and consequently not susceptible of daily and hourly application by them. 173. The only apparatus required for this purpose is a cruci- ble of the capacity of one pint or thereabouts, and a mortar and 8 114 PRACTICAL TREATISE OX LlilES, pestle. The crucible should be perforated near the bottom, in several places, to give an upward cuiTent of air and fac-ilitate the escape of carbonic acid gas, and should be pro- dhS^tfr. '^'^ ^^^ed with a cover Hkewise perforated. When access can be had to a grate fire of anthracite coals, this single crucible may be advantageously replaced by several of smaller size. When more than one* One or more crucibles Is used, however, care must be taken to so reg- ulate the fire, that all will be subjected to an equal degree of heat throughout the burning. 174. The stone to be tried, after being broken into pieces as nearly equal in size as possible, and not ex- Stone broken -1. 1 f . \ 1 . . into equal-sized ceedmg tliree -quarters oi an inch cube, is m- T?^^^^ troduced into the crucibles, supposing several to be employed, each receiving the same number of fragments, if practicable. All the crucibles, with the covers on, are then imbedded in the fire and covered up with coals, so that the top and bottom portions will attain a bright red Bimuitaneously ^^^^ simultaneously. This last precaution is essential to the complete success of the process. In about forty -five minutes after the stone has reached a bright red heat, one of the crucibles is removed from Pieces removed at equal intervals the fire, the Others following in succession at intervals of forty-five minutes. In order to se- cure similar results with a single large crucible, two or three of the fragments are taken out at the end of the first forty-five minutes of bright red heat, and others subsequently, as the periods of time above designated are reached, allowing not less than four and a iialf hours to the last portions, or per- haps six hours, should the stone be very refractory, which will be sufficient to expel all the carbonic acid gas, and to carry Bome varieties of cement stone, if broken up as directed, to the point of incipient vitrification. 175. A long-continued bright red heat operates in a singular manner upon some argillaceous varieties of cement, border- HYDRAULIC CEMENTS, AND MORTAES. 115 ing on the intermediate limes, in conferring j^^^ continued upon them remarkable hvdraulic properties and beat sometimes 1 . 1 1 1 " , • /. best. energy, whicli they do not possess at tlie pomt ot complete calcination, but which may have been present in a lower degree before all the carbonic acid was expelled. In order to render certain the detection of stone possessing this property, when its presence is suspected, it is recommended to continue the calcination of some of the fragments for eight or nine hours. 176. By means of the several aforementioned crucibles, we obtain portions of the stone that are overburnt, other portions that are insufficiently burnt, and an intermediate class, among the several members of which will be discovered good cement, if the stone be capable of yielding it. There will also be indi- cated, to an extent sufficiently exact for practical deductions, the relative degrees of calcination adapted to the several va- rieties operated upon, with their exact and appropriate maxi- mum limits, respectively. These specimens, unless the stone belongs to some grade of common, meagre, or hydraulic limes, will not slake when sprinkled with water. Upon being sepa- rately reduced to powder in a mortar, mixed to a stiff paste with fresh water, and immersed in water either fresh or salt, they will indicate in their respective times of setting, their relative hydraulic energy, and approximately, — though subject to many individual exceptions in regard to the ultimate strength of the gangs, — their value as cements. 177. Whether the stone be suitable for cement, or otherwise, it will be found, with very few if any exceptions, that the underburnt frac^ments, those which contain in „ , , *^ _ Underburnt stone the centre a small core of partially raw stoue, as possesses supe- indicated by its density, color, and hardness, "^"^ ^ '^^^ '^^^' and which effervesce briskly with dilute hydrochloric acid, will be superior in hydraulic activity to the more highly calcined samples, and will set under water at 65° F., in periods vary- ing from five to fifty minutes. Those wluch do not efi'fcrvesce with dilute acid, and have consequently parted with all their 116 PEACTICAL TREATISE ON LEVIES, carbonic acid gas, will exhibit a less degree of hydraulic quick* ness, and will require a longer time by twenty-five to fifty per Some'overbumt cent, to harden under water; while the over- varieties nearly burnt samples, those in which the calcination inert. has proceeded to the verge of vitrification, will, in some instances, be almost entirely wanting in hydraulic activity, and in others, will have this property very much impaired. It by no means follows that this last-mentioned class is inferior to the others in the ultimate energy and strength rj,, of its gangs or mortars ; on the contrary, some ce- necessariiy of ments, the " Portland" for example, are much improved by this degree of burning. Others, however, are rendered entirely worthless by it, so that M. Pet- ot's assertion that " it is equally possible to obtain plastic (that is hydraulic) cements by a super-calcination, and by an incom- plete calcination," must be received in a modified sense. Pet- Eemark by M ^* further remarks, that the fact most worthy ot Petot. Alleged notice is, that at the point of comjplete calcination •'instant of t .n i i i -i .,» inertia" of not Only Will " the stonc not slake, but if treated like ordinary cement, will give a substance nearly inert." "This instant of inertia of plastic cements, be- tween the points of incomplete calcination and supercalcination, seems to us a capital fact in the study of the substances. It ex- plains how a suitable limestone might escape discovery and bie rejected as unsuitable, from a simple fault of calcination, which would not be a fault with fat lime, or with hydraulic lime." Does not inva- 1'^^- ^^ poiut of fact, there is no such " instant riabiy exist. ^ inertia^'' invariably existing between two points of maximum energy, in genuine cements. It may or may not be the case, according to the composition and molecular constitution of the stone. Moreover, some M. Petot s deduc- tion altogether cements have three points of maximum energy, 00 genera . while Others have but one. Those which pos- sess one, in a pre-eminent degree, at the point of vitrification, generally approximate to the intermediate limes in the natui^e HYDRAULIC CEMEXTS, AND MORTAIIS. 117 aud proportion of tlieir constituent ingredients. M. Petot seems to Lave made general a deduction, on evidence drawn from a particular case only, and to have simply opened, far less exhausted, the investigation. 179. M. Yicat's opinion that a complete expulsion of the carbonic acid gas, although operating disastrously upon the intermediate limes, is necessary in order to fully develop the merits of genuine cements, must also be dis- carded as a rule, although individual cases in op^o^ ' ^^ ' support of it are by no means rare. 180. If none of the samples fi'om the crucibles, except those that are considerably uuderburnt, set under water, without being followed by cracks, disintegrations, or increase of volume, the stone belongs to that class termed intermediate or divid- ing limes, already mentioned, and should be rejected with scrupulous care, unless provision can be made „. , ^ . ^^_ for burning it by itself, and for arresting the cal- quired fov inter- luediate limes. cination at the proper time. 181. By carefully subjecting, from time to time, the several undivided layers of a quarry to the trials above indicated, taking care to secure a faithful fullllment of all the conditions specified, so that each will receive jjrecisely the same treat- ment, we are able to ascertain with sufficient accuracy, and to keep constantly in view, the peculiar character of each kind of stone ; such as its appearance when properly calcined ; the requisite degree and duration of heat ; the correct limits of cal- cination ; and consequently the best mode of burning it on a large scale (whether by itself or mixed with the other layers), and the most advantageous proportions in which it should enter into a combination of the whole. 1S2. Experience teaches us that the physical Physical appear- ance of raw stone appearance of calcareous stones, which suih- no criterion of its ciently serves to distinguish and classify them, P™?*^'"'^^^^- when in the natural state, into limestone and marbles of various kinds, furnishes no indication of their qualities after 118 PEACTICAL TEEATISE 0]!f LIMES calcination. Even a cliemical analysis of tlie raw stone is to a certain extent unreliable, and deductions from it, under the most favorable circumstances, can only be regarded as tolerable approximations, and are not unfrequentlj contradictory. The hydraulic induration is due, in a great measure, to the chemical Source of combination of lime and silica, a union M'hicli is hydrauiicity. partially perfected in the dry way during the burn- ing, and is subsequently carried on and completed by the agency of water. The analysis of a cement stone after calcina- tion, should therefore show the commencement of tliis process by the presence of a certain quantity of silicate of lime. QUALITATIYE EXAMINATION OF HTDEAULIC LIMESTONES. 183. Hydraulic limestones are characterized, as a class, by Mineral their fine-grained, compact, or granular texture, characters. presenting a conchoidal fracture, yielding readily to a file or sharp-pointed instrument, and efiervescing more or less freely, on the application of hydrochloric or nitric acids. 184. The prevailing colors are gray, bluish gray, grajnsh white, and drab, with intermediate shades. 185. The powdered mineral is more readily acted on by the acids than the massive form. 186. Hydraulic limestones will generally be found to con- tain silica, alumina, oxide of iron, oxide of manganese, lime, magnesia, potash, soda, with carbonic, sulphuHc, and 'phos- phoric acids, and occasionally some organic matter of a bi- tuminous nature. As some of these may be absent, it will be necessary to ascertain the character of those present, before proceeding to an ultimate qualitative analysis. 187. Eor this purpose, an uuweighed portion of the mineral is reduced to a fine powder in an agate mortar, and digested in one measure of water, for eight or ten hours, aided by the gentle heat of a sand-bath, HYDRAULIC CEMENTS, AND MORTARS. 119 and the solution is then to be filtered clear, and divided into BO many equal portions in wine glasses. 188. Nitrate ofharyta added to one of these . ^ "^ 1 • 1 1 J- Sulphuric acid. gives a white precipitate, which does not dis- appear on the addition of nitric or hydrochloric acid, and indicates the presence of sulphur ic acid. 189. By evaporating another portion to dryness, in a sand- bath, at a gentle heat, and igniting the residue, subsequent addition of hydrochloric acid, followed by . ' „ ,,, Silica, diluting with an excess oi water, will cause the silica to separate as a gelatinous hydrated precipitate. 190. If another portion be treated with pure water of ammo- nia, and gives a pure white gelatinous precipitate, it indicates the presence of alumina, or magnesia, or both. In this case, hydrochloric acid must be added, until the pre- cipitate is re-dissolved, and the solution rendered distinctly acid. If, on the addition of ammonia, the pre- . ., , ,...,,. ., Alumina and cipitate reappears undiminislied in quantity, jnagnesia. it contains alumina only ; if it be distinctly less in quantity, we may infer tlie presence of both magnesia and alumina ; but if no precipitate now appears, it contains magnesia only. 191. If the precipitate above by ammonia has more or less of a brown color, the presence of oxide of iron or manganese may be inferred ; but, if after re-dissolving and adding ammonia as above, the brown color and mano-anese. disappears, it is due to the oxide of manganese only. Should the brown color still continue, it is owing chiefly to the presence of oxide of iron. 192. If, after the addition of ammonia, the solution be filtered to remove the magnesia, alumina, the oxides of iron and manganese, oxalate of ammonia be added 1 fV • 1 • ... Lime, to tlie liltrate, causing a wlute precipitate, it indicates the presence of lime. 193. K oxalate of ammonia be added, until all the lime be 120 PRACTICAL TREATISE OX LBIES, precipitated, and tlien filtered, and the filtrate Potash and soda. ^^ evaporated to dryness, and ignited to destroy the excess of oxalate of ammonia, the residue if found to be sol- uble in water, indicates the presence ofj}otash, or soda, or both. 194. If upon treating the last solution with pure bi-chloride of platinum, no precipitate appears, we may Potash. infer the presence of soda; but it« a yellow precipitate appears, ^o^^A is present in the solution. 195. Tlie yellow precipitate of potash and platinum having been collected on a filter, the filtrate treated with sulphide of hydrogen, and again filtered, to separate the excess of bi-chlo- ride of platinum, and then evaporated to dryness, a residue soluble in water remaining, indicates the presence of soda. 196. E^turning to one of the original wine glass solutions, to which a portion of strong nitric acid must be added, if it be then dropped into a solution oi rriolyhdate of Phosphoric acid. . , ,, • •.. . ♦,. ammonia, and a yellow precipitate appears, it indicates the presence of p?ios^?ioric add. 197. The presence of bituminous matter is BitTimiiioua ^^^^^ ^^ ^^^^ ^^^^ ^^ ^^^ ^^ weight upon igniting a specimen previously dried at 212°F. QUAXTITATIYE EXAMIXATIOX OF HTDEAULIO LIMESTOXES. 198. It is usual, in conducting this process, to ascertain : 1st. The specific gravity. 2d. The amount of hygrometric water. 3d. The amount of phosphoric acid. 4th. The amount of silica and insoluble matter. 5th. The amount of alumina- 6th. The amount of oxide of iron. Tth. The ° ' amount of oxide of manganese. 8th. The amount of carbonate of lime. 9th. The amount of sulphuric acid. 10th. The amount of potash and soda. 11th. The amount of carbonate of magnesia. 199. The specific gravity of the specimen to be analyzed having been determined, a portion of the mineral is reduced to HYDRAULIC CEMENTS, AND MOETARS. 121 fine powder in an agate mortar, and a given quantity, say 50 grains, is placed in a platinum crucible previous- ly counterpoised with its cover. The crucible moisture. and its contents arc then to be placed in a steam bath oven, and heated fur two hours, when it is to be cooled in a receiver over sulphuric acid, and then quickly weighed. The loss in weight is the weight of the uncombined water. 200. The contents of the crucible must then be transferred to a beaker glass, and digested in strong nitric acid, to wliich a little hydrochloric acid has been added, for forty-eight hours, the action being favored meantime by the Phospboric acid, gentle heat of a sand bath. 201. At the termination of this process, the solution is to be filtered, an excess of molybdate of ammonia added to the filtrate, and the whole evaporated nearly to dryness. 202. During the process, the chlorine of the hydrochloric acid, aided by the excess of nitric acid, decomposes the ammo- nia of the molybdate of ammonia, and the molybdic acid goes down with the phosphoric acid, as i^hospJw-molyhdate of am- monia^ in the form of a yellow precipitate, with the formula: 2 (3NH,0.P0,) -f 15(110.4 M0O3). This precipitate is insolu- ble in water and in nitric acid. After diluting the mixture, and giving it time to settle, the precipitate is collected on a filter, washed in pure cold water, and while ^ _ , Phosphoric acid, yet moist, dissolved in ammonia (the beaker glass being rinsed with the latter, and added thereto). 203. From this solution in ammonia, sulphate of magnesia precipitates all the phosphoric acid as ammonia phoi^jjhate of magnesia. This is to be washed with dilute water of ammonia, collected on a filter, dried, ignited at low red-heat, and weighed, — the filter having been burnt, and the ashes added to the reet. 201. Deducting the weight of the filter, every 100 grains of phosphate of magnesia thus obtained, contain 64.06 grains of phosphoric acid I every 100 grains of phosphoric acid may represent 217.60 of phosphate of lime. 122 PRACTICAL TEEATISE 01^ LIMES, 205. This determination o^ phosphoric acid being ^iTi inde- pendent process, the filtered solution left above Ramark. f , ^ n . , IS thrown away, and, as in the start, a new so- lution must be prepared. 206. Fifty grains of the same mineral prepared and dried as before at 212*^, are now to be dissolved in strong hydrochloric acid, the action being favored by the gentle heat of a sand Silica and insoiu- bath for forty-cight hours, after which, the so- bie silicates. j^^j^^j -g ^^ ^^ diluted with water, filtered,— and the silicd and insoluble silicates washed, dried, ignited, and weighed, are recorded. 207. The filtered solution from the preceding is then precip- itated by strong ammonia, and the precipitate, consisting of alvmhia, oxide of iron, and phosphates, after be- Alumina. , ' "^ . -r x- mg well washed, is transferred while moist, filter included, into a strong solution of pure potash, which dis- solves out the alumina. 208. Tliis potash solution, filtered from the oxide of iron, &c., is rendered acid by the addition of hydrochloric acid, and the alumina is then thrown down by an excess of ammonia, with a little sulphide of ammonium. 209. The precipitate thus obtained is washed with hot water, dried, ignited, and weighed. Deducting the weight of the fil- ter, we record the absolute weight of the alumina. 210. The oxides of iron and manganese remaining from the potash solution, are dissolved from the filter in h3^drochloric acid, the solution carefully neutralized bv am- Oiide of iron. '. , , , . . monia, and then, upon the addition of succi- nate of ammonia, succinate of iron is precipitated. 211. Upon filtering this, and adding ammonia to withdraw the succinic acid, the residue is washed, dried, ignited, weighed, and the weight of the oxide of iron ascertained. 212. To the preceding filtrate concentrated to a small bulk by evaporation, sulphide of ammonium is added, causing a pre- cipitate of sulphide of manganese. The latter, collected on a nXDRAULIC CEMENTS, AISTD MORTARS. 123 filter, washed, dried, and thoroughly roasted^ , ,, ii'i'. • 1 J? Oxido of man- changes the sulphide into oxide of manganese^ ganese. which is then weighed. 213. Return now to the first filtrate, caused by the addi- tion of ammonia to the original acid solution, and which con- tains the lime, mao:nesia, and sulphuric acid, ' ^ . Lime, simultaneously. "With the processes described, we precipitate the lime by oxalate of ammonia. Collect it after eight or ten hours repose, on a filter, and weigh it ; de- ducting the ashes of the filter, the weight of carbonate of lime is known. Every 100 grains contain 44 of lime. 214. The filtrate now contains a quantity of oxalate of am- monia, and ammoniacal salts, to decompose which pure nitric acid is added in excess, and the filtrate evapo- , T^ T 1 1 . , . 1 Sulphuric acid, rated to dryness. Kedissolve the residue in hy- drochloric acid, to which an excess of nitric acid has been added, and again evaporate to dryness. This dried residue of nitrates is now d/renched with pure acetic acid, and then wash- ed with water. Upon the addition of acetate of harytes to the solution, the sidphuric aoid present is precipitated as sidphate of harytes^ which is collected on a filter, dried, and weighed. Every 100 grains contain 34.31 of sulphuric acid. 215. The filtrate from the sulphate of barytes is now evap- orated to dryness, and transferred by a little oxalic acid and water into a small porcelain crucible, in which it is heated, and again evaporated to dryness, with an excess of pure oxalic acid, which changes the nitrates into oxalates. 216. The dried residuum thus obtained contains the alkalies and the magnesia, and must then be perfectly Alkaline ignited, to change all the oxalates into carbon- chlorides. ates. In order to separate the alkalies from the other ingredi- ents in this last residuum, it is dissolved and thoroughly washed through a filter with water. The dissolved carbonates contain- ed in the filtrate are changed into chlorides by the aid of a little hydrochloric acid, and then, evaporating the filtrate to dry- 124 PEACTICAL TEEATISE ON LIMES, ness and ignitino-, the saline residue is weisrlied, and the weiarh of the alkaline chlorides of potassium and sodium recorded. 217. Redissolving the mixture of alkaline chlorides in a small quantity of water, a solution of bi-ehloride of platinum is added, and the whole of the chloride of potassium present is changed into the double chloride of platinum and potassium, appearing as a yellow, insoluble precipitate. 218. Being evaporated by a gentle heat to near dryness, weak alcohol is added to dissolve the chloride Potash. of sodium, and any excess of the platinum salt which may be present. The yellow powder is collected on a filter, washed well with alcohol, dried, and weighed. 219. Every 100 grains indicate the presence of 19.31 of jpotdsh^ or 30.51 of the chloride of jjotass-iu7n. 220. The weight of the chloride of potassium thus obtained, deducted from the weight of the mixed alkal- Soda. ine chlorides, gives the weight of the chloride of sodium. 221. Every 100 grains of the latter indicate the presence of 53.17 of soda in the limestone. 222. The magnesia which remains in the portion of the re^ siduum which is insoluble in water, is now dissolved on the filter in diluted sulphuric acid, and after evapo- Magnesia. . , . . . . -, . ., , . rating and igniting m a platmum . crucible, is weighed as sulphate of magiusia. 223. Every 100 grains contain 33.33 of magnesia ; 100 grains of magnesia indicate 210 of carhonate of magnesia. 224; It will be perceived by the foregoing process, that with the exception of the moisture, organic matter, and phosphorio acid, which we estimated in a separate quantity of the lime- stone, all the ingredients have been determined from a single weighed portion, and thus a check over the whole is secured ; for if the sum of the weight, of all the ingredients varies much from the 50 grains of limestone used at the outset, it is proof of errors in the process. HTDEAULIC CEMENTS, AND MORTARS 125 225. Should the amount of silica and insoluhle silicates be l«rge, they should be fused witli three times their weight of carbonate of soda, for three or four hours, by which tliey may be brought into a soluble condition, and the solution treated as in the foregoing, and the sum of the weights ascertained. TABLE rV. 226. ANALYSES OP HYDRAULIC LIMES, CEMENTS, TRASS, AND POZZUOLANA. -a -J i s =3 s =' <« 'ta' rf t I S.6S2 1 .62 .as 25.20 1 < 6.16 3 O 2 s, 2.02 1 o 68.84 3 o A .48 1 'i 1 i § £ = S3 .40 It £ S S 1 10. .38 ....!.... -■4.98 t S.SIM .40 12.11 19.60 3.1 .J 3.S6 40.64 17.98 .72 .3^ + 1.22 * S.6K0 1.64 4.6^ 24.74 16.74 6.30 41.80 4.10 2.22 .6(1 -2.68 4 8.76S n.s4 4.6i: 1.70 58.25 11.16 .74 ,3.26 .20 + 2.85 h ».S4-1 IH-'ii 2.1S 1.S6 43.3C 26.04 1.96 4. "4 .20 + 1.70 1.02 .66 6.80 7 42 + 2.04 — .72 7 8.806 39.74 6.00 1.44 30.74 14,48 .24 H S.(iS8 19.64 1.M 2.38 30.721 36.i(; .64 4.10 .1,1 — .88 » i.Wi 26.0(1 4.64 1.86 28.48| 32.86 1.18 4.7V .26 10 i.liH WM 5.72 5.38 43.32 14.52 1.60 2.78 .20 —1.60 II t.'M 18.46 4.22 2.32 37.51 35.62 .20 1.6S 1.4(1 —1.40 \t S.78li 87.7r t-M 1.26 46.00 17.76 .26 4.02 ,2»> + .44 \i l.'i'X 11. IC 2.52 1.42 40.01 39.CI4 .22 4.U6 ■ .26! + 1.38 14 «.7sa 19.81' 4.4i: .76 33.91 34.06 .3-1 4.78 1.66 + .42 IS S.781 33.80 20.7 27.1 3.96 .88 35.60 63.3 65.0 19.26 22.6 6.3 .50 6.18 .14 1.666 .8 — .32 lA ( 333 ... 1.7 ... n IN 14.0 5.7 11.6 ■63.8 1.6 3.4 •«g ll ?u 11 8.00 90 .. 1.70 45.63 60.00 .39 1.32 1.10 10.48 m 18.20 1.20 .60 . ■ •3C t = ?!■=: 30.400 .150 34.225 49.630 17.380 25.152 9.513 .500 ti . 7.800 .. . 11. ess .. + .06S + .261 ti 1 13.769 2 II 6. o ti 1814 34.30 8.80 3.40 10.20 30.24 6.76 2.66 3.64 + 6.5» "^ «• - -a -2^ =*"4 ^ ~ - 5 Si « 18 00 30.20 35.00 34.08 w.oo 17.75 3.00 + 1.0» + .33 + 5;4I) % 29.77 31.00 88.75 12.00 24.00 8.80 1.31 17.75 1.62 1.04 n * 00 OC 7.50 3.875 9.6 9.2 ^ 7.0 1.4 1.0 4.0 57.0 44.5 5.U vi.a 2.6 8.8 1.0 4.7 + ;4» + ■* <() m 16.67 83.94 19 18 40.31 126 PRACTICAL TREATISE ON UDIES, EEFEKEXCX. No. 1, from Utica, La Salle county, lUinoia. No. 2, " Sandusky, Ohio. No. 3, " Cumberland, Maryland. No. 4, " Shepherdstown, Tirginia. No. 5, " Layer No. 9, from High Falls, Ulster county, New York No. 6, " do. No. 10, " " «' " No. 7, " do. No. 1 1, " " " « No. 8, " do. No. 12, " " '• « No. 9, " do. No. 13, " " " « No. 10, " do. No. 14, " " « " No. 11, " do. No. 15, " " »« " No. 12, " do. No. 16, " " " « No. 13, " do. No. 17, " " " « No. 14, " Layer No. 3, from LawrenceviUe, Ulster county. New York. No. 15, " Akron, Erie county, New York. No. 16, " Point-aux-Roches, Lake Champlain. No. 17, " Layer No. 11, from Round Top Cement "Works, near Hancock, Md. No. 18. Yassy (France) cement. No. 19. Theil (France) limestone (raw). No. 20. Theil hydraulic lime, from the above. No. 21, from Balcony Falls, Rockbridge county, Vii^inia (raw). No. 22, " do. do. do. do. (burnt). No. 23. Calderwood (Scotland) Roman cement (raw). No. 24. Sheppy (England) No. 1 cement stone. No. 25. do. do. No. 2 do. No. 26. Southend (England) cement stone. No. 27. Yorkshire do. do. No. 28. Harwich do. do. No. 29. Trass, ) No. 30. Pozzuolana. f "'"'^ ^^ ^"°- ^reussart, at Strasburg. No. 31, from Lockport, Niagara county, New York (burnt, rather old). 227. The samples from Xos. 1 to 15, inclusive, were analyzed by Professor E. C. Boynton, Oxford University, Mississippi ; IS'os. 16 and 17 by Lieutenant Caleb Huse, Asst. Inst. Cheiu., etc., U. S. Mil. Academy ; Xo. 23 bj Professor F. Penny, Ph. D., F. C. S. ; Xos. 29 and 30 by Berthier; the others were derived from reliable sources. 228. All the manufacturers of cement in the United States, pursue essentially the same process, in preparing the article for market. The only difference -worthy of notice is, that while some use for burning the stone the ordinary perpetual kiln, of HYDRAULIC CE5IENTS, AT^D MOETAKS. 127 a cylindrical form very nearly, terminating at the bottom in the inverted frustum of a right cone, in which the raw stone, broken into pieces of random size, but measur- ■" ^^ , , Kilns used for ing not more than 8" in the longest dimen- burning cement sions, and the fuel (either bituminous or an- thracite coal) are mixed together in alternate layers, extending to the top of the kiln ; others prefer the perpetual '' furnace kiln," in which tlie heat is applied by means of furnaces, suit- ably arranged for wood or coal, near the bottom of the kiln, In some localities, as at Utica, Illinois, intermittent kilns, burning bituminous coal, are used. 229. For kilns of the first above-mentioned class, when an- thracite coal is used, the latter should be broken up very fine. What is technically known as "second screenings," or "pea and dust," at the mines of the Delaware and Hudson Canal Company, and the Pennsylvania Coal Company, has been found to give the most' satisfactory results in Ulster county, New York, among the Rosendale Works, and can be obtained at a trifling advance on the cost of transportation from the mines. 230. Whether anthracite or hituminous coal be used for burning, the quantity requisite and proper to be used will de- pend not only upon its kind and quality, but upon the charac- ter and composition of the cement stone, the form and locality of the kiln, and the skill of the burner. In the works situated on the Potomac River, at Shepherdstown, Hancock, and Cumberland respectively, the Cumberland ^^^ °^ ^"^^ pemi-bituminous coal is used for burning ; and, according to the opinion of Chas. H. Locher, Esq., proprietor of the James River Cement Works, at Balcony Falls, Yirginia, is superior to the bituminous coal used by him, obtained near Richmond, Virginia. 3,500 lbs. Q'-^'^^'^^ ^^ ^"^l ' c; 5 necessary. of anthracite coal is sufficient to burn 100 bar- rels of cement, of 300 lbs. each. 231. The ordinary perpetual kiln is set in operation by first filling it with thin, alternate layers of coal and raw stone, and 128 PEACTICAL TEEATTSE OX LDIES, then igniting it from below with light, dry wood. The layers of stone should not exceed six inches in thickness. The burnt stone is drawn out at the bottom, twice or thrice every twenty-four hours, raw stone and coal being Startlns: the kiln. added in suitable proportions at the top after each drawing. Fig. 11 represents a vertical section, through the ulfkS^"^^*" axis of the kiln and draw-pit, of the kilns used in Maryland and Virginia ; and Fig. 12, of those preferred in New York and Ohio. 232. There are serious defects in the method of burning above indicated, for which no easy and practi- Defects of method ^j remedv has vet been devised, unless it be 01 burning. " " ' the furnace kiln or some modification of it. Some of the stone becomes so much overburnt, having reached the stage of incipient vitrification, as to be not only very vari- able in quality among the products of the sev- Overbumt and | jg^ygj-g ^nd in many cases quite worthless, underburnt stone. J ' j i ' but exceedingly hard and tough, and conse- quently difl&cult to reduce to powder ; while another portion, HTDEAULIC CEMENTS, AND MORTARS. 129 UBiiallj the largest fragments, or those tliat have subsided too rapidly in the drawing, are underburnt and perhaps partially raw inside.* These also, being difficult to grind, should be selected out and subjected to a second calcination. Much of it, however, finds its way into the cement, and as superior activity the subcarbonates are known to be very prompt ^^ ^^^^ subcarbo- in hydraulic energy during the incipient indu- ration, the injurious effect of the adulteration is not detected by ordinary tests. 233. Lying between the two varieties of burnt stone just mentioned, one of which quite generally, and the other quite frequently, produces cement product's '^""^ greatly inferior in quality to that which the stone, properly treated, is capable of yielding, we find another considerable portion, either too much or not enough burnt to develop the maximum energy and value of the cement, or in the general case, a mixture of both of these extremes, which ofiers no distinguishing physical feature by which it is possible to assort it from the rest. With some varieties of stone, these inferior products are yielded, by a heat of moderate intensity and duration, at a stage but ^SLuoE'vTiL little in advance of a condition of incomplete '^^'^^^ diflerent . .17 1 stones. calcination ; with others, they are produced as we approximate to a state of incipient vitrification ; with all, they are essential elements in the individual properties of the stone, each quarry, and even the separate layers of the same quarry, possessing distinct characteristic features in this re- spect, which features are, withal, subject to considerable vari- ations within very narrow lateral limits. The converse of these premises is also true, to wit, that the state of maximum energy corresponds to a condition of incomplete calcination in some cases ; of complete calcination in others ; while in others still, it is only produced by vitrification more or less complete. We * It will be seen hereafter, that some varieties of stone require to be overburnt to the stage of incipient vitrification, to develop their full value as cements. 9 130 PRACTICAL TEEATISE OX LIMES, therefore see tlie necessity for resorting to what ^^^ticm^* appears to be the only efficient method of elim- stones neces- inating these elements of inferiority in hvdrau- Jic cement, viz : a constant daily examination of the stone by adequate tests, combined with a calcination in separate kilns of all those layers in a quarry which possess marked features of dissimilarity. 23i. Suitably burnt cement may therefore contain a nota- ble quantity of carbonic acid gas, and effervesce briskly with „ , . ^ dilute hydrochloric acid, or it may not, accord- requires special ing to inherent properties in the article itself. Each variety requires a special mode of treat- ment, as 1 the duration and intensity of the heat to which it should be subjected. This great difference is, perhaps, mainly due to the variable amounts of silica and the alkalies which the stone contains, but is by no means entire- ^teble cause ^^ dependent on them. Other ingredients ex- ercise an important influence, particularly those which act as fluxes. The obscure reactions which take place at high temperatures, when a compound limestone is under treatment, cannot be accounted for by any general theory. It is fortunate that we are able, in a measure, to comprehend and estimate the results. 235. The great abuse to be abolished, is the mingling of dis- similar stones in burning. "VThen this is done, most if not all T.. . ., minor evils will disappear. The idea that sev- Dissimuar stones ^^ should not be eral kinds of cement stone^ — some of which burned together. , i • j ^ require twenty, some thirty, and some lorty hours, calcination — can be burnt together, in the same kiln, is both theoretically and practically absurd. Very little extra expense would be involved in a suitable separation and classifi- cation of the stone during the process of quarrying, and few of the manufacturers would require any more kilns than they usually keep going. The least extensive works keep from three to live in operation, with one or two in reserve, and there HYDRAULIC CEMEJnTS, AIS'D MOETAES. 131 are fevr quarries that would require a more extensive subdi- vision than these would accommodata 2S6. Besides the several inferior products of the kiln just noticed, which are due to differences in the properties of the stone, there are others of a similar character, which have their origin in causes to a certain extent independent of these properties, and which, with proper precautions, are more or less under control : such as variations in the force of the draught through the kiln, due to changes either in the direction and force of the wind, or in the barometric state of „ , . ' Certain causes the atmosphere ; neglecting to draw the burnt of bad burning ... "^ . . within control. stone witli the requisite care, takmg perhaps equal quantities at stated times, which may be either too much or not enough, depending on circumstances; not preserving the proper proportion between the fuel and raw stone, when adding these at the top, or not adding them at the proper time and in the suitable quantities ; irregularities in the settling of the stone in the kiln at each dra\ving, which result in some portions being exposed to the heat a much longer time than others; the formation of " cinders," or vitrified pieces of stone, which adhere together or to the sides of the kiln, choking the draught, and retarding the expulsion of the carbonic acid gas : these, and many other variable causes, will always operate to such an extent as to render the proper calcination of the cement an operation of the utmost delicacy, and one requiring on the part of the manufacturer, a high order of intelligence, experience, and skill. Even supposing that all the stone yielded by a quarry and introduced into the cement is alike in compo- sition and character, and requires the same treatment in burn- ing, the theory upon which this practice of mixing the fuel and stone together in the kiln avowedly rests, is singularly at fault, and will by no means bear a critical examination ; for, inasmuch as all the coal is consumed, or sup- „, - . . ' -T Theory oi mixing posed to be consumed, during the calcination,— the stone and fuel , , . . not tenable. otherwise it is di'awn in the cement and ground 132 PRACTICAL TREATISE ON LIMES, up in it ; — and as the proportion between the amount of fuel and raw stone, as well as the times of drawing the kilns and the quantities drawn are also pre-established ; and as no provi- sion is made to regulate the force of the draught, with a view to anticipate in a measure the intervention of one of the principal causes of variation referred to, it virtually assumes that a moderate heat, long continued, and a high heat, pro- portionally short in duration, will produce identical results, a premise which, with all its apparent plausibility, is directly opposed to the teachings of experience. 237. A perpetual " flame" or " furnace'' kiln, for burning either lime or cement, patented by Mr, C. D. Page, of Roches- ter, IST. Y., has recently been extensively introduced into the western part of the State of Xew York, which is intended to obviate some of the most glaring defects of all that class of kilns which require the fuel and stone to be mixed together. Either wood or coal may be used for fuel, although the details of the arrangements for supplying the heat are not exactly the same in each case. Figs. 13 to 18 represent sections of these kilns, whose horizontal section of the interior of the cupola is, it will be observed, of an oval or elongated form, with grates and flues ranged along either side. The conjugate axis of this oval, on a level with the fire, should not exceed five feet six inches. Its traverse axis may be increased to any length necessary to attain a given capacity, the coal-grates being correspondingly prolonged ; and when the enlargement is considerable, suitable openings for drawing the burnt stone being made at the proper intervals along the sides. A little above the point where the flame plays directly upon the stone, small horizontal opening?, Q, called " peak holes," are provided, which extend through the walls of the kiln into the cupola, and through which the progress of the burning may be ascertained from time to time, with a view to regulate the times of drawing the burnt stone, and the amount to be drawn. At the bottom of the kiln, and dividing the lower part of the cupola into two symmetrical AND MORTARS. 133 part8,ii vertical division wall, O (Figs. 14, 15, and 16), is placed, which extends a little above the level of the furnaces, the object of which is to prevent a horizontal draught through the kiln. In burning common lime, this is sometimes omitted, or replaced by a wedge-shaped " air-saddle," through which a current of cold air constantly passes, which divides and gradually cools the lime as it falls below the fires, thereby rendering it less liable to injury from spontaneous slak- ing. 238. All who have used this kiln, whether for lime or ce- ment, so far as any statements liave been received from them, consider its success perfect, and speak of it in the highest terms. Mr. Lemuel Thompson, of Eochester, N. Y., who used one of them for burning lime, says: " My kiln is but 28 feet in height, yet I have been able to burn 320 bushels of perfect lime with 3i cords of wood in twenty-four hours, and that, while the kiln was new, and of course, somewhat damp. The fires are applied at four points, producing a uniform heat on all points of the stone, and leaving not a stone unburnt. I find that I have burnt 44,000 bushels of perfect lime, with 394 cords of wood, being 114 feet of wood to 100 bushels of lime on the average ; during which time I let the fire go down many times, owing to want of market for the lime, and by so doing, losing a large amount of heat. I never drew the kiln down the entire period of my running it." 239. One of them is in use for burning cement at Akron, Erie county, N. Y., by Messrs. Newman & Bro. Under date of March 12th, 1859, these gentlemen say : " We are now burning but 100 barrels, on account of the dulness of the market, — we can burn 130 barrels every twenty-four hours with three cords of wood. The peculiar shape of the cupola and furnaces are such, that the cement is perfectly and uniformly burnt, which adds 20 per cent, to the value of our cement over tliat obtained by the old mode of burning. Now, we know just what we can depend upon evQij day ; we get no raw stone, no 134 PEACTICAL TREATISE ON LIMES, cinders, nothing but pure cement. We can grind one-fourth more of this cement and with less power." FiK. 13. Pig. U. Fig. 13 shows a front elevation of the kiln with ten furnaces, designed for anthracite coal, although bituminous coal may be used in it, without any change being required. A sec- tion of the same, through A B, is represented in Fig. 14, and through C D, in Fig. 15. When wood is used for burning, the kiln is constructed, as represented in Fig. 16, with four fur- naces, and in Figs. 17 and 18 with two furnaces. The parts marked K, show the crib at the top of the cupola ; L and JM, are timbers intended to bind the walls together ; Q, are the peak holes, through which the progress of the burning can be watched ; R, the feed ovens, for heating the coal, before it IIYDRAUTJC CEMENTS, AND MOETAllS. 135 passes throuiih tlie dampers, S, into the furnaces, T ; U, the ash-pits ; Y, the di"aw-pit ; and W, a platform in front of the furnaces. i'lK. 15. Fig. 18. Fig. 17. 2-iO. In order to have the advantages claimed for this kiln fully tested, under circumstances that would lead to conclusive results, it was suggested to the Newark & Rosendale Company 136 PEACTICAX TREATISE Olif LIME3, to give it a thorongh trial at their works in Ulster countj, to which they readily consented. They adopted the coal-buniing pattern (Figures 13, 14, and 15), which was erected during the autumn of 1859, under the personal supervision of the patentee. 241. Tlie value of thejlame kiln, as compared with the draw kiln, in which the stone and fuel are mixed together in alter- nate layers, may be inferred from the results given in Table Y. The cements used for the mixtures recorded in this table, were produced by combining, in equal proportions, the upper and the lower series of cement layers as developed in the quarries of the Newark & Rosendale Company, at Whiteport, Ulster county. New York. This is the same combination which that company makes use of in manufacturing for the market. In Table Y., the two cements under trial are designated Flame Kiln cement and Draw Kiln cement. They were samples of two lots made on the same day ; one having been burnt in the new and the other in the old form of kiln. 242. TABLE Y. Shows the ultimate strength of rectangular parallelopipeds of mortar (2" X 2" x 8")? from cement calcined in different kilns, formed in vertical moulds, under a pressure of thirty-two pounds per square inch applied at the upper end until the mortar had " set," and broken on supports four inches apart by pressure from above, midway between the points of support. The mor- tars were kept in a damp place for twenty-four hours, and then immersed in salt water. Age of mortars, ninety-five days. 243. Observations on the following Table. — The Draw Kiln cement of the following table was not quite so quick-setting as the Newark & Rosendale cement usually is. It is possible that the mortars made from it are corres])ondingly inferior in Btrength and tenacity ; although such a result would not, by any means, necessarily follow. Neither of the cements in Table Y. comes up to the standard quality of the best Rosen- HYDRAUIJC CEMEISTTS, AXD MORTAES. TABLE Y. 137 1 ■J -^1 o o B o 5 a Composition of the mortar. =_ c ■^2 III o ^ o ^ a g o a 0. ^ ^1 t£ 'f 1 Plame kiln. Pure cement (stifl' paste.) 4G2 2 II It K 11 II II II II 11 11 <• K 510 447 529 541 573 470 3 II 11 4 II II 5 11 11 ►499^ Z65. 6 II 11 7 11 11 8 Draw kiln. tl u l< II f 11 II 11 II 11 11 11 4(J2 400 ' 400 322 314 391 369 337 5 II 11 10 II II I! 11 II 12 II II 13 II 11 ■360|ZZw. 14 11 fl 15 II 11 16 II II Flame kiln. 11 :i 353 3G9^ 373 17 18 Dry cement vol. 1, Sand vol. 2, (stiff mortar.) 19 II II 11 11 11 11 11 267 20 II 11 II II 11 II 11 259 21 11 II ^ LBCES, eight liours, and ofteuer, if the capacity of the thimble is rather restricted. 257. Moist limestone is said to burn more readilv than that which is drj, a circumstance which is explained by the fact that the presence of aqueous vapor not only offers no obstacle to the evolution of carbonic acid, but in reality mechanically aids the escape of that gas. 258. The great number of trials which have been made with the cement stones from different parts of the country, within the last two years, by subjecting them to every conceivable degree of calcination, point so uniformly to the necessity of ^ , , ^ J exercisino; the utmost care in conductinof this Undoubted ne- ® _ '=> cessity of careful delicate operation on a large scale, that it is im- possible to gainsay its importance. They also establish beyond a doubt the magnitude of the error committed by manufacturers, in mingling the different varieties of stone together in burning. A few of the results will be briefly no- ticed, somewhat in detail. 259. The stone from Kockbridge county, Virginia, from which the James River cement is manufactured, was broken «!tone from J m s ^^^'^ picces of about f of an inch cube, and cal- River Cement ciued at a bright red heat, for periods varying "Works from thirty-five minutes to eight hours. It re- quired three hours to expel all the carbonic acid gas, below which point, all the samples gave a quick and energetic cement, which hardened readilv under water, without beinor gubse- quently thrown down. The pieces burnt for thirty-tive min- utes and one hour respectiveh^, were both partially raw inside. After three hours' burning, a rapid destruction of hydraulic energy ensued, which was in no degree restored when the heat was continued to eight hours. At this point, though not below it, some portions of the stone showed evidences of partial vitrifi- cation. For analysis of this stone, see Table I Y. '' Tlie James River cement," as prepared for market, effervesces briskly with dilute hydrochloric acid, and will indurate under water at 65« HYDKAULIC CEMENTS, AND MORTAES. 145 F., in four to five minutes, and in six to eight minutes, so as to support the liglit and the heavy testing-wires, respectively. 260. At Point-aux-Roches, Lake Champlain, a good cement stone is found, which will sustain, without injury, a somewhat longer calcination than that from Virginia. It has never been used for cement, but when properly burnt, will compare favorably with our best Roches.^'"*^"^* cements, in hydraulic activity. 261. Some of this stone was broken up and burnt as before, samples being removed from the fire at periods of 1, 2, 3, 4, 5, 6, and 7 hours, respectively. It required 6 hours to expel the last traces of carbonic acid gas. All the samples set readily both in the air and in water. That which had received seven hours' burning, however, even when allowed to harden in the air considerably longer than was necessary to support the heavy testing wire, would not bear immersion, but, alter fifteen to twenty minutes, was reduced to the condition of soft paste. For analysis of this stone, see Table TV. 262. Two pieces of stone, from Lockport, N. Y., were sent for trial, the composition of both being almost identical. They are argillaceous limestones strictly speaking, and contain no magnesia. For their analysis, see Table lY. The natural color of this stone is a grayish blue, the texture granular ; the first specimen was fine grained, the second rather coarse. Both were subjected to calcination in a crucible, samples being removed for trial at the expiration of the first half hour of bright red heat, and . From Lockport, subsequently at intervals of one hour, allowing n. Y. nine hours to the last portions. 263. Of the Jlrst specimen, all the burnings set rapidly in the air, but none of them perfectly sustained subsequent con- tinued immersion in water, except the three corresponding to one-half hour's, two hours', and nine hours', calcination. The sample burnt eight hours did not fall entirely to pieces on im- mersion, but swelled slightly and was soon covered with sev- 10 146 PRACTICAL TEEATESE OX LBIES, eral deep craclcs on the upper and lateral surface, in which con- dition it continued to indurate in a satisfactory manner, and underwent no further change. The trials with this stone de- veloped some novel and exceptional properties. Among the several stages of calcination through which it passed success- ively, there were exhibited three points of maximum, and two of minimum, hydraulic energy. The two minima are found on* either side of the sample burnt two hours, while the three max- ima correspond with the samples burnt one-half hour, two hours, and nine hours, respectively. In mixing with water, a consider- able elevation of temperature was exhibited by all the burnings. By working the paste over with the trowel as long as it remains warm, or by reworking it after it has commenced to swell and crack, it loses the objectionable and characteristic properties of the intermediate limes, and will retain its form in water ; but is, at the same time, degraded in hydraulic power to a level with the eminently hydraulic limes. The portion burnt nine hours turned a dark bluish green color, a few hours after it had been immersed in water. This may be due to the carbonate of the protoxide of iron present in the raw stone, which parts with its carbonic acid gas after a long exposm-e to heat. The pro- toxide thus formed would turn green by the absorption of water, becoming the liydrated protoxide of irun (FeOrHO). Tho green color is readily driven off by heat. A more probable hypothesis appears to be, that it is the peroxide (Fe.Oj), which is present in the raw stone. This, losing a portion of its oxy- gen at a high temperature, is converted by a new combination of its elements into the magnetic oxide (FcjO^), a substance known, under certain conditions, to posses'^ the properties of the pozzuolanas. This, however, does not account for the change in color. 264. The curves of the diagram, Fig. 2S, will perhaps illus- trate the peculiarities developed during the calcination more prominently than a written description can. Let o be the ori- gin of co-ordinate, and the horizontal and vertical lines through HYDRAULIC CEMEIfTS, AND MORTAES. 147 fsTiT f **-^ **-H. ^ V7 N'3 ■■r-*^-H ^,v-^_ Tt^ f ^ K'5 K'2 i +.. -1^^ 1 Fig. 28. the axes of abscissas and ordinates respectively. From o lay off on o, d distances proportional to the several degrees of calcination, as determined by the duration of the heat. These distances are marked on the top horizontal line for every half hour, up to nine hours. On the pei'pendiculars, through the points thus determined, lay off distances from the line (?, o\ that shall represent the hydraulic activity of the cements at the several stages of burning. These are positive ordinates, and lie above the line S " o *^=5 S9 " fi-.'l " 542 " 519 " 6S9 " 662 " 516 " 443 " 66S " 595 " 913 694 J 654 lbs 494 817 The results given in Table YII. were so different from those obtained for Table VI., in the character assumed by the vitrified cement, that other trials were made with the same kind of stone in order that all doubts, as to the relative value of the products, derived at the several stages of calcination, might, if possible be removed. The same sized parallelepipeds (2" X 2" X 8") were made without pressure (some with and some without sand). These were put in sea-water when one day old, and kept there, until broken at the age of sixt)/ days, the sup- ports, as usual, being four inches apart. Several trials gave the following average results. The cement was measured by volume of dry powder. TABLE VIIL <» a Degree of calcination. Breaking weight of prisms of |a Cement with- )ut sand. Cement, 1. Siiud, i. 1 557 lbs 64G '• 513 " 670 " 190 lbs. 2 3 4 Number Two, inferior limit of complete caloination Number Three, suDcrior limit of complete calciuation Number Four, vitrified. 2i;4 '^ U.i " 2;!7 " 27S. Ohservations on Tables FZ, VII., and VIII— The dis- 158 PKACnCAI. TBEATISE O'S LIMES, crepancies between the breaking weights of Xnmber Fonr (vit- rified cement) in the three Tables, appear irreconcilable on any other supposition than that of error in recording the results of Table TL It is possible that cements Xumber Three and Xum- ber Four, may have been exchanged accidentally while making the mortars of Table YI. By making this transposition in Table YL, that is, by exchanging the names of cements dum- ber Three and Xnmber Four; the results of the last three tables pre more readily comprehended, cement Xnmber Fonr gi^^ing the strongest of the four mortars in each case, and cement Xuml^er Three, the weakest. 279. We will now, as a matter of interest, con- etruct, in the manner in- dicated in the 11th obser- vation on Fig. SeTgt?. ^^^ the curve Of strength of the loo cement used for Tables TI.. Vn.. and VTH., has- Rg. so. ed on the several progressive stages of calcination, as described in paragraph 266, and the breaking weights given in the three tables. 280. These breaking-weights were obtained under four vary- ing conditions, as regards age and kind of mortar, and the curve of strength for each is given in Fig. 30. 2S1. These conditions (see Tables YL, YH., and YIII.,) are : 1st C'omeiit voL 1, sand toL 3 2d. Pure cement . , Sd. Pare cement . 4th. Cement toL 1, sand yoL 3 Age 95 days, gires curre No. 1. Age 95 daya. gives curve No. 2. Age 60 days, gives curve No. 3. Age 60 days, gives curve No. 4. 282. The abscissas are laid off on the horizontal line from .the zero point to the numbers 1, 2, 3, and 4, in lengths corre- ExDlnnatkm of ^P*^^^i°o ^.o the four degrees of burning (para- Figareso. graph 2G6). On the ordinates through the points HYDKAULIC CEMENTS, AND MORTAES. 159 1, 2, 3, and 4, distances proportional to the strength of the prisms, at the rate of 100 lbs. to ^ of an inch, are laid off. The points thus obtained, fix the position of the curve. 283. The dotted branch a h, of curve No. 1, corresponds to results given in Table VI., on the supposition that they are there recorded correctly, while the full branch supposes the exist- ence of the error already referred to above, to wit, that the averao;e breakino; weights of mortars from cement K^nmber Four, Table YI., is 276 lbs., and from cement Number Three, 82 lbs. and not a& recorded. 284. The fact that curves Nos. 2, 3, and 4 give two points of maximum strength, while curve No. 1 (ioes not, except under the supposition of error, affords a geometrical confirmation of this hypothesis. 285. We have not constructed the curve of strength of any of the American cements, except that made from layer No. 12 of the Ulster Co., N. Y., deposit, recorded in the last three tables, and illustrated by Fig. 30. 286. We see that a proper treatment of this stone requires that the calcination should stop at or below the inferior limit of complete calcination, or be carried to the point of vitrifica- tion, and that, at the point of superior limit of complete calci- nation, and just before vitrification sets in, the mortars are deficient in strength. The impro- Sed in burofng. priety of mixing this stone, for burning, with another differing from it in the period or periods of time neces- sary to reach the maximum points of the curve of strength ; or, of burning many kinds of stone together, whereby several maxima and minima of strength may be developed simultane- ously, needs no comment. 287. If the layers of cement rock preserved individually a uniform character over extensive areas, it would be a simple matter to test them all in the manner above described, con- struct their respective curves of strength, and establish for the manufacturers the necessary rules and precautions for burning ; IGO PRACTICAL TREATISE ON LIMES, bnt the changeable character of the deposits renders such a labor necessarily one of constant recurrence, and one of the appropriate duties of the manufacturer himself. We have not therefore undertaken this work, except so far as seemed necessary to illustrate the subject. 288. The cement stone, after calcination, is reduced to pow. der between ordinary millstones, after being first passed through a "cracker," which crushes it up into pieces not ex- ceeding the size of a pea or a hazel-nut. The cracker is made of cast iron (Figs. 31 and 32), and consists es- sentially of a frustrum of a solid cone called the core, working concentrically within the inverted frustrum of a right hollow cone, both being pro- vided on their adjacent surface with suitable grooves and flanges for breaking up the stone as it passes down between them. The elements of the lower portions of both cones make a smaller angle with the common axis than those pertaining to the upper portions, with a view to lessen the strain, and the effects of sudden shocks upon the machinery, by securing a more gradu- al reduction of the stone to the required size. These lower portions being subject to very rapid wearing, are made of chilled iron, and are moreover cast in separate pieces, in order that they may be replaced by new ones, as occasion requires. The greatest diameter of the core at the top, including the flanges, is 9 inches, at the bottom 5^ to 6 inches, and its height is ]5 to 16 inches. The diameter of the shell, measured within the largest flanges, is 14 to 15 inches at the top, and 5|- to 6 inches at the bottom, a trifle greater than that of the core ; its height is IG^ to 18 inches. One cracker of this size, working with a velocity of SO to 85 revolutions per minute, is sufiicient for a mill grinding 250 to 300 barrels per day. It is custom- ary to provide one cracker for every two run of stone. For the cement mills, the French Burr stone is generally used in HYDRAULIC CEMENTS, AND MOBTAES. 161 this country, except in Ulster county, New York, where the Shawangunk conglomerate or grit (Formation lY. of Professor Eogers' classification of the Rocks of Pennsylvania and Yir- ginia) has been found to be an excellent substitute. In the vicinity of High Falls, it occurs only a few feet below the ce- ment deposit, and in Rochester township, a few miles further west, is extensively quarried for millstones. These are of va- rious sizes, from 2^ to 5 feet in diameter. When driven with full power, one run of the largest size will grind, on an aver- age, 300 pounds of cement (one barrel) in four minutes, as or- dinarily prepared for market, or in six minutes, if ground ex- tra fine, as it should be. To carry the degree of pulverisation beyond a certain point involves a consumption of either power or time which appears to be strikingly out of proportion to the results secured thereby. For example, a cement of which 85 per cent, will pass a fine wire sieve of 6,400 meshes to the superfi- cial inch (No. 80), cannot be ground so that 95 per cent, will pass the same sieve without doubling one or the other of these func- tions. This accounts for the fact that the cements sent to market are, as a general thing, imperfectly ground. The capa- city of a cement to receive sand, other things bemg equal, varies directly with its degree of bo'J^ound tw fineness, which is, therefore, for this reason, an *''''"''''■ important consideration to consumers to say nothing of other advantages secured by approximating to an impalpable powder. Not more than 8 per cent, of a cement should be rejected by a sieve of 6,400 meshes to the square inch. 289. In practice, one solid cubic yard of raw stone is found to yield an average of 2,700 lbs. or nine barrels of cement, ex- clusive of those portions rejected in assorting the burnt stone. 290. The Rosendale cements are packed in barrels from the mill-spout as fast as ground. In Yirginia, the custom prevails of storing the ground element in bulk, until sent to market, a practice which, besides involving additional expense, injures the hydraulic quickness and energy of all cements, except 11 162 PRACTICAL TREATISE OX LIMES, those containing too much free lime, or which border on the intermediate limes. The objectionable properties, in such cases, disappear in time, but invariably at the expense of the hjdraul- iciXj. It must be admitted that there are very few quarries in this country, that do not assume such a character at times, that the cements are of better quality, and may be more safely used by ordinary mechanics when six months old, than when freshly ground. 291, Attempts have been made to economize the power necessary to produce a very high degree of pulverization, by passing the ground cement through fine wire bolts. It was found, however, that these bolts required Bolting cement. i i • such irequent renewal, as to render their use in every way inexpedient. 292. The color of the manufactured cement being due prin- cipally to the presence of a small quantity of oxide of iron, and sometimes of manganese, or to the carbonates of these oxides, which, for all practical purposes, are conceded to be a passive ingredient in hydraulic mortar, should be a matter of indiffer- ence to consumers, except in special cases, as in exterior stucco work or ornamentation, in pavements, and in the fronts of edi- fices, when a particular shade of color is sought for. In fact, the presence of a large proportion of the coloring principle, like that of any other inert substance, might be expected to have a tendency to deteriorate the quality of the mor- Golor of cement. ,,...,. , , . i » tar, by dimmishmg the cohesive strength of the cementing substance, and, therefore, if taken into con- sideration at all, ought, at least, to direct suspicion to the darker varieties. On the contrary, there exists among dealers generally, a strong prejudice in their favor, which, if ana- lyzed and traced to its source, will be found to have had its origin, not in opinions based upon experiment, or even upon a theoretical examination of the substances, but in the per- nicious system of building by contract, so extensively, and it might almost be said, so exclusively practised in this country, HYDRAULIC CEMENTS, AND MORTARS. 163 and under which nine-tenths, and perhaps nineteen-twenticths of our masonry work, is superintended by men whose utmost endeavors are directed to " economy of construction." They, therefore, encourage and cater to a popular belief of their own creation, that a dark colored mortar is necessarily a rich and energetic one, and give the preference to those cements which will sustain a large dose of sand, without presenting the ap- pearance of having been injuriously diluted with it. The fact that some of the cements first discovered and manufactured in this country on the line of the Erie Canal, and in Connecticut Yallcy, which were little more than eminently hydraulic limes, were light in color, while the excellent Parker's Koman ce- ment, which appeared here soon after, was very dark-colored, renders it more difficult to abate this prejudice. No import- ance whatever is accorded to the fact, that the quickest setting cements manufactured at the present day happen to be light- colored, and that the Portland cements, both natural and arti- ficial, though rather slow-setting, have never been surpassed in strength and hardness by any of the natural cements of this country or Europe. 293. As to the oxide of manganese, the idea, at first promul- gated by the chemist, Bergmann, and subse- quently endorsed by Guyton de Morveau, that the hydraulic property was due to the presence . of a few hundredths of that substance, has long since been abandoned, for the obvious reason that some of the best ce- ments known are entirely devoid of it. 29-i. The extent to which the oxide of iron exerts its influ- ence, if at all, upon the induration of hydraulic mortars, is still a subject of controversy, as well as the ques- 11 , . \ . ^ r ■ ^ Oxide of iron. tion whether the virtues clanned for it by some writers, rest with the uncombined peroxide or protoxide, or with a carbonate of one of these bases. The fact, however, appears to be well established that their presence does not con- fer hydraulic activity, whatever may be their action at some Oxide of manga- nese. 164 PEACnCAL TREATISE ON LIMES, subsequent stage of the induration. We also know that, al- though some of the best cements known, as, for instance, the cement of Yassy, in France, and Parker's Roman cement, con- tain a comparatively large amount of the carbonate of the protoxide of this metal, the former .lly^j and the latter .06, there are many good cements in the United States which con- tain less than .02, while there are some meagre, non-hydraulic limes, which contain, after calcination, as much as .10 of the protoxide. It has been suggested by Messrs. Malaguti ed to its presence since some of the most active contain, of all the compounds of iron together, only a minute proportion ; still it is not improbable that ferruginous combina- tions may be developed, which are well adapted to resist the dissolving power of sea-water. 297. The gradual and progressive effects of sea-water upon hvdraulic mortars immersed in it. notwithstand- Effect of sea^ -water on mortara ing the attention which the subject has received not understood. /> -r< • • .-^^ i j • irom ±.uropean engineers, is still enveloped m considerable doubt. It is an easy matter to ascertain that its retarding influence upon the initial hydraulic induration is not very great, if the cement be mixed up with fresh water ; and it does not become very marked when the cement is both mi-xed with, as well as immersed in sea-water. The strength of mor- HYDRAULIC CEMENTS, AND MORTAliS. 1G7 tars, however, is considerably impaired by using Mixing mortars .. . . ,1 . , ' , with sca-vvater sea-water lor mixing them, as is shown by the following table : TABLE IX. Showing the ultimate strength of rectangular parallelopipeds of mortar 2"x2"x8" formed in vertical moulds, under a pres- sure of thirty-two pounds per square inch, applied at the upper end, until the mortar had " set^'' and broken on supports four inches apart by ^a pressure from above midway between the points of support. The mortars were kept in a damp place for twenty-four hours, and then immersed and kept in sea- water. Some of tlie mortars were mixed with fresh water and some with sea-water. The cement was calcined in the Flame Kiln, and the mortars were ninety-five days old. Composition of the mortar. ^■3 Pure cemi'iit mixed with fresh wiiter to a stiff paste. Pure cement mixed with sea-water to a stiff paste. Cement powder, vol. 1, sand, vol. 2, mixed with fresh water.! 2• .0.57 .092 623 14 I Cement repulverized after 3 days' set, vol. 1, .045 .057 .097 .085 .092 .165 &S5 15 m5 16 sand voL 1 209 17 " " " " " .112 .187 204 IS " u u u « .102 .177 271 19 " H U U. u .112 .187 244 20 " " " " " .080 .130 267 21 " " " " " .085 .147 296 22 " " " •» " .097 .145 279 23 " " " " « .100 .160 254 24 " U. U U " 283 25 " " " " " .077 A3a 806 306. Some of the James River cement, manufactured at a different time, and apparently not as good as that referred to in the foregoing table, was obtained. A few prisms were made of this cement without sand, and while quite fresh. The barrel was then reheaded, and kept for one year without be- ing disturbed, when other prisms were made, also without sand. Both sets of prisms were kept in water for 320 days, and then broken on supports four inches riorated James apart, as usual, with the following results : ^'^^' '''°''°'- The prisma formed of the fresh cement, bore as an average of 6 trials, 402 lbs. " " " " stale " " " 6 " 244 lbs. This cement being originally of inferior quality, in conse- quence probably of careless burning, as well as of a careless se- lection of stone, the ratio of deterioration is doubtless much less marked than would have been exhibited by a prime article. 30T. Hydraulic lime also loses its energy by Hydraulic lime , deteriorates hj exposure, m the same way as cement. age. General Treussart tried some of the Obernai and Metz hydrau- 172 PEACTICAL TREATISE OX LIMES, lie limes. The composition of the raw Obeniai obemai andMetz stone was lime, .422; magnesia and iron, .050; hydraulic lime, silex, .105 ; alumina, .043; carbonic acid and water, .380. The Metz lime burnt contains .683 of lime, .090 of magnesia, .170 of clay, and .057 of oxide of iron. These limes were slaked by an infusion of about i of their volume of water. Some of the lime was made into mortar, and formed into prisms, as soon as it was slaked, and while perfectly fresh. Other prisms were formed after the slaked lime had been kept for some time in an uncovered vessel. The ages selected for the lime powder were 15, 25, 30, 45, 60, 90, and 120 days, respectively. Tlie prisms were retained 12 hours in the air, and w^ere then immersed and kept in water. They were broken on supports 4 inches apart, when one year old. The results are given below ; TABLE XL SHOWING THE STKEyGTH OF MORTAES 1 TEAE OLD, IX PRISMS 2" X 2" X 6", EEOKES ON BUPP0RT3 4 IN. APAET, BY A PRESSURE AT THE JIIDDLE POINT. Composition of the mortar. J Obernai lime in powder vol. 1 I Sand vol. 2 Lime and sand same as above . 1 Lime as above vol. 1 , ■{Sand vol.1 JTi-ass voL 1 I Lime, sand, and trass as above I iletz lime in powder voL 1 I Sand vol. 2 ' J Lime as above voL 1 j Sand vol.1 Trass. vol. 1 ' Breakinir weight of the mortars, in poumls. The age of the slaked lime when made into mortar, is given at the heads of the column. o § "e 2 1" OQ ^ " "I- ll -' -" s« •2&4 121 209 116 ISO* 121 132 299 11 304 3S9 44 812 IIT 299 352 22 OD 6 317 on S 495 22 Remarks on the alove Table.— ^e judge from the results given in Table XI. that hydraulic limes deterio- Deteriorated hy- draulic limes and tiass. rate by the absorption of moisture and carbonic acid gas, if left exposed to the air after slaking ; * This sample was found split longitudinally. The two halves were carefully put together, and the prism broken in that way. diminished by the spUtting. The strength must have been HYDRAULIC CEMENTS, AND MORTAKS. 173 but that the evils of such exposure may be counterbalanced by mixing the deteriorated limes with a suitable proportion of truss. This conclusion might have been arrived at from our knowledge that trass and common lime make a good mortar, and that the practical effect on hydraulic limes, of exposure to the air, is to reduce them to the condition of common lime. 308. General Treussart also found by experiment that the strength of hydraulic limes is iniured by air- ,^ , ,. , _ ° _ •' _ ^ '' _ "^ _ Hydraulic lime3 slaking, in a ratio varying directly with their injured by air- hydraulicity, but that mortars composed of one measure of powdered air-slaked lime, one measure of sand, and one of trass gave very good results. 174 PEACnCAL TEEATISE OX LDIES, CHAPTER YI. 809. Calcareous moetae, being composed of one or more of the varieties of lime or cement, natural or arti- ^^^^reous mor- ^q^q}, mixed with sand, will vary in its proper- ties with the quality of the lime or cement used, the nature and quantity of sand, and the method of manipulation. Xo fixed rules for its preparation, that shall be equally well adapted to all the varying circumstances of locality, temperature, and the seasons, can be prescribed. 310. The objects to be attained by the use of mortar are chiefly of two kinds, as follows : JF^irst, to bind together the solid materials Their uses. used in masonry constructions; or, in other words, to produce in each particular case, arti- ficial monoliths, of the required form and dimensions. /Second, to form coverings to tlie solid materials, under the general denomination of stucco Avork. Under this head may be included all exterior covering, and interior plaster work and ornamentation. 311. Sand exercises no sensible chemical action in the com- position and induration of mortars of hydraulic ^^tion of the j.^^^g . .f ^j^g g^^^ ^g silicious, there is believed to ensue a slow formation of silicate of lime, which considerably augments their power of resistance, and in positions excluded from contact with the air, such as the in- terior of thick walls, becomes an important auxiliary in the hardening process. HTDEAULIC CEMENTS, AND MORTAllS. 175 In a general sense, therefore, any mixture of fragmentary substances, like sand, gravel, pebbles, or pieces of brick or stone, formed into a state of aggregation by a calcare- ous cementing matter or matrix, might be termed mortar ; but as this definition would evidently include concrete or beton, Mdiich is made by incorporatino- into ^ , . . J f o Tochnical signifi- mortar, fragments of brick or of stone, shells cation of the term and pebbles, it is perhaps well to retain the ^^^ ^'^' technical signification of the term mortar, by limiting its appli- cation to mixtures of sand and a paste of the cementing sub- stances, reserving for a general classification of mortars and concrete under one head, the more Aggregates, comprehensive denomination of aggregates. 312. The practical strength of aggi-egates, considered with regard to their tenacity, hardness, and power of resisting com- pression, depends upon four essentially distinct conditions : 1st. The constant resistance of the parts enveloped by the matrix, whether composed of sand, gravel, peb- bles, fragments of brick or stone, or a mixture f/^'^Jl^^ "^ ^^- of them all. 2d. The resistance varying, and generally increasing with time, of the matrix or cementing matter. 3d. The force of adhesion between the matrix and the other parts, resulting in part, from the former penetrating tlie in- terstices of the latter, and in part from the chemical affinities existing between them. 4th. The strength due to the interlacement of the enveloped parts with each other, wh ich produces leverage and friction among them, and enlarges the surface of least resistance. 313. It might be inferred theoretically, that the capacity of an aggregate possessing no voids, to resist any particular kind of strain,^ cannot surpass that of its matrix or gang; or rather cannot be equal to it, except when the inherent strength of the enveloped parts, as well as the adhesion between them and the matrix, equals or exceeds the resisting power of the latter. 176 In practice, when these conditions do approximately obtain in exceptional cases, mortars are weakened by weakTned^ V the *^^^ addition of sand or any of the substances sand used. above mentioned. These latter have the im- portant effect, however, of preventing or dimin- ■ ishing shrinkage, of hastening the induration of rich limes, and of rendering all kinds of mortars less liable to crack in drying, which is often of very great advantage. They are, moreover, by far the least costly ingredient of mor- tars, and a due regard to economy compels their use in the largest possible proportions. 314. It might also be inferred that the minimum amount of ^ . , the cementino; material that can be used in any Theoretical mini- ^ ^ mum of cement- case, is exactly equal to the volume of the voids ances. ^^ ^j^^ sand, when the latter is well compacted. This theory supposes that there is no shi'inkage in the matrix while hardening, and that the manipulation is complete. But as these conditions can never be fully attained in practice, it is unsafe to descend to this inferior limit. Moreover, mortars com- Not safelv appli- P^sed on this principle would be deficient in cable in practice, both adhesive and cohesive power, from the fact that the particles of sand would present a large area, practically void of matrix, to the surfaces of the solid ma- terials that are to be bound together, and would, for the same reason, be in more or less intimate contact with each other throughout the mass. In order to avoid these defects, it is customary to determine the amount of cementing matter to be used in any particular. case, bv adding 45 to 50 Proportion of ' , ,. • i ■ i sand to the gang per ccnt. to the vohime ot void space m the of mortars. sand. One method of ascertaining these voids is, to determine the volume of water which a known volume To determine the o^ the sand (damp and well compacted in a ves- Toids in the sand, g^j ^f suitable form) will receive ; another, ap- plicable only when all the particles of sand are derived from the same kind of rock, is to ascertain the weight of a known HYDEAULIC CEMENTS, AND MORTAES. 177 volume of the sand and compare it with the weight of an equal volume of the solid rock, as calculated from its known specific gravity. 315. When sands of various sizes are at hand, a considerable saving of the cementing material may be ^ . . ,.^ ■I ■, . . , Sands of different secured by mixmg them together in suitable sizes can be mixed proportions. To determine this point, take a ^^^^"*^g^°"«ly- measure of convenient capacity, say a little more than one cubic foot, and put in it a known volume, say one cubic foot, of the coarsest variety of sand. Then add to it, little by little, so long as there is no augmentation of volume, the sand which stands next in order of size, shaking the vessel well during the operation. Add to this mixture in the same way the other sands in regular order, so long as there is no increase of bulk. The original volume of the coarsest sand, and the several volumes of the other varieties successively added to it, will indicate the proportion in which they should be combined, in order to produce a mixture possessing the smallest measure of void space which they are capable of yielding. Having made the mixture, its voids may be measured by either of the methods given above, or by subtracting from the known voids of the coarsest variety, the difference between the ao-o-re- ^ .1 i> 1 1 1 , , , Computation of gate volume ol added sands, and their aggre- the voids of gate voids. '"'^^'^ '•'^°'^- 316. The density of sand depends somewhat on its state of humidity and the manner of measuring it. In determinino- the properties of the constituent parts of mortars, due allowance should always be made, as ascertained by trial, for these causes of variation. A convenient method of ascertaining the pro- l)ortion of grains of difi'erent sizes in any given kind of sand, with a view to institute a comparison between different varic^ ties, is by using sieves of various degrees of fine- ness, noting the amount by weight or volume ^'^'''" '''^ '^"*^' retained by each sieve in succession, commencing with th- coarsest. These several amounts, added to that which passej 12 178 PEACTICAL TREATISE OX LIMES Classification of series. tlirougli the last or finest sieve, should be equal to the known amount taken for trial. Sieves are classified into numbers, which correspond with the number of openings embraced in a lineal inch of the wire giauze of which they are made. Those used in the experi- ments reported in this work were Xos. 12, 18. 24, 30, 40, 50, and 60. A few of the many sands that have been examined' are introduced into the following table, which contains an equal quantity of each kind represented by 1,000. TABLE Xn. No. 1. No. 2. No. 3. Calcarfons Sand, from sand, from Governor"* Mixed sili- No. 4. No. 5. Mortar Sand, from Key WesL Islan.lNY. cious sand.!^^,^*^"; Brc^^lyn. Fla. HartH.r* KlcHmond., JS. 1. Weight of grains between in. and -^g in. diameter, "Weight of grains between in. and -^f in. diameter, Weight of grains 1>etween in. and -^q in. diameter, Weight of grains between in. and -^^ in. diameter, Weight of grains between in. and ^ in. diameter, Weight of grains between in. and >-(, in. diameter, Weight of^ grains less than in. diameter, ^.-} Total. .080 .138 .243 .222 .138 .103 .076 .163 .302 .352 .183 .140 .175 .584 .043 .019 .008 .031 .038 .092 .179 .183 .224 .284 1.000 1.000 1.000 1.000 .341 .302 .163 .119 .060 .015 1.000 Percentage of void space by } volume. )' .347 .363 Weight per cubic foot .339 106^ lbs. 103§ lbs. 107^ lbs. * This sand is fine grained, containing a very small proportion of particles exceeding one- thirtieth of an inch in diameter, which is in the condition of rather smooth gravel, heterogen* oosly distributed throughout the mass. 1 cubic f x)t of sand. No. 3, damp and not compacted, weighed 87 pounds. 1 " " " " damp and compacted, " 97 " 1 " " " " dried in an oven and not comp., " 97^ " HYDRAULIC CEMENTS, AND MOETAllS. 1'79 Ictibicfootof sand, No. 3, dried and compacted, weighed lOCj pounds. 1 " " " " comp. and afterwards dampened " 112J " 1.1 1^ cubic feet of loose, damp sand lias its volume diminislued, by shaking, to 1 cubic foot. 1.09 cubic feet of loose, oven-dried sand has its volume diminished, bj shaking, to 1 cubic foot. METHODS OF SLAKING LIME. 317. Lime is usually sent to market in barrels, either in lumps, as it leaves the kiln, or, in the case of those varieties that are more or less meagre, and j^ °j,q market. * consequently difficult to reduce to fine pulp bj any of the known methods of slaking, in the condition of coarse powder to which it has been brought by grinding. In either case, it must be slaked before it can be employed as a matrix for mortar. 318. Three methods of slaking lime are usually described in works on mortars ; on the continent of Eu- rope, the third method, and in the United States, Three methods of the second and third are seldom resorted to in ^^^^^^s I'me. practice. 319. The first or ordinary method termed drowning^ from the excessive quantity of water sometimes injudiciously era- ployed, consists in pouring upon the lumps of lime, collected together in a layer of uniform depth not exceed- ing six to eight inches, either in a water-tight drowi^^"- ° ' °^ wooden box or a basin formed of the sand to be subsequently added in making mortar, and coated over on the inside with lime-paste, to render it impervious to water, a suf- ficient measure of fresh water, — previously ascer- tained approximately by trial,— to reduce the ^t^onJ^.*^^ '''''*^'' whole to the consistency of thick pulp. It is important that all the water required for this purpose, which, with the different limes, will vary from two and a half to three times the volume of the quicklime, should be added at the out- set, or, at least, before the temperature becomes sensibly ele- 180 PRACTICAL TREATISE ON LIMES, vated. In tliis condition the lime will remain entirely sub- merged, and comparatively quiescent, until after an interval of five to ten minutes, the water becomes grad- The slaking. ■,, ■, i ^ , •-,• • ^ ^ ually heated to the boilmg point, when a sud- den evolution of vapor, a rapid increase in volume, and a reduc- tion of the lime to pulp, ensues. The increase of volume is sometimes denominated the "growth." 320. This process is liable to great abuse at the hands of workmen, who are apt to use either too much process*' * ^ Water, thus conferring upon the slaked lime a condition of semi-fluidity, and thereby injuring its binding qualities ; or, not having used enough in the first instance, they seek to remedy the error by adding more after the extinction has well progressed, and a portion of the lime is already reduced to powder, thus suddenly depressing the tem- perature, and chilling the lime, which renders it granular and lumpy. 321. As soon as all the water required has been poured upon the lime, it is recommended to cover up the vessel con- taining it with canvas or boards, in order to concentrate the heat and the escaping vapor, and direct their action upon the uppermost portions dei^rived of immediate to becovefedvm. contact with the Water, by the swelling of tlie portions at the bottom. When it is not practi- cable to apply this covering, a tolerable substitute is found in Sand ma b *^^® sand to bc subsequently added to the used for this mortar. This can be spread over the lime in a layer of uniform thickness, after the slaking has well progressed. Another precaution of equal and perhaps greater importance is, not to stir the lime to'reSi^ft^rest ^^"^^t slaking; but to allow it gradually to absorb the water by capillary attraction and its natural avidity for it, taking care that all portions are supplied with it to that degree requisite to produce a paste of the slaked lime, and not a powder. When the lime is to be used HYDRAULIC CEMENTS, AND MOETARS. 181 for whitewashing or grouting, the water should be added at the outset in hirger quantities than specified .above, and tlie whole mass should be run ofi' -v^^'iiitewasLing. while liot into tight casks, and covered up to prevent the escape of water. 322. In slaking, the essential point is to secure, if possible, the reduction of all the lumps. It will be found difficult to obtain this result with the hydraulic varieties, jjydrauUc limea and the difficulty increases in a direct ratio with slake with diffi- the hydraulic energy, until we reach the inter- mediate limes, or the inferior limit of cement, when the reduc- tion must be effected by mechanical means. Even with those hydraulic limes that do slake, it is often necessary to employ a mortar mill to reduce the lumps, — a condition Mechanical means which should always be secured, as tliese lumps p5*™ed"for rT" constitute not only a dangerous substitute for ducing them, sand, if left intact, but furni;ili when pulverized, the most ener- getic portion of the gang. 323. Slaking hy Immersion. — The second second process method of slaking (by immersio3i\ consists in of slaking. suspending the quicklime, previously broken into pieces of about the size of a walnut, and placed in a basket or other suitable contrivance, in water, for one or two minutes, taking care to withdraw it before the reduction commences. The lime should then be quickly heaped together, or emptied into casks or bins, and covered up, in order to concentrate the heat and prevent the escape of vapor. In this condition it soon begins to swell and crack, and finally becomes reduced to a fine powder, which may be preserved several months without serious deterioration, if packed in casks, and kept from direct contact with the atmosphere. The expense which would ordinarily attend the practical application of this process, and the difficulty, and even impossi- ^, . ^ , , , This process ex- bility of securing with certainty, at the hands of pensive and dim- workmen, the period of immersion, have led to 182 PRACTICAL TREATISE OX LIMES, a modification of it, which consists in sprinkling the broken A modification fragments formed into heaps of suitable size, "fit- -svith one-fom"th to one-third of their volume ot water. This should be applied from the rose of a finely ganged watering-pot, after which the lime should be immediately cov- ered with the sand to be used in the mortar. In this condition it should not be disturbed for at least a day or two, and the Practice in Eu- opinion prevails in the southern portions of the ^op^- continent of Europe that the quality of the lime is improved by allowing the heaps to remain several months, without any other protection from the inclemency of the weather than an ordinary shed, open on the sides. In the vicinity of Lyons this custom very generally obtains, the au- tumn being usually selected for slaking all the lime required for the following season's operation. In Europe, this method of slaking is applied to the fat and slightly hydraulic limes only, and not to those that are eminently hydraulic, upon which it seems to act disadvautageously, by depriving them, in a measure, of their hydraulic energy. 32-i. Spontaneous slahing. — jQuicklime has a great avidity „, . , for water, and when not secured from direct Tnird process — ' Spontaneous or contact with the atmosphere, gradually absorbs air s a mg. moisture from it and falls into powder, exhibit- ing but very slightly, and sometimes not at all, the other phe- nomena usually developed in slaking. The lime is then said to be slaked spontaneously, or air slaJced. 325. It has been claimed by some engineers that this method, if the precaution be taken to stir the Thought to con- -, . ^ , fer hvdrauiicity lime frequently, so as to expose every portion inasUghtdegree. ^^ .^ ^^ ^.^^^'^ contact with the air, confers a slight degree of hydraulicity upon fat lime ; and Culmann, „ „ , in his " Cours sur les Chaux, Mortiers, et Mas- Opinion of Cul- mann needs tics" says, " it produces very advantageous re- rma i n. ^^^^^ upon fat or feebly hydraulic limes that are to be mixed with pozzuolana and used under water." It HYDRAULIC CEMENTS, AND MORTARS. 183 is believed that both of these statements need confirmation. A great and insurmountable objection to the process, however, is the expense of storage room or sheds which it necessarily in- volves, to say nothing of the time required for its completion. Spread out in layers of from ten ofXrd Foceal to twelve inches in depth, some varieties of fat lime might become thoroughly reduced in twenty or twenty- five days; others would require as many weeks; while with a few, the process would continue for a whole iivdrauiic limes year. Hydraulic limes are greatly injured by "^J"''^'^ ^y ^*- spontaneous slaking. Fat limes slaked to powder by the second or third process, are converted into paste with less water, and undergo a less aug-mentation of their oriy-inal Remarks, volume, than when slaked by the first process. 326. By neither of the three processes of slaking, nor any modification of them, have I succeeded in obtaining as great an augmentation of the volume of fat lime measured in the state of paste, as is stated by M. Vicat to belong to the fat limes of France, viz. : that one volume of the quicklime in lumps, by the absorption of 2.91 volumes of water, will give 3.5 volumea of paste. According to the same authority, these limes slaked by im_ mersion to powder, and afterwards reduced to m. Vicat's de- paste, absorb 1.72 of water, giving 2.31 of paste ; Auctions. while, by spontaneous slaking they required 1.88 of water, and gave 2.58 of paste. It is also stated that the hydraulic limes in slaking absorb 1.05 volumes of water lucrease of by the first process, .71 by the second, and .68 ^o^^^^*- by the third, producing respectively 1.37, 1.27, and 1.00 vol- umes of paste. 327. I have repeatedly tried all the limes ofiered to any extent, in the New York market. In slaking them, quantities of five to ten pounds were generally employed ; ^ ^ .^ r ./ 7 Experiments in and the utmost care was taken, in all cases, to slaking American obtain perfect accuracy in the weights and meas- 184 PRACTICAL TEEATISE OX LIMES, .urements, and bj the use of glass and tin vessels to prevent the waste or absorption of water. The glass vessels found most Vessels u d convenient were two cj'lindrical jars, one eight inches in diameter and eighteen inches deep, and the other three inches in diameter and ten inches deep. They were accurately ground off at the bottom to a plane sur- face at right angles to the axis, so as to stand in a vertical position on a horizontal surface, and were graduated to cubic inches, and the small one to fractions of an inch throughout their entire length. The large jar was used for determining the vol- ume of the quicklime and of the resulting powder or paste ; the small one, for measuring the water absorbed in slaking. When the quicklime to be tried was in the condition of lumps, the usual process of ascertaining its volume by the displacement of sand was employed. 328. To hold the lime while slaking, tin cans about one foot square and one foot deep, were found to answer a good purpose. 329. General Totten, from an average of many Results of Gen. • i -n » i Totten's experi- trials at J^ ort Adams, states that one volume oi ^'^^^^- quicklime slaked with ^ its volume of water gave an average of 2.27 of powder ; f of water gave 1.74 ; f gave 1.81, while equal volumes gave 2.06. Slaked by drown- Increaseofvol- i"g» ^.54 volumes of water gave 2.68 of thin "™6- paste; and by sprinkling, 1.70 of water gave 1.98 of thin paste. Mixing the powder with .40 of water gave .66 of thick paste, while .50 gave .76 of thinner paste. One volume of lime slaked spontaneously produced 1.81 of powder, and one volume of this powder and .50 of water gave .75 of thin paste. One volume of quicklime when pulverized, gave .90 of powdered quicklime. 330. TABLE XIII. Shows the results obtained by many trials of slaking applied to the limes in common use in the United States : HYDRAULIC CE>rENTS, AND MORTAES. 185 rMfcirc slaking. =5 Aft«r slaking. 1 Ilatio of mcTMiae ■c " r3 -• 1 Kind of lime used. a 3 C Is 2 3 a i 1/ n 1?- a 3 a. a g 3 ^ s H V- Jl s4 Bf .a J3 E-l ^ o c .it 5 5 5 5 5 1.2 — 7 a > 2*'S.6 269.8 182.4 210.0 — — a — > ■f > 1 Uocklaiid lunii) lime 91.2 86.5 91.2 95.0 87.4 11.19 11.78 13.25 11.06 + 11.12 224.2 24.5.1 29'.i.6 227.0 227.0 2.24 2.36 2.r)o 2.21 + 2.22 + 2.46 + 2 2.s:i + 3 11 K « 3.21- 4 11 11 11 ] ' ' 2.40 5 ( Sinjr Sins: lump lime from 1 ■) Sing Siuff marble j 2.61- C 5 89.S 11.78 24S.9 2.36- 2.79— 7 11 11 11 5 SS.4 197.6 10.67 225.1 2.13 + 2.56- S Itondout ground limo 5 110.2 well shaken. 195.7 10.62 222.3 2.12 + 2.00 + 9 11 U 11 5 110.2 well 201.4 11.37 239.6 2.27 + 2.14 shal(en. 10 11 11 u 5 5 115.9 well "124.5 well shaken. 247.0 209.0 11.37 + 281.2 248.9 2.27 + 2.42 + 11 „ 2.00 12 11 U K 5 5 l'il.5 well slmken. 12S.3 well sliftken. 209.0 197.6 11.44- 11.25 249.9 247.0 2.29- 2.25 2.00 + 13 1.03- 14 Glen's Falls lime in lumps 5 9:11 269.8 1.^.33 2S5.0 2.66- 8.06 + 15 5 9;ii 267.9 12.44 271.7 2.49- 2.92- 10 " " " !!!!!! 5 93.1 279.3 13.50 304.0 2.70 3.26 + 51.2 6.19 260.3 1.24 2.86 to produce of powdet. of powder. for powder for powdef IT 1 " " " slaked 1 ) by immersion ) 5 91.2 ] a iiowder. 181.5 10.50 202.8 2.10 2.54 to i>ru(iuce of paste. of paste. for paste. for paste. H paste. 6S.4 6.62 + 285.0 to pi'uiluce of powdur of powder. IS " " " " 5 87.4 1 "Eoll"^' to produce 10.87 + uf paute. 224.2 of pa&te. 1 I X paste. EXPLANATION OP THE ABOVE TABLE. No. 1. No. 2. No. 3. No. 4. No. 5. No. 6 No. 7 No. 8 Abotrt one-half the quantity of water mentioned was poured on at once, and the balance gradually, with occasional stirring. Most of tlie water was poured on at tlie outset, and the lime was stirred occasionally. All the water (269.8 cubic Inches) was poured on at once, submerging the lime completely, in wliich cuudicion it was left covered up for several hours ■without being agitated at all. 83| cubic inches were first added, and the balance of the 182.4 inches grad- ually, with occasional stirring. The water was poured on gradually, with occasional stirring. The lime was nearly covered up with the water at the outset. When the slaking had weU progressed, more was added, with occasional stirring. Water poured on gradually, with occasional stirring. do. do. do. do. 186 PRACTICAL TREATISE OX LDIES, Ko. 9. AR the water was poured on at the outset, and aft«r the expiration of one hour, the lime was stirred. No. 10. All the water was poured on at once, and the canvas was covered up, and not disturbed until the next day. The paste was very thin and of the con- sistency of cream. No. 11. Water all poured on, and the can covered as before. The paste was much stiffer than Xo. 10, but raiher lesS so than most of the foregoing. No. 12. Water poured on as above, and not disturled untD the following day. Tho paste was not quite so thin as No. 10, but much more so than No. 11. No. 13. Water all poured on, and the can covered as above. The paste was a trifle less stiif than that adopted as the standard in these compari- sons. No. 14. The lime was broken into pieces of 1 to 1^ inch, cube, and 209 cubic inches of water poured on at once. The can was then covered up with canvas and left for several hours, until it had become cool. The lime was then in the condition of a powder, requiring 60-i% cubic inches of water to reduce it to a paste of the requisite consistency. No. 15. The lime was broken up as above, and 805 cubic inches poured over it at the outset. The can was left open, and the balance of the water added in quantities of 20 to 24 cubic inches at a time, until 211 cubic inches had been used. This was just enough to produce a damp powder wliich re- quired 56,-0 cubic inches more to bring it to a paste. No. 16. The lime was broken up as in No. 14, and submerged in 270 cubic inches of water. The can was then covered, and not disturbed until after the ex- piration of four hours. 9-j% inches of water were added to produce the re- quisite degree of consistency. No. 17. The lime, broken as in No. 14, was placed in a basket and suspended one minute in water, of which it absorbed 51^% cubic inc':es. It was then poured into a can, covered up, and not disturljed until the next day, wlien it was found to be reduced to a powder containing about ten per cent of small lumps. After these were pulverized, 130-fV cubic inches of water brought the whole to a stiif paste. No. 18. The lime, broken as above, was suspended in water If minutes, and was then poured quickly into a can, and kept covered up until next day, when it was found very weU slaked, with very few lumps, and none but what could easily be rubbed fine under a spatula. 331. Action of the hydrates in the air. — A paste of the hy- drate of fat lime in free contact with the atmosphere, absorbs carbonic acid gas upon the surface, although mL?il^th-^atr* ^^^ ^^ ^^ ^o\\\\. of complete saturation, and becomes coated with a mixture of hydrate and carbonate of lime, (CaO.COj+CaO.IIO). The gas gradu- ally penetrates the substance, at a rate of progress con- stantly on the decrease, and at the end of one year, according HTBEAULIC CEMENTS, AND MOKTAKS. 18? to M. Yicat, tlie la3'er of impure carbonate is from .10 to .12 of an inch in depth. The same ^^"^H '='^^^"''' authority says, that the absorption and penetra- tion of this gas proceeds more rapidly in tlie liydraulic limes than in the fat limes — a statement which not only needs confir- mation, but is believed to be the converse of what is true. My researches lead me to the same results as those enunciated by Geo. Eobertson, Esq., in a paper recently R^tio of absorp- read before the " Eoval Society of Edinburfrh " tioQ among the - " _ '' ^ . different limes m- viz. ; " The depth to which carbo^iio acid is ah- verseiy as their sorbed into mortar in a given time, and, to ^ "" ^'^" a certain extent, the induration from that cause varies in- versely with the hydraulic properties of the lime, which depend upon the silica contained in itP 332. The incrustation is due in the case of hydraulic limes to the combined influence of reactions, con- „, . „ ' The covering of eiderably more complicated and obscure than subcarhonate those which obtain with the hydrate of fat lime. The hydrosilicate and aluminate of lime (Si034 CaO + 6 HO) and (AlA + 3 CaO + 6IIO) are formed in addition to the hydrocarbonate. Other compounda ■^ foimed. The formation of these compounds of silica and alumina is not confined to the crust on the surface, but takes place throughout the mass, and is really the principal eflBcient cause of the induration of this class of limes, when placed under water, or in humid localities excluded from atmospheric influ- ences. It appears not improbable that these circumstances attending the superficial induration of hydraulic -,..». ,, , , Difficult to meas- limes in the atmosphere, have led to errors in wo the subcar- measuring the depth of the covering of subcar- °' bonate, owing to the difliculty in determining with precision the exact position of the surface which separates the crust formed by the combined influence of exterior and interior causes, from those portions in which the induration is entirely Independent of atmospheric influences. 188 PEACHCAL TEILA-TESE OX LIMES, 333. The hardness assumed by the hydrate in the air is in- timately connected with the process of slaking, tw^n^hardness ^^^ appears to sustain a direct ratio with the of hydrate and increase in volume. The three modes of slakinoj mode of slaking. ^ ^ .... arranged in order of their superiority in this respect stand as follows : 1st. For fat limes : ordinary slaking, spontaneous slaking, slaking: bv immersion. 2d. For hydraulic limes : ordinary slaking, slaking by immer. sion, spontaneous slaking. 334. The hydrates of fat lime, drying in the air, shrink and crack to such an extent, that they cannot be employed in mor- tar for masonry without a large dose of sand. „ . ^ fT 335. Action of the hydrat£ under water. — Hrdrate of lime ^ '' soluble in water The hydrate of fat lime is soluble to the last de- ciianged. It ab- gree in Water frequently renewed. Immersed eorbs water. -^.^ ^|^^ condition of Stiff paste in still M-ater, it absorbs a certain quantity of the fluid, without any augmenta- tion of volume, or sensible change of consistency. The amount thus absorbed depends upon the mode of slaking. A paste formed by the ordinary ox first process takes up .04 of water; if slaked by immersion.^ nearly .11 ; and if a ■> r zuoiana, or ce- to those slaked by the first process, on account ment. . . , , . 01 the more intimate contact between the ingre- dients, and consequently, the more favorable condition for combination developed by the interior compression due to this increase of density. We would also suppose that the same assumption would be „ ^ ,. ,. iustified, in the case of hvdraulic limes which HTdraulic limes '' ' " and pozzuolana. are to receive additions of pozzuolana. This HYDIIAULIC CEMENTS, AND MOETAllS. 189 theory is not fully confirmed by experience, wliicli shows that the latter class, when they are to be mixed with pozzu- olana, may be slaked by either the first or second process, with similar results, and that the third process should invariably be ])ro3cribed. When tliey are to be combined with inert sand only, they should be slaked by the first proce^^s. 336. For fat limes, the second and third methods have been supposed by many engineers to possess some , . ' . ,. . . T Supposed advan- ad vantage; the former, m conierring increased tago of tiie second hardness and tenacity upon the mortar; the for'^f^tiime^a'"*''''^* latter as a means of securing hydraulic proper- ties in a moderate degree ; but as there are some doubts upon these points, particularly as to the alleged superiority of air- slaking, and as any requisite degree of strength, hydraulic energy and quickness may be conferred upon lime mortars with more certainty and with equal economy, by the judicious use of hydraulic agents, either natural or artificial 1 J T T 1 i. r L' That of the third hydraulic lime, pozzuolana, or cement, (particii- process uuimpor- larly the latter in the United States.) the first ta°t i» ^^e , . . . . United States. mode of slaking, inasmuch as it is attended with less original outlay, gives more certain results, and requires fewer precautions at the hands of the workman. The first process may be regarded as the most advantageous in the most advan- nearly every case, provided the precaution is ^'^s^^"^- taken to pour on at the outset all the water reqiiired to pro- duce a stiff paste ^ but no more. 337. For slaking lime, fresh water should be ^^^ ^^^^^^ ^^^^ used, sea- water giving in all cases greatly dimin- for slaking. ished volumes. 338. General Totten announced the following as the results of experiments made at Fort Adams, upon the difi^erent modes of extinction : 1st. Slaking by drowning, or using a large Tlie " drowning" . . ^ process weakeua quantity of water in the process of slaking, the lime. aifords weaker mortars than slaking by sprinkling. 190 PRACTICAL TREATISE OX LDIES, 2d, Experiments with air-slaked lime were ^tS",?' too few to be decisive, but the results were unfavorable to that mode of slaking. 339. Preservation of Lime. — The paste of fat lime, whatever may have been the mode of extinction, may be preserved intact for an indefinite length of time, if kept from Ume p7ste°° °^ contact with tlie air. It is usual to put it in tight casks, or in reservoirs or trenches covered up with sand ; or, when shed-room is available, to form it into rounded heaps similarly protected and under cover. 3i0. The powder derived from the second and third modes Preservation of ^^ extinction may be preserved for several lime powder. months, without sensible deterioration, in cov- ered casks or bins, or if heaped up in dry sheds, and covered over with straw, cloth, or dry sand. 341. Until quite recently, opinions among engineers were divided as to the effect of time upon the quality Gen. Treussart. . r p . v i • i • ri 01 paste 01 tat lime, preserved with suitable precautions fur future consumption. General Treussart en- tertained the opinion that they should be made into mortar and used soon after their extinction. This idea finds few ad- P cti t th vocates at the present day, although the practice present day. in this country conforms to it with singular una- nimity. As before observed, it is customary in some parts of the continent of Europe to slake the lime the season before it is to be used. 342. Fahrication of Mortars. — The relative quantities in Fabrication of which sand and the cementing substance, wlieth- mortars. ^j. [\^q latter be derived from common or hydrau- lic lime, or cement, should exist in mortar, depend in a great measure on the character of the work in which it is to be used ; its locality and position with regard to a state of moisture The proportion of or dryness ; and, if subjected to alternations in the ingredients ^j^-^ respect, the character of the moisture, de- vary with cir- ^ cumstances. pending on its proximity to or remoteness from HYDRAULIC CEMENTS, AND MORTAES. 191 the sea, the nature and magnitude of the forces wliich it will be required to resist, the peculiarities of the climate, and the season of the year in which the work is to be performed. 343. In practice, the actual quantities of the different in- gredients to be portioned out "depend on the varying con- ditions of dampness and dryness, looseness and compactness, powder and paste, in which tbey may be measured." 344. The following data, derived from the work of General Totten and from direct trials, will be found useful in estimat- ing the amounts^ of the different ingredients necessary to pro- duce any required quantity of mortar. One cask = 240 lbs. of lime, will make from 7.80 to 8.15 cubic feet of stiff paste. °"' '"'^ °^ ^^'■ One cask *= 308 lbs. of finely ground cement, will make from 3.70 to 3.75 cubic feet of stiff ni^nt'"'^ °^ "^ paste ; 79 to 83 lbs. of cement powder will make about one cubic foot of stiff paste. One cubic foot of dry cement, shaken down, but not com- pressed, mixed with .33 cubic feet of water (about ^ oi 11 \ .11 . „„ „ One cubic foot of 2^ gallons), will give .63 to .63i cubic feet of stiff cement powder. paste (about 4:j\ gallons). One cubic foot of dry cement powder, measured loosely and without any compression, will measure only .78 to .80 cubic feet, if packed (as at the manufactories) with a wedge-shaped stick or paddle. The data given in the following table (XIV.) are compiled from General Totten's work. The quantities are represented by volume. ♦ 300 lbs. net is the standard barrel, but it usually overruns about ei'^ht lbs. 192 PEACTICAL TEEATISE ON LlilES, TABLE XrV. Lime in thin paste. Cement paste. Sand well compacted. Mortar produced. .00 .00 .00 .45 .69 .25 .68 .18 .78 .00 .25 .75 1.00 1.92 1.00 .50 1.82 1..39 1.00 .91 .71 •78 2.00 2.00 2.00 2.00 2.0 2.1 4.3 4.6 4.3 4.9 5.5 2.25 1.71 1.07 2.49 2 22 1 85 1 95 1 57 1.84 64 water made 2.54 grout. 3.10 " 92 " " 1.04 " " 3 56 " 1 22 " " 3.76 " 2 of mortar with .87 " " 3 " " .87 " " " 1.80 " '•■ 7 " " 2.01 " " 1.80 " 5 " " 1.76 " " 3 " " 1.80 " 2.90 " 3.05 " 6.04 » 6.60 " 6.20 " 6.64 " 7.11 " 345. When mortar is to be made in quantities sufficiently large to warrant the expense, a mortar mill of some appro%'e(i pattern should be provided, for incorporating the ingredients, as the mortar thus obtained is invariably superior to that pro- duced bj the use of the hoe and shovel only. 346. The mill used at Fort Warren^ Boston harbor, during the construction of that work by Col. Thayer, of which a ver- tical section throuo-h the centre of motion is ffiven in Fi^. 33, is thus described by Lieut. AY. H. "Wright, in his " Treatise on Mortars," page 98 : " It consists of a circular trench built of masonry, with slopino; sides. In the trench Descnption of "^ ' i. . -,. mortar mill driven rests a heavy wheel, 8 feet in diameter, fur- 7 orse-power. nigiig(j -with a tire "I inch thick and 12 inches broad, and loaded by having its interior space filled with sand. At the centre of motion is a drum, or circular mass of masonry, 4 ft. 8 in. in diameter, in which is firmly fixed a vertical axis about 8 inches square. With this axis is con- nected the horizontal shaft (also about 8 inches square), which HYDRAULIC CSMEXTS, AND MORTARS. 193 passes through the centre of the wheel, and to which the horse is attached. *'8" ^ STS?' Fig. 33. Description, con- tinued. " The distance from the centre of motion to the centre of the wheel or trench is 7 ft. 6 in., and the radius of the horse- path is 20 ft. " The space comprised between the drum and trench is use^ as a reservoir for the slaked lime. It is sufficiently capa- cious to contain the paste which sixteen casks of lime will afford, and is conveniently divided, by means of movable radial partitions, into sixteen equal parts ; so that the laborer, who prepares the mortar, is relieved of the necessity of measuring the paste. "Tlie mill is protected from the weather by a cheap roof; it is placed in the vicinity of a pump, immediately under the spout of which stands a box, 7 ft. long, 5 ft. broad, 1 ft. 4^ inches deep, used for slaking the lime. This box is connected at one extremity with a small compartment, in the bottom of which is an iron grating, which allows the fluid paste to pass out into the reservoir, but retains the stones and imperfectly slaked lumps of lime. During th<; process of slaking, the compartment is separated from the rest of the box by a 13 194 PKACTICAL TEEATISE 02f LIMES, movable board, wliicli slides in grooves made water-tight ■with a little of the lime putty. " The board being in its place, water is pumped into the box in sufficient quantity to convert the lime, (three casks at once,) into a thin cream that will readily run oil" through the grating. The lime is then added and well stirred, in order to break up the lumps, a large hoe being usually employed for the purpose. When the slaking is completed, the sliding board is raised, and the cream conveyed by means of the trough, E, attached to the grating for the purpose, to the basin, F, where it is allowed to remain as long as possible before it is used." This mill is capable of making six hundred cubic feet of mortar per day of ten hours. By increasing Capacity of mill. the radius of the trench to 12|^ ft., and the radius of the horse-path to 25 ft., the working capacity of the mill would be nearly, if not quite, doubled. 347. The other implements that will be found convenient in the preparation of mortar are a hoe and shovel, diSering little, if at all, from the ordinary form ; a box for measuring lime and cement paste, which should be of conven- requLre?^^"'^''*' lent capacity, say 3 cubic feet, and should be arranged with handles projecting horizontally on two opposite sides, like those of a hand-barrow, and a sec- ond box of the same size as the foregoing, or rather a little larger (say 3^ cubic feet in capacity), so that it Avill contain, loosely thrown in and struck, a volume of sand corresponding to three cubic feet well compacted. This box may be provided with handles like the other, but had better be arranged on a wheel-barrow. 348. To make mortar with the mill above described, the lime paste is first put into the trench from one Processor making ^^ ^j^^ central compartments. To this is added by measurements from the wheel-barrow box, abont one-half of the sand required for the batch, and the mill HTDEAULIC CEMENTS, AND MOETAES. 195 is then set in motion, and the in<^redients thoroughly incorpor ated. The remainder of the sand then folio u's, with such additions of water as may be necessary to bring the mass to the proper consistency. When lime mortar is to be rendered hydraulic by the use of cement or of an alkaline silicate, these had better be added — the cement in powder and the silicate in solution — to the lime paste just before the mill is set in motion, in order that the mixing may be thorough and complete ; ex- cept in the case of very quick-setting cement, when its incor- poration into the mortar should be deferred until the last por- tions of sand are added. 349. This process of slaking the lime with an Excess of water excess oi water was never employed at Fort AVar- not used ia ren, except when hydraulic cement was to be ^^ ^°^' added to the mortar. For mortars composed of lime and sand only, the lime was slaked in the ordinary way Avith a sufficiency of water, simply to produce a thick pulp. The result given in Table XIII., page 185, which may be easily verified on a large scale, indicate, apparently beyond a doubt, that with the limes most extensively in use for public works on our Atlantic coast, the largest augmentation of volume in slaking is secured by adhering to the following directions, viz.: put the lime into a box, break up the larger lumps with a hammer ; pour in at once the quantity of water (ascertained previously by trial) necessary to reduce them to a stiff paste, and then cover up the box so as to prevent, as us'ed'iS^llaking.^' much as possible, the escape of heat and vapor, allowing it to remain in that condition, w^ithout stirring, until the reduction is complete. In order to connect this process with the operations of a mortar-mill, it might be necessary to provide several boxes, so that the lime might, in all cases, have at least forty-eight hours to digest before it is made into mortar, 350. Major E. B. Hunt, Corps of Engineers, formerly charged with the construction of Fort Taylor, Key West, 196 PEACTICAL TEEATISE OX LIMES Florida, has kindly furnished me the following description of the steam mortar-mill in use at that work. EleTation of Mortar-Mill. Fig. 34. 351. Tlce sUam mmixir-v.iU which was erected at Fort Tay- lor in 1S57, Steam mortar- \-. ^e +i,^ ^~x■r^A miiL IS of the kmd devised hy the late Brevet-Major J. Sanders, and was pur- chased and set up un- der his direction. The mill and engine were made by E. C. Stotsen- berg, "Wilmington, Del- aware, and cost $3,466. The frame and house for the mill, and setting them up cost $237, to which should be added the freight and cost of engine-house, making Plan of bt-J-ji.jie ; soaie j in. to 1 lot)- Fisr. 35. HYDKAULIC CEMENTS, AND MORTAES. 19f nearly $5,000 as the cost of the whole in work- Description of ' 1 nil . . , . same, iiig order. ihe engine is about sixteen to twenty horse-power, and has a heavy fly-wheel. Two-thirds of this power would run the mill, though at greater cost foi fuel and at higher pressure. The engine is geared into a fixed cuuncetion with the mortar-mill, which is a tault, as the engine cannot be used for any other pui-pose, without driving the mill, The mill. Figs. 3-i and 35, consists essentially of a pan geared into a cogged connection with the engine, and support- ed on large conical bed rollers ; and of a pair of hollow cast- iron wheels, so joined by an axle, that they revolve in the 0})posite sides of the pan with tlie same velocity as the pan itself. The grinding surfaces have thus a compound or double velocity. Two helical scrapers are fixed to tlie vertical driving shaft of the wheels, and are so shaped as to throw a sort of furrow in the mortar materials when mixing. A scraper is fixed to each end of the horizontal shaft, so as to scrape the faces of the large wheels as they roll around that shaft. Another scraper is also fixed to this axle, so as to scrape the inner face of the pan and to throw a furrow towards the centre. The lime paste is first put in the pan, and is ground while the sand and cement are measured out, on a fixed platform at the level of the bottom of the pan and bordered up close to its rim. The mixed cement and Manner of using •t the mill. sand are shovelled in, and water added until the whole batch is introduced. The greatest resistance is encountered when the dry materials are thrown in, at which time the speed is very much slackened, and the engine requires nearly its full power at the working pressure, if the filling be done very rapidly. As the mixing proceeds, the speed of rev- olution quickens greatly, but is controlled by the engine- driver in proper limits. "When the batch is sufiiciently ground and mixed, it is scooped out by the use of a scoop-shovel, the workman stand- ing on a lower portion of the platform, about a foot below the 19S PRACTICAL TEEATISE OX LIMES, bottom of the pan, and throwing the mortar into a mortar-box which is backed in by a sling cart, so arranged as to carry the batch to the derrick or point of use, and then to ran the box down to the ground by two screws with arms and long links, one at the fore and one at the near end of the box. Each batch of mortar corresponds to one barrel of cement, and the mill has repeatedly made over fifty batches in a day, and can do this as a regular day's work. It requires ^'o^ ikemi^ ^° one engine-driver, one fireman, and from two to five men at the mill, according to the amount of mortar to be made. It has also been used during the last and present season to make the mortar for concrete, which is transported by the sling cart, hoisted by the derrick on the con- crete platform, and then thrown over the broken stone spread out to receive it. Two turnings* mixed it very well. The broken s<-one is hoisted by a light platform carrying five barrels, the usual amount for a batch. This using it for con- crete as well as for masonry mortar, will often make running the mill an economy, when it would not be so, were only the mortar for masons made there. It will hardly be found an economy, to run the mill for less than twenty to twenty-five batches a day. The mortar made in this mill is very much better than that made by hand from the material found at Key Quality of mOl- "West, as the coarse calcareous sand requires made mortor. ' pulverization to make the mortar work well. It is what the masons call "woolly," when made by hand, and requires a much larger dose of cement or lime, to Avork properly under the trowel. The brick- work joints with mill-made mortar are observ- ably thinner than with the hand-made mortar, thus giving a saving of mortar per cubic yard. The gain by using the mill, is rather in the superior qual- * These turnings are described in the third step of the method of manipulation practised at Forts Richmond and Tompkins, Xew York. (Paragraph 369.) HYDRAULIC CEMENTS, AND MOETAES. 190 ity and saving of quantity of the mortar, than j^dvantago of in the cost of mixing, though, when large oper- *^® ™'^- atives are steadily maintained, there is a great gain under thia head, when circumstances favor its easy distribution. Ordinarily, a hatch needs to be ground not „. . , . '' ' "^ Time required in less than seven minutes, and not beyond fifteen maijr mortar ^ 1 • 1 T • • 1 with the mill mmutes from the time the lime paste is put m the pan. If the grinding be carried much beyond this time, the mortar is decidedly impaired, and sets very slowly. This is ascribed, in part, by Major Hunt to the extreme pulverization of the calcareous sand, whereby the void spaces are made all small and nearly uniform, and partly to the incessant breaking up of the incipient setting by long continued grinding." 352. Another mortar-mill^ successfully used by the designer, M. Greyveldinger, on the works connected with the drainage of the Boulevard de Sevastopol, Paris, is repre- sented by Fig. 36 ; it consists of a hopper of J[;,g^er7miL sheet-iron. A, closed at the bottom by a disk, B, surmounted with a cone, C ; the disk and cone receive a rapid, rotary motion by means of the cogwheel D. The hopper is provided with a rectangular opening, E, i of a metre (7.9 inches) in width, and of which the height can be varied at 200 PEACTICAL ;:KEATI3E ox LUITS, pleasure by means of a sheet- iron slide controlled bv a ratchet and cog-vrheel, F. Below the hopper, is a cylindrical spout, G. containing a revolving screw, to the core of which, iron points are attached at regular intervals. Jets of water regu- lated at pleasure bj hand, by means of the stop-cock K. are let into the funnel J, at the bottom, through a hose leading to a reservoir of water. 353. The dry ingredients of the mortar having first been roughly mixed with a shovel, and if necessary, passed through a screen, are introduced into the hopper. Tlie rotation of the disk and cone completes the incorporation of the dry mate- rials, and imparts to tliem a centrifugal motion which in- sures a constant flow from the opening E, into the funnel J, where they receive the requisite supply of water, and pass into the spout G. The motion of the screw carries the mortar to the other end of the spout, completes the mixture, and dis- charges it into barrows or buckets placed to receive it. M. Greyveldinger had four buckets arranged on a revolving plat- form, M. By means of the crank X, the buckets are passed under the opening in the spout, and thus filled in succession without wastinn; the mortar or arrest in cr the motion of the machine. Two men at the crank L, can work the machine. 354:. At the Boulevard de Sevastopol, Paris, motion was derived fi-om a one-half horse-power engine, by means of a belt working on the drum. 0. 355. There were required to tend the machine eight labor- Force required to ers, to measure the materials, fill the hopper, ^ '*■ take away the mortar, &c.. one intelligent fore- man to regulate the opening in the hopper and the supply of water, and one engineer. 356. The average daily expense, neglecting the wear and tear, is as follows : HtDEAULIO CEJIENTS, AND MORTARS. 201 Nine men at three francs ... fr. 27 One engineer, ..... 4 Coal 2 33=$6.10 357. The capacity of the machine was thirty . 'Its capacity. cubic metres (38.3 cubic yards) ot mortar, per day, of ten hours. Cost of making one cubic metre, 1.10 fr., and of one cubic yard, sixteen cents. 358. Estimating the laborers at ninety-one cents per day, the engineer at $1.50, and supposing the other expenses to remain the same, the cost of making one cubic yard of q^^^ ^f making mortar would be twenty-eight cents. The cost naortar with it. of making the mortar at Fort Warren, with the mill consisting of a heavy wheel turning in a circular trough by horse-power, and labor at ninety-one cents per day, was thirty-nine cents per cubic yard. Mr. G.'s mill will answer for the quickest set- ting cements, as only eight seconds of time elapse after the materials receive the water, before the mortar is discharged in- to the buckets. 359. Extensive operations requiring large quantities of mor- tar are frequently carried on by experienced engineers, without the aid of a mortar-mill of any kind. "When jjakinjr mortar ordinary lime mortars are thus made by hand, ^7 l^^^d. it is customary and convenient to slake the lime by the first method described, and in no greater quantity than may be re- quired for immediate use. The operation should be conducted under a shed. The measure of sand required for the " batch" is first placed upon the floor, and formed into a basin for the reception of the unslaked lime. After this the latter is put in, and the larger lumps broken up with a mallet or hammer ; the quantity of water necessary to form a stiff paste is let on, from the nozzle of a hose, or with watering-pots, or even ordinary buckets. The lime is then stir- ©f slaklug°mne? red with a hoe, as long as there is any evolution of va])or, after which the ingredients are well mixed together 202 PEACnCAL TEEATISE OX LUTES, witti the shovel and hoe, a little water being added occasionally if the mass be too stiff. At this stage of the operation, it is customary to heap the mortar compactly together, and allow it to remain until required for use. When circumstances admit, it should not be disturbed for several days, and during the pe- riod of its consumption should be broken down and '' temper- ed" in no larger quantities than may be required for use from day to day. 360. It is believed that certain slight modifi Slight modifiea- . ^, , . i j /• j tions recommend- cations ot this common metlioQ ot procedure ^" can be made, with decided advantage in the final results. They may be indicated as follows : 361. First. All the hme necessary for any required quantity of mortar should be slaked at least one dav be- Slake the lime at . , , t • ^ ^ least one day be- lore it IS incoi-porated With the sand. fore it is waited. 3^^. Second. The sand-basin, to receive the unslaked lime should be coated over on the in- In a water-tight . ■■ . i t ^ basin. Side With lime-paste, to prevent the escape 01 water. All the necessary 363. Tfiird. All the water required to slake water to be pour- , , . .re i t i 1 i ©d on at once. the lime to a Still paste, should be poured on at once. This will completely submerge the quick- lime. The heap should then be covered over with tarpaulin or old canvas, and left until next day. 364. Fourth. The ingredients should be Mix ingredients, ^ ^ • -, -, i^ ^ i and heap up for thoroughly mixed, and the mortar Jieaped up ^^^' for future use. 365. The mortar used by Lieut.-Col. J. G. Barnard, Corps of Engineers, in the construction of Forts Richmond and Tomp- kins, Xew York harbor, was made by hand. "When required for stone masonry, or concrete, it was composed of hydraulic cement and sand, without lime. 366. *Each batch of mortar, or concrete, corresponded to one * These data were furnished by Captain iL D. McAlester, of the Engineers, at that time Assistant to Lieutenant-Ckilonel Barnard, Corps of Engineers. llYDBAULIO CEMENTS, AND MOETAES. 203 cask, or 308 pounds net, of hydraulic cement powder. Four men constituted a gang for measuring out and y^^,^^^ ^^ ^^^ mixing tlie ingredients, who proceeded to the ulation. several steps of the process in the following order : 367. Fh'st. The sand is spread in a rectangu- jjj^ ^^^^ ^^^ ^q, lar layer of two inches in thickness. ™ent together, dry. 368. Second. The dry cement is spread equal- ly all over the sand. 369. Third. The men place themselves, shovel in hand, two on each side of the rectangle, at the angles, incorporating the facing inwards. Furrows of the width of a ingredients. shovel, are then turned outwards along the ends of the rectan- gle, until the whole bed is turned. The two men on one side thuG find themselves together, and opposite the two on the other side, having, of course, left a vacant space transversely through the middle, of double the width of a shovel. They then move back to their original positions in turning furrows as be- fore, when the bed occupies the same space that it did previ- ous to the first turning. The turning is executed by succes- sively thrusting the shovel under the material, and turning it over about one angle as a pivot. Each shovel thus moves to the middle of the bed, where it is met by the one opposite, when each man moves back to the side in dragging the edge of his shovel over the furrow he has just turned. 370. Fourth. A basin is formed, by drawing all the mate- rial to the outer edge of the bed. _,. . ° Adding the water. 371. Fifth. The water is poured into the basin thus formed. 372. Sixth. The material is thrown back upon the water, absorbing it, when the bed occupies the same space that it did at the beginning. 373. Seventh. The bed is turned twice, by the process described above. If required for mason's use, the mortar is then heaped up, to be carried when and where required. If for concrete, (the mortar occupying the rectangular space, as at first). 304 PRACTICAL TfiEATISE OX LIME3, ^ 374. Eighth. The broken stones are spread equally over the bed. 375. JTinth. A bucket of water, more or less, (depending upon the quantity of stones, their absorbing power, and the temperature of the air), is sprinkled over the bed. 376. Tenth. The bed is turned once as before, and then heaped up for use. The act of heaping up, brSntonel*^^ ^^^^^ i^ ^^^^ with care, has the effect of a second turning. 377. The time consumed in making a batch of mortar is a little less than twenty minutes ; in incorporating the broken stones, ten minutes more. 378. "When the mortar is required in very small quantities, to avoid deterioration, instead of proceeding to the fourth step of the manipulation, the mixture of cement and sand is heaped up, and the water added and paste formed with the hoe, in such quantities as are required. 379. Com_positio7i of 2fortar. — The mortar at Forts Eich- mond and Tompkins, whether required for stone themor'tar.^ ° masonry or for concrete, contained one cask* (or 308 pounds net) of hydraulic-cement powder, which produced 3.70 to 3.75 cubic feet of stiff paste ; and three casks, or about twelve cubic feet of loose sand, equal to 2.44 casks (about 9.75 cubic feet), well compacted. These ingredients being incorporated, produced 11.75 cubic feet of rather thin mortar. 380. Compositio7i of Mortar used at Fort Warren. — The ^ • • , mill-made mortar for the stojie masonry at Fort Composiuon of •' the Fort "Warren "Warren was composed of lime, hvdraulic ce- mortar. ^ • i c ^^ ■ " • ment, and sand, m the lollowmg proportions, viz.; One cask dry cement (325 lbs. net), producing 3.75 to 3.85 cub. ft. of stiff paste. 0/ie-/iaZ/ cask of Rockland lime (120 lbs. net), producing four cub. ft. of stiff paste. Nineteen and orte-fourth cubic feet of loose sand, equal to fourteen and a half cubic feet well compacted. * The average net weight of a barrel of cement is 303 pounds. HYDRAULIC CEMENTS, AND MOKTARS. 205 These ingredients being well mixed, make eighteen and a half cubic feet of good mortar. For mortar for hrick masonry, the same quantities of lime and cement received but fifteen and three-quarters cubic feet of loose sand, equal to twelve cubic feet well compacted, giving sixteen cubic feet of good mortar. Estimating the cost of the lime at .70 cents per cask of 240 lbs. net, the cement at $1.62|- per cask of 325 lbs. net, and the sand at .50 cents per gross ton, labor at .91 cents, and horses .40 cents per day of ten hours, and we have the following analysis of the cost of the two kinds of mortar used at Fort Warren : ; MORTAR FOR STONP] MASONRY. Mortar for ^ ^^^^' cement, 325 lbs. net=385 cubic feet of paste, at Btone masonry. $1.62^ $1,630 \ cask lime=four cubic feet of paste, at 70c 350 14.67 cubic feet sand, at 50c. per ton 496 Labor of men, at 91c. per day 245 Labor of horse, at 40c. per day 028 Total cost of a batch of 18-i cubic feet of mortar, corresponding to one cask of cement $2.75 Cost of 1 cubic foot of mortar. 14^ " 1 " yard " 3.93 MORTAR FOR BRICK MASONRY. Mortar for ^ ^^^ cement, at $1.63 $1.63 brick masonry. k cask lime, at 70c 35 l"i cubic feet sand, 50c. per ton 409 Labor of men, 01c. per day 208 " horse, 40c. per day 024 Total cost of a batch of mortar of 1 G cubic feet, corresponding to one cask of cement 2.621 Cost of 1 cubic foot of mortar 16^ " 1 " yard " 4.40 381. Some engineers object to the use, in works of impor- tance, of mortar containing so large a proportion of sand as that adopted at Forts Richmond and Warren ; others again very sel- dom add lime to their cement mortars. Touching this last-men- tioned point, recent experiments show, with a uniformity quite gatisfactorv, that most American cements will sustain, without 206 PEACTICAL TEHATISE OX LDIZS, any great loss of strength, a dose of lime paste equal to that of the cement paste ; while a dose equal to ^ to f the volume of cement paste mav safely be added to any ener- Proportion of --r-. ii* ' • ^ i • ^ lime that may be getic iCosendale cement, without proaucmg dete- mliSr^ **°'^''' rioration in the quality of the mortar, to a degree requiring any serious consideration. Js^either is the hydraulic activity of the mortars so far impaired by this limited addition of lime paste, as to render them unsuita- ble for concrete, under water or other submarine masonry ; while, for constructions not subject to immediate submersion, or the action of the returning tide, it is to be preferred on many accounts. By the use of lime, we secure the S'Sif w °'' double advantages of a rather slow moi tar— one that is in no danger of setting before it reaches the mason's hand — and a cheap mortar. We also avoid the principal serious objection to the use of a quick-setting mortar, due to careless and tardy attendance on the masons, and conse- quently the constant breaking up of the incipient set on the mortar-board, whereby cements are degraded in energy to a level with ordinary hydraulic limes. 352. If the lime paste had been replaced by cement paste in the Fort TVarren mortars, the mortar for stone Companson of ce- • _ meat and of lime masonry would have cost $5,96 instead of $3.93 per cubic yard, and that for brick masonry $6.69 instead of ^iAO ; while if lime paste had been used ex- clusively, the cost would have been only $2.53 for the first, and $2.72 for the second. 353. In extensive operations it is well to have a mortar-box and cai't for transporting the mortar from the jja^j^ ' mill to the work. The box should be made of stout planks, and be about 5i feet long, S^ feet wide, and 9 to 10 inches deep, and so arranged that it can be readily slung up underneath the oart, by means of a windlass. Figs. 37, 33, and 39 represent the cart and box used with entire satisfaction at Fort TVarren and elsewhera HYDRAULIC CEMENTS, AND MORTARS. 207 Fig. 37. EL'. 3S. Fig. 39. POIXTIXG MORTAR. 384. In laving up masonry of any character, whether with common or hydraulic mortar, the exposed edges of the joints will naturally be deficient in density and hardness, and, therefore, unable to withstand the destruc- J^nedTry.*'"^ " tive action of the elements ; particularly varia- tions in temperature, producing extremes of heat and cold. It is therefore customary, to fill the joints as compactly as possi- ble, to the depth of about half an inch, with mortar pi-epared especial !}'■ for the purpose. This operation is called ^'' pointing ^^ and the mortar, '''pointing mortar.^'' The cleaning out of the joints to the requisite depth should take place while the mortar 208 PSACnCAL TKEATI5E OX IJ;MES, is new and soft ; and (in stone masonry) when the stones come in contact, or nearly so, the joints mnst be enlarged, to the width of about three-sixteenths of an inch by a stone-cutter. 3S5. Pointing mortar is compounded of a paste of finely ground cement, and clean sharp silicious sand, Composition of . ■ i i "poinring in such proportions that the volume of cement paste shall be very slightly in excess of the volume of voids in the sand. These voids should be care- fully ascertained. The measure of sand will generally vary between 2^ and 2f that of the cement paste ; or by weight, one of cement powder to from 3 to 3^ of sand. The mortar, when ready for use. should ap}>ear rather incoherent and quite deficient in plasticity. The mixing should take place under shelter, in an iron or stone mortar, or some other suitable vessel, and in quantities of not over Made np in small two or three pints at a time. qoantities. 3S6. Before pointing, the wall should be thor- The wa 1 should oughly saturated with water, and kept in such te/™°po1ntiiig, ^ condition, that it will neither absorb water and not allowed from the mortar, nor impart any to it, — two to diy rapidly ... afterwards. conditions of special importance, the first being . paramount. Walls should not be allowed to dry too rapidly after point- ing, but should be kept moist for several days, or better still, for two or three weeks. Pointing in hot weather should there- fore be avoided, if possible ; or else some temporary shelter from the direct action of the sun's rays should be provided. 3S7. For pointing masonry in courses, the tools required be- sides an ordinary mason's trowel are, a straight- Tools reouired j -l j. • j^ j. ^ n • in pointing. edge, about six feet long; a caulkmg iron, measurincj three inches bv one-eighth of an inch on the edge ; a hammer, and some conveniently shaped iron or steel instrument for polishing the surface of the joint in the last stage of the operation. The mortar is put in the joint with the trowel, the straight-edge being placed HYDRAULIC CEMENTS, AND MOETAES. 209 against tlie wall, just below the joint, as an Manner of using auxiliary. The joint is then well caulked with * '*^"' the caulking iron, bj repeated blows of the hammer, until a film of water shows itself on the surface of the mortar ; after which, mortar is again put in, and the caulking repeated. In using the straight-edge, two men, one at each end, can conveni- ently work. The operation is continued until the joint is entire- ly full. The mason then rubs and polishes the joint, under as great a pressure as he can exert, and finishes off by using the straight-edge and ~ trowel point, to remove any mortar spread out upon the stones on either side, make the pointing straio-ht, and give the appearance of exact equality in the thickness of the joints. 388. In pointing rubble masonry, the same general direc tions are applicable, but the use of the straight-edge has to be dispensed with. INTERIOR PLASTERING. 389. The signification of the term plastering will be limited to the covering of interior walls and ceilings, interior plaster- Exterior plastering will be denominated "stuc- '''^■ CO," although the technical signification of the latter term is much more limited, and refers to a mixture of white lime, putty, and white sand or powdered ^^'''^^^' marble, used for inside finishing, and to a coating made with this compound. ^ 390. Among the implements used by the plasterer, the prin- cipal ones are the hawk, tlie plastering or lay- ing-on trowel, the float, and straight-edges of '^''°^' various lengths. 391. The hawk, used by the plasterer for conveying and holding the mortar, while he applies it Avith the trowel, is a piece of board about eleven inches ^'''^'^' square, and is held by a handle fixed beneath in the centre of, and at right angles to the board. 14 210 PRACTICAL TREATISE OX LIMES, 892. The trowel for laying the mortar consists of a steel blade about 3 inches by 9 inches, rounded slight- ly at the front end, and a little convex on the face, with a wooden handle on the back parallel to the blade. 393. The hand-float is of wood, similar in shape to the trowel, and is used to rub down the finished work and make it solid, smooth, and even. A cork* float is used upon surfaces that are to receive a high degree of polish with the trowel. 39i. The mortars used for inside plastering exclusively, are Mortars used for " coarse stuff"," "fine stuflf," "gauge stuff," or plastering. hard-finish, and "stucco." 395. Coarse sUiff is nothing more than common lime mor- tar, suitable for brick masonry, to which has Coarse stuff. tit . /. ii • i t i i been added a quantity of well-switched bul- lock's hair, to act as a kind of bond. The following proportion is a good one : 1 cask lime = 8 cubic feet of paste. Sand 16 to 18 cubic feet. Hair 1\ do. do. 396. "When ample time for hardening cannot conveniently be allowed, it will be advantageous to replace 12 to 15 per cent, of the lime paste in the coarse stuff, by an equal volume of the paste of hydraulic cement or plaster of Its uses. -n • r^ " nf n • • ^ Pans. Coarse stun forms the principal part of all inside plastering. For the second coat, in three-coat work, the quantity of hair given above may be slight!}' diminished. 397. 2^ine stuff is made of pure lump-lime slaked to paste with a moderate quantity of water, and after- Fine stuff. . , ^ •' wards diluted with water to the consistency of cream, and then placed where it can stiffen by evaporation to the proper condition for working. 398. Fine stuff is used for the finishing coat, but ncvci- with- out the addition of sand or plaster of Paris, ex- its uses. /. 1 • cept for what is termed a "slijiped coat. HYDRAULIC CEMENTS, AND MORTARS. 211 Even for slipped work, a little fine sand is sometimes added, to make the paste work more freely. 399. Gauge sivff^ or hard-finish, is composed of fine stuff (lime putty) and plaster of Paris, in proportions regulated by the degree of rapidity required in ?"¥^ ^*"'^' «'' 11. . . A •/ ^ hard-finish. hardening. As it sets rapidly, it is always pre- pared in small quantities at a time, not more, for instance, than can be used up in half an hour. It is used for the finish- ing coat of walls, and for cornices, mouldings, and other kinds of ornamentation. For finishing, the proportions are three to four volumes of lime putty to one volume of plaster of Paris, and for cornices, &c., about equal volumes of each. 400. Stucco is composed of lime putty and white sand, with a preponderance of the latter. The usual pro- portions are three to four volumes of sand for ^'""°°' one volume of putty. Stu-co is only used for the finishing coat. ^^ "'®'' 401. According to the English plasterer's nomenclature, ap- plying the first coat, which is always done with coarse stuff", is technically termed " renderino- " Plasterer's iV ^. ^_ //..... ^' nomenclature. if on masonry ; " laying," if on laths in one or two coat work; and "pricking up," if on laths in three-coat ^^-ork. In the United States, the first coat of three-coat work on laths is called the "scratch" coat, instead of the "pricked up" coat. The other terms, with the English signification, are retained here. 402. In "rendering," the joints of the masonry should be raked out to the depth of half an inch, the sur- face freed of dust, and the walls moistened p .. . /^ii .jj 1 recaiitions in yj\(X masonry, it smoky or greasy, should also rendering. be scraped out and roughened. 403. One-coat .t'or^.-Plastering in one coat without finish, either on masonry or laths, that is, either ren- dered or laid, though the most inferior kind of °'''"'''^* ^""'^ covering for walls, is frequently used for attics and kitchens in 212 PE ACTIO AL TREATISE 0]S" LIMES, cheap houses, and for cellars, vaults, and places of like character. The coarse stuff is applied in the same manner as the first coat in two-coat -work, described below. A light hand-floating is of great advantage to this kind of work, 40-i. Two-coat worh. — Plastering in two coats is done either in a " laying coat and set,^'' or in a " screed coat and 5(?^." The screed coat is also called the floated coat. It is more commonly applied as the second coat in three-coat work. Laying the first coat in two-coat work, is resorted to in common work instead of screeding, when the finished surface is not required to be exactly even, to a straight- edge. It is performed in a pretty thick coat, — say half an inch, — more care being taken to secure a smooth and even sur- face than in the scratch coat for three-coat work, because, in the latter case, all the irregularities are removed by the screed coat which follows. In both the laying and the Coarse stuff to be g^ratch coats, the coarse stuff should be well ■well tempered. ' tempered, and of such moderate consistency, that when pressed with force against the laths, it will penetrate between them, and bend down over them on the inside, so as to form a good key. A common fault in lath- laSg.'' ^^""^^ '° i^g' is to place the" laths so close together, as to render it imjiossible to obtain a strong key. 405. Except for very common work, the laying coat should be hand-floated, to give it density and solidity. This is done bv using the float in the rio-ht hand, and a hair- Hand-floating. i " i i , t . i i ^ i i • brush holding water, m the leit ; both instru- ments passed quickly over the wall at the same time, the brush preceding the float, and wetting the surface to the required degree. The firmness and tenacity of plastering is very consid- erably increased, by hand-floating, and at a moderate expense. 406. Hand-floatino^ must take place while Must take place . ^ , . . . , , whUe the mortar the moi'tar IS green, when it is intended as a IS green. preparation for the setting coat. AND MOKTAES. 213 407. In two-coat work, performed in a screed coat and 8et^ the first coat must be put on in " screeds" and " filling out." The screeds are strips of mortar six to eight inch- es in width, and of the required thickness of the describe! first coat, applied at the angles of the room, and parallelly, at intervals of three to five feet, all over the surface to be covered. These screeds are carefully worked on, so as to be accurately in the same plane, by the frequent appli- cation of the straight-edge in all possible directions. When these have becoine sufficiently hard to resist the pressure of the straight-edge, the "filling out" of the interspaces flush with the surface of the screeds takes place, so as to produce a continuous, straight, and even sur- The screed coat \a face. The surface should then be hand-floated as described above. 408. After the first coat, whether it be a laying coat or a screed coat, has become partially dry, so as to resist the pressure of the trowel, it is ready fur the setting, or finish- ing coat. This may be either in dipped work, Finishing. stucco, hastard stucco, or hard-foiish. In all cases, the surface to receive it must be roughed up with a birch or hickory broom, or some suitable instrument, and if too dry, must be moistened. 409. A slipped coat is merely a smoothing ofl" of a brown coat (coarse stufi"), with the smallest quantity of lime putty that will answer to secure a comparatively even surface. It is seldom sufficient to cover the fiJl^lm^°^ browning up entirely. 410. A small quantity of white sand, seldom S-and sometimes ,. ^, , . ^. 111 used in the slipped exceeclmg three per cent., is sometimes added ooat, when slip- to the putty to make it work more freely. The P^r^teTtt '' '^' trowel alone is used for this kind of finish. It answers very well for surfaces that are to be finished in distem- per, or with paper-hangings of common or medium quality. 411. Finishino; or setting in stucco is suitable for a screed 214 PRACTICAX TEEATISE ON LIMES, Stucco finishing. coat, but is never applied to laying or to inferior work, on account of tlie extra labor ■which it Applied vrith requires. The stucco is applied with the trowel, to the thickness of about one-eighth of an inch, keeping in view the fact that the straight surface gained by screeding can only be preserved by applying the set in „ , , ^ a coat of uniform thickness. The stucco is well To be hand- floated, hand-floated, the water-brush being used freely while so doing:. After the wooden float has been used, the surface is again floated in the same manner with the cork float, which being soft, leaves the surface in good condition for polish- inof. The polishins: is performed with the trowel Pohshing. ° , , . . i • • j and brush ; this operation, however, is omitted, when the stucco is intended to present a rough appearance for painting, or for any style of ornamentation in distemper. 412. Bastard stucco, like stucco, is also used as a settincr coat on screed work. It is done in stucco mortar, containing a smaller quantity of sand than is Done m stucco suitable for genuine stucco, and sometimes a mortar with a ];^^|q ^^^^^ There is no hand-floating in this diminished dose _ _ ^ of sand. kind of work, and the trowelling is done witL less labor than that conferred on trowelled stucco, as above Is superior to described. Bastard stucco is superior to slipped sUpped work. work as a preparation for papering, 413, Hard-finish is applied with the trowel, to the depth of about one-eighth of an inch. It may be polished with the water-brush and trowel, but the hand- float cannot be used upon it. Hard-finished walls, though fre- quently painted, are by no means so well adapt- Cannot be ^ ^^ ^^^ Ym.^ of covering as stuccoed walls. hand-iioated. " ^ ^ They may, however, be well finished in distem- per; a suitable composition for this purpose consists of ten pounds of Paris white and one pound of glue, May be well '- _ a o ' finished in colored as required. The advantage of hard- s emper. finish over stucco consists in its requiring less 5YDRAULIC CE3IENTS, AND MORTAES. 215 labor to apply it. It is extensively practised in the United States. 411:. Three-coat work. — T1\\q first and second coat are termed respectively the scratch coat and hrown coat, and *^ -^ ^ . Tnree-coat work. the third is either hard-finish^ or stucco. 415. The scratch coat, or first coat, is applied in the same manner as layinn. with this exception, that, as it •^ *'' -^ .' Scratch coat, is simply intended to form a good foundation for the screedhuj which follows, its thickness need not exceed one- quarter to three-eighths of an inch. When completed, and partially dry, though still quite soft, the mortar is scratched over nearly to its entire depth, with a pointed stick, in two systems of parallel scorings at right angles to each other, run- ning diagonally between the extreme limits of the surface cov- ered. These scorings are about two inches apart, and assist the adhesion of the coat which follows. 41G. The second coat is applied in " screeds" and " filling out," in all respects as described in screed-coat and set work. 417. The finishing or setting is also applied as before de- scribed 418. Table XY. gives an estimate of labor and materials for 100 yards of lath and plaster work : TABLE XV. Materials. Rockland lime Lump lime for tine stuff. Plaster of Paris Laths Hair Common sand ■White " Nails Mason's labor Laborer Cartage Cost of 100 yards $25.50 Three coats Ilard-tiiiishcd work. 4: casks. 2,000 4 bushels. . 7 loads. . . . 1\ bushels. 13 lbs t days §4.00 .85 .70 4.00 .80 2.00 .25 .90 7.00 3 00 2.00 Two coats Slipiied work. 3^ casks $3.33 2,000 3 bushels. . . . G loads 4.00 .60 1.80 13 lbs ^^\ days 2 " .90 6.12 2.00 1.20 I$19.95 216 PEACTICAL TREATISE OX UDIE3, - EXTERIOR PLASTERDs'G, OR '^ STUCCO." 419. Mortars composed of the paste of common lime and sand, either with or without the addition of Common mortars plaster of Paris, are unsuitable for covering unfit for outside '■ ' ^ work. surfaces exposed to the direct action of the ele- ments. 420. Lime, however, forms the basis of many excellent out- side stuccos, and, by proper treatment, may be rendered very durable. 421. If the water for mixing the mortar contains coarse sugar or molasses in solution, the effect on the solidifi- waxer* ^^^^' cation of the outer surface of the stucco is very beneficial. This method is practised by the natives of India, as reported by Captain Smith in his transla- tion of Yicat. The proportions for the sweetened water are about one pound of sugar to eight gallons of water, except for the outer or hand-floated coat, in which one pound of sugar should be mixed with two gallons of water. 422. Powdered slaked lime and smith's forge scales mixed up with bullock's blood in suitable proportions, Sies'^ ^'^^^ ^^^® ^ durable and moderately hydraulic mor- tar, which adheres well to masonry previously coated over with boiled oil. It is used for outside stucco. 423. The custom in the United States is to use hydraulic cement and clean sand, mixed up with a suffi- 2^."^''*^°'^''* ciency of water to produce the ordinary consist- ency of mortar for plastering, and in such quan- tities that all may be used up before the batch begins to set. The proportions are one volume of stiff cement paste to 1.66 vol umes of damp, compact sand ; or, if measured dry, one volumu of cement powder to two volumes of loose, dry sand. 424. When masonry, either of brick or stone, is to be stuc • coed, the joints should be raked out to the depth same. of half an inch ; the surface cleansed of dirt and HYDRAULIC CEMENTS, AND MORTARS. 217 dnst, and then tlioronglily wetted, (with a hose, if possi- ble,) so tliat the mortar will not be too rapidly deprived of its moisture by absorption, and its strength and density thereby impaired. If the surftice is greasy, it should be scored with an axe. 425. The mortar is applied in two coats laid on in one oper- ation. That for the first coat should be some- „. ^ , „ First coat of what tliinner than that for the second, in order rather tiiia that it may be pressed into thorough contact W'ith the wall, arfd enter and fill up all the joints and other openings. The second coat is applied upon the „ . . Second coat. first, wlnle the latter is yet sott, so that the same workman finishes off as he goes along, never covering more than two or three superficial feet at one time. The two coats thus laid should form one compact coat, of about one-half inch in thickness. The finished stucco should be kept shaded from the direct rays of the sun ^q j^g protected for some days, and moistened from time to f™"^ ^""- ^^'^ '' kept moist. time. 420. As a modification of the above process, the first coat is sometimes omitted, or rather replaced by a wash of thick cream of pure cement, applied with a Se process".^ stiff" brush, from time to time, just before the mortar is put on. If the brush-work is faithfully done, and not allowed to dry before the surface receives the stucco, an inti- mate contact and firm adhesion are sure to result. 427. A necessary precaution in this kind of work is to secure the services of a faithful workman, one who will , 1 • . 1 1 ,. 1 Precaution. not spare Ins strength, or Jay any oi the mortar on too loosely, or on too dry a surface ; otherwise, there M'ill be portions without adhesion, that will be thrown off" on the first occurrence of frost. 428. After the stucco has been on for a few days, the whole surface should be carefully ^^S^^^^ Bounded with a small iron instrmnent like a 218 PRACTICAL TREATISE OX LDIE3, tack-liammer, when all places destitute of adhesion ■svill be readily detected by their hollow sound. From these, the stucco should be carefully removed, the surface roughened and ■wetted, and new mortar applied. 429. ^any of the best cements of the United co1ot^™^°*° States are of too dark a color to furnish an agreeable shade for the exterior of dwelling houses. A very simple remedy for this is to use light colored or white sand, in whole or in part. "When this is not practicable, lime paste may be added, without material injury, until its volume equals that of the cement paste. Lively tints may be obtained by a judicious use of the several ochres, singly or combined. 430. The principal causes of the gradual de- SnJr^'J-rp^'^r tcrioration and decav of mortars left in the open air are : 1st. Ordinary changes of temperature, producing expansions and contractions, which, being unequal in the 1st cause. . . ,' ,. ., , . several materials ordmanJy used m masonry, tend to cause a separation of the mortar from the more solid parts. 2d. Alternations of freezing and thawing, by 2d cause. which exfoliations and disintegrations are pro- duced. 431. As a creneral fact, within certain limits, General fact 1.,,,. ^ - ^ ^ • ^n.^- solid bodies resist the action oi frost in propor- tion to their density, or inversely as their capacity for imbibing water ; but this rule is not capable of strict application, and it is quite possible for one mortar to be a better Some mortarg n • ^ !> ^ i.\ ii. i resist frost better proot agamst irost than another less porous than others that j^ j^g character. Moreover, of two mortars of are less porous. equal density, one may be materially impaired in tenacity and hardness by the action of frost, while the other exhibits few, if any, evidences of its effects. 432. Immersed in water, more especially sea-water, mortars HYDRAULIC CEMENTS, AND MOBTAES. 219 are subjected to the solvent action of the salts ^^^^^^ of certain principally the sulphates of magnesia and salts in sea- soda, — and certain gases contained in the water. Between tides, are witnessed the effects of a combination of the foregoing causes, modified and sometimes augmented by the circumstance, that the protecting coat of marine animals and shells, to which many submarine construc- ,, . . 1 •Ti. • Exposure tions ni a measure owe ttieir stability, is between the tides. seldom found at all, and at best, but very im- perfectly, in positions not subject to constant submersion. It is hence, not an uncommon thing to see the mortar of that portion of a structure between high and low water, in a more advanced stage of decay than that above or below. 433. The effects of frost on mortar may be ascertained by subjecting it to repeated action of artificial frigorific mixtures. To do this, the mortar should be four or five , , , , 1 • J 1 /• (? • /.To ascertain the months old, and in the lorm oi a prism oi effects of frost. suitable size, say 2" X 2" X 8". Ascertain the strength before the freezing trial, by breaking the prism, near one end, on supports four inches apart. Then saturate the largest piece with water, put it in a thin, water-tight bag of India-rubber or gutta-percha cloth, and immerse it in one of the frigorific mixtures given below, where it should be kept until the temperature of the mixture rises above the freezing point. The sample should then be laid in some warm, dry place, until it is completely thawed out. After eight or ten repetitions of this process, the strength of the mortar should be ascertained as in the first instance, when the effect of frost will become known. 220 PRACTICAL TREATISE OX LIMES, TABLE XTL nUGORIFIC MIXTCRES. Mixtures. 5 Thermometer a sinks. Mixtures. Thermometer sinks. Snow or pounded ice Common salt ^ ) 2 § 110-5" F. Snow or potuided ice. . Common salt 2 - '-to— 12»F. Sal ammonia , 1 IS 24 10 5 5 3 ~| S Ito— 18° F. 3 J Snow or pounded ice Common salt Sal ammonia Kitrate of potash . . . Snow or pounded ice.. Common salt Nitrate of ammonia . . . 12 5 5 3 £> Jto-25T. 6 ) 434:. The process of a French chemist, M. Brard, for esti- „ T, ,, matins the probable effects of frost on stone, M. Brard s pro- e r cess. o-iven in the "Annales de Chimie et de Fhvsi- & * que," volume 38, is equally applicable to mortar. It may be stated very briefly as follows, viz. : Prepare a cold saturated solution of sulphate of soda, then bring it to the boiling point, and suspend in it, by a string, for thirty minutes, the sample under trial. Then pour the liquid, free of sediment, into a flat vessel, and suspend the stone over it in a cellar. When efflorescences appear on the specimen, it must be dipped in the solution, say two or three times a day for about a week ; at the end of which time the quantity of earthy sediment in the ves- sel, collected on a filter and weighed, will indicate the effect to be expected from frost on the same sample. The sample under trial might also be of such a form, that its strength could be tested before and after subjection to the above process. M. Brard, however, makes no recommendation of the kind, and it is perhaps unadvisable when operating upon stone. 435. The subject of the action of sea- water on mortars, par- Effect of the sea- ticularly the pozzuolana mortai-s used in the water on mortars. Mediterranean Sea, and the conflict of opinion thereon among European engineers, has been referred to in brief terms in Chapter IV. To estimate by preliminary ex- periments the probable effects of sea-water on mortars, in any HYDEAULIC CEMENTS, AND MOllTAKS. 221 given case, is a difficult thing: in fact, there are so many ele- ments of uncertainty involved in it, that many engineers deem it impossible. Nevertheless, M. Yicat proposed in 1857 "a new mode of trying sea-mortars in the labora- .. _. ^, •' " _ M. Vicat s new tory," which, as it emanates from high au- method of testing thority, is entitled to notice. The mortar to be tried, when mixed up, is pressed, while green, into an earthen vessel. The vessel should be full and should be kept closely covered, to prevent contact with the air. At the expiration of one month break the vessel, so as to free the , ., . .IT..' . Immerse the mor- mortar, and then immerse tne latter in water ^^j. jjj ^ solution eontaininor four or five thousandths of anhy- of anhydrous sul- ^ _ "^ phato of magnesia drous sulphate of magnesia. Reaction takes place, — -the water dissolves the sulphate of lime formed, its presence being detected by oxalate of ammonia, wliich yields a precipitate of oxalate of lime. •136. The solution of sulphate of magnesia should be re- newed until no more of this oxalate is formed, j^gnew the so- and even beyond that point, for greater cer- lution. tainty. 437. If the sample shows no external signs of decay after ten months, break it open and examine the frac- Examination of ture. If the interior is in a state of perfect pres- specimen. ervation, treat some fragments, taken from the inside, by the game process applied to the original sample. If these frag- ments remain intact, for a given time, {yet to he ascertained) the mortar may be pronounced suitable for sea constructions. For cement mortars, twenty months' successful resistance to the solution of sulphate of magnesia is considered ample by M. Yicat. For mortars of pozzuolana or hydraulic lime, it is not considered entirely safe to assign a minimum of two years ; while it is by no means impossible for a mortar that fails to stand this test to sustain immersion in the sea, from the fact that the protecting coat, before referred to, is formed on the exposed surface. 222 PRACTICAL TREATISE ON LIMES, 438. M. Minard, Engineer des Fonts et Chaussees, (retired,) concludes a review of M. Yicat's work in the ^pinYcir'*^'^ " ^nnales des Fonts et Chaussees" for 1858, as follows : " The only means of knowing the action of the sea on a new mortar is to immerse it in the sea, in the locality where it is to be used. Substituting chemical operations in laboratories for the sea itself, involves us in new disasters." HYDRAULIC CEMENTS, AND MORTAES. 223 CHAPTER TH. 439. Concrete or JBeton. — These terms, by no means origin- ally sjnonj-mous, have become almost strictly so by usage. As generally undei"stood in modern practice, they apply to any mixture of mortar (generally hj'draulic), with coarse materials, such as gravel, pebbles, shells, or fragments of _, » . . . tile, brick, or stone. Two or more of these mate- " concrete" and rials, or even all of them, may be used together. More strictly speaking, as originally accepted, the matrix or gang of heton possesses hydraulic energy, while that of concrete does not. 440. As lime or cement paste is the cementing substance in mortal', so mortar itself occupies a similar relation to concrete or beton. Its proportion should be determined in accordance with the pi-inciple, that the volume oftJie cement- „ ^ ^ ' '^ Proportion of ing suhstance should always he somewhat in ex- matrix to the /. , 7 7 /» • 7 • , 7 . coarse materials. cess oj the volume oj voids in the coarse 7nate- rials to he united. The excess is added as a precaution against imperfect manipulation. 441. In England, some years ago, when concrete first came into extensive application, common or feebly hydraulic lime, Buch as the Blue Lias limestone yields, was generally used for the cementing substance. The quicklime, having been first reduced to a powder by mechanical means, was incorporated with the sand and coarse materials in the dry Btate. Water, in sufficient quantity to slake Concrete of quick, the lime, being then added, the concrete was 224 PEACTICAL TREATISE OX LIMES, rapidly mixed up witli a pug-mill or with shovels, conveyed away in barrows or carts, and used while hot. Used while hot. _ "^ , ^ .'-.,,. It was employed extensively for loundations, or as a substratum in light and yielding soils. In order to se- cure the requisite degree of compression and density, it was customary to throw it into its position from a height, and some- times to ram it afterwards. In mixing the materials for fat Its contraction lime concrete as usually composed, there is a and subsequent contraction of about ^ in volume ; this is suc- ezpansion. it, -it • i ceeded by an expansion, when the setting takes place, of about f of an inch for every foot in height, which does not entirely cease for a month or two afterwards. 442. Concrete of fat or feebly hydraulic lime has been ex- tensively employed in Europe for making artifi- in B^urope ^ "^^ ^'^^ blocks of any required form and dimensions, which, after attaining in the air a degree of hard ness and strength sufficient to render the handling of them safe and practicable, are laid up in walls with mortar joints, like ashlar-work. The practice of 443. Of late years, the practice of laying fat crete^o-ettino- ^nto 1™^ concrete hot lias grown into disrepute disrepute. among English architects and engineers. They now prefer that the lime should be thoroughly slaked, reduced to a pulp, and made into mortar with the sand before the coarse materials are added. This process is always followed in making beton. The advantages of it are, immunity from the danger of partial slaking before use, superior homoge- neousness in the mass, and economy in the amount of lime required. 444. Neither the English method of making concrete to be .^ ,. ^ ^, , used while hot, nor the practice of forming ar- Enghsh methods ' _ ^ _ ^ ^_ little used in the tificial blocks which must attain in the air a United States. . , „ . , . -, c ^i certain degree oi resisting power beiore tliey can be placed in the work for which they are designed, have ever received any extensive application in the United States. HYDEAULIC CEMENTS, AND MORTAES. 225 445. Natural hydraulic cement, to which, un- nydrauii'> cement der circumstances requiring only a moderate f^ the^uuited^^'^ degree of energy and strength, paste of fat lime States. is sometimes added, in quantities seldom greatly exceeding that of the cement, is almost invariably used as the basis of the con- crete mortar ; and the concrete, when made, is at once deposited in its allotted place, and well General practice, rammed in horizontal layers of about 6 inches in thickness, until all the coarser fragments are driven below the general surface. ' The ramming should take place before the cement begins to set, and care Precautions m ■t to J ramming, and in should be taken to avoid the use of too much the use of water. water in the manipulation. The mass, when ready for use, should appear quite incoherent. Concrete should . . . . . be incoherent be- contammg water, however, m such quantities, fore ramming. that a thorough and hard ramming will produce a thin film of free water upon the surface, under the rammer, without causing in the mass a gelatinous or quicksand motion, 446. It will be found in practice that cements vary very consid- erably in their capacity for water, and that fresh ground cements require more than those that have become stale. An excess of water is, however, better than a deficiency, particularly wlien a very energetic cement is used, as the capacity of this substance for solidifying water is great. A too rapid desic- cation of the concrete might involve a loss of ^TaTtidenc; cohesive and adhesive strength, if insufficient of water, water be used. 447. Concrete is admirably adapted to a variety of most im- portant purposes, and is daily growing into more extensive use and application. For foundations in damp and yielding soils, and for subterranean and submarine masonry, under almost every combination of circum- ^^ges of "^concrete, stances likely to occur in practice, it is superior to brick- work in strength, durability, and economy ; and in some exceptional cases, is considered a reliable substitute for the best 15 226 PE ACTIO AL TREATISE CIS" LIMES, Btone, while it is almost always preferable to the poorer varieties. 448. For submarine masonry, concrete possesses the advan- Advantages for ^age, that it may be laid without exhausting the Bubmarme works, -water, (which under the most favorable circum- stances, is an expensive operation,) and also without the aid of a diving-bell, or submarine armor. On account of its continuity and impermeability to water, it is well suited to the purposes of a substratum in soils infected with springs, for sewers and conduits, for basement and sustaining walls, for columns, piers, and abutments, for the hearting and backing of walls faced with bricks, rubble, and ashlar-work, for pavements in areas, base- ments, and cellars ; for the walls and floors of cisterns, vaults, &c. Groined and vaulted arches, and even entire bridges, dwelling-houses, and factories, in single monolithic masses, with moulded ornamentation of no mean character, have been con- structed of this material alone. 449. The methods pursued in mixing mortar on the fortifica- tions of Boston and New York harbors, and at Key West, Florida, have been described in brief and general terms in Chapter YI., paragraph 346 and following. The manner of incorporating the broken stone fragments, as practised on the works at New York, is also briefly alluded to in the 7th, 8th, 9th, and 10th steps in the method of manipulation, parag)-aphs 373, 374, and 375. When the coarse fragments vary very much in their sizes, and these have been separated by a screen, as may be the case with gravel and pebbles collected in the usual way, a more thorough incorporation may per- haps be secured by spreading them first on the platform with the smallest sizes at the bottom, and then distributing the mortar uniformly over the mass. This process was followed in Boston, and is thus described by Lieutenant Wright, in his work on mortars : 450. " The concrete was prepared by first spreading out the gravel on a platform of rough boards, in a layer from eight to HYDRAULIC CEMENTS, AND MORTARS. 227 twelve inches thick, the smaller pebbles at the ^ . ■ Incorporating the bottom and the larger on the top, and after- coarse ingiedi- , T ii ^ •. •!• 1 ents by ho,nd. wards spreading the mortar over it as nnitormly as possible. The materials were then mixed by four men, two with shovels and two with hoes, tlie former facing each other, and always working from the outside of the heap to the centre, then stepping back ; and reconnnencing in the same way, and thus continuing the operation until the whole mass was turned. The men with hoes worked, each in conjunction with a shov- eller, and were required to rich well into the mortar, each shovelful, as it was turned and spread, or ratWer scattered on the platform by a jerking motion. The heap was turned over a second time in the same manner, but in the opposite direc- tion, and the ingredients were thus thoroughly incorporated, the surface of every pebble being well covered with mortar. Two turnings usually sufficed to make the mixture complete, and the resulting mass of concrete was then ready for transpor- tation to tlie foundation. " The success of the operation, however, depends entirely upon the proper management of the hoe and shovel, and though this may be easily learned by the laborer, yet he seldom ac- quires it without the particular attention oj^ the overseer.'''' 451. In Europe, machinery is sometimes employed for incor- porating the ingredients of concrete, when large quantities are required. 452. The concrete for the bridge over the River Tlieiss, Hun- gary, completed in the year 1857, was prepared with a machine extensively used in Germany at that time. It consists of a cylinder about four metres (13 feet) in length, , Machine used in and 1.2o metres (four teet) in diameter, open at Hungary formix- both of its extremities and revolving fifteen to *"g '^o^'^'^e'^e- twenty times per minute around its axis, which is inclined to the horizon at an anajle of six to eiffht deg-rees. The stone and mortar are thrown from the wheel-barrow into a hopper, which empties them into the upper end of the cylinder. The mixture 228 PEACTICAL TEEATISE OX LIMES, is produced bj the rotation of the cylinder, from the lower end of which the concrete drops into either wheel-barrows or carts. The inner surface of the cylinder is smooth and coated with sheet-iron ; the proportion of the material i^ measured by reg- ulating the number of wheel-barrow loads of mortar and of stone, as these are poured into the hopper. The incorporation of the ingredients is complete. The cylinder is kept in motion without cog-wheels or pulleys, simply by means of a leather strap which passes over its exterior surface ; the motive power was furnished by a locomotive, which worked a heavy mortar- mill at the same time. This machine easily mixes from 80 to 100 cubic metres (105 to 130 cubic yards), in ten hours, and (when worked in connection with a mortar-mill) at a trifling expense. (See Annales des Ponts et Chaussees, Yol. XYII., 1859.) 453. Another machine for making concrete, the mortar hav- ing been previously mixed, is represented by Figures 40, 41, 42, 43, and 44, the latter being a top view. It is always used in a vertical position, and being comparatively light and port- able, and worked altogether by hand, possesses the advantage that, for founding in dry positions, or where the water has been exhausted, it can be suspended with its lower end resting on ,, , . , . the position to be occupied bv the concrete, and Machine for irii- ' ^ , " ing concrete one handling of the materials be thereby saved. worked by hand. ..,• i .,/. As it IS moved successively irom one position to another, during the progress of the work, it is followed up by laborers who level off and ram the concrete already de- posited by it. In using this machine, the mortar and coarse materials, after having been measured, are placed in the top compartment, a. Fig. 40. The levers, hh, Fig. 44, being then put in motion, the materials fall successively from one compart- ment to another, little by little, and finally reach the bottom thoroughly and completely mixed. As the top compartment becomes empty, the ingredients for another batch of concrete are placed in it. HTDEAULIC CEMENTS, AND MORTARS. 229 ilff Fig. -10. Fig. 43. Fi- 44. 454. Wheel-barrows are generally used for conveying the concrete from the platform on which it is 1 . . . , , 1 mi 1 Wheel-barrowa mixed, to its position in the work, ihe plat- for conveying form should be so arranged, if possible,-that concrete. the distance to be passed over will not exceed twenty or twen- 230 PEACTICAL TREATISE OK LIMES, ty-fiv^e yards. The concrete having been emptied from the barrows into its position, is levelled off with a hoe, and rammed in layers six to ten inches in thickness. 455. The instrument used for ramming concrete is generally a cylinder of wood six to eight inches in diameter, and about eight inches high, shod with sheet-iron on the lower end, and having a handle, three to three and a half feet long, in- serted in the other end, in the prolongation of the axis. For greater convenience, a hand-piece is sometimes attached at a suitable height on the handle. 456. When concrete is made by a machine, particularly one Sling-cart for con- ^^^ ^^^7 portable, and not conveniently kept in veying concrete. close proximity to the place to be concreted, a sling-cart, like that described in paragraph 383, would be a valuable auxiliar to the work. The box slung underneath the cart, could be replaced by a platform arranged to i-eceive a certain number of square boxes of convenient size for handling when filled. With a view to economize labor, the mill should be adjusted so as to discharge the manufactured concrete di- rectly into the boxes. 457. The device for confining the concrete layers laterally, so as to give to the finished work the desired A boxing neces- _^ sary in making form, will, of coursc, to a certain extent, depend concrete walls. ,, , , j ... p , i •, yj, on the character and position ot the work, it required for foundations, or for the backing of walls, or in any position not exposed to view, or not requiring a smooth finish, a rough, movable boxing, composed of two or more planks, with their edges together, and well secured by battens on the back, will suffice. I" 458. When it is required to give a smooth finish to the con- crete wall, and when it is essential that the direction and po- sition of the surfaces should be maintained with great accuracy, special attention should be directed to the boxing. 459. A device by'Mr. E. E. Clarke, of New Haven, Conn., to be used in erecting concrete houses, has been pronounced HYDRAULIC CEMENTS, AND MOETAES. 231 both convenient and satisfactory, wliile it apparently leaves nothing to be desired on the score of simplicity improved mov- and economy. It consists essentially of a wood- able boxing. en clamp, the vertical parallel arms of which can readily be adjusted by means of traverse screws, to any required thick- ness of wall. These arms sup- port the planking which deter mines the thickness of the wall, and are attached — one fixed, and the other movable — to a horizontal brace. When in use^ the entire apparatus is kept in position by securing this brace to some fixed point of sup- port. In carrying up the walls of a building, these points of support are provided on the in- side, being vertical posts secured to the ground, in the first in- stance by braces, and afterward to the flooring joists of the up- per stories. Hollow walls. Fig. 45 rep- resents this apparatus in position for laying a hol- low concrete wall, not intended to be furred on the inside. The hollow is secured by means of a movable plank, called a core, a trifle thinner on the lower than on the upper edge, so that it can be moved after the concrete is rammed around it. The ties between the inner and the outer walls may be common bricks, and these are placed under the '' core" in each of its positions, as the building progresses. The "core" is notched on the lower edge, so as to fit down upon the ties flush with Fip:. 45. Ficr. 46. 232 PRACTICAL TEE ATI SE OX LlilES, their lower beds. Fig. 46 represents a side view of the core. The width of the hollow should be from two to three inches, the thickness of the inner wall from four to five inches, and that of the outer wall ten inches and upwards, as determined, to give the requisite strength. The hollow is sometimes placed in the centre of the wall, a practice which may be admissible in buildings not intended for residences. For these latter, when a thickness of five inches for the inner wall is exceeded, it should be furred for plastering, to prevent the condensation of moisture. 460. The apparatus in common use on the continent of Europe and in some portions of South America, in constructing pise work, would answer in forming walls of for pIs/wodT^ concrete, and would, besides, be less expen- sive, and perhaps more easy of adjustment and use than that shown in Fig. 45. It consists simply of a box- ing of planks, kept in place by upright posts on the exterior, at suitable distances apart, say four or five feet. The lower ends of the posts are mortised and keyed into horizontal cross- piec^ called futtocks, which reach entirely through the wall, and are withdrawn, and the holes filled up, after the box is filled with the pise or concrete, and a new course is to be com- menced. The upper ends of the posts may be kept in position by similar cross-pieces, but the more common practice is to confine them by lashings of rope or cord, tightened or loos- ened at pleasure by a stick used as a lever for twisting up the lashings. The wall may be made hollow by a core like that shown in Fig. 45.* * Pise work is formed of clay or earth rammed in layers. The best material is clay which contains small grarel. and is of such consistency, that it can be dug with a spade. Th.e clay must first be thorousrhly beaten up and passed through a screen to remove stones larger than a hazel-nut. and then moistened to a uniform consis- tency, so that, when moulded into form by hand, it wiU not fall to pieces under water. In forming walls, the pise is rammed, like concrete, in layers from three to four inches in thickness, care being taken not to carry up the walls too rapidly, lest the lower portion be pressed out of shape, while damp and plastic, by tlie weight of the superincumbent mass. Except in very dry climates, the exterior of walls in pise should be protected, by a coat of mortar, from the action of rain. The walls should be thoroughly dry, before being plastered. HYDRAULIC CEMENTS, AISTD MOETAES. 233 4G1. ^^itliin the last ten years, the practice of hoUow concrete buildino- concrete houses with hollow walls, has ^^ f '^ becoiiiino: o ' exteusively used. received considerable attention, both in the United States and in Europe. In Sweden and Northern Ger- many, it is quite common. The facility with , . 1 ^1 ,. , 1 .■^ .• n Its facilities aud which the lire, smoke, and ventilating Hues can advauta-us. be arranged in the wall, by using movable tubes during the progress of construction, the partial immunity from risks by lire, the security against the ravages of rats and other vermin, and the equality of inside temperature through eudden changes of. weather, secured by this method of construc- tion, judiciously followed, specially recommend it to the at- tention of American architects, particularly in those districts where the ingredients of concrete are plentiful and inexpen- sive, and timber or good building stone scarce. There are many recent examples of its successful application among us. 462. Fence or railing posts, of the minimum size consistent with the requisite degree of strength, may be lirmly set and retained permanently in their upright position by surrounding them with concrete, or rather, by inserting them in a concrete foundation. The mortar for this purpose need Post foundations. not be very rich in cement, aud in quantity, might barely exceed the volume of voids in the coarse mate- rials. One foundation properly prepared would serve for an indefinite period of time, and the posts could be renewed as often as decay rendered it necessary. It is believed that by slightly tapering the lower end of the posts so as to render their removal simple and easy, and by lowering the entire foundation so as to place its upper surface below the reach ot a plough, an excellent and inexpensive system of movable fences for farmers' use could be devised. 463. The quick-setting varieties of hydraulic Use of cement for cement have recently been quite extensively tiaStfL mak- applied to drainage and sewerage purpose.^, i°a the pipes. in a mode at once new and peculiar. The mortar, composed 234: PEACTICAL TEEATISE OX LIMZS, I 1\. fl of 2 to 2^ measures of clean coarse sand to one measure of the cement powder, mixed with a small quantity of water, is mould- ed into pipe in sections of suitable length, say about three feet, and of any required diameter of bore up to 3^ or 4 feet. These sections, on being joined together with cement mortar, form a continuous water-tight tube. The junction may be secured by means of the ordinary " hub"' joint, or by the "bevel" joint referred to below. The essential parts of the machine for mai^ufacturing these pipes are : Firsts a sheet-iron cylindrical "case" in which the pipe is formed, its diameter being of com-se the same as the exterior diameter of the pipe. This cylinder is open longitu- dinally on one side, the two edges along the opening being turned out at right angles, thus forming flanges, by means of which the case can be tirmly held together with wooden clamps. Stcoiid^ a solid cast-iron cylindrical " core" equal in diameter to the '* bore" or interior diameter of the pipe. "When tliis " core" is placed concentrically in the case, the cylin- drical opening between the two, forms the mould for the pipe. J7ttV<:?, a hollow cylindrical cast-iron ram- mer or *' plunger" which fits over the core, so as to pass freely between the " core" and the " case." It is used for compressing the mortar. Tliese several parts are represented separately by Figs. 48, 49, and 50, in which a, a, is the " case" clamped together at t, i; h, the " core," and c, the " plunger." They are combined together into a machine, worked by hand, which is represented by Fig, 51, in which A is the outside case and FiR. 49. Fig. 50, HYDRAULIC CEMENTS, AND JIOETARS. 235 B, the " core" not jet in position. This is suspended above the case. The phinger C is partially seen just below the hopper. The bottom of the mould is composed of a ring, ' , . . 1 , days alter exposure to the air, it began to crack all over the surface, and was very deficient in cohesive strength and solidity. That mixed with fresh water retained its sharp corners and angles perfectly ; no cracks or other evidences of decomposition appeared. The blocks remained solid and compact and when broken for examination it appeared that the adhesion to the pebbles was very good, and that every void wa^ perfectly filled. 496. There is reason to believe that the cream of cement would be improved by the addition of 8 to 10 per cent, of fat lime paste, and that the long pipe can be advantageously re- placed by a syringe or force pump of suitable The cement paste /. i? "^ •.. • *^ • j .^ ^i ^ ^i i ■would be im- lurm ; tor it IS evident that the pressure due to proved by a nttle |.|^g vertical height of the pipe, supposing a perfect fluid to be used, is only partially se- cured by the semi-fluid cement, and can only be augmented by nTDEAULIC CEMEIO'S, AND MORTAKS. 251 tliinning the paste, or by lengtliening the pipe. Any arrange- ment, by means of which a stiifer paste can be injected, would be an improvement. 497. We infer from the foregoing results that a thin paste of Rosendale cement is worthless for concrete, if mixed up witli sea-water, while with fresh water, it will harden when injected under water, either fresh or salt, and affords the means of submarine construction, that may be of great value under certain circumstances. 498. TABLE XVIII.* Mortars. Concretes. Resistance of the concrete to rupture. Composition in volumes. 3 a = ■?' 1 = o — >■ Compo- sition in volumes 3 u 5 S W, or breaking weight in lbs. found "by experi- ments. Calculated value of R. or resistiince per square inch to a force of exten- sioa *t c 1 1 1 1 1 1 ^ « 1 i i .i 1 1 2. 3 i 1 a i 1 1 i 1 3. :< i 3 10 days, lbs. 20 days, lbs. 60 d-iys. lbs. 10 davs. lbs.' •20 d.ays. lbs. 60 days, lbs. 1 .62 1.6J 1.24 1.12 1..56 1.03 1.— 1.— 1,087 800 856 492 1,093 1,322 1,065 646 1,376 1,504 1,480 481 92 99 95 92 261 196 208 123 2(;2 339 257 160 328 360 352 122 i .43 1.45 1.11 1.00 1.40 1.11 1.03 1.40 1.14 1.01 778 778 492 889 954 668 1294 1016 906 90 92 92 190 190 123 215 231 165 299 235 219 i .38 404 315 271 448 4 63 359 430 633 600 88 92 88 103 83 73 113 117 93 109 157 148 i .35 1.05 227 149 163 346 289 240 542 437 404 90 92 92 63 45 48 90 77 66 135 111 104 i .34 1.— 1.45 ' 1.13 1.03 , 141 114 114 304 218 202 392 326 306 88 88 88 42 37 37 80 60 56 101 85 77 i .32 .96 1.45 1.13 1.03 : 1 191 136 176 192 196 181 381 337 370 90 90 90 55 42 51 55 56 52 98 88 96 * From experiments made at Boulogne-sur-mer by Engineer Yoisin, published in " Annales des Ponta et Chaussiies" for 1858. 252 PRACTICAL TREATISE 0^" LIMES, Table XYIII shows the resistance of prisms of concrete made with the natural Portland cement of Boulogne- Strength of con- gui-.mer. The prisms were 5.9056 inches cretes of natural -c Boulogne Port- square in cross section, and were broken by a land cement . , , . , ., , ., . " ^ load at the middle, while resting on supports 31.496 inches apart. The formula "W = li —. X was used in deducing the values of R. (See paragraph 554,) 499. TABLE XIX. GmXG TRIALS MADE AT FOET ADAilS, R. L. EX GES'EEAL TOTTEX, Df JTXE, JTLT, AKD AUGUST, 1837, OF THB STBESGTH OF COXCEETES MADE D« DECEMBER, 1836. OOCi— Ow ^ "^ *Z C"— —^tt O^^ ^^t- ooo cc^ ^ (^ ' * a LJ .-' 1-^ ,.— ^- 1"^ ■ -J ^ ^ *^ '|^«4 1-^04 * "C ComjK.sition of the '•X ': : •£..'£■. : -t ::'£•.•£■.'•£■.}'£■ ■ '£ '• '• c mortars. \\-ii Hi Hi Hi Hi Hi'HiH'^ Hi ^ I^X-^ -X— wx— ;,x— ,ux— ;^x — ^'j.,- :^3'-— ttcM i Granite fragments ^ ■i with 1 mifiisure of > I mortar. S 1 4973 4142 2775 3989 2721 2045 2056 lost 1574 E = 311 260 174 251 171 129 130 99 ( Granite frasments j 2 < with 2 measures V 1 of mortar. ) 4063 49S3 5064 40SS 5366 1547 3537 1643 1972 E = 255 312 817 313 836 ( Brick frasments ) ■< with 1 mcjsur* of ^ 1 mortar. ) 8 3242 2117 4127 3254 1788 2136 1567 8^9 E = 201 133 259 205 118 184 98 229 ( Brick fragments ) « •< with 2 measures > 1 of mortar. ) 2S05 5047 2S26 4232 1176 3655 3S56 2320 4803 E = 176 316 277 265 74 229 242 146 801 i Stone gravel with 1 ) 5 < measiu« of mor- y I tar. S 1097 1049 1240 1256 1066 E = 69 66 78 79 67 i Stone gravel Trith 2 1 -; measures of mor- > 6 4347 4247 2655 1295 8351 i tar. S E = 147 267 167 82 210 I Brick eravel with 1 "| 7 measure of mor- > tar. J B = 5437 841 61 S3 887 30SS 194 lost 4726 296 [■Brick pravel with 2^ , 8 ■j measures of mor- V I tar. J 6025 5712 5490 8142 2699 B = 8n 35% 843 197 169 9 j Stone fragments \ \ grouted. j B = 8273 ' 1W« 206 1 116 2012 127 1158 73 1178 74 j Brick fragments 1 ( grouted. j 1C34 ! 23'i5 2S69 2726 2770 j E ==| 103 145 ISO 1 171 1 111 1 ! The results crjven in the above table show the weight in HYDBAULIC CE3IENTS, AND MORTAHS. 253 pounds required to break prisms of concrete, 12" X G'' X 6" the distance between the supports being 9 inches. In the table, one measure of mortar corresponds to the vohime of voids in the irranite, or brick frao:meuts used, and two measures to twice that volume. The values of E. are computed for this work from the formula, paragraph 554, The cement was from Ulster county, New York, and the lime from Fort Adams, and was very slightly hydraulic. The volume of voids in the granite and brick fragments was .48 and in the stone and brick frag- ments .39. The lime paste was passed through a paint mill just before using it, and the coarse fragments were drench- ed with water just before mixing them with the mortar. 500. The quay walls and certain y-arts of the Mole of Al- giers, as described by M. Poirel in "Memoires '^ ' V „ .1 Mole of Algiers. sur les Travaux a la mer, 1841, were buut by pouring and ramming concrete into caissons, sunk in position, and lined with tarred cloth, a system borrowed from the Italian engineers, who repair breeches in walls by casting down bags of concrete, from which the mortar exudes in sufficient quan- tity to bind the whole together. M. Poirel also employed concrete as artificial blocks of 360 cubic feet each, weighing 22 tons, formed and allowed to set in wooden moulds in the air For concrete immersed green, the mortar was composed as follows : paste of fat lime, one volume ; powdered pozzuolana, two volumes. The mortar for forming the artificial concrete blocks in the air was composed of: paste of fat lime, 1 ; powdered pozzuo- lana, 1 ; sand 1. In both cases, one volume of the mortar mixed with one volume of broken stone, gave one volume of concrete in place. The pozzuolana which succeeded best was the Roman, and it was used in the state of fine powder, being, in fact, quite inert if left in coarse grains, like sea-sand. 501. In executing the new Graving Dock, No. 3, at Toulon, 254 PRACTICAL TREATISE OJf LIMES, Graving Dock, M. Noel, the engineer, adopted a concrete fonn • ,a ouon. Nation, laid under water while green. It was 400 feet long, 100 feet wide, with an average thickness of 15 feet, all in one mass. This area was first enclosed on three sides with close piling, lined on the inside with tarred canvas. Having thus prepared a solid foundation at the requisite level, the concrete hearting of the side, head, and gate walls of the dock was laid under water in caissons of appropriate dimen- sions, leaving nothing but a lining or rovetment of masonry to complete tliese walls. The total quantity of concrete was 654,300 cubic feet in the bottom, and 418,600 cubic feet in the sides. The mortar of this concrete was composed of one vol- ume of paste of fat lime, and two volumes of finely pulverized Italian pozzuolana. 502. At Marseilles, M. Pascal made use of immense blocks Jetties at Mar- ^^ Concrete, allowed to harden in the air three f'eilies. months before immersion, for the protection of the outer or seaward slopes of the jetties, which enclosed the basins and docks of that harbor. The concrete blocks weighed about 22 tons each, and were formed in moulds of 353 cubic feet capacity. The mortar was composed of three parts of Theil hydraulic lime slaked by immersion and measured in powder, and five parts of sand ; for a more active mortar, one-third of the lime was replaced by an equal quantity of Italian pozzuolana. One volume of this mortar was mixed with two parts of broken etone. For concrete to be immersed immediately, two A'olumes of mortar to three volumes of broken stone were used. 503. M. Pascal expressed his preference for good hydraulic lime, over any pozzuolana mixture, or any natural or artificial cements, provided plenty of time could be allowed to harden before immersion. 504. The Cherbourg breakwater is composed of a hearting of rubble, d pierre perdue, upon which rests, at the level of ordi- nary low water, a bed of concrete seven feet thick, composed HYDRAULIC CEMENTS, AND MORTARS. 255 of lime mortar and broken stone. Tlie parapet restinf]^ on tins platform is thirty feet wide at the base and thirty-one feet high towards the sea. Recently it was found necessary to protect the exposed base of the wall seaward by huge artificial blocks capable by their inertia of resisting tlie waves of the Atlantic. These blocks contained 720 cubic feet each, and weighed forty-four tons, and were formed by rubble masonry, built up by hand on platforms, in positions subjecting them to submersion at each returning tide. The stone used was mostly tlie schistous rock of the neighbor- hood, and the mortar was composed of either Parker's or Me- dina cement and sand, or Portland cement and sand. The three cements were sometimes mixed together. The propor- tions were one volume of Parker's or Medina cement to one and a half of sand, or one volume of Portland cement to two of sand, or intermediate proportions, when the cements were mixed together. Rabble masonry was preferred to concrete for these blocks, as no wooden moulds were required. These blocks have satis- factorily withstood the action of the waves for fourteen years. 505. At Dover and at Alderney hreakwaters Portland cement has been extensively used in forming artificial blocks, which were laid in the jetties instead of blocks of ashlar. The jetties have ashlar facings or revetments. The blocks of con- crete at Dover were composed of — 1 vol. Portland cement, 2 " Coarse shingle. 2 " Fine " 2 " Sand, 4 " Spalls of the Island stone, Mixed together in a box which revolves eccentrically. The concrete blocks were madein moulds, in which they were allow- ed to harden eight or ten days, and were then subjected to two or three months' exposure, before submersion by the aid of a diving-bell. 256 PEACnCAL TEEATISE OX LlilES, At Alderney, the concrete is composed of — 1 part Portland cement, 2 " Sand. 4 " Shingle, Formed in moulds into which irregular masses of rubble, to the extent of thirty-eight or forty per cent, of the whole, are rammed. Some lime-blocks which were used there were composed of — 2 parts Coarse shingle. 2 " Fine " 1 " Sand, 2 " Spalls of the Island stone. 1 part pound Aberthaw lime. The cement blocks are tested by lifting them four days after they are made, and the lime-blocks eight days after. At these ages respectively they were required to sustain their own weight. For handling tlie blocks, two pieces of stone around which the concrete is rammed, are introduced into each. These stones act as a dovetail, being broader at the bottom than at the top, and have lewis holes in them. The cement blocks were required to be two months old, and the lime-blocks four months in summer and six in winter, before they were placed in the works. Two cubic yards of cement-concrete required five and a half bushels of dry cement, and the same quantity of the lime-con- crete required six and one-eighth cwt. of blue Lias or Aber- thaw lime. 500. In the United States concrete has for many years been very extensively employed in the construction of the civil and mihtary public works of the country, and recently in the foun- dations and even the exterior and partition walls of private residences and factories. HYDRAULIC CEMENTS, AND MOKTARS, 257 507. TABLE XX. SHOWING THE COST OF VARIOUS KINDS OF MASONRY PER CUBIC TAKD, AlfD THE VOLUMES OF MORTAU REQUIRED FOR EACH. it 1 1 g C C t. 1 » 3 c — > = '^ ■? Cost per cubic s g o c ^isi yard «f masonry Kind of maaonry. i •= ° ^■3 . laid in. a •Si xg-= § S 5 a V ^ II -w J- s » i^ a cS ■" x c ^- — § £ >> 5 i "o 5 =-.2 S ~ "^ — c C t. a >■ C O" :5 ub.ft. bbls. bbls. $ c. $ 0. $ c. Pough masonry in rubble stone, " or the refuse of (Quarries called " grout," from ^ to ^^ cubic ft. in 10.8 1 .5G5 1.22 .90 4.10 5.00 volume. Ordinary masonry in blocks, large "j and small, not in courses, witL 1 their joints rough hammer dress- 8.1 .423 .92 .62 7.00 7.62 ed. Masonry in large masses, headers' and stretchers dovetailed, as or- dinarily used for facing sea-walls, - LO .05 .11 .08 9.00 9.08 sustaining walls, good hammer- dressed beds and joints kept full. ^ Ordinary masonry in courses of 20 ' in. to 32 in. rise. 1.5 .08 .17 .12 5.70 Ordinary masonry in courses of 12 in. to 20 in. rise. 2.0 .105 .22 .16 2.19 Brick masonry 8.0 .42 .90 .66 5.70 6.40 Concrete (the vol. of voids in the coarse fragments being about .30.) of good quality, . . 11.0* .54 1.75 1.21 2.19t 3.40 ■ 2.21 ; of medium " 9.0* .41 1.06 .65 1.56i of inferior " 8.0* .37 .97 .60 1.45^ 2.05§ Rubble masonry, dry («. e. without ) mortar) f 3.00 tc ) 3.30 The cost of materials delivered at the work has been assumed to be as follows : cement, $1.20 per barrel ; lime, $1.00 ; bricks, $4.25 per thousand ; sand and gravel, 80 cents per ton ; granite fragments produced from stone-cutters' chips, at 55 cents per Remarks on Table XX. • These mortars nre not exactly identical in the proportion of paste and sand, t Coarse ingredients entirely of granite. X Coarse ingrodiiuts entirely of gravel. § Coarse ingredients entirely of graveL Note to Second EJiiion.— With cement at $2.50 per barrel, lime at $2.00, labor at 81.50 per day. and sand close at hand, good concrete is estimated at $6.00 per cubic yard. — Q. A. G. 17 2o8 PEACTICAL TEEATISE ON LlilES, cubic yard, neglecting the cost of stock ; labor, $1.00 per day, and the necessary superintendence. The work is supposed to be of some extent, and the operations to continue without inter- ruption through the season. For walls under two feet in thickness, the prices in the table will be increased somewhat. The rate of increase for thin hol- low concrete walls, which require movable boxing on both faces, will probably reach but not exceed 10 per cent., while for the other kinds of masonry the increase of expense will be more moderate. HYDRA.ULIC CEMENTS. AND M0BTAB9. 259 CHAPTER YIIL 508. In a memoir submitted to the French Academy of Sci- ences in the year 1856, entitled "General Considerations upon Hydraulic Materials used for Constructions in the Ocean," to which reference is made iu ohXneyandRivot. other parts of this work, the authors, MM. Chatoney and Rivot, Engineers of Roads and Bridges, are led, as the results of their experiments, to some deductions some- what at variance with the established usage of European engi- neers. As many of the points to which they direct special attention can have no practical interest to American engineers, they will not be noticed here. 509. From page 159 of their memoir we quote as follows : " We have supposed until now, that the cements should be tempered with a quantity of water just sufficient to obtain the consistency requisite for working it ; but, when- ^^^^ ...^^^end ever it is possible, it is better to use pure ce- pure cement to . ^ ., ^.. . .,1 bo used with an ment m a semi-liuid condition, viz. : with a g^^ess of water. great surplus of water ; in becoming solid, it rejects the water not necessary for hydration, and its texture is much more compact than when tempered to ordinary consis- tency ; it may be said that the molecules, left to themselves in a more liquid medium, arrange themselves better ; they are more watery and carry Jess air with them ; for this double reason the mortars are less porous." 510. M. Vicat arrays himself against what he terms this new 260 PEACTICAL TEEATISE OX LIMES doctrine, and pertinently asks how it is possible this d^tr^r*'^^^ ^^^^^ ^^^^ augmentation of volume, due to a sur- plus of water, can be attended with an increase of density, when the mortars have attained their final harden- ing, Tliat skilful experimenter at once set to work in his labor- atory to disprove this statement of !MM. Chatoney and Eivot. For this purpose, glass tubes of equal diameters (nearly two in- ches) were procured, and into them were introduced, respective- ly, the several natural cements from Grenoble, Paris, Vassy, and La Valentine, mixed in one case, in the proportion of 50 parta of water to 100 parts of cement, and in another in the propor- tion of 120 parts of water to 100 of cement. The pastes were stirred with a glass rod until they began to stiffen. The tubes being of equal diameters, the volumes of the several pastes were directly proportional to their altitudes in the tubes. At the expiration of two mouths, the glass tubes were care- fully broken, the cement cylinders removed, and their relative hardness, weight, and capacity of imbibing water obtained, with the following results : TABLE XXL Ko. Condition of the pasta iHardnese Weight Capacity of imbibition. For the stiff paste, after naturally drying ) \ j qqq in the air, ( j For the diluted paste, after naturally drying ( in the air, j .075 1.000 .375 1.000 2.570 511. The experiment was pushed further in the following manner. The semi-fluid condition of the paste favored a subsi- dence of the heavier particles, which caused greater density at the bottom than at the top of the tube. Other cylinders were formed by pouring in tlie paste, and allowing it to assume a state of rest, and subsequently to harden without agitation. The relative hardness as indicated by the penetration of the HYDRAULIC CEMENTS, A^D MOETAKS. 261 point was then obtained at the top and bottom of the cylin- ders, with the following results : TABLE XXIL „ I />,,.-,., . Hardness as measured by ^0. Condition of the paste. Lj^^ penetration of a point. „ , . , ■,-,.< Top of cylinder, Valentine cement tempered to a good consistency. •< gQ^fQ^j gf do. Same, precipitated spontaneously from a semi- \ Top of do, fluid mixture. ] Bottom of do. Grenoble cement tempered to a good consistency, j g^^jQjQ Qf ^q Same, precipitated spontaneously from a semi- j Top of do. fluid mixture. ( Bottom of do. 21 21 00 05 33 33 01^ 09 512. The results given above were obtained with what are generally termed quick-setting cements. When mixed to a stiff paste, they will set in twenty to tliirty minutes. Similar trials were made, and simihxr results obtained . , , ., . ^ . ,1 , . i . • , M. Vicat and In- with cements ot interior hydraulic activity, spector-Geueral that required two to three hours to set. M. ReibeU's expen- ^ enco. Vicat concludes, therefore, that a large dose of water invariably injures cement mortar. Inspector-General Keibell, who used the Boulogne cement made from tlie septaria, in 1852, for the works at Cherbourg, found that it did not harden between the stones when employed in a semi-fluid state {en coulis). Some of this cement was forwarded to M. Vicat by the Inspector-General for trial, and gave the follow ing results after ninety days immersion : TABLE XXIIL No. Condition of the paste. Tenacity per sq. centimetre, (.3937" X.3937") 1 2 3 For 100 parts Boulogne cement tempered with 50 parts water, a iQO u u u a a g-j a a j^QO <« " « » It gQ a a 8.20 kilograms. 6.45 3.75 " These results, says M. Vicat, were found to correspond with those obtained at Cherbourg. 262 PRACTICAL TEEATISE OX LIMES, 513. There is, perhaps, little doubt that the la=rikrrt Tables, results reported by M. A'icat are, in the main, correct, although much depends on the age of the cement, and the manner of its preservation ; newlj-raade cement takes a much firmer consistency with a given quantity of water, than that in which the uucorabined quicklime has be- come spontaneously slaked. 51-i. Tlie trialis witfi tubes were greatly exaggerated^ and fur- nish no conclusive refutation of the deductions of M. Chatoney, for that engineer recommends for his thin paste four parts of water to ten of cement, while M. Yicat used with the same quantity of cement five parts of water to obtain his maximnm consistency, and twelve parts for the minimum, being an excess of water equal, in the two cases respectively, to 25 per cent., and 3u0 per cent, over the maximum quantity adopted by M. Chatoney. 515. It will be seen that M. Yicat made his trials with the natural cements : M. Chatonev, on the other '• Portland^ oe- . ment used ea hand, had reference to the " Portland'" cement which had been used by him " to stop the infil- trations of water under the cut stone of the apron of the Florida Dock, at Havre," the beton on which the apron rested having become so decomposed under the influence of sea-water that the pebbles were no longer bound together by the mortar. The following preliminary experiment was made : A box about six and a half feet long, two and a quarter feet wide, and four inches deep was filled with the pebbles used for concrete, and covered up with a board well loaded down with weights. Into one of the comers of this box was then poured through a vertical tube 1.57 inches in diameter, and 17 feet four inches high a mixture of five parts of Portland cement and two parts of water.* M. Chatonev savs : " When the box was taken to * Some Modes of o ou cr ^ noticed in anoQier part of tiiis woriE, -were made in this ingiiii«»r oQ GovHiioc's IsUud, New York, in the aatumn of 1S60. HYDRAULIC CEMENTS, AND MOKTARS. 263 pieces the cement was found to have penetrated among the peb- bles to the extremities of the box, and had transformed them into excellent beton, more compact than could have been made by- masons upon a stand." Tliis experiment was deemed so satis- factor}^ that the infiltrations under the dock-apron were stopped by an injection of liquid pa::te of Portland cement. Some of this cement, whicli, after completely filling the vacant spaces, had overflowed the apron, and attached itself firmly to the cut- stone, was removed and kept in sea-water for testing. It fur- nished the following results : 516. TABLE XXIY. Giving the tractile strength of mortars of pure Portland cement mixed to a cream with two-fifths of its volume of water, injected into and kept in sea- water: Age of mortar. Weight required to break the prisms by a force of extension. 15 days, 45 " 335 " 1341 pounds per square inch. 207J " " 233i " " " 517. It is claimed for the Portland cement by those who have given the subject attention, and are acquainted with its use, that however favorably it may compare • 1 1 1 * /. -n Alleged superi- with the best natural cements oi Europe, when ority ot Port- employed as a stilf mortar, — and experiments ^""'^ temont. appear to establish its superiority with singular unannnity, — its most prominent and valuable properties are displayed when employed under conditions similar to those which obtained at Havre, that is, when mixed with a surplus of water, capable of producing a semi-fluid or creamy consistency {en couUs). "When thus treated, it sets rather slowly, some varieties retain- ing the plastic condition for hours ; and while hardening, it is said to reject a portion of the excess of water. 26-4 PRACTICAL TREATISE 0>' LDIES, 518. The deductions of M. Yicat in the laboratory from tri- als with the natural cements of Grenoble, Paris, -rr J 1 1 -L • 1 T ^ Ticat's deduo- V assy, and elsewhere, burnt m tne ordmary tions to be receir- waj, must therefore be received with some can- ^^ "^^^ caution. tion, when we attempt to compare them with practical results, obtained with a cement produced, as the " Portland" is, under the peculiar condition of a vitrifying heat. 519. It does not appear that any trials of strength were made with concrete formed by the process of injection, prac- tised by M. Chatoney. Compared with the resisting power of the cementing substance itself mixed with an excess of water, such concretes must be strong, as the conditions are peculiarly favorable to the development of the adhesive properties of the cement.* * M. Vaudrey, Engineer des " Fonts et CLaussees," -who succeeded M. Darcel in the service of the Seine Navigation and Paris Bridges, made use of the natural Bou- logne "Portland" cement in preference to the Roman, in reconstructing the St. Michel's Bridge in Paris. A notice of this work published in the Annales dea Ponts et Qjauss^es for 1857, volume liv., furnishes the following extracts : " Engineers daily meet with occasions for using Roman cement, (natural hv- drauUc cement). Ther acknowledge that great inconveniences arise from the mor- tars setting much too rapidly, which renders it necessary to prepare it in smal quantities at a time. The proportion of cement used generally renders these mor- tars very expensive. With ' Portland' cement the mortar can be made up in small quantities and by the most economical process, as the setting begins only aftei eight hours. The workmen eonseq\iently have the time necessary for using the mortar. Moreover with a much smaller percentage, the ' Portland' produces a more resisting mortar than the Roman cement." In reconstructing the St. Michel'a bridge, a portion of the old masonry that had stood for two centuries, was left in the buttresses. For the new masonry of tliese buttresses the mortar was composed of — 1 cubic metre (1.3 cubic yard) of river sand, 250 kilogrammes (550 lbs. avoir.) of Portland cement. In its fabrication, the sand and cement were first mixed dry, the water being added after these two substances had become thoroughly incorporated. Its amount necessarily varied with the state of dampness of the sand ; it was on the average j 125 litres (132.1 quarts) water for 1 cubic metre (1.3 cubic yard) of sand. The analysis of the cost is : For 1 cubic metre of sand Fr. 3.20 250 kil Portland cement (at Fr. .08 per kiL) 20.00 Cost of fabrication 2.50 Price of one cubic metre of mortar Fr. 25.70 (Which is equal to $3.64 per cubic yard). HYDEAULIC CEME]S"rS, AND MORTARS. 265 520. Tills seems a suitable place to introduce the results ob- tained with some American cements, mixed to Trials of Ameri- diffcrent degrees of consistency. These are can cements. given in the following table : TABLE XXY. Showing the ultimate strength of rectangular parallelopipeds of pure cement mortar, 2" X 2" X 8" formed in vertical moulds under varying conditions of consistency and compres- sion, and broken on supports four inches apart, by a pressure from above, midway between the supports. The mortars were kept in a damp place twenty -four hours, and were then im- mersed and kept in salt water until broken. The numbers from 1 to 23, inclusive, were 59 days old ; those from 24: to 59, inclusive, were 320 days old. " According to the specifications of the contract, the mortar of cement made in the proportion of 3 voL of sand for 1 vol. of cement, and moulded into prisms .04 metre x .04 metre (1.57 in. x 1.57 in.), and immediately deposited in water must, al the end of eight days, resist, -n-ithout breaking, the tractile strain of 40 kilogr. (88.16 pounds). This clause at once excludes the Roman cements, which, under these conditions, break under the tractile strain of 12 to 15 kilogr. (26+ to 33 pounds]." "The Boulogne, 'Portland' cement generally bears 80 kilogr. (176.33 pounds). It weighs about 1.100 kilogr. (2.425 pounds) per cubic metre. (68i pounds per cubic foot)." "The proportion of 250 kilogr. of cement for one cubic metre of sand corre- sponds to a quantity of cement less than one fourth that of the sand." "The prisms bear after eight days a weight of 30 kilogr. (66.1 pounds). This cement was manufactured by MM. Demarle & Co. of Boulogne-sur-mer (see par- agraph 87) who delivered it to the works in Paris for eight francs per hundred kil- ogrammes (67 cents per hundred pounds)." Mr. Vaudrey further remarks: "When the Roman cements first appeared in the market, their price was far from being so reasonable ; I firmly beheve that the price of the ' Portland' cement will be considerably reduced after some time. A great many localities possess the elements necessary for the manufocturing of that cement. I shall mention, among them, the layers of marl above those of gj-psum at the Buttes Chaumont where some hydraulic lime and Roman cement are already manufactured. However, for the 'Portland' cement, a precise proportion of 21 per cent, of clay is necessary. •' The calcination is a very important element in the manufacturing of all cements; the less calcined they are, the quicker they set ; but in proportion as they set oinckiy, their power of resistance diminishes. I have no confidence in very qtiick- setting cements." 266 PRACTICAL TREATISE ON LIMES, Kind of cement. Ccmpotition of tlie mortar. Penetra- tion of point ill in inches. James River . i 4 vol. dry cement I j A ""ck ert-am poured 1 1 '2-ti vol water f "i '"'"^ nioulds and shaken V ' 1 ■ ■ ' ( down. ) I 4 vol. dry cement 1 . ,ji I Brand, ) .297 .410 .4-2(t split si-lit .300 split ,300 .4^10 .076' 125 I .090: .ua .122' ISO .140 .216 .260 .167 .2.52 ,190 .2HI ,1S0 .25*1 split split 240 .250 .250 .230 .060 070 .067 067 077 .065 .060 .057 a thin paste . a very thin paste . a thin paste 236 346 291 1-2811 291 299 I 275 267 J 497i 447 557 I 557 I 4l6j 322") 259 J 228 \ ^2504 252 25;t 291 I " 232 I 24;^ J 375-) 461 J 402 "1 .137 371 .125 3.=i5 .110 425 .137, 409 J 392?. 32 lbs. a stiff paste . / Eosendale, •< DelafieldA I Baxter. a thin paste a very thin paste . • stiff paste 321b 112 .200 140 .237 122 .227 102 .190 180 .130 175 .130 067 .127 070 .12(1 064 .114 057 .110 070 .090 100 .ISO 110 .200 l.io .240 .ISO .2MI AW .240 ,1M .2!>0 .177 .277 .142 .240 -400 MS) U46 644> 404 L 306 f 644j 650) 644 V635I 613 .O.V.' .090 .057 .105 .047 .OS." .035 .07'. .050 .0S7 .140 .080 .037 .075 .040 .050 621 605 404 401 409 413 425 4.i6 1184 1141 SOS 795 816 862 -07 707 613 STli HYDKAULIO CEMENTS, AND MOllTAES. 267 GENERAL DJ;DUCTI0N8 FROM TABLE XXV. Ist. The two Rosendale cements offer better results than that from James Eiver. The results of the table are rather discrepant. 2d. Nu great advantage appears to be gained by mixing the paste stiff, provided it is in condition to set under compression. Delaiield and Baxter's cement gave much the best results when mixed stiff. 3d. When neither is subjected to compression dunng setting, a thin paste prodiices about as strong a mortar as a stiff one. Nos. 1 to 8, and Nos. 14 to 17. 4th. Between the limits of !,*„- to 2,«„ vol. of water to 4 of cement, there is a variation of about 13 percent, in the average resistance of the mortars, the lowest average resistance corre- sponding to two vol. of water to four of cement. This result must be regarded as a discrepancy due to imperfect manipula- tion. Nos. 1 to 8, 14 to 17, and 18 to 23. 521. From numerous laboratory experiments „ r p ti d carried on at Cherbourg, in order to test the cement used at 1- A 1 (< T-. 1 1 11 1 • .1 Cherbourg. quality oi the ' rortland cements used m the construction of the breakwater, it was ascertained that their averaijre resistance to a force of traction wlien mixed stiff and without sand, and kept in salt water 45 days wa^ 266 lbs. It was not customary to reject any whose strength did not exceed 170 to 185 lbs., this being as high a degree of resistance as the cements marmfactured for the trade generally attained. 522. Table XXVI. contains results which afford the means of comparing the tractile strength of the Roman and artificial Portland cements. The trials were made by M. Darcel, Engineer of Roads and Bridges, and of Roman and were reported in the " Annales " for the year ^""^"^^'f ' ^'^'^^^^"^ 1 •' cement. 1858. Two varieties of Portland cement, the French (natural), ajid the English (artificial), and two of Roman, the Paris and the Yassy, were employed. The variations in the two varieties of the same article, were so 268 PRACTICAL TEEATI5E ON LDrES slight in both cases, that the diiferences are not retained in the table. M, Darcel's trials were made in the open air upon quadrangular pnsins of 1.57" X I.IS" in cross section. " After having dried for six weeks, the prisms were suspended by one extremity supporting at the other extremity a plate which was loaded, until the prisms broke by extension." TABLE XXYI. Giving the tractile strength per square inch of cement mortars i2 days old, kept in the open air. Prop-onion of sand for 1 of cement 1 2 3 4 5 6 1 8 9 10 Resistance j>er &quare inch, in lbs. Portland cement IJoman cement 284i 142i :-?; »H142til2S |116|106| :: t ■■^ ■'9*1 67 1 57 42| 99^: 92ij 95J 35*25,^1 523. MM. Belgrand and Michelot, from their experiments, give the results, found in the fol- lowing table, obtained with cement mortars containing no sand. The mortars were kept immersed, and it appeared to be immaterial whether it was in sea or fresh water. TAELE XXYH. Roman and natural and arti- ficial Portland cements without Eand. Kind of cement. Age of cement. ^^^-'^^^<^ ^ ^ V^^S ° stram per sqiiare mch. Souloone (oatoral) Portland 1 rear. C40 to 7 1 1 pounds. do. 427 to 49S '• Fngl'ah (artificial) Portland Roman cement fix»m " Septaria.'" do. 170 to 213 " 524. Those gentlemen also state that mortars composed of one volume of Boulogne ** Portland*' cement and ity of Boulogne fouT volumes of sand ofier as great a resistance Portland cement ^. ^^^^^ composed of One volume of Enghsh HYDRAULIC CEMENTS, AND MORTARS. 269 Trials of English . Portland and Ro man cements in New York. " Portland" and two volumes of sand, and are superior to those of Roman cement without sand. This comparison, as regards the Roman cement, is the same as that furnished hy Table XXY., from the experiments of M. Darcel. 525. Some trials made in New York City^ in 1860, in the regular course of these experiments, upon Eng- lish Portland and Roman cements, supposed to be about three months old, taken from well-con- ditioned barrels, gave the resistances shown in the following table : 526. TABLE XXVIII. Showing the ultimate strength of rectangular prisms two inches square in cross section, of Portland and Roman ce- ment mortars, which set under a pressure of 32 pounds per square inch, broken on supports four inches apart, by a force applied at the middle. Tlie mortars were mixed quite stiif, and were kept immersed in sea-w^ater. The cement was measured by volume in loose powder. i Penetration of point, izi ■i='3 o Age of mortar. in inches. c-r i^ .c?? i s Kind of cement Comiiosition of the mortar. ■s'f i K j: - ' c _u c-T 5 ^1 3 > c § i 1 impact 2 impacts. ^il 1 English Portlund I'uro cement 3J0 days. .032 .057 .077 .105 1:1 } i^^« 2 3 " " 1 vol. cement and 1 vo . sand, " " .060 .095 YSk \ ^^263 4 " " 1 •• •' 1 " " .072 .112 6 6 u " 1 " " 2 1 " " 2 '* u u .057 .072 .O'.IO .107 '■^f 950 1 English Roman. 1 " " 1 " 20 " .132 .205 ^in ''' 8 u u 1 u u 1 " U tk .152 .238 9 U it 1 « u 1 " 100 " .080 .130 iU ^ 10 1 '^ " 1 .090 .130 527. From the foregoing we derive the following table : TABLE XXIX. Showing the resistance per square inch to a force of extension, of mortars of Roman and Portland cement deduced from Table by the formula Wi= | R ^——a' 1/ 270 PEACTICAL TEEATI5E OX LIMES, Kind of cement. English Portland. English Roman . Composition of the mortar. Age of mortar. Pure cement 320 I voL cement, 1 voL sand, . >( 1 " " 2 " " ii 1 " " 1 " " 20 1 " " 1 " " 100 Value of R, or tractile strength per square inch. 1152 pounds. 948 " 713 182 " 439 " 528. Trials were made (see Table XXX.) with a sample of English Portland cement, not obtained from with English the lot which I'nmish the results recorded in Portland" cement. rp.^^|g XXTII. The pHsms were made of rather stiff mortar, rammed into a mould but not pressed ; thej were 1" X 1" in cross section, were kept in sea-water 270 days, and then broken, on supports three inches apart, by- pressure applied to the middle. The cement was measured in volume of loose powder. The table contains the average of many trials. Some of the mortars were tested as many as thirteen times. TARLE XXX. No. of the mortar. Composition of the mortar. |"Weight, in pounds, j supported before ' breaking. Pure cement paste, Cement, volume 1 " 1 " 1 " " 1 e, 306 . Sand, volume 1, 313 >i it 2, 204 11 (1 3, 91 (( It 4, 74 K U 5, 45 529. The only Ajneriean mortars formed in the same mould Trials of Ameri- ^hat were used for the table just given, and can cement. hence fumishing a fair comparison, were made of cement from layer Xo. Nine, at High Falls, Ulster county, iSTew York. It was calcined to a "cinder," and then treated in all respects like mortar Xo. One of the last table, in regard to age, conditions of submersion, manner of breaking, and every other particular. The results are given below : HYDRAULIC CEMENTS, AND MOKTAES. TABLE XXXI. 271 Ko. of the mortar. Composition of the mortar. Weight,inlb8. siipimrted be- fore breaking. A-Ta^e breaking weiifbt. Pure cement paste 209 300 271 273 2:)9 269 .273^ Remark. — "We see that there is no remarkable superiority of strength in the mortars of pure Portland cement, Table XXX., and similar ones of American ce-' ment, Table XXXI. The Portland cement may not have been as good as usuaL 530. Trials were made with Portland and Koman cements at the London Crystal Palace ^0^^^, Exhibition, in 1851. The following data are taken from the report thereon : Portland and Roman cemec tried at London. 1. A prism of neat Portland cement, 4 months old, 4 inches square in cross sec- tion, on supports 16 inches apart, broke with 1,580 lbs. at the centre. 2. A prism of Roman cement, from the Harwich stone, same size as No 1, 7 months old, broke at 380 lbs. same bearing. Cement supposed to be defective. 3. A prism of Roman cement, from Sheppey stone, same as No 1, supported 1,100 lbs. before breaking. 4. A prism of Portland cement, 6 months old, 2" x 24" cross section, broke •with a tractile strain of 2,280 lbs. (equal to 414, 'i, lbs. per sq. inch). 5. Two 6 in. cubes of Portland stone, cemented with Portland cement, bore 4,500 lbs. tractile strain, when the hook gave way. Cement 4 months old. 6. Two 6 in. cubes, as above, united with Roman cement, broke at 2 J 80 lbs. (77| lbs. per sq. inch) when 5 months old, by separating from the stone, leaving the cement perfect. 7. A block of neat Portland, 3f " x 2^", one month old, tore asunder with a weight of 3240 lbs. (393 J lbs. per sq. incli). TRIALS IN A HYDRAULIC PRESS. 8. A block, all Portland cement, 18" high and 9" x 9", bore a pressure equal to 108^ tons on the square foot. 9. A mi.xture of 1 sand and 1 cement bore 80 tons per square foot. 10. do. 4 do. 1 do. do. 80 do. do. do. 11. do. 7 do. 1 do. do. 44^ do. do. da 12. A block, all Roman cement, broke at 22^ tons. 13. A mixture of 4 sand and 1 Roman cement would not bear any pressure. 14. A block of Portland stone 1^" x 1" broke up at 23 cwt. 272 PEACTICAL TREATISE OX LUTES, 15. A block of neat cement 12" x 2f " deep x 2^" horizontally, with supports 9t in. apart^ loaded at centre, broke with 9^ cwt. 16. A block of neat cement 12" x 2f " deep x 2^ ' wide, with supports 9 inches apart, scales broke with 25 cwt on centre. The experiment was repeated, and the cement broke with 42 cwt. 17. A block of 1 volume cement and 2 volumes fine shingle sand, 12" x 2}" deep x 2f ' wide, 8 inches bearing, broke with 10 cwt on the centre. 18. A fire-brick beam 14 in. wide. 9 inches deep, and 6 ft. 4 in. between the bearings, joined with neat cement and loaded uniformly over a central space 2 fl 4 in. long, broke through the bricks in two places with a weight of 20J cwt 19. A fire-brick beam, 14" wide x 10" deep, with 5 ft. 3 in. between the sup- ports, jointed with neat cement and loaded over a central space 2ft. 4 in. long, broke (through the bricksj in two places with 30 cwt 2^. Several o[ the fragments of brick-work, when thrown against a stone with force, broke in all^ases through bricks and not through the joints. 'SoTE. Erperiments made in En?laiid show that Portland cement adheres better to the Port- lind stone than to any other materiaL Its advantage for exterior stucco consists in its agreeable color natnTallT, its power of resisting frost, and its fireedom from yegetaticMi. 531. The trials undertaken to ascertain the adhesion of mor- , ,^ . ^ tar to the solid materials used in constructions. Adhesion of mor- ' tars to sohd ma- go to show that such experiments involve manj elements of uncertainty, and require to be con- ducted with great care. The first tests were with Croton Point front bricks, of which a large number were cemented to- gether face to face, at right angles to each other, as represented by Fig. 2, paragraph 32, and kept 320 days. Some were wetted with a sponge every two or three days, while others were kept dry. In tearing the bricks apart, at the expiration of the time spe- cified, it was found that, in a majority of cases, the surface of contact of the brick and mortar remained intact, the adhesion to the brick overcoming the cohesive strength either of the bricks themselves, or of the mortar composing joint between them. The results, therefore, although interesting for other reasons, furaish no entirely satisfactory measure of the power of adhesion. In fact, they are fair indications of the resistance offered by these materials to a force of traction, and incidentally, of the time which must elapse before the adhesive power to bricks of the several mortars tried exceeds this limit of resistance. HTDRAULIC CEMENTS, AND MOKTARS. 273 532. In giving the results, it will be necessary, in many in- stances, to give a diagram of the surface of fracture. In such cases, the splitting of the joints whereby a por- .. ^,, , . 1 , . 1 . Diagram of results. tion or the mortars remams upon each brick, is represented by a dotted surface, the tearing out of a part of the brick is shown by a surface shaded in parallel lines; and a clean separation from the bricks by a plain white surface. When the fracture takes place continuously either in brick or mortar, or is a continuous separation of one from the other, or when the end of ^ brick breaks off, the fact is so stated, and no. diagram given. Each marginal sketch, Table XXXII., repre- sents the area of the entire joint between two bricks. 533. The bricks were left on shelves in the open air, and those marked thus, *, were wetted with a sponge two or three times a week. 534. TABLE XXXII. Showing the resistance which Croton bricks cemented together crosswise, in pairs, face to face, offer to a force of traction ap- plied at right angles to the surfaces of contact. The " siftings" used in some of the mortars are the coarse particles of un- ground cement, which would not pass wire sieve No. 80. Age of mortars, 320 days. 8* Kind of cement. Delafleld & Baxter. . . Composition of mortar. Tb« measDrements are by volume. Stiff paste of pure cement . Breaki'g wi'iirlit by force of trac- tion, in lbs. 1,09T 1,101 I less ) < than V I m ) KemarkB. Fig a. End of brick broke off. Fig. 6. End of brick broke off. 18 274 PEACTICAL TEEATISE ON LIMES, Kind of cement Composition of mortar. The measarementa are by Tolume. Breaki'g wclsht by force of trac- tion, in lbs. Bemarkf. Lawrence Cement Co. Stiff paste of pore cement. ID Kingston & Boaendale. 898 1,25S 1,242 1,284 1,39S 1,22T &/^,mm %#^ End of brick broke off. Continuous fracture in the brick. End of brick broke off. Fig. d. ima^ End of brick broke off. Fig. «. IS* U Hancock, Maryland. 1« IT ». 19 21 ts 18 Newark & Rosendale, James River Delafleld & Baxter Cement in powder 8, siftings 1 , Cement in powder 4, siftings 1 . 1,284 1,055 648 777 1,023 617 1,213 859 1,278 820 979 End of brick broke off. Fig./ End of brick broke off. Fig. flr. \ . \ Fig.; End of brick broke off. Fig. i. Brick broke off. F Fig.j. Fig.*; HYDRAULIC CEMENTS AND JIOETAES. 2^5 Kini ol cement Composition of mortar. The mea«uremeiiU are by volume. lireaki'g wi-i(,'ht by force of trac tiuii, in lbs. Kemarks. 24* 25 26* 97 Delaflcld &, Baxter... M 88* 86* 89 40 Cement in powder 4, Billings 1 Cement in powder 2, Eiftings 1 Cement In powder 1, eiftings 1 Cement in powder 1, siftings 2. Cement in powder 4, sand 1 843 1,182 1,211 1,310 1,246 1,180 1,043 1,029 698 812 682 1.102 1,096 974 1,058 Fig. I. End of brick broke . M Continoons separation from the brick. Bri«k broke oB. 1,492 'Fig. I. 259 1,451 918 1,086 608 822 Fig. J. defective. Fig. K. Fig. L. Fig. M. Continnous splitting tlirougii tLe murtar. Fig.O. 2T8 PRACTICAL TEEATISE OX LniE3, Kind of cement Composition of mortar. Tba me«enremcnte «re ^ toIqid*. Brenki": by force of trac- tion, in lbs. B«maite « I Kewark Lime and I I Cement Mfg. Od. ) Cement in powder 1, saod 2. 893 .Fig. P. 634 &16 F!g.Q. Continnoos sejiaratioa from the brick. 535. The positive deductions fro/n tJie foregoing table appear to be as follows : 1st. That particles of unground cement exceeding -^^ inch in diameter mav be allowed in cement paste without sand to the extent of fifty per cent, of the ■whole, vrithont detriment to its adhesive or cohesive properties, -while a cor- responding proportion of sand injures the strength of the mortars in these respects about forty per cent. 2d. That when these unground particles exist in the cement paste to the extent of sixty-six per cent, of the whole, the adhesive strength is diminished about twenty-eight per cent. For a corresponding proportion of sand, the diminu- tion is sixty-ei^rht per cent. Si The addition of these siftings exercises a less injurious effect upon the cohesive than upon the adliesive property of cement. The converse is true when sand, instead of siftings, is used. 4.th. In all the mixtures with siftings. even when the latter amounted to sixty-six per cent, of the whole, the cohesive strength of the mortars exceeded its adhesion to the bricks. The same results appear to exist when the siftings are replaced by sand, until the volume of the latter exceeds twenty per cent, of the whole, after which the adhesion exceeds the cohesion. 6th. At the age of 320 days (and perhaps considerably within that period), the cohesive strength of pure cement mortar exceeds that of Croton front bricks. The converse is true when the mortar contains fifty per cent or more of sand. 6th. When cement is to be used without sand, as may be the case when grouting is resorted to. or when old walls are to be repaired by injections of thin paste, there is no advantage in having it ground to an impalpable powder. 536. The ingenions device mentioned below, for laving: stone- masonrv in cement-mortar under water, was Device for laying " stone under water suggested to me bj Major B. S. Alexander, IIYDr.AULIC CEMENTS, AND MORTARS. 270 Corps of Engineers, and was, I believe, practised "by that officer in the construction of the Minot's Ledge Light-House, Boston harbor. It consists in protecting the mortar from the dissolv- ing action of the water during the descent of the stone to its bed, by an envelope of muslin sufficiently loose in texture to allow the mortar to ooze through between the fibres, and thus form a bond with the stone previously laid. The idea is an- alogous to that followed by some Italian engineers in repair- ing and protecting submarine masonry by concrete, rammed into position in bags of loose, open texture. It may be ap- plied in the following manner, viz. : a piece of muslin of suitable quality, and somewhat larger than the bed of the stone to be laid, is first spread out on a horizontal surface and cov- ered with a coat of mortar of the thickness desired in the work, and of an area somewhat exceeding that of the bed of the stone. On this mortar the stone is then carefully placed and allowed to remain there until the mortar begins to stiffen a little, the margin of the cloth exterior to the stone havino- been folded up against the sides of the latter, and secured there by cords leading over the top. Th? stone is then lowered to its position on the wall, rammed into place, and not again dis- turbed. 537. Some trials made with a view to test the efficacy of this method of construction, although giving discrepant results, show, that if applied with Test of device ^^ above mentioned, care, it may be made to subserve a good pur- pose. Bricks were cemented together in pairs, as shown in the table last given. Some of them had cement paste only between them, others had a single layer of muslin next to one of the bricks, and others had muslin in the centre of the mortar joint. Other trials were made with prisms, 2"x2" in cross section, with a layer of muslin extended transversely across and through the prism, midway between the supports on which the prisms were broken. 638. Cement ^aste without sand was used in all cases, and 280 PRACTICAL TREATISE OX UQIES, Same continued. the samples were ninety -six days old when broken. "VTater was applied to them with a sponge two or three times a week, dnring the entire period. All the bricks were cemented while thoroughly wet. Table XXXni. contains the results. The numbers 15, 16, 17, and 18 were dipped in sea-water just before being cemented. 539. TABLE XXXHI. Showing the adhesive and cohesive strength which mortars of pure cement paste can attain, through a layer of com- Tvro wet bricks cemented together, without muslin. 6 " 6 u ^ u 8 9 « 10 u 11 13 14 u 15 « 16 u 17 H 18 - I with wet mnslln in | the middle of the V [ joint. ^ I j with muslin soaked | in creau of (.-ement > nest to jne of them ) muslin soaked in 1 cream of cement, I and bricks dipped j in sea-wat«r. J o_. j Continuous separation •^'^n from brick. SSllFig. 8. 930 Fig. T. 90S!End of brick broke off. r.-!)\S Continuous separation 94 Separated alon? the muslin. 1061 I 9TS End of brick broke off. I '(^ Separated alnn? the muslin. 115:3 End of brick broke off. 672 Separated along the muslin. 719 " " 1153 £-, J Continuous separation "'^n from brick. HYDRAULIC CEMENTS, AND MORTARS. 281 Same continued. mon tlu'n muslin. The mortar set under a pres- sure of thirty-eiojlit pounds per square inch, or about 500 pounds on the pair of bricks. Age of mortar, iiinetj-six days, 540. OBSERVATIONS ON THE FOREGOINQ TABLE. 1. The average resistauce, where there is a continuous separation from the muslin, is 507 pounds. 2. The average resistance, where there is a continuous separation from the brick, and no muslin was used, is 425 pounds. 3. The average resistance, where there is a continuous separation from the brick, and muslin was used, is 446 pounds. 4. The average resista^nce of all the cases where muslin was used, is 568 pounds. 5. The average resistance of all the cases where muslin was not used, is 692 pounds. 6. The case of muslin soaked in cream of cement next to one of tlie bricks, gave the best average result, viz. : 826 pounds ; the next best being when the bricks are put together without muslin, which gave an average of 632 pounds. 1. The three greatest resistances in the above table were obtained when muslin was used. In two of these (Nos. 10 and 12), the end of one brick broke ofiF; in the third, (No. 15,) the separation took place continuously along the muslin. 8. The worst results, when muslin was used, were obtained when the latter waa placed in the centre of joint, and not in contact with either brick, the differ- ence being very considerable, as an inspection of the table will show. The muslin used in these trials was much thicker than would be necessary in practice. 541. TABLE XXXIV. Other trials with muslin. Showing the strength of rectangular jprisms 2" x 2" in cross-section, some of them having a layer of muslin transversely across the prisms, midway between the sup- ports, and some having none. The prisms were ninety-six days old, of pure cement paste, the supports four inches apart. The pressure was applied in the middle. 1 Nature of test t %■ tn . C aj S -5 Bemorks. 1 2 3 Piece of muslin transversely across the prism 11 It 11 11 No muslin was used 113 103 353 337 322 304 Broke along the muslin. 4 11 II 5 11 II 6 n II 282 PEACTICAL TREATISE OX LI5IES 542. OBSERTAnOSS ox THE FOREGOIXG TABLE. 1. The average breaking weight of the prisms containing mushn, is 107 pounds: and of those containing no mushn, 329 pounds. 2. The Sth observation of Table XXXIII. is corroborated, viz. : that the most dis- advantageous place for the muslin is in the bodv of the mortar. 3. With thin musliu of loose texture, both the adhesion and cohesion through the muslin would undoubtedly b§ much greater than the foregoing Tables (XXXTTT. and XXXIY.) indicate. 543. TABLE XXXY. Showing the adhesion to Croton front Iricl's sand ^on^ the ad^ and jine cut granite^ of mortars containing dif- hesive properties ferent proportions of sand. The mortar was of of mortars. the consistency ordinarily used for brick masonry, and the bricks were used wet, and were pressed well together by hand. They were wetted with fresh water every alternate day for 29 days, the age of the mortar when tested. Each re- sult is the average of five trials. The right-hand column shows the ratio of the adhesive strength of the several mortars, assum- ing that of pure cement to be 1. Composition of the mortar. Materials cemented. c3 1 2 3 4 5 6 •7 8 9 10 11 12 Pure cement paste i uic urixiciii pii:MC 1 voL cement powder, 1 vol. sand 1 " " " 2 Pure cement paste 1 vol. cement powder, 1 vol. sand 1 " " " 2 " Croton bricks. . . 421 It 215 (1 ii 169 94 71 (1 59 stone or bricks varies con- eiderably among the difi'erent kinds of these materials, and par- ticularl}' with their porosity. "With the same material, it varies with the consistency of the mortar, and the quantity of sand which it contains. HYDEAULIC CEMENTS, AND MOKTAllS. 283 545. TABLE XXXYI. Showing the adhesion to venj fine cut granite of pure ce- ment made by the Newark & Rosendale Co., mixed with different proportions of water. The blocks measured 4" x 8" on the face, and were cemented together in pairs, face to face, at right angles to each other, and kept in fresh water. The stones were pressed together by hand, as in laying bricks, and were pulled apart at the expiration of 96 days by the device, shown in Fiur. 5. ^ Composition of the mortar. I'll ? a 1 380 1 2 |?Uo*lbs. 3Uj 3 4 \^ jj ^, jj ,j „ 5 6 T 8 9 10 11 12 1 vol. loose, dry cement, and -iX- vol. water. Consistency of very thick cream U it (( U (4 U « il U fcb U ti K 11 1 vol. loose, dry cement, and ^J- vol. water. Consistency of ordimiry mortar. 611] .5*4 1 591 ( hm J 400 . 449 f 47-2 J ?71 « 20. " 546. For the sake of economy, it is customary to add lime to cement mortars, and this may be done, to a considerable extent, when in positions ^^ke oT^Jnomy^ where hydraulic activity and strength are not re- quired in an eminent degree. The following table contains the results of trials with cement paste and mixtures of cement and lime paste, without sand. The cement was the dark Kosendale of excellent quality. 547. TABLE XXXYII. Showing the ultimate strength of rectangular jparaUelopipeds (2" X 2" X 8") of cement paste, and mixtures of cement and lime paste without sand, formed in vertical moulds, under a pres- sure of 32 lbs. per superficial inch, and broken when 95 days 284 PEACTICAL TBEATISE OX LIMES old, on supports 4 inches apart, by a force applied at the middle. The mortars were kept in sea-water from the time thev were one day old. CompositioD of the oement Penetration of the '\B.~-i ^.S-.^ 2 I>uint in inches. j^ '£ E r's.^-— 1 impact, i impiacts. j-S ; .^ , Pure cement paste. (Average of two trials.) Cement paste, 1 voL Lime paste, X vol . ivol. J vol. ITOI. ivoL JvoL 1 vol .114 .112 .117 .107 .155 .160 .147 .155 .155 .150 .150 .120 .200 .180 .187 .IsO .»t7 .210 .ISO .200 .IKt .ISO .200 .220 330 .270 .195 .163 .192 .1S7 .250 .250 .243 .250 .265 .2(>0 .195 .200 .300 .220 .395 .295 .325 .330 .3" to .890 .293 .290 .300 .»*<• .260 .3&0 994 957 .025 .034 .000 996 992 931 S63 S47 7So 769 597 570 613 5S2J 5971 574 55i 550 3t^1 36:r 355 l,002iIbB. 9791 565J •• 5691 50 J 75 J 3391 316 I oftsix 2S6 I **^-* 2S0j 548. Other mortars of light colored Hosendale cements and lime, mixed, formed into blocks of the same size, preserved and broken in precisel}^ the same manner as the foregoing, gave the following results when 95 days old. The average of four trials is given in each ease. TABLE XXXTTTL No. of the mortar. Composition of the mortar. Breaking weight, in Ibe. 1 2 C€ment paste, 1 volume. Lime paste. ^ volume 1 " " i " 73S 723i 732 3 " 1 " " f " 4 1 " " 1 " 603 Effect of lime on the strength of cement mortar. 549. Observations on Tables XXXVII. and XXXr//Z— 1st. TTe infer from the last ta- bles (XXXVII and XXXVni.), that the dark HYDRAULIC CEMENTS, AND MOIITARS. 285 colored Rosendale cements are less able to sustain a large dose of lime than those that are light colored, and that the latter suffer no serious deterioration of strength until the amount of lime paste exceeds the amount of cement paste. It does not necessarily follow that the ingredients which confer color on the cement are the cause, either immediate or remote, of this difference. The light colored Rosendale ce- ments are confined to one locality, that of High Falls, and it may be that local causes, operated at the period of, or subse- quent to their deposition, which so modified or changed the molecular or chemical condition of some of the ingredients, as to cause this variation, and at the same time be beyond the reach of ordinary analytical research. 550. 2d. In Tables XXXYII. and XXXYIII., no record is made of the effects which the addition of lime has on the hy- draulic activity of the cement. In regard to Efifect of lime on , . . , i. • 1 1 1.1 i. the hydraulic ac- ting pomt, however, numerous trials show that tivity'of cemeat a gang composed of equal proportions of the mortars, pastes of Rosendale cement and lime is sufficiently quick set- tino- for all purposes, except when immediate submersion is required ; and possesses, besides, the positive advantage over pure cement of coming to the hands of the masons in a better working condition, and is not liable to have its incipient set constantly disturbed on the mortar board, and its ultimate strength thereby impaired by remixing. There is a remarka- ble difference in the capacity of cements to withstand this degrading treatment. The extent to which they are affected by it seems to vary directly with their hydraulic activity. Thus, the Rosendale cements, which require 25 to 30 minutes to set at 65° F., will bear reworking much better than those James and Potomac River cements, which harden in five or six minutes. We would expect that the extent of the disturbance of the crystallization would be in direct proportion to the hy- draulic activity. 551. The use of alkaline silicates {soluble glass) as a means 286 ef conferring hydraulic energy upon fat lime has been reverted to iu foregoing portions of this work. Experiments uniformly indicate that its efficiency for such purposes, has been overrated. It may, and probably can be advantageously applied to the reclamation of the intermediate limes, (those in which the hy- draulic energy is exerted powerfully and rapidly when first mixed, but which soon yield and fall down under the action of the sluggish free lime present) ; but for fat limes, they appear 80 unsuitable, that even the statements of M. Kuhlmann him- self are insufficient to authorize their use. When added to the intermediate limes, they appear to exert their influence by giv- ing up their silica to the free lime present, thus neutralizing or perhaps only retarding its action, until the hydraulic principle has time to exert its indurating power. 552. Presuming, under ordinary circumstances, that the ad- dition of soluble glass to a paste of fat lime not only conferred hydraulicity, but augmented the strength of the Effect of soluble ' j. • i j j. ^ •j.t ^^ glass on the mortars, some trials were undertaken with the Btrength of mor- double silicate of potash and soda, in order to test its relative value when thus employed, aa compared with hydraulic cement itself. The specific gravity of the soluble glass used was 39° Beaume, at 62° F. Prisms of the usual size were made and kept in the air ninety-five days, when they were broken in the usual manner, on supports four inches apart. In the following table, the breaking weights are given in the right hand column. The first and second samples were formed under a pressure of 32 pounds per square inch, the others without pressure. The adliesion to bricks cemented together transversely is as follows : Formo,Uror|^-'-'«J:S| 9^ ,b3. ilimepaste 1.0 i sand 3.0 [•STl'.ba. soluble glass .125 ) HYDBAULIC CEMENTS, AND MOETAES. 287 TABLE XXXIX. J2i Composition of the mortar, in volumes. 5 t- Q) K« ■"' •-■2 -9 1 2 3 4 5 6 7 8 9 10 11 12 Lime paste, 1.0, sand, 2.0, soluble glass, .11. . 1.0, " 2.0, " " .11.. " 1.0, " 2.0 " 1.0, " 2.0 " 1.0, " 3.0 " 1.0, " 3.0, soluble glass, .08. . " 1.0, " 3.0, " » .10. . " 1.0, " 3.0, " " .125. " a.O, " 3.0, cement paste .50. . " 1.0, " 3.0, " " .33.. " 1.0, " 3.0, " " .25.. " 1.0, " 3.0, " " .166. 40 54 "I 67f 65 24^ 23 18 182J 166J S2 94J It injures the strength and ad- hesive properties of mortars. 553. From the foregoing results, wliich are the averages of many trials, it may be inferred that the double alkaline silicate, while it renders common mortar h^'draulic, injures its strength and its adhesive properties, and is greatly inferior to cement as a hydraulic agent, in both eflSciency and economy, irrespective of tlie degree of energy required. At the same time, it is con- ceded that in many cases, particularly for hardening soft and porous stones and concrete M'alls or stucco work, after these are well dried, it is of value when judiciously applied. Its use has, however, been attended with many failures, even in France, where the subject has received mucli attention, and we are yet without an easy and entirely practicable method of manipula- tion, that can safely be intrusted to the hands of oi'dinary me- chanics. Silicate of soda should be employed rarely if at all. 554. The experiments undertaken to ascertain the law of progressive increase in the strength and hard- ^ , Increase of ness of mortars of American cements do not ex- strength and hard- , 1 , • 1 /» ^> rm uess of mortars. tend over a very large period of time. The re- sults obtained, however, afford the means of a very fair com- parison between the strength of these mortars and some placed on trial at Toulon, with a view to determine the combinations 288 PEACTICAL TBZATTSr OX LIMllS, to be used in the construction of the dock in that harbor, under the superintendence of M. Xoel, Engineer-in- chief of Koads and Bridges. The trials at Toulon -were made during the rears lS4cO to 1S44, upon rectangular prisms 1.57 inches vride by .984: inches deep ; they were broken on supports 2.36 inches apart, by a pressure at the middle. A comparison of the results obtained in the two cases has been made by using the formulas : (1.) W_| E ^' - 1 (2.) W= I E 'if"-^ In the general formula (1) W represents the weight which the prism bears at the moment of rupture ; h, the breadth, and d. the depth of the prism ; I. the distance between the supports, and a, the weight of that portion of the prism represented by L The value of R, the co-efficient of mpture, having been ob- tained from the above equation from M. Xoel's prisms, by substituting for "W, h, d, L and a, their known values as reported we readily obtained the value "W for M. Xoel's mortar when the prisms are supposed to be two inches square in cross sec- tion, and broken on supports four inches apart, like the Amer- ican mortars, by substituting in equation (2) the deduced value of R, and the value of h', d', I', and a', corresponding to the American prisms. 555. T^e results of the computations above mentioned, which are the resistances to rupture of rectangular prisms 2"x 2" in cross section, resting on supports four inches apart, are given in Fig. 56, by curves constructed with abscissas, which represent the resistances or breaking weights, laid down, to a scale of ^ of an inch to 20 pounds, and with ordinates, which represent the age of the mortars to a scale of ^^ of an inch to twenty-five days. The mortara were kept in salt water until broken. The proportions of cement^ lime, and sand are given by vol- ume in all cases. HYDRAULIC CEMEXTS, AND MORTARS. 289 lbs. - ' iHinJ^, 1 Sliar, \21S fl>0 - - 1100 - lOJO - ma. 95a: - - - B50 - m - i \ --^'" ^ \ — '~"~\ 750 " - : S J_ ^ ^-^ " 709 - J, ' yr r"-^ .J .;..w- (iSP - - 1 1 1. ■4- ^- "*" . *-r''-^" 1 GOO - r ; 5S0 - - 1 1 /' s --— -• -- 500 / 1 1 V / / L — - --'^ <5ff " --f^-^';. // 1 - — ' 5 J — _ 1 1 - f . 1-4 / 10P f // A / ■-" JTO ■ h I Vx iW.- 1 A y ii<> - 1/ '/ zas." 4 / —'-'*" "i m"^ ¥ / \ - - — '' too / y'^' 1 S9 -^ 1/ / 1 i -^ i : 1 Dayi. :0 60 IfO 200 300 400 500 600 700 SOO nol iif. 55. 290 PRACTICAL TEE ATI SE OX LIMES, No. 1. ITortar composed of tvro parts Roman pozzuolana and 1.50 parts Theil ■hydraulic lime. No. 2. Mortar composed of two parts Roman pozzuolana and 1 part ordinary lime. Ko. 3. Mortar composed of two parts Roman pozzuolana and 1 part Theil hy- draulic lime. No. 4. Mortar composed of two parts sea-sand and 1 part Theil hydraulic lime. No. 5. Mortar composed of one part Roman pozzuolana, one part TheU hydraulic lime, and one part sea-sand. * No. 6. Mortar composed of one part Roman pozzuolana, one part ordinary lime, and one part sea-sand. No. 7. Mortar composed of one part Rosendale and Kingston cement and one part sand. No. 8. Mortar composed of one part Ogden's Rosendale cement, and one part sand. No. 9. Mortar composed of one part Hudson River cement, and one part sand. No. 10. Mortar composed of one part Lawrenceville Cement Manufacturing Co., and one part sand. 556. Of the four American cements represented in Fig. 56, Nos. 7, 9, and 10 are what are known as " dark" colored, and take the initial set, so as to support the ,V inch wire, loaded to ^ of a pound, in from twenty-five to thirty minutes, at a tempera- ture of 65° F. Is'o. S is a " light" cement, manufactured from Layer Xo. 16 at High Falls, (see paragraph 55). It sets very rapidly, (in from five to eight minutes,) when first mixed, provided the paste is not mixed too long, and is left entirely undisturbed ; but if the manipulating process continues beyond the time when the in- duration properly begins, the continual breaking up of the in- cipient set destroys the energy very much. It is far more sensitive in this particular than the slower acting cements, 7, 9, and 10. It may be further remarked that of the three American cements whose trial extended through the period of one year, the two slower setting " dark" colored varieties are inferior in strength to the other which is " light" colored and quick, until all attained the age of about three hundred days, when this condition of things is reversed. From this point onwards, the former increase in strength very rapidly, and the latter quite moderately. At four hundred days, the ''light" ce- HYDRAULIC CEMENTS, AND MORTARS. 291 ment is no stronger than a mortar of 1^ parts Tlieil hydraulic lime and 2 parts of Roman pozzuolana, (curve 1). 557. TABLE XL. Showing the strength of mortars of various cements made into prisms 2" X 2" X 8" in vertical moulds, un- ^^^^^^^^^ ^, ^^^, der a pressure of 32 pounds per square inch, tms of sundry , , , ,. • 1 it ceiaeuts. and broken on supports tour mclies apart, by a pressure midway between the supports. The prisms were kept in sea-water aftet- the first 24 hours, and were 320 days old •when broken. The breaking weights given are averaged from many trials. The cement was measured in powder. Kind of cement used. Breaking weights of inor tars composed of Pnre ce- ment. Cement, vol. 1, San.1, vol. 1. Cement, vol. 1, Sand, vol. 2. 1 2 3 4 5 6 7 8 9 10 U 12 13 14 15 16 17 18 19 EnglisVi Portland (artificial) Cumberland, Md Newark and Rosendale Delafield and Baxter (Rosendale) " Hoffman " Rosendale " Lawrence " Rosendale Round Top, Md TJticii, 111 Shepherdstown, Va Akron, N. Y Kingston and Rosendale Sandusky. Ohio James River, Va * Roman cement, Scotland The following were broken when one year old: Lawreuceville Manuf. Co. (Rosendale) Sandusky, Ohio Kensington, Ct Lawrence Cem't Co. (Rosendale) "Iloffman" Brand. Round Top, Md lbs 1,536 954 841 83G 849 777 732 747 764 720 554 553 802 954 875 lbs. 1.2G0 920 500 692 607 600 756 618 651 556 464 623 910 709 911 840 lbs. 950 558 500 532 562 450 603 500 638 380 506 * This cement appeared to be inferior in hydraulic energy to Roman cement generally, and had probably been injured by age and exposure. 558. From General Treussarfs experiments with mortars of fat lime and trass, or pozzuolana, it may be in- Qgn Treussart'a ferred that these two substances possess very experiments. 292 PEACnCAL TKEAllSE OX LDEES nearly equal merit, as agents for conferring strength and hy- draulic energy on common mortar. He says pozzuolana gave rather the better results with the same kind of lime ; although " in general there was little difference between the trass and the pozzuolana used." The results given in the following table were obtained by that engineer, and are introduced here as affording a just medium of comparison between such mortars, and those of the same age (one year) recorded in the table last given. (Table XL.) . 559. TABLE XLI. Breaking weights of pozzuolana and trass rnxyriars, one year old, formed into prisms 2" X 2" X 6", and resting on supports four inches apart. The lime was slaked to powder and meas- ured in that condition. The prisms had been kept in water. ^1 Composition of the mortar. 2^-^=f ^ ~ ^~ , ~ i^-^ 1 Strasburg lime, 1 roL, sand, 1 voL, trass, 1 vcd. 2 Stra-sburg lime, 1 vol trass, 2 Tosed to the air for a month or more after slaking, than if made into mortar when perfectly fresh ; and also that a mortar composed of one volume of lime powder and two volumes of trass, is injured if HYDRAULIC CEIIEXTS, AND JIOETAES. 293 a portion of the trass be replaced by sand. General Treussart also found that air slaked lime did not give as good results as lime slaked to powder with water. CHAPTER IX. 4. ' 561. W/iite alhaline effioresences upon the surface of brick ^ walls laid up in mortar, of which natural hy- • ^^ '^ \ . , , Emoresences on draulic lime or cement is the basis, frequently brick walls laid in , , • 1 , 1 1 ir cement mortar. produce a most unsightly appearance, and oner a grave objection to the use of cement for masonry exposed to view, or where it is desired to preserve any agreeable shade or tint, or retain the natural color of the brick employed. 562. On stone, these effloreseiices never at- tain a formidable aspect, and with the denser ^^ever formidable ^ ' on stone walls. varieties are almost imperceptible, being confin- ed exclusively to the pointing of the joints; but on brick work, they not unfrequently spread themselves over the entire surface of the wall. 563. A more serious ol)jection than any due to appearance simply, is furnislied by the lact t^^ii^Jtion!^ '^'^^ that the crystallization of these salts within the pores of the bricks, into which they have been absorbed from the mortar, is certain to cause disintegration. Even stone, particularly the most porous varieties, is not exempt from the efi'ects of this destructive agent, which acts, especially the soda salts, in many respects like frost. 564. The exudation of those alkaline solu- tions, which, in crystallizing, produce deleterious jratmosphere. salts, appears to be favored by a humid state of the atmosphere, and is, therefore, more prominently developed on the sea-shore than in localities more inland. 565. At KeiCjport, R. /., pints of it may at From Fort Adams, any time be collected from the walls of Fort Adams. Being almost entirely soluble in water, it is removed 294 PEACTICAL TKEATISE OJ^ LIMES, bj rain from all localities exposed to the direct action of this element, to be reabsorbed, in a great measure, before tbe aque- ous solution has time to run off. 566. A portion of this Fort Adams' efflorescence takes the Analysis of Fort ^'"^^""^ ^^ ^^"° ^^^^^ ^^ needles, frequently pro- Adams' efflores- jecting more than one inch from the face of the wall. Other portions present the appearance of fine snow. "WTien collected in a mass, it closely resembles Epsom salts in appearance, and is not unlike it in taste. Its composition, as determined bj analysis, is reported by Profes- sor Boynton, of the University of Mississippi to be as follows : Carbonic acid 19.90 Water expelled at a low red heat 52.30 Lime 04 Soda 27.96 Sulphuric acid 10 Magnesia 06 100.36 567. Another sainjyle of eff/yrescence from the ruins of an embrasure target erected at West Point in the " . , 1 . . , . ^rom West Point year 1854, subjected to quahtative analysis, gave carbonate of potash as tlie principal ingredient. Its ap- pearance upon the surface of the bricks, resembled that of a thin, rough coating of white sugar. It was readily removed as a powder by scraping. 568. M. Kuhlmann ^ of Lille ^ France, who gave his attention to this subject many years ago, and who has !*r.?!'I^^°'''^ from time to time published his investigations, expenence. * o ' without proposing any efficient remedy for the evils complained of, notices some efflorescences of a much more complicated composition than those from Fort Adams. Pro- fessor Kuhlmann found, that although efflorescences of nitrate of potash (saltpetre), or ammonia, were of no rare occurrence, those of carbonate and sulphate of soda were much more com- mon, and that many stone and brick walls, laid up in hydraulic HYDEAULIC CEMENTS, AND MORTARS. 295 mortar within periods quite recent, were covered with exuda- tions of caustic and carbonated potash, containing chlorides of potassium and of sodium, 569. One source of these salts of soda and potash is, beyond doubt, tlie hydraulic lime or cement used in the mortar; derived partly from the stone itself and'^poush ^ ^° * and partly from the ashes of the fuel used in calcination, when the burning takes place in ordinary draw kilns. About 35 lbs, of anthracite coal are required to calcine 1 bbl. (300 lbs.) of cement, and no precaution whatever is taken, to separate the coal ashes. From the same cause, the cement; also becomes adulterated with iine particles of unconsumed. coal, amounting sometimes to three or four per cent, of the whole. When the cement is coarsely ground, these particles are plainly visible, but in the condition of impalpable powder, they are lost to the naked eye, 570. Proximity to the sea, where the atmosphere is a con- stant source, will account for the preponderance „ • •. . .i. ' -^ ^ Proximity to the of carbonate of soda in the walls of Fort Adams, sea favors eiHo- 11 /'I !• 1 1 T • rescence. a,s well as lor the exceeumgly large volume oi efflorescence. It seems improbable that the mortar could be the origin of so much alkali. 571. Three plausible methods of obviating the appearance of these salts suggest themselves : Firsts to add some chemical re-agent that will 1 • • 1 • ^1 Remedies, permanently hx them within the body ot the mortar by converting them into insoluble compounds. Second, to render them, deliquescent either before, or after they form those compounds that effloresce. Third, to Haponify them by adding some oily substance. 572. Under t\\ejirst method, potash can be managed very well. Ilydrofluosilicic acid converts it into a well-known insoluble compound, while the action upon the soda, if present, is not disadvantageous. Potash, however, is harmless in its effects, compared with soda. The sulphate of soda, likely to be formed 296 PRACTICAL TEEATISE OX LIMES, in the vicinity of large cities, from the absorption of the sul- phuric acid o:as, acts like frost in crystallizinor, 573. The second method does not seem to give promise of success. 574. The tfdrd method, on the contrary, does promise success, and our trials under it have been numerous. "We liave found it convenient to make common lime the vehicle for conveying the fatty substance to the cement, and here take occasion again to call attention to the fact that lime paste may be added to a cement paste in much larger quantities than is usually prac- tised in important works, without any considerable loss of ten- sile strength or hardness. There is no material diminution of strength until the volume of lime paste becomes nearly equal to that of the cement paste (see Tables XXXYII. and XXXVIII.), and it may be used within that limit without apprehension, under the most unfavorable circumstances in which mortars can be placed. 575. To secure a complete dissemination of the fatty matter, it should be mixed up with the caustic lime, so comte^n. ^^^^ ^^ \^Q2X and other phenomena developed in slaking will complete the incorporation. Its amount will depend upon the proportion between the cement and lime pastes in the mortar, and may vary between 5 and 10 per cent, of the weight of the quicklime, when the latter is employed simply as a vehicle. 576. In examining and judging results, in diSti^gtheTiais. o^<^^^ ^^ ^^^'^^ ^TVQx&, to be apprehended from the minute quantity of alkali generally present in cement, and from the apparently precarious law which seems to control its appearance in the efflorescent state, the amount of alkali was, in many cases, greatly increased, (some- times several hundred per cent..) by adding to it from a solu- tion of the salts taken from Fort Adams. This solution was mixed with the water used for making the mortar. With the mortar thus prepared, bricks were cemented together and laid nXDKAULIC CEMEXT3, AND MORTAES. 297 away in pairs, some of them bein<^ moistened occasionally, and others left dry. Cakes of the mortar not in contact with brick were also preserved. In all cases where there was any considerable excess of the alkaline ingredients, a plentiful crop of crystals appeared on the surface within a day or two after the mortar wag prepared. Ko additional efflorescence took place after these were removed. In no case was there any efflorescence from mortar containing the fatty substance, but to which no saline ingredients had been added. Itjs believed that the pro}X)rtion of the several ingredients in practice should be from 8 to 12 pouTids of the fatty substance to 100 pounds of quicklime, and 300 pounds of cement powder. The cheapest kinds of animal fatty matter will answer. 577. It would not be safe to pronounce at once in favor of this method of remedying the evils of efflorescence. It certainly appears to give promise of success. INDURATION OF MORTARS OF FAT LIME. 578. We have indicated, paragraph 331, that the hardening of fat lime mortars could be partially attributed to the absorp- tion of carbonic acid gas, producing carbonate of lime (CaO. CO 2). The lime absorbs only about one-half the quantity of car- bonic acid (COi), necessary to convert the whole into carbonate of lime ; or, in other words, only ^^^c adc^^ about one-half of the lime becomes thus con- verted, the formula for the hydrate present being CaO.COsX CaO. II. But the hardening of the fat lime mortars cannot be entirely attributed to the formation of carbonate of lime. For we know that mortar, in the centre of thick walls, which never becomes carbonated, nevertheless possesses a fair degree of adhesiveness and hardness. Some mortars, 300 years old, examined in Dresden by Petzholdt, yielded a strong lime water when digested in fresh water, and must therefore have con- 298 PBACnCAL TEEATTSE OX LDCES, taiiied caustic lime. Another portion of the same mortar effer- vesced freely with cold dilute muriatic acid, and after a few minutes yielded a stiff jelly, proving the previous combination of lime and silica. Analysis of mortars of fat limes and sili- cious sand 100 years old, and of the limes which furnished them were also made. 579. From, the experiments ofJPetzholdi^ certain conclusions were drawn : 1st. That there was more soluble silica in the lime mortar than in the original lime. 2d. That there was three times as much soluble silica in the mortar three hundred years old, as in the mortar one hundred years old, and consequently, 3d. That there must have been a chemical combination be- tween the lime and the silicious sand. 4:th. The presumption is that the silicious compound formed, acted as an indurating agent. But we do not find in these trials a reason Mortars contain- for the induration of mortars containing none VIS calcareous said only. but calcareous sand. Analyses do not prove a chemical combination between the lime and the raw limestone composing this sand, and we must therefore look to the crystallization of the hvdrate of lime durinor the process of desiccation, for the cause of the hardening in this case. 5S0. The gang of ordinary lime mortars is a mechanical mixture of a paste of hydrate of lime and Ordinary mortar lime Water, and in drving, small crvstals a mechanical , iiit t*'i ^ • mixture. ot soluble lime are deposited on the adja- cent surfaces, and adhere with such force to them, as to increase very materially the strength of the aggre- gates, when the sm-faces become closely approximated, as is the case with mortars. In practice, the proportion of sand would be such, that the hydrate will form the thinnest possible stratum between the grains. Mortars containing a deficiency HYDEAIILIO CEMENTS, ATs^D MOETARS. 299 of sand, indurate very slowly. Wherever the soluble lime comes in contact with air, or even with water, carbonic acid is absorbed, and subcarbonates formed, which accounts for the superior hardness of the surface of mortars. When carbonic acid is thus absorbed, its chemical equivalent of water escapes from the hydrate ; hence the dampness of newly-built walls, and newly-plastered rooms. To the foregoing causes collec- tively, therefore, to wit : the chemical formation of silicate of lime and carbonate of lime, and the crystallization of the hydrate between and upon the surfaces of the sand, we must ascribe the solidification of common mortars. 581. Mortars of commion lime^ suitably compounded, "set," or lose their plasticity in a very few days, and acquire strength with such rapidity, that in Setting of mor- ., . ,.11 Tf. 1 . tars oi' commcti the erection ot the largest edinces, there is no lime. occasion to wait for the mortar to harden. They become sufficiently strong to resist a powerful force of compression long before they exhibit any adhesion to the solid materials. Such mortars obtain their maximum strenofth and liardness only after the lapse of years and even centuries. THEORY OF HYDRAULIC INDURATIOK 582. Tlie ingredients of hydraulic limestones may be sepa- rated by analysis into two distinct classes of substances: 1st. Ordinary carbonates of lime, of mag- nesia, and of the oxides. h^uuf Ul 2d. Yarious silicates, that is, combinations ^^°'^®- of silica with alumina, lime, magnesia, the alkalies, &c. Not unfrequently, the only ingredient, except those of the first class, is almost pure silica. In burning, the first effect is to expel carbonic acid ; the second, to efiect a combination between the lime, magnesia, &c., thus liberated, and a por- ^ur^iQ^^*^* ^^ tion of the silicates or silica, producing com- 300 pounds liaving an excess of base, and therefore easily attacked bj acids. In fact, burnt hydraulic lines are generally qnite Boluble in acids, leaVing gelatinous silica. Another portion of the silica remains uncombined until it is brought into contact with lime in the presence of water, when it unites with the lime held in aqueous solution. 583. A lengthy discussion of the reciprocal actions of the several substances entering into the composition Theory of hy- of hydraulic mortars, which take place during draulic induration , , • ,> i i i i continued. the burning ot the stone, and the subsequent induration of the mortars, will not be attempted. A brief reference to the parts played by the principal ingre- dients, particularly the lime, magnesia, silica, and alumina, would seem to be required. The hydraulicity of mortars is the result of combinations between these substances, effected or commenced during the calcination, in the production of compounds which become hydrated in the presence of water, and afterwards undergo a species of crystallization, technically- termed " setting." The reactions begun by the agency of heat, are therefore continued and perfected by the agency of water. 584. We will first take a silieious limestone for example, capable of producing fair hydraulic lime, as dis- Products of sih- tiuguished from cement, like many of the beds cious limestones. o ? j found in the calciferous sand rock, (paragraph 9), containing carbonate of lime in excess, and silica in every stage of subdivision, ordinarily found in fine quartzose sand. If the several ingredients are homogeneously mixed in the raw Btone, a proper, that is to sa^', a complete calcination of this stone results in a combination of all the silica, not in the state of inert sand, with its equivalent of lime. The resulting hy- draulic lime will contain free caustic lime, inert sand, and a silicate of lime, of which the formula in the general case will be SiOa.SCaO. Tlie hydraulic virtue of this variety of lime is derived in a sreat measure from this silicate. When mixed into a paste with fresh water, the silicate combines with six HYDKAULIC CEMENTS, AND MORTARS. 301 equivalents of that substance, producing the liydrosilicate of lime (SiOj.CaO + OlIO). All our experience and researches go to prove that silica plays a most important part in the Boliditication of hydraulic limes and cements, and that the de- gree of hardness attained depends on the molecular condition of the silica, and the amount of base M'hich ultimately com- bines with it. In the formation of silicate of lime, the limit of saturation should never be reached, for this requires two equivalents of silicic acid (silica) to three of lime (^SiOs.SCaO), and contains .48 of lime and .52 of silica — a compound pos- sessing no hydraulicity at any stage of calcination, and con- taining double the proportion of silica deemed most advan- tageous for mortars. From analyses of mortars of the Theil hydraulic lime, it was discovered that the liydrosilicate con- tained .25 of silica, .47 of lime, and .28 of water. Besides the silicate of lime formed during the calcination, there is another, formed by a transfer of soluble lime to the silica, which, from the heterogeneous character of the stone, does not combine under the influence of heat. 585. If the limestone contains alumina in addition to the siUcaj or, in other words, if clay be one of its constituent ele- ments, in proportions suitable for ordinary hy- draulic lime, carbonate of lime still being in when alumina is excess, the reactions which take place during the calcination and the quality of the resulting product will depend on the intensity and duration of the heat. When this is simply sufficient to expel all the carbonic acid, a separate and independent combination of lime with silica and alumina takes place during the burning, producing silicate and alurainate of lime, both of which become hydrated by taking up six equiva- lents of water. The resulting hydrosilieatcs are represented by the formulas Si03.3CaO-hCIIO, and A103.3CaO+6HO. 302 PRACTICAL TREATISE OX LIMES, Synthetical experiments appear to indicate that the alumin- ate is the least stable of these two substances. 586. If we vary the conditions of calaination in the last „„ , „ . mentioned case, by auo^mentina; the intensity Effect of augment- > ^f o o j ing intensity and and duration of the heat to that degree neces- duration of lieat. . , • -n .• p sary to cause partial vitntication ot some por- tions, but not of all, the product becomes heterogeneous. In those portions burnt the most, the silica, alumina, and lime are combined together by the heat under certain reactions that at present appear to be rather obscure. This is more especially the case, when other substances are present, which may act as fluxes, MM. Chatoney and Rivot incline to the opinion that the silicates of alumina and of lime are both formed, and that these compounds, in the presence of water, are decomposed, the results being aluminate and silicate of lime, which become hydrated by combining with three equivalents of water. In that case, the formula for these compounds will be Al.Oa.SCa 0+3H0 and SlOa.SCaO+SHO. Tlie fact that these chemical reactions require for their completion only half as much water as when the heat is less intense during the burning, may be intimately connected with the superior hardness of some of the gangs made from vitrified cement. In those portions least burnt, the aluminate and silicate of lime are separately formed by the action of heat, and these combine directly with 6 HO, as in paragraphs 584 and 585. 587. If we suppose the clay to he in excess in the limestone, as is generally the case with marls, a moderate when the clay is burning, just sufficient to expel tlie carbonic in excess. ^^-^^ causes a separation between the alumina and silica of the clay, the alumina remaining practically inert, while the silica combines with the lime, producing SiOs.SCaO. This becomes hydrated by taking up six equivalents of water, producing a hydrated silicate of the same composition as that recorded in paragraphs 584 and 585. A high heat produces rather complicated and obscure reactions on this class of sub- HYDRAULIC CEMENTS, ATsD M0ETAE3. 303 stancee. A partial triple combination of alumina, silica, and lime takes place during the burning, and the compounds thus formed become hydrated under conditions not very thoroughly understood. 588. The setting of mortars of fat lime and pozzuolana, natu- ral or artificial, is likewise due to the formation of hydrated compounds of lime with silica and *^"[*"" ^^^S^* "™' J 1 and pozzuoiana. alumina. The lime attacks the silica and alu- mina, freeing them from previous combinations, when such exist, and slowly forms with them SiOs.SCaO, and AI5O3. 3CaO. 589. It has been recommended to allow these mortars to remain mixed for some time, before tempering . . .To remain mixed them just previous to use, a precaution which some time before rests upon a plausible, and doubtless, a sound ^^ip^""^' °'^ ^^®- theory ; for while the combinations of lime with silica and alumina previously exist in the hydraulic limes and cements, (having been formed during the calcination and are, therefore, in condition to become hydrates at once, in presence of water,) the conditions are quite different with mortars of fat lime and pozzuolana, in which the silica and alumina have to first free themselves from combinations peculiar to, and existing in the pozzuolana before they can form in the wet way those com- pounds, whicli afterwards become hydrates, and confer hydrau- licity. From this we can comprehend why fat lime should be used in preference to hydraulic lime for pozzuolana mortars, since the compounds formed during the burning of hydraulic lime will have become hydrates, and will have initiated the hydraulic set, before those formed in the wet way between the free caustic lime and the pozzuolana will have completed the preliminary decomposition : and because, for the same reason, if we employ hydraulic lime, it is only the excess of caustic lime in it that combines advantageously with the pozzuolana. The operation in the mortar of two dissimilar powers, one com- posing^ and the other decomjjosh^g in cliaracter, might operate 30,4 PRACTICAL TREATISE OX LIMES, disadvantageously. The conditions should be such, that the different combinations of the lime with the silica and alumina, no matter how, when, or where formed, should become hj- drated simultaneously. 590. Magiieda plays an im.portant part in the setting of . ^. . mortars derived from the aro-illo-mao^nesian Action of mao:iie- ~ Bia on the setting limestones, such as those which furnish the Rosen dale cements. The magnesia, like the lime, appears in tlie form of the carbonate (MgO.COo). During calcination, the carbonic acid (COo) is driven off, leaving prot- oxide of magnesia (MgO) which comports itself like lime in the presence of silica and alumina, by forming silicate of magne- sia (SiOs.SMgO) and aluminate of magnesia (AlsOg.S^MgO). These compounds become hj-drated in the presence of water, and are pronounced by both Yicat and Chatoney to furnish g-ano-s which resist the dissolving action of sea-water better than the silicate and aluminate of lime. This statement is doubtless correct, for we know that all of those compounds, whether in air or water, absorb carbonic acid, and pass to the condition of subcarbonates, and that the carbonate of lime is more soluble in water holding carbonic acid, and certain or- ganic acids of the soil in solution, than the carbonate of mag- nesia. At all events, whatever may be the cause of the supe- riority, it is pretty well established by experience, that the ce- ments derived from the argillo-magnesian limestones furnish a durable cement for constructions in the sea. In Marshal Yaillant's report to the French Academy of Sciences, from the Commission to which MM. Chatoney and Rivot's paper was referred in 1856, this superiority of the magnesian hydrates is distinctly asserted ; but the Commission appear to have been led to erroneous inferences in regard to the conditions under which it is expedient or possible to take advantage of this prop- erty. We quote from the first part of their report, as follows : " On pourrait en conclure qu'il serait utile de remplacer la chaux par la magnesie pour fabriquer les mortiers hydrau- HYDRAULIC CEIIENTS, AND MOETARS. 305 Hqnes ; mais la magnesie n'est pas assez repandue dans la na- ture pour qu'on puisse I'employer a 1' exclusion , , , 1 , V. r 1 Opinion of Mar- de la cliaux dans les constructions a la mer. ^^^^^^ vaiUant. En tout cas, il faut proscrire avec soin le mel- ange de ces bases, c'est-a-dire Temploi des calcaires magnesiens, attendu que les silicates et aluminates formes par la magnesie ne s'hydratent pas avec la meme vitesse que ceux formes par la chaux, et qu'ils risquent d'ailleurs d'etre partiellement decom- poses apres I'immersion par la chaux restee en exces, si le me- lange n'a pas ete longtemps digcre au prealable dans une faible quantite d'eau. En d'autres termes, ces mortiers ne presentent aucune homogeneite, aucune chance de stabilite dans la prise." It is needless to say that the " careful proscription" of "mag- nesian limestones" so forcibly inculcated in this quotation is altogether too comprehensive. While we are not prepared to say that tbe double carbonate of lime and magnesia, called dolomite, containing a single equivalent of each of the bases, although eminently hydraulic, could, in practice, be relied upon for hydraulic mortars, even in localities where the supply is sufficiently abundant for such a purpose, yet it is certain, that many magnesian limestones, especially those which contain clay, do furnish good cements, and that the Rosendale brands, our chief and best reliance in the United States, are derived from this class, and are by no means open to the objection ad- vanced above, viz. : that they offer " neither homogeneousness nor chance of stability in setting." Some portions of the de- posit of Rosendale cement stone contain as high as .39 of car- bonate of magnesia to .40 of carbonate of lime ; others, as low as .14:48 of carbonate of magnesia, to .2848 of carbonate of lime. Between these extremes are found numerous interme- diate proportions. 591. Recent analyses of American cements j^jnencan co- show that they all contain more or less of the ments contaia alkalies, sometimes caustic and sometimes in the form of chlorides of sodium and potassium. The chlorides are 20 306 PRACTICAL TEEATISE OX LIMES, present in all the Rosendale cements, as well as in tliose from Shepherdstown, Virginia, and Akron, Erie Co., iS^ew York. The alkalies promote hydraulic induration in their own pecu- liar way. "VTe know that mortars of Amoricau cements part with soda and potash when immersed in water, and render the latter alkaline; and that alumina and gelatinous silica are soluble in potash; also that a solution of an alkaline silicate' readily gives up its silica to lime. We may therefore presume that the alkalies, particularly the potash, act by first dissolv- ing the silica and then transferring it to lime, at the same time that the water acts by dissolving the lime and carrying it to the silica. "WTien the silica is 592. "When the silica, present in suitable form in excess. ^^^ entering into combination, is in excess of the equivalent required by the lime and magnesia, the proportion should be adjusted in practice, as far as possible, by adding paste of fat lime, otherwise the mortar will be deficient in strength and liable to crack. Several prisms (2"x2"x8") were made of the paste of James River cement without sand, and kept in water until they were 320 days old. This cement contains nearly fifty per cent, of silica, although the analysis does not state in what form it exists. Some of the prisms broke in handling. They were all covered over more or less with cracks, were quite brittle, and ranged rather above the average hardness of mortars of pure cement paste as shown by the penetration of the needle. On supports 4" apart those that remained whole gave an average breaking weight of 346 lbs. The fracture was quite jagged and angular, although each of the small surfaces composing it was in itself, compara- tively smooth and conchoidal. The first impact of the needle split most of the prisms, and none of them withstood the second. When the block did not split, the effect of the first impact was to raise up the mortar in thin scales around the needle. Fig. 5g. nyDRAULIC CEMENTS, AND MORTARS. 30 7 The general appearance of the fraction is given in Figs. 56 and 57. None of the prisms left in the air conduct- ed themselves in this peculiar way, although they gave low breaking weights, the average Leing only 330 lbs. A paste of this cement is improved by the addition of lime paste, up to the limit of 75 to T / M- • ^ ^ Fig. 57. 1(10 per cent. Inert sihca in cement acts simply as an adulterating agent, and takes the place of so much sand. THE IIAEDENING, BY ARTIFICIAL MEANS, OF STONE, BPJCK, MORTAR, &c. 593. "Within the last twelve or fifteen years, the attention of engineers and architects has been directed, in a manner more than usually active, particularly in Europe, to the destructible character of many of the materials in most common use for the walls of constructions of all kinds. The consequence is, that a variety of methods have been devised, and to a limited extent practised, for increasing their durability. 594. No material will retain through a long The hardest stone series of vears the same appearance as when liable to giadual dceuy. fresh from the hands of the workman. Even the hardest, most solid and compact rocks, such as granite, sienite, gneiss and the densest silicious rocks, exhibit after long exposure, indubitable evidences of " weathering ;" while many buildings erected within the last quarter of a century, of some varieties of the limestone, marble, and sandstone of this country, the Bath, Reigate, and Caen stone of the British Isles, and their corresponding formations on the continent of Europe, are already in an advanced state of decay. 595. Of all the causes of progressive destructibility in stone 308 .,, ^. - none are more active or more diflScult to sruard Alternations of o heat and cold, a against, than frequent alternations of lieat and cause. 1 1 1 /■ • IT Tx cold, and or moisture and dryness. However slight a change of temperature may be, all bodies will expand when it is raised, and contract when it is lowered, although some, even among different kinds of stone, are much more sen- sitive to those variations than others. In the United States, the thermometer will vary 110 to 120 degrees between the severe frosts of winter and the direct rays of the summer's sun ; extremes which, operating in conjunction with the presence of moisture in the pores of the solid body, alternating not only with the seasons, but oftentimes, especially in the winter, with the recurrence of night and day, between the opposite condi- tions of water and ice, cannot but result in a change in the state of aggregation of the body, and, if the latter be more than or- dinarily porous, in serious disaggregations near the surface. This will be more especially the case, if the mass be made up of several substances of different specific gravities, and of unequal capacity for resisting the expanding power of heat. 596. The methods devised for increasing the durability of stones, hoicks, tiles, &c., are doubtless equally well adapted to mortar work, such as exterior stucco or concrete, and may with propriety be noticed here. In fact, those modes which now give the best promise of efiicacy, base their claims to pub- lic support, in a great measure, upon their alleged applicability to such purposes, particularly to the restoration of monuments, statuary, interior and exterior ornamentation, «fec. 597. The methods of artificial induration are reduceable to The general twO, as follows : methods of artifi- First. By means of those mixtures or solu- cial induration. . i . i i i ^• ^ tions, which, wliether applied to the surface with a brush like paint or oil, or by immersing the solid body in them for a longer or shorter time, act simply as mechanical protectives against the penetration of moisture, by forming either an impervious coating upon its surface, or, by penetrat- HYDEAULIC CEMEIfTS, AND MOKTAKS. 309 ing to a greater or less deptli, close up tlie pores, and render it non-absorbent. Second. By means of those aqueous solutions, which possess the properties of reagents, and which, when entering the inter- stices of the solid, give rise to certain chemical reactions by combining with it, or with other and difi'erent solutions ap- plied before or after, whereby insoluble solids are produced, and the density and hardness, and consequently the durability and strength of the solid are increased. 598, Amoncr the first class may be noticed „ , ^ , ^ - '' Examples belong- a patent " for indurating and preserving stone," ing to the first granted in England in 1847. The stone to be operated upon was first dressed to the required form, and then thoroughly dried in a heated chamber, or by some other suita- ble contrivance, to drive off the moisture. The solution, com- posed of resin dissolved in turpentine, oil, wax, tallow, or some other fatty substance, being brought to the boiling point in a vessel of the requisite dimensions, is retained at that tempera- ture while the stone is immersed in it. Ordinarily, two hours' boiling has been found sufticient to impregnate the stone to the depth of one inch. A similar process was patented in England in 1853, in the application of which it is recommended to operate upon the stone in air-tight chambers, exhausted, or partially so, of the air, by wliich means a more thorough impregnation of the material is secured. Several varieties of indurating mixtures were recommended by the patentee, only two of which we will give. The first is composed of resin dissolved in naphtha, turpentine, or spirits of wine, mixed with gutta percha dissolved in coal-tar naphtha, and when heated, mixed still further with some kind of oil, after whicli well pulverized " anti-corrosia" is added. Another mixtm-e is made from unslaked lime, to which is added, whilst slaking, oil, or soap fat, and Russia tallow. When the slaking is completed, the whole is placed in a vessel with alum water, 310 PEACTICAL Tr.E.'.TI3i: OX LIMES, pulvei'ized " anti-corrosia," and proto-sulpliate of iron, and a solution made from potatoes and beer settlings. After settling, the solution is decanted for use. Another patented process consists in the repeated applica- tion, with a brush, of a solution of bee's wax in coal-tar naph- tha, which is varied when the natural color of the stone is to be preserved, to white wax dissolved in double distilled cam- pheue. ' 599. Without discussing the respective merits of these Fr thod t iiisthods, we will simply suggest that no process practicable ai- of indurating and preserving stone, that re- quires the handling and removing of heavy masses, will ever be likely to reach an extensive application in the United States. The characteristic impetuosity of our peo- ple, the very active competition existing in all departments of industry, and the low scale of prices to which this state of things has given bii'th, excludes the idea that any slow, plod- ding, and costly method, however valuable and efficacious for attaining a desirable end, can enter into successful competition with one that is more rapid, less expensive, and easy of appli- cation. It is also unlikely that any plan for indurating and preserving architectural stonework, that cannot be advan- tageously executed without complicated appliances, and aftei the building is erected, will ever become of any practical utili- ty ; and it is equally unlikely that an 3^ solution of resin, wax, or like substances in the fixed or essential oils, which, whether applied hot or cold, merely remain mechanically interposed in the interstices of the solid body, can ever furnish other than a temporary protection. t 600. The methods of preservation which belong to the second Examples belong- ^^'^^S' i" ^^^^^^^ the indurating media are ap- ing to the second plied in the condition of an aqueous solution method. possessmg reacting powers, rest upon a more scientific basis, and are essentially different from those referred to abovo. Mr. Fred. Eansome gives the following particu- HYDEAULIC CEMENTS, AND MORTARS. 311 lars of a process for vvhicli lie procured a pat- Ransome's pro- ent in England : It " consists in the employ- ment of two or more separate solutions, which, by mutually acting u})on each other, produce within the pores of the stone an indestructible mineral precipitate. In operating, the stone may either be iminersed in, or saturated on the surface with a weak solution of silicate of soda or potash, and afterwards with a solution of chloride of calcium or barium, when an insoluble silicate of lime or baryta is formed in the pores of the stone, rendering it impervious to moisture, and in- susceptible of injurious effects from atmospheric influences. Or, instead of a silicate of potash or soda, a solution of sul- phate of alumina may be employed, and then, by an applica- tion of baryta, a compound of sulphate of bary tes and alumina is formed." This process, although apparently closely re- ^j Kuhimann's scmbling that recommended by Professor Fred, general process. Kuhlmann, of Lille, briefly referred to in paragraph 551, differa from it in the important particular of its alleged adaptation to all kinds of stone, and of using, in all cases, two solutions in- stead of one, the increase of density of the stone operated upon, being due to the solid compound formed by the mutual decom- position of the two fluids employed ; whereas M. Kuhlmann recommends his process of silicatization to the hardening of soft limestones and marble, whether in the walls of buildings or in the form of monuments, ornamentation, or statuary, to calcareous mortars of all kinds, and to all works of whatevei character made of plaster, such as mouldings, casts, &c. GOl. The following extract is taken from the " Report of the Commission charged by the Minister of Agri- 1 r~\ ^ T -r. 1 TIT- 1 Report of Com- culture. Commerce, and Public W orks, with the misniou on Kuhl- examinatioij of M. Kuhimann's processes of sili- ™''°''^ process. catization." "77/6 liquor of Jlin is— siVicaie of potash or silicate of soda- is the base of the new process. As far back as the year 1810, 312 PRACTICAL TREATISE OX LIMES, Bome examination into the origin and nature of the efflores- cences on walls, had given M. Kuhlmann an opportunity to establish, beyond doubt, the presence of potash and of soda in most of the limestones of all geological epochs, in larger pro- portions in the hydraulic limestones than in those suitable for common lime. What influence can they exert ui^on the hy- draulic property? M. Kuhlmann is of the opinion that, under the influence of carbonate of potash or of soda, the silicious limestones give rise by calcination, to double combinations of lime, of silica, or alumina, with an alkali, analogous to those obtained by the calcination of some species of hydrated mine- rals, such as the apophyllite, the stilbite, and the analcime ; that these compounds, subsequently put in contact with water, undergo a reaction analogous to that which causes the consoli- dation of suljAate of lime, viz. : a hydration, and as a conse- quence thereof, an induration. " The principal effect produced by the potash and the soda, is to convey a certain portion of silica to the ash and soda lime, giving birth to silicates, which, while they absorb the water with avidity, retain only such quantity of it as is necessary for their composition as hydrates, and for their induration. I^^umerous facts support this theory : fat lime, placed in contact with a solution of silicate of potash, is immediately transformed into hydraulic lime ; mortars of fat lime, injected several times with a solution of alkaline silicates are transformed into hydraulic mortars ; lastly, with the vitre- ous alkaline silicate, and lime more or less energetic, hydraulic cements can be produced, which can be utilized in localities where none but fat lime is found in the quarries. 602. Sllicatization. — M. Kuhlmann^ by noticing the great affinity of lime for silica, left free in the nascent state, from its combination with potash, was also led to study the action of the silicates of potash and of soda upon the soft limestones and chalk. He noticed the fact, that if chalk is placed in contact, at the ordinary temperature, with a solution of silicate of pot HTDKAULIC CE:ME^'TS, AND MORTAES. 313 ash, it is partially changed into a sili(tio-carbonate of lime, while a corresponding portion of potash is displaced ; that the chalk gradually hardens in the air, and becomes harder than the best hydraulic cements ; that the same chalk, made into a paste with the silicate, possesses the property of strongly adhering to the surface of bodies on which it is applied. He has thereby discovered a mastic suitable for the restoration of public mon- uments, and for the fabrication of works of moulding. Carry- ing his experiments still further, he found that the chalk, in the state of rock as found in nature, if repeatedly immersed in a solution of silicate, and alternately exposed to the action of the atmosphere, is capable of absorbing a considerable quantity of silica, and after some time acquires great hardness on its surface; that the induration, at first superficial, penetrates by degrees towards the centre, so much so that a sample, experi- mented upon fifteen yeai's previously, and placed before the Commission for inspection, had acquired that induration to a dejith of nearly one centimetre (.39 in.) This " silicatization," as M. Ivuhlmann styles his process, is due to the decomposition of the silicate of potash, partly by the carbonate of lime, and partly by the carbonic acid of the air. A solution of silicate of potash left in the air, will, in effect, after some time, form a gelatinous and contractible deposit of silica, and a layer of car- bonate of potash. The deposit of silica acquires, after some time, a hardness suflicient to scratch glass. Of two balls of chalk of the same size and quality, both silicatized in the same manner, the one left in the open air acquires a greater hard- ness than the other placed under a glass receiver, where the air is free from carbonic acid. By this process, therefore, there is formed a kind of a hydrated silicio-carbonate of lime, which indurates while gradually abandoning its water of hydration, and a contractible deposit of silica, which also augments the hardness of the stone. The carbonate of potash produces on the surface a perceptible exudation or efflorescence, which de- creases by degrees, and at last totally disappears, without hav- 314 Pr.ACTICAL TREATISE 0:^" LI3IES, ing altered the surface in any manner. Bj means of the hj- drofluo-silicic acid, M. Kuhlmann has succeeded in obviating the inconveniences tliat may arise therefrom, while he at the same time increases the progressive induration " Calcareous stones thus prepared assume a compact texture, a smooth appearance, and are capable of receiving a fine polish. The induration is singularly favored by heat. Some porous limestones, immersed in a boiler, under a high pressure, con- taining a bath of silicate of potash, assumed soon after removal all the characters of compact silicio-calcareous stones, without the slightest intervention of the carbonic acid of the air. 603. '* M. Kuidmann experimented upon other porous stones^ and observed that the action of the carbonic acid of the air upon silicate of potash, was sufficient to cause on the surface of the stones a consolidation varying in intensity with their porosity. 601. Upon the sulphate of lime or plaster, the action is sen- siblv the same, but is more rapid, and possesses Action on sul- " , . ^ • • • , ^ \ ^ e phate of lime. the mconvenience oi givmg rise to sulphate oi potash, which, by crystallizing, has the property of disao-o-resatincT the surfaces. In this case the solution must be more diluted, in order to secure a slower action, although producing a sufficient consolidation for avoiding the effects of the crystallization of the sulphate of potash. 605. " Mode of application. — The solution of the silicate of potash, as manufactured by M. Kuhlmann for the market, is quoted at 35° by Beaume's areometer. It is sufficient to dilute it in twice its volume of water, in order to obtain the degree of concentration most suitable for induration. Upon recent con- structions, the application can be made without preparation ; on old ones, it is preceded by a thorough washing of the surface, using for this purpose a hard brush dipped in a dilute solution of caustic potash. Upon large surfaces, the applications are made with force-pumps or syringes, care being taken to collect, by means of ridges made of potter's clay, at the foot of the wall, the liquid in excess. For sculptures and certain portions of HYDKAULIC CEME.XTS, A:>D MOKTARS. 315 buildings, soft bruslies, or more advantageously pencils, are made use of. Experience has shown that three applications made during three days consecutively, are sufficient to properly harden the stone. The quantity of solution absorbed varies with the nature and porosity of the stone ; the cost of the silicate never reaches above 75 centimes per square metre (12 cts. per square yard) for the most porous stones." 600. " This process, having been applied to the new sculp- tures of the Lille Bourse, to the works of res- Examples. toration of St. Maurice Church, to the construc- tion of a new church at Wazemmes, to the Seclin Hospital, in some works of military engineering, and in private construc- tions at Lille, has completely succeeded." 607. " As early as 1811, MM. Benvignat, Marteau, and Yerly witnessed the efficacy of this process. It was also practised elsewhere, at Versailles, Fontainebleau, the Chartres Cathedral, the Lyons City Hall, the Louvre, and Notre-Dame at Paris. Very able engineers, such as MM. Lassus, Lefuel, and Violet- Leduc, have obtained from it the most satisfactory results."* 608. " Stone Dyeing. — M. Kuhlmann observing that the sili- catization of constructions and sculptures gives rise to various discolorations w^hich showed the joints "more dis- Manao-ement of tinctly, was led to find a remedy for this defect the color. in his process. By means of the double silicate of manganese and potash, he obtained a blackish solution applicable to cal- careous stones of too light a color. By diluting in the silicious solution some artificial sulphate of baryta, those limestones * Although proofs, apparently the most conclusive, of the efScacy of the alkaline silicates as indurating agents, may be multiplied, the subject still appears to bo surrounded with practical difficulties ; and the advocates of tlie new theory meet at every turn reports of unsatisfactory results or mortifying failures. The "London Athenaeum" of August, 1859, contains a statement that the exterior walls of Notre Dame, and the Palace of the Louvre are in a very unsatisfactory condition, that the rains had apparently destroyed the preservative powers of the silicate, before the surface had, by the absorption of carbonic acid gas, attained a degree of hardness sufficient to resist their action. — Authoe. 316 PRACTICAL Tr.EATISE OX LtSIES, ETC. that are too dark are lightened up. lie found that the pcrous limestones submitted to ebullition in solutions of metallic sul- phates of oxides, insoluble in water, cause the fixing, at a certain depth, of said oxides in intimate combination with the sulphate of lime. With sulphate of iron, he obtains a rusty color more or less dark ; with sulphate of copper, a magnificent green dye ; with sulphate of manganese, brown hues ; with a mixture of the sulphates of iron and of copper, a chocolate color, &c. He also observed that the double sulphates thus formed penetrate into the stone and also increase its hardness." THE END. APPENDIX. DESCRIPTION AND ANALYSIS OF THE COST OF SEVERAL QUALITIES OF CONCRETE USED IN THE CONSTRUCTION OF THE FORTIFICATIONS ON STATEN ISLAND, NEW YORK HARBOR, DURING THE YEARS 1870 AND 1871. DESCRIPTION OF MATERIALS USED. Portland Cement. — Portland cements from three localities were used during the two seasons, viz., fi*om Stettin, Germany, from Boulogne Sur-Mer, France, and from the Thames, near London, England. They were found to differ very little in quality. The tests of strength made from time to time showed the Boulogne cement to be a little superior to either of the others, but the difference in tliis respect was about compensated by its extra cost. The Bouloarne and the London Portland cements used on the Staten Island works through two consecutive seasons, as well as several thousands of barrels received in New York, and tested, either for private use, or for officers of the corps of Engineers located at distant points, have, with one exception, been found to be fully up to the standard exacted by the English and the French Engineers. The use of the Stettin cement on the fortifications has been 318 APPENDIX. limited to one invoice, which was entirely satisfactory as to quality, hut fell short in weight seven pounds to the cask. In- asmuch as manufacturers of Portland cement invariably sell by weight, this difference is of no moment, except to dealers and consumers who purchase by the cask. STA^^)ABD QUALITT OF THE CE3IEXTS USED. Portland cement should weigh not less than 106 lbs. to the struck imperial bushel, loosely measured, and should be ground so finely that at least ninety per cent, of it wOl pass a Xo. 35 wire gauze sieve, of 47 wires to the lineal inch each way, When mixed with fresh water into a paste of the consistency of stiff plasterers* mortar, without sand, and pressed into a mould, it should, at the end of seven days, sustain a tensile strain of 500 lbs. on a sectional area of 2^ square inches, (1| inches by 1^ inches) equal to 222 lbs. per square inch, having been kept six days in water. This is a combination of the tests applied by the English and the French engineers, that is, it is the lowest English standard of weight, the highest of tensile strength, and the ordinary French standard of fineness. Cement of this quality can be made with as much ease and certainty as that of a lower grade, while the increase in the cost of manufacture, due to the consumption of extra fuel and grind- ing power, is but trifling. As it is not a wise policy to pay ocean freight on an imported cement of inferior quality, the highest standard of excellence should be exacted. Lirne. — The lime was quarried, burned, and ground at Kon- dout, Ulster Co., X. Y. It is known in the market as Pondout ground lime. One barrel of this lime (268 lbs. net) produces 2f bbls. of fine powder loosely measured, when slacked with 15 gallons of water. If water be added in suitable quantities, the 2f bbls. of loose powder will yield If bbls. of paste of the consistency of plasterers' mortar. This lime is not pure white, but slightly drab in color, and . . APPENDIX. 319 altliough it does not possess any perceptible hydraulic properties, it is generally thought to make a stronger mortar than the white limes. Rosendale Cement. — The Eosendale cement was from the manufactory of the Xewark and Rosendale Company. Its quality ranges rather above the average of American cements. It weighs from 70 to 74 lbs. to the bushel, loosely measured, and when made into a stiff paste without sand, and pressed into a mould, it will attain, in seven days, having been six days in water, a tensile strength of l-iO to 150 lbs., seldom greater, on a sectional area of 2 1- square inches, equal to 62 to 66 lbs. to the square inch. It is, like other Eosendale cements, subject to very considerable variations in quality from time to time, and often falls gi-eatly below this test. Stone. — The stone used in the several kinds of concrete des- cribed below, was prepared by crushing ordinary limestone in a Blake's stone-breaker. The fragments were of all sizes below a two-inch cube, and were of various shapes, being generally quite angular and ir- regular in form. This stone cost $2.00 per ton of 2,210 lbs., delivered to the wharf at the fort on Staten Island. Gravel. — The gravel was the usual mixture of smooth gravel and pebbles from the sea-shore, with the sand screened out. It varied from the size of a pea to that of a hen's egg, and cost $1.60 per ton of 2,210 lbs., delivered on the Government dock at the works. Both gravel and stone varied in size from time to time with the different cargoes, sometimes running a little larger, and fre- quently much smaller, than the general average given above, requiring corresponding changes in the proportions used for making concrete. The mixture containing the least measure of voids was the one constant!}' sought, and it was always found between the limits of eleven and fifteen volumes of stone, to fifteen of gravel, that is, fifteen measures of gravel were mixed with from eleven to fifteen measm-es of broken stone. 320 APPENDIX. The following table gives the proportions of some of the mixtures tried at various times, with different sizes of stone and gravel : 13 measures stone ] -j cn^ 15 " gravel j ^^^^^ ^^^ 15 measures stone ] . ■, c^., 15 - gravel f ^^^^^ ^4^ 111 measures stone ) .j n^ « ^ 1K u ^ r voids 2oy%% 15 " gravel j ^"'^ 22 measures stone ] .j ^^,, 15 " gravel \ ^°^^« ^^'^^ 12 measures stone ) .-, n^.^ 15 " gravel [ ^^^^^ ^^^^ 27 measures stone ) . -, oav 15 " gravel [ ^^^^^ ^^^ Mill-made concrete, for all the various uses to which it is ap- plied, possesses sufficient superiority in quality over that manipu- lated bj hand, as to justify the expense of suitable power and machineiy, when operations of considerable magnitude are to be carried on. The more thorough manipulation secured by machin- ery enables a smaller proportion of the cementing substance to be used, and effects a saving in the cost of both materials and labor. Portland cement of good quality, containing no quick-lime and weighing, say, 106 lbs. to the struck bushel loosely measured, requires 42 to 44 per cent, of its volume of water to convert it into a paste of the consistency of masons' mortar. When quick- lime is present, which is often the case with cements when first made, a larger amount of water is needed. Portland cements that have been overburnt, or those that have become injured from age or exposure, by the absorption of moisture from the atmosphere, and the spontaneous conversion into hydrates, of tke silicates and aluminates and any excess of quick-lime formed in the kiln, require less water for mixing than they otherwise would. APPENDIX. 321 The followhif^ tables show the quantities of paste and mortar of ditfereut qualities, some with and some without lime, that can he made with one barrel of cement as the basis : Cestent Paste. Bonloirne Portland Cement (France). I Water. | Papte produced. 1 bbl. (.-100 lbs. nett) = 1.34 bbls. loose powder , ]K £;aIlon8 1 " '• =1.40 Ih^ •' 1 " = 1.3:} " " 1 HI " 1.17 bbls. 1.19 " 1.12 " As an average, therefore, from the foregoing table, 1 bbl. of Boulogne Portland cement, as packed for market, will produce 1.35 bbls. of I00S& powder, and 1.16 bbls. of paste of the con- sistency of plasterer's mortar. Mortar. 1 Stettin Portland Cement (Germany). Sand. Water. Mortar produced. 1 IK bbls. 1 1 bbl. = 392 lbs. r.ett 14 gallons. 2 J 11 >. ik 1 m '• 180 '• 3 1 " " " 2 20 2.54 " 4 1 " " " 3 25 3.an •' 5 1 " " " 4 m " 4.(M) " 6 1 " " " 5 35 4.77 " 7 1 " " " 5 — 5.40 " 8 1 ^* ** ** 6 42 5.70 " Mortar. Boulogne Portland Cement. Sand. Water. Mortar produced. 1.12 bbls. 1 1 bbl. (400 lbs. nett) 16 gallons. 2 1 2! 1.38 " 3 2 2:3* " 2.54 " 4 3 28i 3.31 " 5 4 3.H " 4.19 " 6 5 4^ " 4.92 " 7 6 51 5.ti5 •' Cement and Lfme Paste. Boulo<:ne Portland Cement. 1 bbl. (400 lbs. 1 " nett) = 1 40 bbls. loose powder. = 1.35 " = 1.35 " = 1.31 " = 1..33 " = 1.34 " Gnmnd Lime slaked (powder.)j 1. Water. bl)ls. 1.25 1.25 1.50 1.50 1.50 calls Paste profhiced. 2 1.85 1.92 2.27 2.34 •,'. 1 5 Mortar. Boalogne Port. Cement. Slacked Lime powder loose. Water. Paste produced. Additional Sand.' Water. Mortar produced. 1 1 bbl.=r 1.31 bbls. loose pow. 21 " = l.:« " 'f 81 " = 1.34 " 4 1"= ].:« " 1.5 bbl. 1.5 " 1.5 " 2.H2 " 32* galls 3-.'* •' 3-H " 2.27 bbls. 234 " 2.15 " 8 8 8 10 :i0 ... 27i ... :m- ■ ■ ■ 7.ti.> bi)i.- 7.i;9 " 7..'-.4 '• 10 37 •' 322 APPENDIX. 3I0RTAR. Ro^endale Cement. ?and. Water. Mortar produced. 1 2 3 4 5 1 bbl. (300 lbs. nett). Ibbl. 2 " 3 " 4 " 15 gaUs. i7e ■• 21 •■ 25 " 30 " 1.0.i bbls. 1.69 '• 2.50 " 3.27 " 4.05 " Concrete Xumber 1. 1 Bbl. German Portland cement (393 lbs.) |3.45 ^ ^5 ^ ^^^^^ concrete mortar. 5i damp sand loosely measmed, f . 66 ) 6 ;; pravel and pebbles from seashore |1.94 [ ^Jg^ ^bls. ^ "^Ztr^S^t 9 broken stone, $3.28 j gg, ^^^ ^^^^^ ^^ ^^^^^ One batch of concrete composed as above, makes tifty cubic feet of rammed concrete. This is an average of several batches. This concrete is of first-rate quality, being compact, free from voids, and strong. It is richer in mortar than "would be neces- sary for most purposes. The cost of the materials for one cubic yard of this concrete delivered at the concrete bed ready for use, omitting the Custom-house duty on the cement, amounts to $4.86 The cost of mi.xing, transporting, and ramming the concrete, per cubic yard, amounts to $1.37 Lumber and timber, and carpenters' labor in setting up same, $ .32 Total cost of concrete per cubic yard, $6.55 The cost of labor is based upon the following prices for a day's work of ten hours : sub-overseer, $3.50, mason or carpenter set- ting plank, $3.80, and laborers, $1.80. The labor in constructing concrete magazines, in consequence of the extra work in setting the planking at the entrance angles and doors, and in making and setting the centres, and the con- sumption of extra lumber, will amount to about $1.90 per cubic yard instead of $1.69, as given above. Concrete Ku:Nn3ER 2. 1 Bbl. German Portland cement (393 lbs.) $3.45 j_ ^ 5^ ^^^^ concrete mortar. 6 damp sand loosely measured, $ .06 ) 5 " gravel and pebbles from seashore, $1.62 | Mixed together and shaken 9 " broken stone, $3.28 f down, contains 30^ of voids. One batch of Xumber 2 makes 50 cubic feet of rammed concrete. The materials for one cubic yard of concrete Number 2, cost, delivered at tlie concrete bed, $470 Cost of mixing, transporting, and ramming, per cubic j'ard, $1.37 Lumber and tfmber, and carpenters' labor in setting up same, $ .33 Total cost of concrete per cubic yard. $6.39 APPENDIX. 323 Concrete Number 3. 1 Bbl. Boiilojrne Portland cement (400 lbs.) $3.45 1 1 " Slaked ground lime in powder, $ .58 > =7. Bbls. mortar. 7 " loosely measured damp sand, $ .42 ) 13 " Gravel and pebbles from seashore, $4.20 / =,?^^ ^5'^; V^^^^^ *°' 1.S " Broken stone L 74 f ^^^''^' ''"^ shaken down. One batch of concrete Number 3 makes 86-^ cubic feet of rammed concrete. /Strength of the mortar. The mortar with which concrete Number 3 is made, composed of 1 bbl. Portland cement, 1 bbl. of slaked ground lime in powder, and 7 bbls. of sand, possesses, when two months old, a crushing strength of 300 lbs. to the square inch, the test being applied to 5 inch or 6 inch cubes. Cost of concrete Number 3. Cost of mutoiials for one cubic yard, $4.18 Cost of mixing, transporting, and ramming, per cubic yarcl, $1.37 Lumber and tuuber, and cariieuters' labor in setting up same, $ .32 Total cost of concrete per cubic yard, $5.87 Concrete Number 4. 1 Bbl. Boulogne Portland cement, (400 lbs.) $3.45 ) « n r>i 1 U " Slaked ground lime in powder, $ .72 =7.9 Bbls.concrete mor- 8 " loosely measured damp sand, $ .48 ) '^'" 16 " Gravel and pebbles from seashore, $5.17 / =,7^ ^^^\\ m\^^(\ to- 16 " Broken stone, $5.82 l ^''".'^'Vy^^^'.^'^^^™ '^•^^™' ' . ^ ) with 24^ of voids. One batch of concrete Number 4 makes 105 cubic feet of rammed concrete, of suitable quality for most kinds of massive work. It contains the greatest admissible proportions of gravel and broken stone. The quality of the concrete would be im- proved by using 18 barrels of gravel and 14 of broken stone, instead of 16 barrels of each. Strength of tiie mortar. The mortar of concrete Number 4, composed of 1 barrel of Portland cement, 1;^ barrels of slaked ground lime in powder, and 8 barrels of sand, possesses a crush- ing strength of 220 lbs. to the square inch, when two months old, the pressure being applied to 5 inch or 6 inch cubes. Cost of concrete Number 4. Cost of materials for one cubic yard, $4.02 Cost of mi.xiug, transporting, and ramming, per cubic yard, $1.37 Lumber and timber, aud carpenters' labor in setting up same, $ .32 Total cost of concrete per cubic yard, $5.71 324 APPENDIX. CoNCKETE j^uMBER 5 (made with Rosendale cement) : 1 Bbl. Rosendale cement (300 lbs.) $1.77 ) 3 " Damp loose sand, | .18 J- =3.27 Bbls. concrete mortar. 5 " Broken stone, $1.82 ) This batch of concrete, as the average of an entire season's work, has been found to yield 21. T5 cubic feet, rammed in position. Strength of the mortar. The mortar of concrete ISTumber 5,^ composed of 1 barrel Rosendale cement and 3 barrels of sand, possesses a crushing strength of 130 lbs. per square inch when two months old, the test being applied to 5 inch or 6 inch cubes. Cost of concrete Number 5. The materials for one cubic yard cost $4.67 Cost of mixing, transporting, and ramming, per cubic yard, $1.37 Lumber and timber, and carpenters' labor in setting up same, $ .32 Total cost of concrete per cubic yard, $6.36 Concrete Number 5 is the standard quality of Rosendale cement concrete generally adopted upon government works. It pos- sesses sufficient strength in foimdations and thick walls for any position in which concrete is usually placed. The nearest approximation to it in quality and strength, of any of the Port- land cement concrete used at Fort Tompkins, is concrete Num- ber 6 given below. Concrete Number 6. In this concrete the proportion of mortar to the broken stone, adopted for the Rosendale cement concrete Number 5, has been carefully maintained. Portland cement, 1 Bbl. $3.45] Ground lime, 1 Bbl. producing of lime 1 = to 10.37 Bbls. of concrete powder 2| Bbls. $1.50 ( mortar. Sand, 10 Bbls., $ .60 J Broken stone, 16 Bbls., $5.82 > One batch of concrete produces 69^ cubic feet, rammed in position. Strength of the mortar. The mortar of concrete Number 6, composed of 1 barrel Portland cement, 1 barrel ground lime (producing 2f bbls. slaked powder), and 10 bbls. sand, possesses a crushing strength of 154 lbs. to the square inch when two APPENDIX. 6Zb months old, the pressure being applied to 5 inch or 6 inch cubes. Coxt of concreie Number 6. Cost of materials for one cu])ic yard, $4.41 Cost of mixiniT, transporting, and ranimiiis:, per cubic j'ard, f^ , Lumber and limber, and carpenters' labor in setting up same, $ .32 Total cost of concrete per cubic yard, §G.10 This concrete therefore possesses two advantages over con- crete Number 5, viz. : the mortar, although used in the same proportions to the broken stone as in Kumber 5, costs nearly 11 per cent, less, and is more than 18 per cent, stronger. Hand-made concrete. All the several kinds of concrete described above were made by hand, after the manner indicated in paragraphs 366 to 376. AVhen lime was used, the slaked lime powder and the dry cement were rudely mixed together on the mortar-bed before the sand and water were added. Mill-made concrete. The mill used for mixing concrete is a cubical wooden box measuring four feet on each edge in the in- side. It is provided on one face with a trap-door about two feet square, close to one of the angles, and is mounted on an iron axle, passing through opposite diagonal corners. An ar- chimedean screw mortar-mill, for mixing the concrete mortar, is used in connection with the box, and both are driven by a small engine of about six-horse power. Eight revolutions of the box, made in less than one minute, are found to be quite suf- ficient to produce the most thorough incorporation of the mortar with the broken stone and gravel. Every piece of stone, and every pebble and gravel, become completely coated over with mortar. In making the mortar, the cement, liiue, and sand are first rudely mixed together with shovels on the mortar-bed, and are then passed through the mill once; one measure of the dry mixture (about a cubic foot), alternating M-ith one small measure of water. The precise amount of water necessary is determined by trial, and will vary from time to time with the more or less moist condition of the sand. 326 APPENDIX. Four men with baiTows are employed in conveying the con- crete materials (the mortar, broken stone, and gravel) into the concrete box, one barrow full of the mortar (2 cubic feet) alter- nating vrith three heaped up barrows full of the coarser ingre- dients (7 cubic feet). The materials are dumped into the box from a staging, erected on the level of the trap-door when at its highest point. One charge of the box contains : 4 barrows of mortar (8 cubic feet). 6 beaped up barrows of broken stone (14 cubic feet). 6 " " *' gravel (14 " ' ). After mixing, the trap -door is opened and the contents de- posited on the platform below, by two or three revolutions of the box. The concrete box produces such a thorough and com- plete trituration of its contents, that it is not necessary that the mortar should be mixed beforehand. The mortar-mill, as an auxiliary, may therefore be dispensed with. The ingredients of the mortar (the cement, hme, sand, and water), after being pro- perly proportioned by measure and rudely mixed together with shovels, require no further preparation, but may at once be added to the coarse materials in the box. . The method of charging the box by barrows, practised at the Staten Island works, is not considered the most economical that can be de\'ised. A crane or derrick worked by the same engine that turns the box, and having a sweep of sufficient length to reach the mor- tar-bed, and the piles of broken stone and gravel, would doubt- less be an improvement. A concrete box employed by General Duane in Portland Harbor, Maine, is operated in this way. One box of the capacity above described (-i'x-i'xi' on the inside) will mix from 95 to 100 cubic yards of concrete in one day of ten hours, and will do the work very much better than it can be done by hand, and at a saving of from 15 to 20 per cent, in the cost of labor. INDEX. PRrascraph. Absence of upper layers of Rosendale cements ; 40 Absorption of carbonic acid by Iime«, ^ 98, £31. 578 Abundance of common limestones in the U. S 1 Abuse in biimin " " '• Chatony 1:14 " means of hardening stone, brick, mortar, etc 59.3-C'i7 " Portland cement 88. 12,S-132 " Pozzuolana-mortars, in the sea 1.0 Pozzuolaua's. . 124, 135-1:39, 150, VA Balcony Falls, Va., cements at. . . . 15, 79, 124 Barnegat limestone '0 Baryta, nitrate of IR-'^ Bas'altic sands 102. 111.119 Bastard stucco 4n8. 412 Belgrand & Michelot's experiments <>f..523. 5-,'4 Beton or concrete 101, 4 S9-.50T •• definition of, &c 4:59-440 Bi-chloride ol' platinum 194-19.) Bird's-eye limestones 7,11 Btuminnus matter..-. li'7 Black river group of limestones 7, 11.15 Block* of concrete 494, 496, 5(10, 505 Blue lias limestones 4h1 Blue limestone of Kittatinny Vall.>y 11 and marls of the West 11 Blup ridge Quarry, Va 79 Bolting cement 291 i Boulogne pebbles or Septaria 87, ula 328 IXD^X. P&raeTApK BoulogTie Portland cement 87-95 Boolo^e Eomau cement ft"2 Box for lowering concrete in water. 466-4t>8 Brard's frost test 434 •• Breaking the set" destroys hydraulic energy 144 BreakingVeight of cement and lime without sand 54T-550 " " of pure cemeut 520, 529 " " of Portland and Roman ct-ments. ... 5-i6. 529. 53^1 " " of pure and mixed American and European cement?. K5. 557 BreakiDs weight of Tra#* and Pozzuolao* m< inars .V>9 Brick maf-onrr, mortar for S&i hardened artificially .. 593-ti07 Brown coat 414 Bmce, N.. cement works of 65 Burning cement stone*, abuse in 235 capri Lines variation? while. 268- "^7 " care lo be exercised in 28^ " defects of method ol 2;i2 " kilns for 2.37-i53 " neces*irv of care in, 25B observations on... 233-236. 2fi3-2<7 Burning hydraulic limestone. 582. 5t4-56«, 590 " where alumina is pres«ut. .. 585-^587 " Bilicion« limestones — 584 Calcareous beds of calciferons group 11 " clay for Boulogne Portland cement 87-91 '* bed? on Potsdam sandstone.. 6 '* m.nerais, purest 10ft " mortar, definition of 3 9 uses of 310 •' sand, mortars containing onlv 579 sandrock 7, 8.'9. 11 Calciferons group or formation 7-11 Calcination of Portland cement 89 conduct of cem'is during.26S-287 ~ of oissimiiar stones 171 " improves Pozzuolauas. 135, 136, 264 " of St. Leger hy. lime 133 " of artificial cement 127, 130 Caldnm the base of lime 96 Capacity of Cumberland cement works 77 " " James River •' " 79 " " Kensington (Conn.) cement works... 83 Capacity of Louisville (Ky.) cement worke 82 •• " '• Round Top •* •' " 75 '■ Sandusky (O.) " " 81 " " Shepherdstown (Va.) cement works 78 Capacity of Utica iTll ) cement works.. . 80 •■ Dclafield & Baxter cement works 63 Capacity of Hudson River cement works 67 " Lawrence Cement Co 60 " " Lawrenceville Cement Man- nfStrtnriu^ Co . . 69 Capacity of works of Kaguire, Crane & Co." 68 Capacity of works of Martiiis&Clearwater 66 •• ' the Isewark Lime & Cement Manufacturing Co 58 Capacity ot works of Newark and Kosen- daie Co. 61 Capacity of works of Ogden Rosendale Co. 64 '• " •* •• Rosendale Cem't Co. 62 ■• '• •• " Roseudale & King- ston Cement Co 70 Pirtpraph. Carbonate of lime 96 " " " in hydraulic limestones 4 " " " on sea-walls 160 " " magnesia in hydraulic lime- stones 4 Carbonate of magnesia on sea-walls 160 Carbonic acid absorbed br limes. 9S. 103, 331. 573 Caustic linxe in cement mortar 44, 49, 123 Cements at certain stases of burning.,.. 269 American, trials of 520 •' artiliiial hydraulic 125-145 '* of Black River limestone 15 » •' color of 292 Cement deposits, heterogeneous 167 in Ulster Co 44 " for drain-pipes 463 " and hydraulic iimes 102-100 '■ action of. in sea-water 158 Cementing substance, theoretical mini- mum of 314 Cements will not slake 109 Cement and lime mortars compared 382 Cement manufactory at Akron. X. Y 84 Cement works at Balconv Falls. Va. 15.' 79. 124. 226. 261, 295 " " cost of running 82 " " at LockjKirt. X. Y 84 " " '■ Chittenauso. X. Y 84 " " " Favettev;lle. " .... 84 " '• Ma'nlius. X Y 84 " " '• Kensintrton. Conn. .. 24 " " in the West 24 " " on the Potomac 15 Cement mortars, the effect of lime iu, 549, 550 '■ •■ harden simuitaueuusly throughout 36,37 " *' why iime is added to. . 546 " '• precautions in te^ting.28-29 " " pr;;poriion of lime in, .381 Cements, the basis of concrete mortar in the U. S 445 Cement paste, through muslin 537-o-i2 Cements, precautions in testing 122 with excess of water' 509 " preservation of 298 " (Rosendale) contain alkaline salts 16 Cement stone, analysis of English 226 •' diffic'nliy in selecting JTO " " prominent features of. . . 46-95 " " general features of layer? ol, 168 " " hydninlicity of nnde'rburut 177 •' " in Mississippi 25 " " inertness of overburnt 177 " " kilns for burning 228-2:j2, 237-241 " " observations on buruing of, 23:1-2.36 " " preliminary trials of. . . 172-182 " stucco, hydraulic 423-429 Cements, some good at all stages of burn- ing 268 Cements, with silica in excess 592 Chalk and clay, for artificial cement. 128. 129 Changeable character of cement stones. . 40 Character of limestones. .. 163-165, J 83-1 6<> j Characteristics of intermediate iimes ... 110 I '• '■ pnrel:me# .. % 1 Chatx)ney and EivoL, on hydraulic mate. rialr. 151.1.52 Cbaux limites of Vicat 43. 110 ' Chazy group of limestones 7, 11 I Cherbourg breakwater 5(4 I Chittenango, X. Y., cement works at 84 INDEX. 329 Claseiftcation of hydraulic lime? 107, 108 " " limes for mortar 102 Coarf e c tuff for plasteriufj, :W4-3'.»0,103, 404, 409 Cofferdam, by Maj. Hunt 473 Cohesive strength of cement throutrh muslin ..... 539, 540 Color of cement 57, 2!)2 " " stH ceo, management of 429 Combinations of good and bad limestones for cements.. . .- 44 Commercial limestone 101 Common limes 102-104 '• " paste, under water 103 " " Concrete contaiiiinsr.. . 490—492 " mortars, for onti'ide stucco 419 Comparison of cement and lime mortars 3S2 Composition of concrete at Lovell's Isl- and 488, 4S9 Composition of mortar 379-380 •' " pointing mortar 385 Compound limestones... .^ 2 Concrete or beton 161, 439-507 definition of 4.39 blocks 500-.505, 515 " for the Cherbourg breakwater 504 " coarse inuredients of 476-5(J" " use of in the U. S 500 " of Forts Richmond and Tomp- kins 4'^3, 484, 486, 487 " injected under water 494-^97 " general practice iu making. 445, 44ri " rammini; 455 " jetties at Marseilles 502 " laid underwater 464-475 " English mode of making 444 " maiie by machinery 451-4.t3 *' materials for 478 " may contain conim• •' '• at Fort Tompkins. . 4aO, 4S7 " " plastering 418 " " roofing concrete at Ft. Warren.. 493 " " manuwcturiiig cement. ... . 82 " " various kinds of masonry 507 Cracker for grinding cement 288 Cretacious formation for Portland cement 87 Cioton-bi'icks, adhesion of moriarsto. 531-543 Crucil)le tests of cement stones 40, 17;i-182 Culmann on slaking 325 Cumberland cement, strength of 5.-17 works, Md., 77,78 " stone, analysis of 226 Curves of energy of cements 20;j-208 *• " strength of cements 279-285 Darcel on Roman and Portland cement, 522-524 Decay, hardest stone liable to 594 Device for compressing grceu mortars.. . 33 PllMgTIiph, Devices for laying stone under water — 53fi " constructing walls of concrete, 457-162 Delafleld & Baxter's cement, strength of, 557 works.. 6:j. 124 Delesse on Boulogne Portland cement.. 87-95 Dem.irli' & Co., Boulogne, France 87 Destructibility of stones, causes of .595 Deteriorated cements 301 '• strength of James River 30* Deterioration of cement and lime in air, 298-307 Difference in burning for artificial cement 131 Dissimilar stones, burning of 171 Distemper 4l3 Dividini' Hmes of Vicat 43, 143, 180 Doloniitic earths as pozzuolanas VH Dover* Alderney Breakwaters 505 Drain-pipes, cement for 463 Draw kilns and flame kiln?,. .241-243, 249-2.56 Drowning, slaking lime by 319-322 TotteiPs experiments on 338 Dunlop's Cnek, Va., cement from 15 Duponfs mill, for grinding cement 88 Durability of stone 590-607 Eaton, transition sandroek of 10 Efflorescences, mural 561-577 Eneriry, curves of hydraulic 264-26t> ••'hydraulic. ISl, 12-2 English cement, analysis of 226 European limes and pozzuolanas, in sea- water 150-161 Europe, pozzuolanas found in •. ■"? Examination of limestones 166-227 Excess of caustic lime, in mortar — ... 44-49 Experiments on limes and pozzuolanasl.50-161 Experiments in slaking limes 3-27-330 " " by General Tot- ten 3->9, 338-344 Experiments based on change of tempera- tiii'y 1*24 Exterior plastering or stucco 419^29 Fabrication of mortars 342-:583 Fat hmes 102,103 Fayetteville, N.Y., cement works at 84 Feburier. experiments of 157 Fertilizer, poor lime as 105 Fine stufl' for plastering 394, 397-399 Finishing coat 398, 399, 408-413, 417 Flame kiln 241-243 Floated coat 404 Formation I. of Rogers' classification .... 6 II. " " 7, 11, 12 VI. " " , «8 Formula for rupture 497, 527, 5o 1 Forge scales 135 Fort Adams, efflorescences at 565, 566 experiments by General Tot- tenat... l-L 49? Fort Carroll, laying conrrete at 404, 40o ForiB Riclimoud and Tompkins, concrete fj,r 48;J-4'^7 Fort Tayior, mortar mill used at T28 •' Warren, cost of concrete at 493 Fossiliferous limestone 11 France, arenes found in 116 •' artificial cements in l"2o " pozzuolanas found in 112 Fresh water for slaking 3-J' Friiioiitic mixtures ■ • • '*■>' Frost, its etlect on mortars 4.10-W4 Fuchs ou Alkaline silicates 14b 330 IXDEX. Fuel for burning cement 230, 254 Ganjre stuff 399 frernral feature of cement deposit? 168 Geotrraphical localities of ar^'illo-masne- sian limestones of New York, New Jersey, and Virginia 13, 14, 15 Glenn's Falls lime 330 Gneiss-sand, as pozziiolana 139 Governor's Island, concrete blocks at 515 Granites Ill, 119 Granwacke 102, 111, 119 Grindins; cement 2S&-291 Growth, in slalting process 319 Guadaloiipe. pozzuolana of 112 Hand-floating 403, 405-407. 411, 413 Hand-made mortar 159. 36.V-3T8 Hardening of stone, etc.. artificially ..593-607 Hardening of cements nnder water 107 Hardening under water, classification b:ised on 102 Hard finish 399,408,41.3, 414 Hardness of arnees-mortar 116 " cement mortars 510-515 " mortars, method of testing. . .31 Harwich Roman cement 86 Helderberg division of hyd. limestones... 18 Heterogeneity of cement deposits 167 Hii:h Falls cement, trials with 529 Hoffman brand of cement 60, 302, 3a3, 5:>^ Holland, trass found in 11.3, 114 Hydrate of fat lime in the air 331-338 '■ lime as a chemical compound 9ti " " magnesia 590 Hydraulic activity 121. 122, 123, 124, 276 . " Cements in sea-water 158 " cement stucco 423-429 " cements require no sand 109 " cements, from Onondaga Salt group 18 " cements, classification of... 102-109 " energy, how destroyed 144 " induration. thcoiT of 583-592 " limes 102. 107. 108. 307, 308 " " slake with difficulty 322 " limestones, examination" of. 166-308 " " effects of bnrnins. 582, 584^8"?, 590 " limestones, qualitative exami- nation of 183-197 " limestones, quantitative ex- amination of 198-227 Hydranlicity of arenes, theory of 116, 117 " index of, m Theil Lime 156 " maximum and minimum of, 26.3-285 " cause of 182 " of underbumt cement stones 177 Hydro-chloric Acid, in analyses, 189, 190. 200. 202. 2««. 208. 210. 214. 216 Hvdro-chloric Acid, pozzuolanas soluble in 112 Hydrogen, sulphite of. its use 195 Hydro-sUicate in artificial cement 140 Illinois, limestones in 3 Immersion, slaking by 32.3 Impact, hardness of mortars by 31 Impurities in limestones 101-109 Increa;se of strength of mortars 554->55S " of voiume in slaking lime, iW, 103, 105, 107 Index of hydranlicity 156 Indiana, deposits of limestones in 3 ParaerapV Indurating mixtures 598 Induration by absorption of carbonic acid 331 in the air 103 artificial 597-«»7 " of hvdranlic limes 334 " hydraulic, theory of. 582-592 " ofmoriars of fat'limes... 578-581 Inertia, instant of 177-179 Inertness of overbunit cement 177 Inferior cement stone used 43 Ingredients of artificial Portland ce'nent.88.132 "concrete 476-507 " " hydraulic limestones 4. 5(*2 " " natural pozzuol.-iiias Ill '' " Si. Leger hydraulic lime... 1:3 Interior plastering 389-418 Intermediate limes 869 •• improved by age 30J " '• nniit for use, 47^9. 52. .^3, 143. l.*0 " - in the United States.109, 110 " " when used under water. 110, 143 Iron, oxide of, how detected, &c.., 191, 307, 2. 149. 551 '• " efflorescences 5t;8 " process of silicalizaiion.. 60i<-6ll7 " process of stone dyeing 608 Enhlmann''s report 16 Laitance 468. 474. 475 Lathing, common faults in . 404 Lawrence cement 6-5. 55? Cement Co 6U. 61 Lawrenceville Manufacturing Co 69 Layers of cement, general feature, of.. 168 •' •' Rosendale cements :<9 Laying 401. 4a3-405 coat and set 404 " concrete under water 464-475 " stone under water, device for, o:i6-648 Lisfht Rosendale cement 57 Liquor of flints 60' Lime in cement mortars 57 '• diver>itied chajacter of. . Iti3-165 " examination of l(itJ-308 " hydraulic, eflucts of burnini;, ^ 58-', 584-587, 590 " " mineral character of 183 analysis of 183-227 "Filicioiis, products of burning 584 Limestones underburnt 136 Lockport, cement works at... .84, 226, 2(;2-2U5 Louisville cement works 82, 124 Lovell's Island concrete, Boston 488, 489 Machine for breaking stone 479-482 " " making concrete 451-4."i3 " " *• drain pipes 463 Magnesia a protection of sea walls 161 deposit, 18, 19 " how detected in limestones, 191, 212 '• hydrates of 590 " limestones of the West 10 Maguire, Crane & Go's cement works 68 Malasruti & Diirocher on mortars 294, 296 Manganese, how detected in limestones, 191, 212 " oxide of 293 Manlius, cement works at. 84 Manufactnrei s neglect assorting the stone 42 Marseilles, concrete for jetties at 5i:2 Martins & Clearwater's cement works... 66 Martinique. pozzuoUnas found in 112 Masonry, cost of various kinds of 507 " volumes of mortar in 507 Massachusetts, limestone in. 22, 23 ^laxinium and minimum hydraulicity — 269 Meagre limes 102 Memoir by Chatoney & Rivot,151, 152, 508-519 Method of burning ( emeuts 232 Method of slaking lime 317. 3.59-364, 383 " " testing strength of mortars, 27, 32, 531-535 Mills for grinding clay 88 " " " ^chalk 128-1.32 Minard's opinion ol tests for mortar.... 438 Mineral character of limestones 183-186 Mississippi, limestones in. 25 Mixing sands lor mortars 315 Modifications of ordinary method of slaking lime 360-364 Moisture aosorbed by lime 98 Molybitate of ammonia 196,201, 202 Mortar, action of magnesia on setting of .')90 ol arenes, with rich lime 116 " artificial hydraulic 125 " of arliticial puzzuolanaa in sea water 1 50 Mortar liox and cart 383 '* cement hardens simultaneouslv throughout 36, 37 Paraifrapti. Mortar of common lime, where employed 104 " " •' setting of 5Sl " containingcalcareoussandonly. . 579 " cost of making 3.5(i-3.58 " definition of the setting of 120 " disinteirration of 4.3IM38 " effect of frost on 430^:i4 " effect of sea water on 43.5-^38 " fabrication of 3 12-383 " of fat lime, induration of ... 578-581 " fiigoriftc mixtures for testing. .. 433 " of intermediate lime 110 " made of lime and trass, or lime and pozzuolanas 558-560, .5-8, 589 Mortar making by hand 8.59, 36."i-378 " mill 345, 546, 3.J0-358 " mill at Ft. Tavlor 3M). .351 " mill (if M. Grevveldinger.... 3.J2-3.^)8 " mill for grinding chalk 132 " mill for grinding Portland ce- ment 129 " of the mole of Algiers 154-l'i6 " a mechanical mixture 508 " l)ointing 384-388 •' of Portland cement, its superi- ority 517-519 " proportion ol ingredients for, 344, 3';9 " for various kinds of masonry 507 " for stone and brick masonry 380 Mortars, strength of certain 1.55 Mortar, technical signification of term.. 311 •' used for plastering 394-400 Mud, arsrillaceous, for Portland cement. . 129 Mural efflorescences. 561-577 Muslin, its use in laying stone under water 53l at Cherbourg ,521 ' '* " nst-d "en conlis"*.... 515-517 I Portland and Roman cement mortars. compared 522-530 ' Potash and soua. how detected. | 19:J-»5, 21fr-221 " " in bvdr. limestones. 16.111,193.194, " " in mural efflorescences.. 569 ; Potomac River, cement works on, 15. 71-78, 268. 275 Potsdam sand-tone 6 Pimillv. cement of 295 Pozzuolana li'2. 111. 112,152-154.156, 15T. 295 analysis of 226 " artiiicial 150, 157 " Italian m sea water, 152, 15:3. 155. 157. 295 " with fat lime 558-559,588-589 " Roman mortar 5.55 Precautions in selecting cement stones. . 170 with slaked lime .321. 3.23 " in selecting cement for test- ing 2S. 29 " in mixing good and bad cements 44 Preliminary trials of cement stones.. 172-182 Preparation of lime and clay cement. .. l-i6 for qualitalive examination. 187 Preservation of cements 298. 299 '•limes 3:39-341 Pricking up 401 Process of silicifying 146-149 Prominent features of cement stones. . 46-95 Properties of arenes 116 '• Boulogne Portland cement. 92 " '• pozzuolanas 112 " " triss 113 Proportion of alkaline siliciite 145 Proportion of in;;redieut3. St. Leger hyd. lime 133 Proportion of ingredients for mortars 344 Proportion of iime and clay in artificial cement 126 Paraprap*. Proportion of lime for cement mortars.. . 381 " " sand to gang of mortars. .. 314 *' '• clay in Portland cement. .. 87 Protecting coat lor sea walls 160 Proximitv to sea favors efflorescence 570 Psammiles HI, 119 Pure Cement with excess of water 509 Pure limestone 96 Purest calcareous minerals 103 Qualitative examination 1?.S-197 Quantitative examination 198-227 Quarries of water lime 20 Quarry of hydiaitlic lime. Massachusetts, Ti Quicklime, how produced 96 mixea with allcaline silicates. 112 Ravier's report on cements and pozzno- lanas 155-156 Ramming concrete under water injtirious 4';9 Rans<>me"s process for hardening, etc 600 Remedies for efflorescence 7.. .. 571-577 Remedy for feebly hvdrauiic limes, etc. . . 145 Renderins 401-403 Report by M. Delesse, on Boulogne Portland cement 87-94 Report of M. Ravier, on seaworthy ce- ments and pozzuolanas 155, 156 Restoration of deteriorated cements. 301-;3'>4 Revetting concrete walls with stone. 471-473 Rhine, trars in the vaUcy of the 113, 114 Rockland lump-lime 3:30 Roman cements ffi. S6. 324. 226, 292. 294 Roman cement mortars, strength of. ..557-523 Roman and Portiaiid cement mortars compared , .. ... 52*^-533, 5"-7 Roufiout ground lime 3:30 Rotrfiug con rete for archee 493 Rosenaalecemeuis 2U. 26, 2it0 Roseudale Cement Co.. Lawrence brand 62 " cements contain alkalies 591 " cement mortars, strength of, 5J0. 557 *• " etone. where fonnd, 21, 38 " " layers of 39 '* " injected under water, 494-497 Rosendale and Kingston Cement Co... 70 " " " mortars .. .555, 557 Round Top cement strength of 557 " " •' works, Md., 75. 76, 124, 225 Rubble masonry, pointing of 388 Rupture, instant of 34 Sand, computation of voids in 315 '• used in testing 29 " in Portland C'-meiit* 87 " not necessary for hyd. cement paste 109 Sand, proportion of in mortars 314 Sand rock, cjileareous 7 " " transition of Eaton 10 " sifting the 316 " used in mortars 311, :313 " usually added to pozzuolana. 112 Sandusky cement mortars 557 works 81, 124 " liraestoi;e. analysis of 2'j6 Sand, why used in mortars 104 Sapouifving salts in efflorescences.. . 574-577 Scratchcoat 401. 404.414, 415. 4;9-4i9 Schists 111.119 Screed coat and set 404. 407, 415, 416 Sea-wallA, murtar of, how protected 160 INDEX. 300 00 Paragraph. Sca-watcr, cements able to resist loS " " pozziiolana mortars in 150 " " its ert'ect on hydraulic mortars 297 " " its effect on mortaru arti.ici- ally tested 4:35-438 Sea-water; Kiiropean limes etc in.l50-lW, 435 " " tor mixiiij; cement 495 Section of Kosciidale cement deposits 44 Septaria, far lioiiiun cement... 80, t>7, 121, 512 Settinj; of mortar detined liO " " nu)itar!', action of magnesia on the 590 Setting of mortars of common lime 5ol " mortars injiuenced by tempe- rature 124 Shawangnnk conglomerate 288 Sheet plies in founding with concrete ... 470 Sliepherdstowu cement couiaius alkalies. 591 " " mortars,strengthof 557 " " works, Va., 72-74 " " limtstone 226 SheppyKoman cemi'Dt 86 Shrinking does not occur in cements 109 " of paste of fat liTie 103 Sifting cements for testing 29 " sand for mortars ... 316 Silica in hyd. limestone" 4 " how detected 169,206,225 ' " in poor limes 106 " when in excess in cements 592 Silicate of potash or of soda 606, tiOT Silicatization 146-149 " definition of the term 602 Silicious limestone, products of burning. 5s4 Sing-Siug lump lime, slaking of 330 Slaking, experiments by Gen. Totten on, 329 " hydraulic limes 107 " by immersion 323 " lime, ordinary method of. 359-364 " '• effects of 96,104 " lime, methods of. .. 317-3*3 " poor or meagre limes 105 " spontaneous or air 324-325 Slaty limestone 10 Sling-cart for conveying concrete 4.56 Slipped work 408, 409,412 Slow setting of Portland cements 93 Smeaton's opinion of trass 115 Smith's forge scales for stucco work 422 Soda and potash, how detected, 194, 195, 220, 221 Soda and potash in hyd. limestones 16 " " '• in elBorescences 569 Soluble glass, in mortars 551, 553 " ■' with bad limestones... . 49, 141 Solubility of lime in water 97 Source of hydraulicity 182 Spontaneous slaking 324-325 St. Leger hydraulic lime 133 Stone-hreaking machine 479-4.S2 " cutters' cliips for concrete 477 " dyeing 608 " hardening 593, 607 " masonry, mortar for ... 380 " revetment of concrete walls.. 471-473 Strength of mortars injured by alkaline silicates 553 Strength of iigsregates 312 " " certain mortars 155 " concrete experiments on the 498, 499 " of mortars, increase of. . . 554-557 Stucco 389, 400, 408, 411, 414 Subaqueous works, common lime in 104 Subaqueous work, concrete for 448 Sugar water iu preparing stucco 421 Par.iffrapti. Sulphate of lime 148, 604 " magnesia for testing effect of sea water 435-137 Sulphate of soda for testing lime 99 Sulphide of hydrogen 195 Sulphuric acid, how detected 188,214 " " a solvent for pozzuoiaua. 112 Temperature, hydraulicity influenced by, 12;j, 124 Tennessee, limestones in 3 Teutaculate deposit 20, 39 Testing mortars, method of 27-29 " wires used by Gen. Totten 121 Test for limes by oxalic acid !t9 " general character of, for mortars.. 30-32 " of limestones in crucibles 46 Theil, hydraulic liine 151, 156,502 " " " mortar, strength of. 555 " lime, analysis of i\>6 Theoretical minimum of cementing sub- stances 314 Theory of the formation of hiitance 475 " •' hydraulic induration 582-592 " " the hydraulicity of a; enes 117 " " mixing cement stones and fuel not tenable 230 Theory of subaqueous induration 117 Thickness of Rosendale cement beds 39 Three-coat work 414-417 Tools requirea in plastering and pointing, 387, 390-392 Tostain's opinion of pozzuolanas 152 Totteu's (Gen.) experiments ou mortars 121 " " slacking lime 3-^8, 338-344 Totten's (Gen.) trials of strength of con- cretes 499 Toulon Graving Dock, concrete blocks for 501 Tractile strength of Portland and Roman cements 521, 524, .V27, 530 Tractile strength of pure Portland cement 516 Transition sandrock of Eaton 10 Transverse strain of mortars 30 Trass, analysis ot 226 " mortars with fat lime 5.58-560 " orTerras 1U2, 111, 11:J-115, 157 " where found 113,114 Treatment in burning hydraulic limes, rnesian hydrates 590 Variations of temperatare, influence set- tin? 12:i, 124 Variety of cement stones requires variety of treatment 2M Vassy, cement of 25U, 295 Vicats dividing limes 43.110 and Reibell's experiments... 51(>-518 " mode of trying sea-mortars in laboratory .' 435-437 Vicat on nainnl Bonlogne Portland ce- ment T 95 Vicat's opinion of artificial hydraulic limes 127 Vicat' s opinions on the needle- test 35 Para^TAtih. " " " slaking 336 " researches on the effects of sea- water 159-lfil. 295, 296 Virginia and Pennsylvania beds of com- pound limestones 3, 15 Vitrnvius speaks of pozznolana 118 Volcanic origin of pozzuulaua 113 Water absorbed bv the Boulogne ce- ments ' 92 Water, intermediate limes under 110 areues under 116 " laying Concrete in 4»;4. 466-46S, 475 '• hardening of limes in 102-107 " hydraulic cements under 109 " layiDiT concrete under 404-175 Water-lirnestone 20 Western cements, where made 24 West Point, efflorescence from 567 West Springfield. Mass., limesiones 22 Wheelbarrows I.ir conveying concrete 454 Whitewashing, lime for 321 Wire test of pure cement 122 bv General Totten 121 IXDEX TO APPEXDIX. Pa«. Analysis of cost of concrete 322-325 Comparison of Portland and Rosendale concrete 325 Concrete mixer 325.326 Composition of various concretes.. . 322-3-.'4 Gravel for concrete 319 Mill-made concrete 32<) Mortar, volumes ot 321, 322 P»g»« Mixtures of broken stone and gravel 319. 3-20 Portland cement 31 7 Kosendalc cement 319 Standard qualities of cements 318. 319 Stone for concrete 319 Strength of concrete mortars 321-325 Voids in mixtures of stone aud gravel . . . 320 Volumes of cement paste 321, 322 SCIENTIFIC BOOKS PUBLISHED BY D. YAN NOSTEAITD, 23 Murray Street & 27 Warren Street, NEW YORK. Weisbacli's Mechanics. Netv and Hevised Edition, 8vo. Clotli. 110.00. A MANUAL OF THE MECHANICS OE ENGINEEEING, and of the Construction of Machines. By JuLirs "Weisbach, Ph. D. ' Translated from the fourth augmented and improved Ger- man edition, by Ecklet B. Coxe, A.M., Mining Engineer. Vol. I. — Theoretical Mechanics. 1,100 pages, and 902 -wood-cut illustrations. Abstract op Contents. — Introduction to the Calculus — The General Principles of Mechanics — Phoronomics, or the Purely Mathematical Theory of Motion — Mechanics, or the General Physical Theory of Motion— Statics of Rigid Bodies — The Application of Statics to Elasticity and Strength — Dynam. ics of Rigid Bodies — Statics of Fluids— Dynamics of Fluids — The Theory of Oscillation, etc. " The present edition is an entirely new work, greatly extended and very much improved. It forms a text-book which must find its way into the hands, not only of every student, but of every engineer who desires to refresh his mem- ory or acquire clear ideas on doubtful points.'' — Manufacturer and Builder. " "We hope the day is not far distant when a thorough course of study and education as such shall be demanded of the practising engineer, and with this view we are glad to welcome this translation to our tongue and shores of one of the most able of the educators of Europe." — The Technologist. 2 SCIEXTIFIC BOOKS PUBLISHED BY Francis' Lowell Hydraulics. Tliird Edition. 4to. aoth. $13.00. LOWIXL HTDEAULIC EXPEEniEXTS — being a Selec- tion from Experiments on Hydraulic Motors, on the Flow of Water over Weirs, and in Open Canals of Uniform Eectangular Section, made at LoweU, Mass. By J. B. Fraxcis, Civil Engineer. Third edition, revised and enlai^ed, including many Xew Ex- periments on Gauging Water in Open Canals, and on the Flow through Submerged Orifices and Diverging Tubes. With 23 copperplates, beautifully engraved, and about 100 new pages of text. The work is divided into parts. Pabt L, on hydraulic motors, includes ninety-two experiments on aa improved Foumeyron Turbine TTater-Wheel, of about two hundred horse-power, with rules and tables for the construction , of ffimilar motors ; thirteen experiments on a model of a cenire-vent water- wheel of the most simple design, and thirty-nine experiments on a centre-vent water-wheel of about two hundred and thirty horse-power. Pabt IL includes seventy-four experiments made for the purpose of deter- mining the form of the formula for computing the flow of water over weirs; nine experiments on the eflEect of back-water on the flow over weirs; eighty- eight experiments made for the purpose of determining the formula for com- puting the flow over weirs of regular or standard forms, with severah table* of comparisons of the new formula with the results obtained by former experi- menters; five experiments on the flow over a dam in which the crest was of the same form as that built by the Essex CoHipany across the Merrimack River at Lawrence, Massachusetts; twenty-one experiments on the effect of observing the depths of water on a weir at different distances from the weir ; an exten- sive series of experiments made for the purpose of determining rules for gauging streams of water in open canals, with tables for fecili taring the same ; and one hundred and one experiments on the discharge of water through sub- merged orifices and divei^ng tubes, the whole being fully illustrated by twenty-three double plates engraved on copper. In ISoo the proprietors of the Locks and Canals on Merrimack River con- sented to the publication of the first edition of this work, which contained a selection of the most important hydraulic experiments aiade at Lowell up to that time. Li this edition the principal hydraulic experiments made there, subsequent to 1855, have been added, including the important series above mentioned, for determining rules for the gauging the flow of water in open canals, and the interesting series on the flow through a Eubmerged Yentori's tube, in which a larger flow was obtained than any we fimd recorded. i>, VAIf NOSTRAJSrj). Francis on Cast-iron Pillars. 8vo. aoth. $2.00. ON THE STEENGTH OE CAST-IEON PILLAES, \vith Tables for the use of Engineers, Architects, and Builders. By James B. Feancis, Civil Engineer. Merrill's Iron Truss Bridges. Second Edition, 4to. Clath. $5.00. IRON TEUSS BEIDGES FOE EAILEOADS. The Method of Calculating Strains in Trusses, with a careful comparison of the most prominent Trusses, in reference to economy in combination, etc., etc. By Brevet Colonel William E. Meekill, U.S.A., Major Corps of Engineers. Nine lithographed plates of illustra- tions. " The -n^ork before us is an attempt to give a basis for sound reform in this feature of railroad engineering, by throwing 'additional light upon the method of calculating the maxima strains that can come upon any part of a bridge truss, and upon the manner of proportioning each part, so that it shall be as strong relatively to its own strains as any other part, and so that the entire bridge may be strong enough to sustain several times as great strains as the greatest that can come upon it in actual use.' " — Scientific Americnn. " The author has presented his views in a clear and intelligent manner, and the ingenuity displayed in coloring the figures so as to present certain facts to the eye forms no inappreciable part of the merits of the work. The reduc- tion of the ' formulte for obtaining the strength, volume, and weight of a cast- iron pillar under a strain of compression,' wiU be very acceptable to those who have occasion hereafter to make investigations involving these conditions. As a whole, the work has been well done." — Railroad Gazette, Chicago. Hnmber's Strains in Girders. ISmo. Cloth. $3.50. A H.\NDY BOOK FOE THE CALCULATION OF STEAINS IN GIEDEES and Similar Structures, and their Strength, con- sisting of Formula) and Corresponding Diagrams, with numerous details for practical apphcation. By William Humber. Fully illustrated. 4 SCIENTIFIC BOOKS PUBLISHED BT Slireve on Bridges and Roofs. 8vo, 87 wood-cut illustrations. Cloth. $5.00. A TEEATISE ON THE STEENGTH OF BEIDGES AXD EOOFS — comprisiug the determination of Algebraic formulas for Strains in Horizontal, Inclined or Eafter, Triangular, Bow- string, Lenticular and other Trusses, from fixed and moving loads, with practical apphcations and examples, for the use of Students and Engiaeers. By Samuel H. Shezve, A.M., Civil Engineer. Nearly ready. The rules for the determination of strains giren in this -work, in the shape of formulas, are deduced from a few well-known mechanical laws, and are not based upon assumed conditions ; the processes are given and applications made of the results, so that it is equally valuable as a text-book for the Student and as a manual for the Practical Engineer. Among the examples are the Greithausen Bridge, the Kuilemberg Bridge, a bridge of the Saltash type, and many other compound trusses, whose strains are calculated by methods which are not only free from the use of the higher mathematics, but are as simple and accurate, and as readily applied, as those which are used in proportioning a Warren Girder or other simple truss. The Kansas City Bridge. 4to. Cloth. $6.00 WITH AN ACCOUNT OF THE EEGIMEN OF THE MIS- SOUEI EIYEE, and a description of the Methods used for Founding in that Eiver. By 0. Chaxxjte, Chief Engineer, and Geokge MoKisoy, Assistant Engineer. Illustrated with five lithographic views and twelve plates of plans. IUustratio7is. Views. — View of the Kansas City ' tion "Works, Pier Xo. 3. IT. Founda- Bridge, August 2, 1869. Lowering ; tion Works, Pier No. -4. V. Founda- Caisson No. 1 into position. Caisson I tion Works. Pier No. 4 VI. Caisson for Pier Xo. 4 brought into position, i Xo. 5 — Sheet Piling at Pier No. 6 — View of Foundation Works, Pier No. Details of Dredges — Pile Shoe — Beton 4. Pier No. 1. ■ Box. VTL Masonry — Draw Protec- Plates. — I. Map showing location ' tion — False Works "between Piers 3 of Bridge. 11. Water Record — Cross ■ and 4 VIII. Floating Derricks. Section of River — Profile of Crossing j IX. General Elevation — 176 feet span. — Pontoon Protection, m. Water ; X. 248 feet span. XI Plans of Draw. Deadener — Caisson No. 2 — Founda | Xlf. Strain Diagrams. D. VAN' NO STRAND. Clarke's Quincy Bridge. 4to. Cloth. $7.50. DESCRIPTION OF THE lEON RAILWAY Bridge across the Mississippi River at Quincy, Illinois. By Thomas Curtis Cl.iske, Chief Engineer. Illustrated with twenty-one lithographed plans. Illustrations. Plates. — General Plan of Missis- sippi River at Quincy, showing loca- tion of Bridge. 11a. General Sections of Missis:-jippi River at Quincy, show- ing location of Bridge, lib. General Sections of Mississippi River at Quin- cy, showing location of Bridge. III. General Sections of Mississippi River at Quincy, showing location of Bridge. IV. Plans of Masonry. V. Diagram of Spans, showing the Dimensions, Arrangement of Panels, etc. VI. Two hundred and fifty feet span, and de- tails. VII. Three hundred and sixty feet Pivot Draw. VIII. Details of three hundred and sixty feet Draw. IX. Ice- ! breakers. Foundations of Piers and Abutments, Water Table, and Curve of Deflections. X. Founda- tions of Pier 2, in Process of Con- struction. XI. Foundations of Pier 3, and its Protection. XII. Founda- tions of Pier 3, in Process of Construc- tion, and Steam Dredge. XIII. Foun- dations of Piers 5 to 18, in Process of Construction. XIV. False Works, showing Process of Handling and Set- ting Stone. XV. False Works for Raising Iron Work of Superstructure. XVI. Steam Dredge used in Founda- tions 9 to 18. XVII. Single Bucket Dredge used in Foundations of Bay Piers. XVIII. Saws used for Cut- ting Piles under water. XIX. Sand Pump and Concrete Box. XX Ma- sonry Travelling Ci'ane. Whipple on Bridge Building. Svo, Illustrated. Cloth. $4.00. AN ELEMENTARY AND PRACTICAL TREATISE ON BRIDGE BUILDING. An enlarged and improved edition of the Author's original work. By S. Whipple, C. E., Inventor of the Whipple Bridges, &c. The design has been to develop from Fundamental Principles a system easy of comprehension, and such as to enable the attentive reader and student to jiidge understandingly for himself, as to the relative merits of different plana and combinations, and to adopt for use such as may be most suitable for the cases he may have to deal with. It is hoped the work may prove an appropriate Text-Book upon the subject treated of, for the Engineering Student, and a useful manual for the Practio- ing Engineer and Bridge Builder. 6 SCIENTIFIC BOOKS PUBLISHED BY Stoney on Strains. New arid Revised Edition^ with numerous illustrations. Royal 8vo, 664 pp. Cloth. §15.00. THE THEORY OF STEAINS IX GIEDERS and Similar Shuc- tures, -with Observations on the Application of Theory to Practice, and Tables of Strength and other Properties of Materials. By BorDOx B. SioNEr, B. A. Roebling's Bridges. Imperial foUo. Cloth. $25.00. LONG AKD SHOET SPAN EAILWAT BEIDGES. By Johx A. EoEBLixG, C. E. Illustrated with large copperplate engrav- ings of plans and views. "^ lyist of Plates 1. Parabolic Truss Railway Bridge. 2, 3, 4, 5, 6. Details of Parabolic Tru3s, with centre span 500 feet in the clear. 7. Plan and View of a Bridge over the Mississippi River, at St. Louis, for railway and common traveL 8, 9, 10, 11, 12. Details and View of St. Louis Bridge. 13. Railroad Bridge over the Ohio. Diedrichs' Theory of Strains. Svo. Cloth. $5.00. A Compendium for the Calculation and Construction of Bridges, Hoofs, and Cranes, with the AppHcation of Trigonometrical Notes. Containing the most comprehensive information in re- gard to the Eesulting Strains for a permanent — t Load, as also for a combined (Permanent and Eolling) Load. In two sections, adapted to the requirements of the present time. By Joh>- Died- EiCHS. Illustrated by numerous plates and diagrams. " The want of a compact, universal and popular treatise on the Construc- tion of Roofs and Bridges — especially one treating of the influence of a varia- ble load — and the unsatisfactory essays of different authors on the subject, induced me to prepare fliis work." D. VAN NOSTRAND. Whilden's Strength of Materials. 12iHo. Cloth. $2.00. ON THE STEENGTH OF MATEEIALS used iu Engineering Construction. By J. K. Whilden. Campin on Iron Roofs. Large 8vo. Clotli. $3.00. ON THE CONSTRUCTION OF lEON EOOFS. A Theoretical and Practical Treatise. By Feancis Campin. With, wood-cuts and plates of Eoofs lately executed. " The mathematical formulas are of an elementary kind, and the process admits of an easy extension so as to embrace the prominent varieties of iron truss bridges. The treatise, though of a-practical scientific character, may be easily mastered by any one familiar with elementary mechanioa and plane trigonometry." Holley's Railway Practice. 1 vol. folio. Cloth. $12.00. AMEEICAN AND EUEOPEAN EAILWAY PEACTICE, in the Economical Generation of Steam, including the materials and construction of Coal-burning Boilers, Combustion, the Varia- ble Blast, Vaporization, Circulation, Super-heating, Supplying and Heating Feed- water, &c., and the adaptation of Wood and Coke-burning Engines to Coal-burning ; and in Permanent Way, including Eoad-bed, Sleepers, Eails, Joint Fastenings, Street Eailways, &c., »S:c. By Alexaxder L. Hollet, B. P. With 77 lithographed plates. " This is an elaborate treatise by one of our ablest civil engineers, on the con- struction and use of locomotives, with a few chapters on the building of E.ail- rotvds. * * * _AJ.l these subjects are treated by the author, who is a first-class railroad engineer, in both an intelligent and intelligible manner. The facts and ideas are well arranged, and presented in a clear and simple style, accompanied by beautiful engra^dngs, and we presume the work will be regard- ed as indispensable by all who are interested in a knowledge of the construc- tion of railroads and rolling stock, or the working of locomotives." — Scientijic American. 8 JS CIENTIFIC B O OKS P UB LI SHED B T Henricfs Skeleton Stractures. 8vo. Cloth. $3.00. SKELETON STEUCTUEES, especially in their Application to the building of Steel and Iron Bridges. By Olaus Hen":rici. With folding plates and diagrams. By presenting these general examinations on Skeleton Stmctnres, with particular application for Suspended Bridges, to Engineers, I venture to ex- press the hope that they will receive these theoretical results with some confi- dence, even although an opportunity is wanting to compare them with practi- cal results. 0. H. Useful Information for Railway Men. Pocket form. Morocco, gilt, $3.00. Compiled by "W. G. HAMiLTOif, Engineer. Third edition, revised and enlarged. 570 pages. " It embodies many valuable formulae and recipes useful for railway men, and, indeed, for almost every class of persons in the world. The ' informa- tion ' comprises some valuable formulae and rules for the construction of boilers and engines, masonry, properties of steel and iron, and the strength of materials generally." — Railroad Gazette, Chicago. Brooklyn Water Works. 1 vol. folio. Cloth. $30.00. A DESCEIPTIVE ACCOUNT OF THE CONSTEUCTION OF THE WOEKS, and also Eeports on the Brooklyn, Hartford, Belleville, and Cambridge Pumping Engines. Prepared and printed by order of the Board of Water Commissioners. With 59 illustrations. Contents. — Supply Ponds — The Conduit — Kidgewood Engine House and Pump "Well — Eidgewood Engines — Force Mains — Ridgewood Reservoir — Pipe Distribution — Mount Prospect Reservoir — Mount Prospect Engine House and Engine — Drainage Grounds — Sewerage Works — Appendix. D. VAN JSrOSTBAN-D. Kirkwood on Filtration. 4to. Cloth. $15.00. EEPORT ON THE FILTRATION OF EIVEE WATERS, for the Supply of Cities, as practised in Europe, made to tlio Board of "Water Commissioners of the City of St. Louis. By James P. Kirkwood. lUustrated by 30 double-plate engravings. Contents. — Report on Filtration — London "Works, General — Chelsea "Water "Works and Filters — Lambeth Water Works and Filters — Southwark and "Vauxhall Water Works and Filters — Grand Junction Water Works and Filters — West Middlesex Water Works and Filters — New River Water Works and Filters — East London Water Works and Filters — Leicester Water Works and Filters— York Water Works and Filters — Liverpool Water Works and Filters — Edinburgh Water Works and Filters — Dublin Water Works and Filters — Perth Water Works and Filtering Gallery — Berlin Water Works and Filters — Hamburg Water Works and Reservoirs — Altona Water Works and Filters — Tours Water Works and Filtering Canal — Angers Water Works and Filtering Galleries — Nantes Water Works and Filters — Lyons Water Works and Filtering Galleries — Toulouse Water Works and Filtering Galleries — Marseilles Water Works and Filters — Genoa Water Works and Filtering Galleries — Leghorn Water Works and Cisterns — Wakefield Water Works and Filters — Appendix. Tnnner on Roll-Turning. 1 vol. 8vo. and 1 vol. plates. $10.00. A TREATISE ON ROLL-TURNING FOR THE MANUFAC- TURE OF IRON. By Peter Tunner. Translated and adapted. By John B. Pearse, of the Pennsylvania Steel Works. With numerous wood-cuts, 8vo., together with a folio atlas of 10 litho- graphed plates of Rolls, Measurements, t&c. " We commend this book as a clear, elaborate, and practical treatise upon the department of iron manufacturing operations to which it is devoted. The writer states in his preface, that for twenty-five years he has felt the necessity of such a work, and has evidently brought to its preparation the fruits of experience, a painstaking regard for accuracy of statement, and a desire to furnish information in a style readily understood. The book should be in the hands of every one interested, either in the general practice of mechanical engineering, or the special branch of manufacturing operations to which the work relates.'' — American Artisan. 10 SCIENTIFIC BOOKS PUBLISHED BY G-lynn on the Power of Water. 12mo. Cloth. $1.00. A TREATISE ON THE POWER OF AVATER, as applied to drive Flour Mills, and to give motion to Turbines and other Hydrostatic Engines. By Joseph Glyxn, F.R. S. Third edition, revised and enlarged, with numerous illustrations. Hewson on Embankments. 8vo. Cloth. $2.00. PRINCIPLES AND PRACTICE OF EMBANEING LANDS from River Floods, as applied to the Levees of the Mississippi. By William Hewson, Civil Engineer. " This is a valuable treatise on the principles and practice of embanking lands fi-om river floods, as applied to the Levees of the Mississippi, by a highly- intelligent and experienced engineer. The author says it is a first attempt to reduce to order and to rule the design, execution, and measurement of the Levees of the Mississippi. It is a most useful and needed contribution to scientific literature. — Philadelphia Evening Journal. G-riiner on Steel. 8vo. Cloth. $3.50. THE MANUFACTURE OF STEEL. By M. L. Getjner; ti-ans- lated from the French. By Lenox Smith, A. M., E. M., with an appendix on the Bessemer Process in the United States, by the translator. Illustrated by lithographed drawings and wood-cuts. " The purpose of the work is to present a careful, elaborate, and at the same time practical examination into the physical properties of steel, as well as a description of the new processes and mechanical appliances for its manufac- ture. The information which it contains, gathered from many trustworthy sources, will be found of much value to the American steel manufacturer, who may thus acquaint himself with the results of careful and elaborate ex- periments in other countries, and better prepare himself for successful com- petition in this important industry with foreign makers. The fact that this volume is from the pen of one of the ablest metallurgists of the present day, cannot fail, we think, to secure for it a favorable consideration. — Iron Age. 1\ VAir NOSTRAXB. H Baiierniaii on Iron. 12mo. Cloth. $3.00. TEEATISE ON THE METALLUEGY OP lEON. Contain- ing outlines of the History of Iron Manufacture, methods of Essay, and analysis of Iron Ores, processes of manufacture of Iron and Steel, etc., etc. By H. Batjerman. Eirst American edition. Eevised and enlarged, with an appendix on the Martin Process for making Steel, from the report of Abram S. Hewitt. Dlustrated with numerous wood engravings. " This is an important addition to the stock of technical works published in this country. It embodies the latest facts, discoveries, and processes con- nected with the manufacture of iron and steel, and should be in the hands of every person interested in the subject, as well as in all technical and scientific libraries." — Scientific American. Auchinoloss on the Slide Valve. 8vo. Cloth. $3.00. APPLICATION OP THE SLIDE VALYE and Link Motion to Stationary, Portable, Locomotive and Marine Engines, with new and simple methods for proportioning the parts. By William S. ArcHixcLoss, Civil and Mechanical Engineer. Designed as a hand-book for Mechanical Engineers, Master Mechanics, Draughtsmen and Students of Steam Engineering. All dimen- sions of the valve are found with the greatest ease by means of a Printed Scale, and proportions of the link determined loitJiout the assistance of a model. Illustrated by 37 wood-cuts and 21 lithographic plates, together with a copperplate engraving of the Travel Scale. All the matters we have mentioned are treated with a clearness and absence of unnecessary verbiage which renders the work a peculiarly valuable one. The Travel Scale only requires to be known to be appreciated. Mr. A. writes so ably on his subject, we wish he had written more. London En- gineering. "We have never opened a work relating to steam which seemed to us better calculated to give an intelligent mind a clear understanding of the depart- ment it discusses. — Scientific American. 12 SCIENTIFIC BOOKS PUBLISHED BY Slide Valve by Eccentrics, by Prof. C, W. MacCord. 4to. niustrated. Cloth, $4.00. A PEACTICAL TREATISE ON THE SLIDE YALTE BY ECCEXTEICS, examining by methods, the action of the Eccen- tric upon the Shde Yalve, and explaining the practical proces- ses of laying out the movements, adapting the valve for its various duties in the steam-engine. For the use of Engineers, Draughtsmen, Machinists, and Students of valve motions in general. By C. W. MacCokd, A. M., Professor of Mechanical Drawing, Stevens' Institute of Technology, Hoboken, X J. Stillinan's Steam-Engine Indicator. 12mo. Clotli. $1.00. THE STKAM-ENGENE INDICATOR, and the Improved Mano- m.eter Steam and Yacuum Gauges ; their utility and application By Patti. SnLLiU-X. New edition. Bacon's Steam-Engine Indicator. 12mo. aoth. $1.00. Mor. $1.50. A TREATISE ON THE RICHARDS STEAM-ENGINE IN- DICATOR, with directions for its use. By Chakles T. Pokteb. Revised, with notes and large additions as developed by Amer- ican Practice, with an Appendix containing useful formulfe and niles for Engineers. By F. W. Bacon, M. E., Member of the American Society of Civil Engineers. Illustrated. In this work, Mr. Porter's book has been taken as the basis, but Mr. Bacon has adapted it to American Practice, and has conferred a great boon on American Engineers. — Artisan. Bartol on Marine Boilers. Svo. Cloth. $1.50. TREATISE ON THE MARENE BOILERS OF THE UNITED STATES. By H. H. Baetol. Hlustarated. J). VAN NOSTRAND. 13 Gillmore's Limes and Cements. Fourth Edition. Mevised and Enlargd. 8vo. Cloth. $4.00. PEACTICAL TEEATISE ON LIMES, HTDEAULIC CE- MENTS, AND MOET/VES. Papers on Practical Engineering, U. S. Engineer Department, No. 9, containing Eeports of numerous experiments conducted in New York City, during the years 1858 to 1861, inclusive. By Q. A. Gillmore, Brig-General U. S. Volunteers, and Major U. S. Corps of Engineers. AVith. numerous illustrations. " This Tyork contains a record of certain experiments and researches made under the authority of the Engineer Bureau of the War Department from 1858 to 1861, upon the various hydraulic cements of the United States, and the materials for their manufacture. The experim.ents were carefully made, and are ■well reported and compiled.' — Journal Franklin Institute. Grillmore's Coignet Beton. 8yo. Cloth. $2.50, COIGNET BETON AND OTHEE AETIEICIAL STONE. By Q. A. GiLLMOKE. 9 Plates, Yiews, etc. This -work describes with considerable minuteness of detail the several kinds of artificial stone in most general use in Europe and now beginning to be introduced in the United States, discusses their properties, relative merits, and cost, and describes the materials of which they are composed The subject is one of special and growing interest, and we commend the work, embodying as it does the matured opinions of an experienced engineer and expert. Williamson's Practical Tables. 4to. Flexible Cloth. $2.50. PEACTICAL TABLES IN METEOEOLOGY AND HYPSO- METEY, in connection -svith the use of the Barometer. By Col. E. S. WiLLIAMSOM, U. S. A. U SCIEXTIFIC BOOKS PUBLISHED BY Williainsoii on the Barometer. 4to. Clott. $15.00. ON THE rSE OF THE BAROMETEE ON SUEYETS AXD EECOXXAISSANCES. Part L Meteorology in its Connec- tion with Hypsometry. Part EL. Barometric Hypsometry. By E. S. WiLLiAMsox, Bvt. Lieut-Col. U. S. A., Major Corps of Engineers. TTith niustrative Tables and Engravings. Paper Xo. 15, Professional Papers, Corps of Engiaeers. " Sax Fkaxcisco, Cal., Feb. 27, 1867. " G«ii. A. A Humphreys, CMef of Engineers, TJ. S. Army : " General, — I have the tonor to submit to you, in the following pages, the results of my investigations in meteorology and hypsometry, made with the view of ascertaining how far the barometer can be used as a reliable instru- ment for determining altitudes on extended lines of survey and reconnais- sances. These investigations have occupied the leisure permitted me from my professional duties during the last ten years, and I hope the results will be deemed of sufficient value to have a place assigned them among the printed profes£donal papers of the United States Corps of Engineers. ** Very respectfully, jovjs obedient servant, "R. S. "SVTLLIAMSON, " Bvt. Lt.-C-oL U. S. A, Major Corps of U. S. Engineers." Yon Cotta's Ore Deposits. Svo. Qoth. $4,00. TPEATISE OX OPE DEPOSITS. By Ber>-hard Yox Cotta, Professor of Geology in the Eoyal School of Mines, Freidberg, Saxony. Translated firom the second German edition, by Feedzeick Pruee, Jr., Mining Engineer, and revised by the author, vrith numerous illustrations. " Pro£ Yon Cotta of the Freiberg School of Mines, is the author of the best modem treatise on ore deposits, and we are heartily glad that this ad- mirable work has been translated and published in this country. The trans- lator, Mr. Frederick Prime, Jr., a graduate of Freiberg, has had in his work the great advantage of a revision by the author himself, who declares in a prefatory note that t.big may be considered as a new edition (the third; of his own book. " It is a timely and welcome contribution to the literature of mining in this country, and we are grateful to the translator for his enterprise and good judgment in undertaking its preparation ; while we recognize with equal cor- diality the liberality of the author in granting both permission and assist- ance." — Ekstract from Betiew in Engineering and Mining Journal. D. VAJV JSrOSTBAJSrjD. 15 Plattner's Blow-Pipe Analysis. Second edition. Eevised. 8vo. Cloth. $7.50. PLATTNEE'S ]SL\NUAL OF QUALITATIVE AXD QUAN- TITATIYE ANALYSIS WITH THE BLOW-PIPE. From the last German edition Eevised and enlarged. By Prof. Tn. EiCHTEK, of the Eoyal Saxon Mining Academy. Translated by Prof. H. B. Coii>'WAXL, Assistant in the Columbia School of Mines, New York ; assisted by John H. Caswell. Illustrated witli eighty-seven wood-cuts and one Lithographic Plate. 560 pages. " Plattner's celebrated work has long been recognized as the only complete book on Bloiv-Pipe Analysis. The fourth German edition, edited by Prof. Richter, fully sustains the reputation -which the earlier editions acquired dur- ing the lifetime of the author, and it is a source of great satisfaction to us to kno-w that Prof. Eichter has co-operated with the translator in issuing the American edition of the work, which is in fact a fifth edition of the original ■work, being far more complete than the last German edition." — SilUman's Journal. There is nothing so complete to be found in the English language. Platt- ner's book is not a mere j)ocket edition ; it is intended as a comprehensive guide to all that is at present known on the blow-pipe, and as such is really indis- pensable to teachers and advanced pupils. " Mr. Cornwall's edition is something more than a translation, as it contains many corrections, emendations and additions not to be found in the original. It is a decided improvement on the work in ite German dress." — Journal of Applied Chemistry. Egleston's Mineralogy. 8vo. Illustrated with 34 Lithographic Plates. Cloth. §4.50. LECTUEES ON DESCEIPTIYE MINEEALOGY, DeUvered at the School of Mines, Columbia College. Br PROFEsson T, Eglestox. These lectures are what their title indicates, the lectures on Mineralogy delivered at the School of Mines of Columbia College. They have been printed for the students, in order that more time might be given to the vari- ous methods of examining and determining minerals. The second part has only been printed. The first part, comprising crystallography and physical mineralogy, will be printed at some future time. 16 SCIENTIFIC BOOKS PUBLISHED BY Pynclion's Chemical Physics. Ifew Edition. Revised and Enlarged. Crown 8vo. Cloth. |3.00. IXTEODUCTIOX TO CHEMICAL PHYSICS, Designed for the Use of Academies, Colleges, and High Schools. Illustrated with numerous engravings, and containing copious experiments Ts-ith directions for preparing them. By Thomas Huggles PrxcHO>', M.A., Professor of Chemistry and the Natural Sciences, Trinity College, Hartford. Hitherto, no work suitable for general use, treating of all these subjects within the limits of a single volume, could be found ; consequently the atten- tion they have received has not been at all proportionate to their importance. It is believed that a book containing so much valuable information within so small a compass, cannot fail to meet with a ready sale among all intelligent persons, while Professional men, Physicians, Medical Students, Photograph- ers, Telegraphers, Engineers, and Artisans generally, will find it specially valuable, if not nearly indispensable, as a book of reference. " We strongly recommend this able treatise to our readers as the first work ever published on the subject free from perplexing technicalities. In style it is pure, in description graphic, and its typographical appearance is artistic. It is altogether a most excellent work." — Eclectic Medical Journal. " It treats fully of Photography, Telegraphy, Steam Engines, and the various applications of Electricity. In short, it is a carefully prepared volume, abreast with the latest scientific discoveries and inventions.' — Hart- ford Courant. Plympton's Blow-Pipe Analysis. 12mo. Cloth. $2.00. THE BLOW-PIPE : A System of Instruction in its practical use being a graduated course of Analysis for the use of students, and all those engaged in the Examination of Metallic Combina- tions. Second edition, vrith an appendix and a copious index. By Geoege W. PLYiiPiox, of the Polytechnic Institute, Brooklyn. " This manual probably has no superior in the English language as a text- book for beginners, or as a guide to the student working without a teacher. To the latter many illustrations of the utensils and apparatus required in using the blow-pipe, as well as the fully illustrated description of the blow- pipe flame, will be especially serviceable." — Xew York Teacher. D. VAN' ROSTBAN^I). lire's Dictionary. Sixth Edition. London, 1872. 3 vols. 8vo. Cloth, 125.00. Half Russia, $37.50. DICTIONAEY OF ARTS, :MAXUrACTUEES, AND MINES. By Andrew Uke, M.D. Sixth, edition. Edited by Egbert Hunt, E.E.S., greatly enlarged and rewritten. Brande and Cox's Dictionary. New Edition. London, 1872. , 3 vols. 8vo. Cloth, $20.00. Half Morocco, $27.50. A Dictionary of Science, Literature, and Art. Edited by W. T. Brande and Eev. Geo. W. Cox. New and enlarged edition. Watt's Dictionary of Chemistry. Stipplenientary Voliane. 8vo. aoth. $9.00. This volume brings the Record of Chemical Discovery down to the end of the year 1S69, including also several additions to, and corrections of, former results -which have appeared in 1870 and 1871. *.,* Complete Sets of the Work, New and Revised edition, including above supplement. 6 vols. 8vo. Cloth. $G2.00. Rammelsberg's Chemical Analysis. 8vo. Cloth. $2.25. GUIDE TO A COUESE OF QUANTITATIVE CHEMICAL ANALYSIS, ESPECLA.LLY OF MINEEALS AND FUE- NACE PEODUCTS. Blustrated by Examples. By C. F. Eaiijielsberg. Translated by J. Towler, M.D. This work has been translated, and is now published expressly for those students in chemistry -whose time and other studies in colleges do not permit them to enter upon the more elaborate and expensive treatises of Fresenius and others. It is the condensed labor of a master in chemistry and of a prac- tical analyst. 18 SCIEXTIFIC BOOKS PUBLISHED BT Eliot and Storer's Qualitative Chemical Analysis. Xeiv Edition, Revised. 12mo. Illustrated- Cloth. $1.50. A COiTPEXDIOrS :M"AXUAL of Qr.iLITATrTE CHEMI- CAL ANALYSIS. By Chakt.ks "W. Eliot and Fua>-x H. Stoeee. Eevised with, the Cooperatioii of the Authors, by William Eep- LET XicHOLs, Professor of Chemistry in the Massachusetts Insti- tute of Technology. " This Manual has great merits as a practical introduction to the science and the art of which it treats. It contains enough of the theory and practice of qualitatiTe analysis, " in the wet way,'' to bring out all the reasoning in- Tolred in the science, and to present clearly to the student the most approved methods of the art. It is specially adapted for exercises and experiments in the laboratory; and yet its classifications and manner of treatment are so systematic and logical throughout, as to adapt it in a high degree to Ihat higher class of students generally who desire an accurate knowledge of the practical methods of arriTing at scientific facts." — Lutheran Ohserzer. *' 'We wish every academical class in the land could have the benefit of the fifty exercises of two hours each necessary to master this book. Chemistry would cease to be a mere matter of memory, and become a pleasant experi- mental and intellectual recreation. We heartily commend this little volume to the notice of those teachers who believe in using the sciences as Tng-ana of mental discipline." — College Courani, Craig's Decimal System. Square 32mo. Limp. 50c. WEIGHTS AXD MEASUEES. An Account of the Decimal System, with Tables of Conversion for Commercial and Scientific Uses. By B. E. Cbaig, M. D. " The most lucid, accurate, and useful of all the hand-books on this subject that we have yet seen. It gives forty -seven tables of comparison between the "Fnor lish and French denominations of length, area, capacity, weight, and the Centigrade and Fahrenheit thermometers, with clear instructions how to use them ; and to this practical portion, which helps to make the transition as easy as possible, is prefixed a scientific explanation of the errors in tiie metric system, and how they may be corrected in the laboratory." — 2sation. B. VAX NOSTRAND. 19 Nugent on Optics. 12mo. Cloth. $2.00 TREATISE ON OPTICS ; or, Light and Sight, theoretically and practically treated ; with the application to Fine Art and Indus- trial Pursuits. By E. Nugext. With one hundred and three illustrations. " This book is of a practical rather than a theoretical kind, and is de- signed to afford accurate and complete information to all interested in appli- cations of the science." — Round Table. Barnard's Metric System. 8vo. Brown cloth. fIS.OO. THE METRIC SYSTEM OF WEIGHTS AND MEASURES. An Address delivered before the Convocation of the University of the State of New York, at Albany, August, 1871. By Fbedekick A. P. Barnard, President of Columbia CoUege, New York City. Second edition from the Revised edition printed for the Trustees of Columbia College. Tinted paper. " It is the best siimmary of the arguments in favor of the metric 'weights and measures with which we are acquainted, not only because it contains in small space the leading facts of the case, but because it puts the advocacy of that system on the only tenable grounds, namely, the great convenience of a decimal notation of weight and measure as well as money, the value of inter- national uniformity in the matter, and the fact that this metric system is adopted and in general use by the majority of civilized nations." — The Nation. The Young Mechanic. niustrated. 12mo. Cloth. $1.75. THE YOUNG MECHANTC. Containing direetions for the use of all kinds of tools, and for the construction of steam engines and mechanical models, including the Art of Turning in Wood and Metal. By the author of "The Lathe and its Uses," etc From the English edition, with corrections. 20 SCIEXTIFIC B OKS P UBLISHED B Y Harrison s Mechanic's Tool-Book. 12mo. Cloth. $1.50. MECHANIC'S TOOL BOOK, with practical rule.s and suggestions, for the use of Machinists, Iron Workers, and others. By W. B. Haeeisox, Associate Editor of the "American Artisan." Illustra- ted with 44 engravings. " This work is specially adapted to meet the Trants of ilachinists and "work- ers in iron generally. It is made up of the work-day experience of an intelli- gent and ingenious mechanic, who had the faculty of adapting tools to various purposes. The practicability of his plans and suggestions are made apparent even to the unpractised eye by a series of ^well-executed wood engravings." — PhUaddphia Inquirer. Pope's Modern Practice of tlie Elec- tric Telegraph. Seventh edition. 8vo. Cloth $2.00. A Hand-book for Electricians and Operators. By Fbaxk L. Pope. Seventh edition. Revised and enlarged, and fully illustrated. Extract from Letter of Prof. Morse. " I have had time only cursorily to examine its contents, but this examina- tion has resulted in great gratification, especially at the fairness and unpre- judiced tone of your whole work. " Tour illustrated diagrams are admirable and beautifully executed. " I think all your instructions in the use of the telegraph apparatus judi- cious and correct, and I most cordially wish you success." Extract from Letter (^ Prof. G. W. Hough, of the Dudley Ohsertatory. " There is no other work of this kind in the English language that con- tains in so small a compass so much practical information in the application of galvanic electricity to telegraphy. It should be in the hands of every one interested in telegraphy, or the use of Batteries for other purposes." Morse's Telegraphic Apparatus. Illustrated. Sro. Cloth. $2.00. EXAMIXATIOX OF THE TELEGRAPHIC APPARATUS AXD THE PROCESSES Ds TELEGAPHT. By S.v3rrEL F. B. MoESE, LL.D., United States Commissioner Paris Universal Exposition, 1867. D. VAN XO STB AND. 21 Sabine's History of the Telegraph. 12mo. Cloth. $1.25. HISTORY AND PROGRESS OF THE ELECTRIC TELE- GRAPH, with Descriptions of some of the Apparatus. By Robert Sabine, C. E. Second edition, with additions. Contents. — I. Early Observations of Electrical Phenomena. II. Tele- graphs by Frictional Electricity. III. Telegraphs by Voltaic Electricity. IV. Telegraphs by Electro-Magnetism and Magneto-Electricity. V. Tele- graphs now in use. VI. Overhead Lines. YTL. Submarine Telegraph Lines. Vin. Underground Telegraphs. IX. Atmospheric Electricity. ShafFner's Telegraph Manual. 8vo. Cloth. $6.50. A COMPLETE HISTORY AND DESCRIPTION OF THE SEMAPHORIC, ELECTRIC, AND MAGNETIC TELE- GRAPHS OF EUROPE, ASIA, AFRICA, AND AMERICA, with 625 illustrations. By Tal. P. Shaffxer, of Kentucky. New edition. Cnlley's Hand-Book of Telegraphy. 8vo. Cloth. $5.00. A HAND-BOOK OF PRACTICAL TELEGRAPHY. By R. S. CvLLEi", Engineer to the Electric and International Telegraph Company. Fourth edition, revised and enlarged. Foster's Submarine Blasting. 4to. Cloth. $3.50. SUBMARINE BLASTING in Boston Harbor, Massachusetts- Removal of Tower and Corwin Rocks. By John G. Fosteb, Lieutenant-Colonel of Engineers, and Brevet Major-General, U. S. Army. Illustrated with seven plates. List of Plates. — 1. Sketch of the Narrows, Boston Harbor. 2. Townsends Submarine Drilling Machine, and Working Vessel attending. 3. Submarine Drilling Machine employed. 4. Details of Drilling Machine employed. 5. Cartridges and Tamping used. 6. Fuses and Insulated Wires used. 7. Portable Friction Battery used. 22 SCIENTIFIC BOOKS PUBLISHED BY Barnes' Submarine Warfare. 8vo. Cloth. $5.00. SUBMAEINE WAEFAEE, DEFENSIVE AND OFFENSIYE. Comprising a fall and complete History of the Invention of the Torpedo, its employment in War and results of its use. De- scriptions of the rarious forms of Torpedoes, Submarine Batteries and Torpedo Boats actually used in War. Methods of Ignition by Machinery, Contact Fuzes, and Electricity, and a full account of experiments made to determine the Explosive Force of Gun- powder under Water. Also a discussion of the Offensive Torpedo system, its effect upon Iron-Clad Ship systems, and influence uj)on Future Naval Wars. By Lieut. -Commander Johx S. Baexes, U. S. N. ■ With twenty lithographic plates and many wood-cuts. " A book important to military men, and especially so to engineers and ar- tillerists. It consists of an examination of the various offensive and defensive engines that have been contrived for submarine hostilities, including a discus- sion of the torpedo system, its effects upon iron-clad ship-systems, and its probable influence upon future naval wars. Plates of a valuable character accompany the treatise, which affords a useful history of the momentous sub- j ect it discusses. A great deal of useful information is collected in its pages, especially concerning the inventions of Scholl and Yekdu, and of JoxES' and Hunt's, batteries, as well as of other similar machines, and the use in submarine operations of gun-cotton and nitro-glycerine." — N. Y. Times. Randall's Quartz Operator's Hand- Book. 12mo. Cloth. $3.00. QUARTZ OPERATOR'S HAND-BOOK. By P. M. Randall. New edition, revised and enlarged. Fully illustrated. The object of this work has been to present a clear and comprehensive ex- position of mineral veins, and the means and modes chiefly employed for the mining and working of their ores — more especially those containing gold and silver. D. VAJSr NOSTBANJ). 23 MitcheU's Manual of Assaying. 8vo. Cloth. $10.00. A MANUAL OF PEACTICAL ASSAYING. By John Mitchell. Third edition. Edited by William Ckookes, F.E.S. In this edition are incorporated all the late important discoveries in Assay- ing made in this country and abroad, and special care is devoted to the very important Volumetric and Colorimetric Assays, as weU as to the Blow-Pipe Assays, Benet's Chronoscope. Second Edition. Illustrated. 4to. Cloth. $3.00. ELECTEO-BALLISTIC MACHINES, and the Schultz Chrono- scope. By Lieutenant-Colonel S. V. Benet, Captain of Ordnance, U. S. Army. Contents.— 1. BalUstic Pendulum. 2. Gun Pendulum. 3. Use of Elec- tricity. 4. Navez' Machine. 5. Vignotti's Machine, with Plates. 6. Benton's Electro-Ballistic Pendulum, with Plates. 7. Leur's Tro-Pendulum Machine 8. Schultz's Chronoscope, with two Plates. Michaelis' Chronograph. 4to. Illustrated. Cloth. $3.00. THE LE BOULENGE CHRONOGEAPH. With three litho- graphed- folding plates of illustrations. By Brevet Captain E. Michaelis, First Lieutenant Ordnance Corps, U. S. Army. " The excellent monograph of Captain Michaelis enters minutely into the details of construction and management, and gives tables of the times of flight calculated upon a given fall of the chronometer for all distances. Captain Michaelis has done good service in presenting this work to his brother officers, describing, as it does, an instrument which bids fair to be in constant use in our future ballistic experiments.' —J.r/ny and Navy Jounuil. 24 SCIENTIFIC BOOKS PUBLISHED BY Silversmith's Hand-Book. Fourth Edition. Illustrated. 12mo. Cloth. $3.00.. A PEACTICAL HAND-BOOK FOE :MINEES, MetaUurgists, and Assayers, comprising the most recent improvements in the disintegration, amalgamation, smelting, and parting of the Precious Ores, with a Comprehensive Digest of the Mining Laws. Greatly augmented, revised, and corrected. By Julius SixvEBSMiTH. Fourth edition. Profusely illustrated. 1 vol. 12mo. Cloth. $3.00. One of the most important featuxes of this -work is that in -which the metallurgy of the precious metals is treated of. In it the author has endeav- ored to embody all the processes for the reduction and manipu l ation of the precious ores heretofore successfully employed in Germany, England, Mexico, and the United States, together with such as have been more recently invented, and not yet fully tested — all of which are profusely illustrated and easy of comprehension. Simms' Levelling. 8vo. Cloth. $2.50. A TEEATISE ON THE PEINCIPLES AND PEACTICE OF LE'N'ELLES^G, showing its application to purposes of Eailway Engineering and the Construction of Eoads, &c. By Fkedzkick W. SiiiMS, C. E. From the fifth London edition, revised and corrected, with the addition of Mr. Law's Practical Examples for Setting Out Eailway Curves. Hlustrated with three Hthographic plates and numerous wood-cuts. " One of the most important text-books for the general surveyor, and there is scarcely a question connected vrith levelling for which a solution would be sought, but that would be satisfactorily answered by consulting this voliime." — Mining Journal. " The text-book on levelling in most of our engineering schools and col- leges." — Engineers. " The publishers have rendered a substantial service to the profession, especially to the younger members, by bringing out the present edition of ilr. Simms' useful work." — Engineering. D. VAN NOSTEAJSri). 25 Eads' Naval Defences, 4to. Cloth. $5.00. SYSTEM OF NAVAL DEFENCES. By James B. Eads, C. E. Eeport to the Honorable Gideon Welles, Secretary of the Navy, February 22, 1868, with ten illustrations. Stuart's Naval Dry Docks. Twenty-four engravings on steel. Fourth Edition. 4to. Cloth. $6.00. THE NAVAL DRY DOCKS OF THE UNITED STATES. By Chaeles B. Stuaet. Engineer in Chief of the United States Navy. List of Illustrati07is. Pumping Engine and Pumps — Plan of Dry Dock and Pump-Well— Sec- tions of Dry Dock — Engine House — Iron Floating Gate — Details of Floating Gate — Iron Turning Gate — Plan of Turning Gate — Culvert Gate — Filling Culvert Gates — Engine Bed — Plate, Pumps, and Culvert — Engine House Roof — Floating Sectional Dock — Details of Section, and Plan of Turn-Tables — Plan of Basin and Marine Railways — Plan of Sliding Frame, and Elevation of Pumps — Hydraulic Cylinder — Plan of Gearing for Pumps and End Floats — Perspective View of Dock, Basin, and Railway — Plan of Basin of Ports- mouth Dry Dock — Floating Balance Dock — Elevation of Trusses and the Ma- chinery — Perspective View of Balance Dry Dock Free Hand Drawing. Profusely Illustrated. 18mo. Cloth. 75 cents. A GUIDE TO ORNAMENTAL, Figure, and Landscape Draw- ing. By an Art Student. Contents. — Materials employed in Drawing, and how to use them — On Lines and how to Draw them — On Shading — Concerning lines and shading, with applications of them to simple elementary subjects — Sketches from Na- ture. 26 SCIEXTIFIG BOOKS PUBLISHED BY Minifies Meclianical Drawing. Eighth Edition. Eoval 8vo. Clotli. $400. A TEXT-BOOK OF GE0MI:TRICAL DRAWING for the use of Mechanics and Schools, in which the Definitions and Rules of Geometrj are famiHarlv explained ; the Practical Problems are arranged, from, the most simple to the more complex, and in their description technicahties are avoided as much as possible. With illustrations for Drawing Plans, Sections, and Elevations of Buildings and Machinery ; an Introduction to Isometrical Draw- ing, and an Essay on Linear Perspective and Shadows. Illus- trated with over 200 diagrams engraved on steel. By Wii. MrsTFix, Architect. Eighth Edition. With an Appendix on the Theory and Application of Colors. " It is the best work on Drawing that we have ever seen, and is especially a text-book of Greometricai Drawing for the use of Mechanics and Schools. No young Mechanic, such as a Machinist, Engineer, Cabinet-Maker, Millwright, or Carpenter, should be without it." — Scieiiiific American. '• One of the most comprehensive works of the kind ever published, and can- not but possess great value to builders. The style is at once elegant and sub- stantial"' — Penn-syltania Inquirer. " Whatever is said is rendered perfectly intelligible by remarkably well- executed diagrams on steel, leaving nothing for mere vague supposition ; and the addition of an introduction to isometrical drawing, linear perspective, and the projection of shadows, winding up with a useful index to technical terms." — Gl-a-sgoir Mechanics Jouriud. E^^ The British Gkivemment has authorized the use of this book in their schools of art at Som.erset House, London, and throughout the kingdom. Minifie's Geometrical Dra-wing. yew Edition. Enlarged. 12mo. Cloth. $2.00. GEOMETPJCAL DRAWING. Abridged from the octavo edition, for the use of Schools. Illustrated with 48 steel plates. New edition, enlarged. '• It is well adapted as a text-book of drawing to be iised in our High Schools and Academies where this useful branch of the fine arts has been hitherto too much neglected-" — Boston Journal. Bell on Iron Smelting. 8vo. Cloth. $6.00. CHEMICAL PHENOMENA OF IRON SMELTING. An ex- perimental and practical examination of the circumstances which determine the capacity of the Blast Eurnace, the Temperature of the Air, and the Proper Condition of the Materials to be operated upon. By I. Lowthian Bell. " The reactions which take place in every foot of the blast-furnace have been investigated, and the naiure of every step in the process, from the intro- duction of the raw material into the furnace to the production of the pig iron, has been carefully ascertained, and recorded so fully that any one in the trade can readily avail themselves of the knowledge acquired ; and we have no hes- itation in saying that the judicious application of such knowledge will do much to facilitate the introduction of arrangements which will still further economize fuel, and at the same time permit of the quality of the resulting- metal being mauitained, if not improved. The volume is one which no prac- tical pig iron manufacturer can afford to be without if he be desirous of en- tering upon that competition which nowadays is essential to progress, and in issuing such a work Mr. Bell has entitled himself to the best thanks of every member of the trade." — London Mining Journal. King's Notes on Steam. ThirteentJi Edition. 8vo. Cloth. $2.00. LESSONS AND PRACTICAL NOTES ON STEAM, the Steam- Engine, Propellers, &c., &c., for Young Engineers, Students, and others. By the late W. E. King, U. S. N. Revised by Chief- Engineer J. W. King, U. S. Navy. " This is one of the best, because eminently plain and practical treatises on the Steam Engine ever published. ' — Philadelphia Press. This is the thirteenth edition of a valuable work of the late "W. H. King, U. S. N. It contains lessons and practical notes on Steam and the Steam En- gine, Propellers, etc. It is calculated to be of great use to j'oung marine en- gineers, students, and others. The text is illustrated and explained by nu- merous diagrams and representations of machinery. —iJoato/i Daily Adver- tiser. Text-book at the U. S. Naval Academy, Annapolis. 28 SCIENTIFIC BOOKS PUBLISHED B Y Burgli's Modern Marine Engineering. One thick 4to vol. Cloth. $25.00. Half morocco. $30.00. MODEEN MAEINE ENGINEEEING, appUed to Paddle and Screw Propulsion. Consisting of 36 Colored Plates, 259 Practical Wood-cut Illustrations, and 403 pages of Descriptive Matter, the whole being an exposition of the present practice of the follow- ing firms : Messrs. J. Penn & Sons ; Messrs. Maudslay, Sons & Field ; Messrs. James Watt & Co. ; Messrs. J. «& Gr. Eennie ; Messrs. E. Napier & Sons ; Messrs. J. & W. Dudgeon ; Messrs. Eavenhill & Hodgson ; Messrs. Humphreys & Tenant ; Mr. J. T. Spencer, and Messrs. Forrester k Co. By N. P. Buegh, Engineer. PRDfCiPAi, Contents. — General Arrangements of Engines, 11 examples — General Arrangement of Boilers, 14 examples — General Arrangement of Superheaters, 11 examples — Details of 'Oscillating Paddle Engines, 34 ex- amples — Condensers for Screw Engines, both Injection and Surface, 20 ex- amples — Details of Screw Engines, 20 examples — Cylinders and Details of Screw Engines, 21 examples — Slide Valves and Details, 7 examples — Slide Valve, Link Motion, 7 examples — Expansion Valves and Gear, 10 exam- ples — Details in General, 30 examples— Screw Propeller and Fittings, 13 ex- amples Engine and BoUer Fittings, 28 examples - In relation to the Princi- ples of the Marine Engine and Boiler, 33 examples. Notices of the Press. "Every conceivable detail of the Marine Engine, under all its various forms, is profusely, and we must add, admirably illustrated by a multitude of engravings, selected from the best and most modern practice of the first Maiine Engineers of the day. The chapter on Condensers is peculiarly valu- able. In one word, there is no other work in existence which will bear a moment's comparison with it as an exponent of the skill, talent and practical experience to which is due the splendid reputation enjoyed by many British Marine Engineers." — Engineer. " This very comprehensive work, which was issued in Monthly parts, has just been completed. It contains large and full drawings and copious de- scriptions of most of the best examples of Modern Marine Engines, and it is a complete theoretical and practical treatise on the subject of Marine Engi- neering." — American Artisan. This is the only edition of thn above work with the beautifully colored plates, and it is out of print in England. ' J). VAN' NOSTBARB. 29 Bourne's Treatise on tlie Steam En- gine. Ninth Edition. Illustrated. 4to. Cloth. $15.00. TEEATISE OIS/ THE STEAM ENGINE in its various applica- tions to Mines, Mills, Steam Navigation, Eail-^vays, and Agricul- ture, with the theoretical investigations respecting the Motive PoTver of Heat and the proper Proportions of Steam Engines. Elaborate Tables of the right dimensions of every part, and Practical Instructions for the Manufacture and Management of ever)' species of Engine in actual use. By Johii Botiene, being the ninth edition of " A Treatise on the Steam Engine," by the "Artisan Club." Illustrated by thirty-eight plates and five himdred and forty-six -wood-cuts. As Mr. Bourne's work has the great merit of avoiding unsound and imma- ture views, it may safely be consulted by all who are really desirous of ac- quiring trustworthy information on the subject of which it treats. During the twenty- two years which have elapsed from the issue of the first edition, the improvements introduced in the construction of the steam engine have been both numerous and important, and of these Mr. Bourne has taken care to point out the more prominent, and to furnish the reader with such infor- mation as shall enable him readily to judge of their relative value. This edi- tion has been thoroughly modernized, and made to accord with the opinions and practice of the more successfxxl engineers of the present day. All that the book professes to give is given with ability and evident care. The scien- tific principles which are permanent axe admirably explained, and reference is made to many of the more valuable of the recently introduced engines. To express an opinion of the value and utility of such a work as The Artisan Club's Treatise on the Steam Engine, which has passed through eight editions already, would be superfluous ; but it may be safely stated that the work is worthy the attentive study of all either engaged in the manufacture of steam engines or interested in economizing the use of steam. — Mining Journal. Isherwood's Engineering Precedents. Two Vols, in One. 8vo. Cloth. $2.50. ENGINEEEING PEECEDENTS FOE STEAM MACHINEEY. Arranged in the most practical and useful manner for Engineers. By B. E. IsHERWooD, Civil Engineer, U. S. Navy. With illus- trations. 30 SCIEN'TIFIO B OKS P UBLISHED B Y Ward's Steam for the Million. New and Revised Edition, 8vo. Cloth. $1.00. STEAM FOE THE MILLION. A Popular Treatise on Steam and its Application to tlie Useful Arts, especially to Naviga- tion. By J. H. Waed, Commander U. S. Navy. New and re- vised edition. A most excellent work for the young engineer and general reader. 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It will lead, we hope, to the introduction of Geology into many schools that have neither time nor room for the study of laro-e treatises." — The Museum. D. VAIST NOSTEAJSTD. 31 Rogers' Geology of Pennsylvania. 3 Vols. 4to, with Portfolio of Maps. Cloth. $30.00. THE GEOLOGY OF PENNSYLVANIA. A Government Sur- vey. With a general view of the Geology of the United States, Essays on the Coal Formation and its Fossils, and a description of the Coal Fields of North America and Great Britain. By Henry Darwin Eogers, Late State Geologist of Pennsylvania. Splendidly illustrated with Plates and Engravings in the Text. It certainly should be in every public library ^.nroughout the country, and likewise in the possession of all students of G-eology. After the final sale of these copies, the work will, of course, become more valuable. The work for the last five years has been entirely out of the market, Imt a few copies that remained in the hands of Prof. Rogers, in Scotland, at the time of his death, are now offered to the public, at a price which is even below what it was originally sold for when first published. Morfit on Pure Fertilizers. With 28 Illustrative Plates. 8vo. Cloth. $20.00. A PRACTICAL TREATISE ON PURE FERTILIZERS, and the Chemical Conversion of Rock Guanos, Marlstones, Coprolites, and the Crude Phosphates of Lime and Alumina Generally, into various Valuable Products. By Campbell Morfit, M.D., F.C.S. Sweet's Report on Coal. 8vo. Cloth. $3.00. SPECIAL REPORT ON COAL ; showing its Distribution, Classi- fication, and Cost delivered over different routes to various points in the State of New York, and the principal cities on the Atlantic Coast. By S. H. Sweet. With maps. Colbnrn's Gas Works of London, 12mo. Boards. 60 cents. GAS WORKS OF LONDON. 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Chapter V. — Rifling and Projec- tiles ; Standard Forms and Practice Described ; Early Experiments ; The Centring System ; The Compressing System ; The Expansion System ; Armor Punching Projectiles ; Shells for Molten Metal ; Competitive Trial of Rifled Guns, 1862; Duty of Rifled Guns: General Uses, Accuracy, Range, Velocity, Strain, Liability of Projectile to Injury ; Firing Spherical Shot from Rifled Guns ; Material for Armor-Punching Projectiles ; Shape of Armor-Punching Projectiles; Capacity and Destructiveness of Shells; Elongated Shot from Smooth Bores; Conclusions; Velocity of Projectiles , Table . Chapter VI. — Breech-Loading Advantages and Defects of the System ; Rapid Firing and Cooling Guns by Machinery ; Standard Breech-Loaders Described. Part Sec- ond : Experiments against Armor ; Account of Experiments from Official Records in Chronological Order. Appendix. — Report on the Application of Gun-Cotton to Warlike Purposes — British Association, 1863; Manufacture and Experiments in England ; Guns Hooped with Initial Tension — History; How Guns Burst, by Wiard, Lyman's Accelerating Gun; Endurance of Parrott and Whitworth Guns at Charleston ; Hooping old United States Cast-iron Guns ; Endurance and Accuracy of the Armstrong 600-pounder; Competitive Trials with 7-inch Guns. 34 SCIENTIFIC BOOKS PUBLISHED BY Peirce's Analytic Meclianics. 4to. Cloth. $10.00. SYSTEM OF ANALYTIC MECHANICS. Physical and Celestial Mechanics. By Bejjj.vmin Peirck, Perkins Professor of Astronomy and Mathematics in Harvard University, and Consulting As- tronomer of the American Ephemeris and Nautical Almanac. Developed in four systems of Analytic Mechanics, Celestial Mechanics, Potential Physics, and Analytic Morphology. 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KEY TO THE SOLAR COMPASS, and Surveyor's Companion ; comprising all the Rules necessary for use in the field ; also, Description of the Linear Surveys and Public Land System of the United States, Notes on the Barometer, Suggestions for an outfit for a Survey of four months, etc., etc., etc. By W. A. BuET, U. S. Deputy Surveyor. Second edition. CliaTivenet's Lunar Distances. 8vo. Cloth. $2.00. NEW METHOD OF CORRECTING LUNAR DISTANCES, and Improved Method of Finding the Error and Rate of a Chro- nometer, by equal altitudes. By Wm. Chauvenet, LL.D., Chan- cellor of Washington University of St. Louis. D. VAN NOSTRANI). 35 Jeffers' Nautical Surveying. Illustrated with 9 Copperplates and 31 Wood-cut Illustrations. 8vo. Cloth. $5.00. NAUTICAL SURVEYINa. By William N. Jeffees, Captain U. S. Navy. Many books have been -written on each of the subjects treated of in the sixteen chapters of this -work; and, to obtain a complete knowledge of geodetic surveying requires a profound study of the whole range of mathe- matical and physical sciences ; but a year of preparation should render any intelligent ofl&cer competent to conduct a nautical survey. Contents. — Chapter I. Formulae and Constants Useful in Surveying • II. Distinctive Character of Surveys. III. Hydrographic Surveying under Sail ; or, Running Survey. IV. Hydrographic Surveying of Boats ; or, Har- bor Survey. V. Tides— Definition of Tidal Phenomena — Tidal Observations. VI. Measurement of Bases — Appropriate and Direct. VII. Measurement of the Angles of Triangles — Azimuths — Astronomical Bearings. VIII. Correc- tions to be Applied to the Observed Angles. IX. Levelling — Difference of Level. X. Computation of the Sides of the Triangulation — The Three-point Problem. XL Determination of the Geodetic Latitudes, Longitudes, and Azimuths, of Points of a Triangulation. XII. Summary of Subjects treated of in preceding Chapters — Examples of Computation by various Pormulce. XIII. Projection of Charts and Plans. XIV. Astronomical Determination of Latitude and Longitude. XV. Magnetic Observations. XVI. Deep Sea Soundings. XVII. Tables for Ascertaining Distances at Sea, and a full Index. List of Plates. Plate I. Diagram Illustrative of the Triangulation. II. Specimen Page of Field Book. III. Running Survey of £. Coast. IV. Example of a Running Survey from Belcher. V. Flying Survey of an Island. VI. Survey of a Shoal. VII. Boat Survey of a River, VIIL Three-Point Problem. IX. Trianffulation. Coffin's Navigation. Fifth Edition. 12mo. Cloth. $3.50. NAVIGATION AND NAUTICAL ASTRONOMY. Prepared for the use of the U. S. Naval Academy. By J. II. C. 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Edited by Fkancis Herbert Joynson. Illustrated with 18 folded plates. " The aim of this work is to be a guide to mechanics in the designing and construction of general machine-gearing. This design it well fulfils, being plainly and sensibly written, and profusely illustrated." — Sunday Tirnes. Barnard's Report, Paris Exposition, 1867. Illustrated! 8vo. Cloth. $5.00. PEPORT ON MACHINERY AND PROCESSES ON THE INDUSTRIAL ARTS xlND APPARATUS' OF THE EXACT SCIENCES. By F. A. P. Barnard, LL.D.— Paris Universal Exposition, 1867. " We have in this volume the results of Dr. Barnard's study of the Paris Exposition of 1867, in the form of an ofiicial Report of the Government. It is the most exhaustive treatise upon modem inventions that has appeared since the Universal Exhibition of 1851, and we doubt if anything equal to it has appeared this century."— Jowrwrti Applied Chemistry. 38 SCIENTIFIC BOOKS PUBLISHED BY Engineering Facts and Figures. ISrao. Cloth- $2.50 per Volume. AX AXXUAL EEGISTEE OF PEOGEESS IX MECHAXI- CAL EXGIXEEEIXG AXT> COXSTEUCTIOX, for the Years l>6o-64-65-G6-67-6S. Fully illustrated. 6 volumes. Each Tolume sold separately. Beckwitli's Pottery. 8vo. Paper. 60 cents. OBSEEYATIOXS OX THE AIATEELALS and :5J:anufacture of Terra-Cotta, Stone-AYare, Fire-Brick, Porcelain and Encaustic Tiles, with Eemarks on the Products exhibited at ihe London International Exhibition, 1S71. By Akthxtk Beckwith, Civil Engineer. '• Everything is noticed in this book which comes under the head of Pot- terr, from fine porcelain to ordinary brick, and aside from the interest which all take in such manufacture.*, the work will be of considerable value to followers of the ceramic art." — Evening Mail. Docld's Dictionary of Manufactures, etc. 12mo. aoth. $-2.00. DICTIOXAEY OF 3IAXUFACTUEES, MIXIXG, MACHIX- EEY, AXD THE IXDUSTELIL AETS. By Geobge Dodd. 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