iBl!iffitlk»l!lti»»!SS!M«M!ii«S(Saii^ "IT a^atttell Itttivetattg Cibracg atiiara. ^tw fork ..H*..J,.-.Lo»ejoy To renew this book coty the pall No. and give to the libxarian. ■mL4^ HOME USE RULES *^ "%l !^ " ^*" ^°°^ subject to recaH -AJ All borrowers must regis- ter in the library to borrow books for home tise. AU books must be re- turned at end of college year for inspection and Limited books must be returned within the four j[t and not renewed. It return aU books before leaving town, OfEcers should arrange ^or the return of books wanted during their absence from town. Volumes of periodicals and of pamphlets are held in the library as much as passible. For special pur- poses they are given out for a limited time. Borroweis should not use their library privileges for the benefit of other persons. Books of special value and gift books, when the giver wishes it, are not allowed to circulate. Readers are asked to re- port' all cases of books marked or mutilated. Do not deface books by marks and wiitine. TC 784 C5™" ""'"*"">' '-''>™T 1924 022 883 528 Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924022883528 THE NICARAGUA CANAL /(,/,».>■ //-;■/. .t f ij li / REPORT OV TBE SURTEY AND ESTIMAT;pg OF tHB COST OF CONSTEUCnMO IHK 1 •7- IITER-OCEAm SHIP CMALi FBOU THS iHARBOR OF SAN JtTAK DEL NOBTE, (G»ErrowN,) ON rHE ATLANTIC TO IHE HARBOR OF BRITO, ON THE PACIFIC, IX THi: STATE 0F ppARAGlJA, CENTRAL AMERICA, MAtUS F0& TH1E AMERICAN, ATLANTIC AND PlCIFIC SHIP CANAL CO, IN THE YEARS 1880-61-62. By ORVILLE W. CHILDS, Chief Enb^eee. J. D. FAY, Pbingipai. Assistant. NEW YORK: WM. 0. BRYANT & CO, PRINTERS, 18 NASSAT7 STREET. EEPOET SURVEY AND ESTIMATES OF THE COST OF CONSTEUOnNQ THE IMER-OCEANIC SHIP CANAL, FEOM THE HAEBOR OF SAN JUAN DEL NORTE, ON THE ATLANTIC, TO THE HAEBOR OF BRITO, ON THE PACIFIC, IN THE STATE OF NICARAGUA, CENTRAL AMERICA, MADE FOB THE AMERICAN, ATLANTIC AND PACIFIC SHIP CANAL CO., IN THE YEARS 1860-51, BY ORVILLE W. CHILDS, Chief Enginbee. J. D. FAY, Peinoipal Assistant. »♦ • •» NEW YORK: WM. 0. BRYANT & CO., PRINTERS, 18 NASSAU STREET. 1852. INDEX. Pages. Topographical description 5 Line from Salinas Bay to Rio Sapoa and Lake Nicaragua 9 Line nortli of Rivaa de Nicaragua examined 11 Northern route via Rio Tipitapa, Lake of N^icaragua, &c IS Description of the line as located from Lake of Nicaragua to the Pacific at Brito 19 Brito harbor, &c 26 Description of work, BB o ■s n o o o Hi o .2 .a o B i o c (0 U3 to i-H iH -^ CG i £- CO 1-H OS 00 •saijni m 33[bi raojj -jsia; CO 3 •-< 1:- I-H OS a CO 1:- oc «-H I-H 1-H OS •so|Tni ui raBp o; ure^) raojj •jsi(j J:- CO I-H CO o CO oc CO CO* o 1 Hi C I J 1 1 rH C4 CQ ■* la CO Jr- 41 Twenty-four chains above dam No. 7, the canal, as before stated, is taken from the river, and with the ex- ception of three spurs which approach the river, re- quiring in passing them an extreme depth of cutting severally of 38, 47j and 42j feet, the line occupies highly favorable grounds, having an average elevation of about 9 feet above the surface of the river a distance 7.53 miles to the divergence of the Juanillo branch of the river; here the valley of the San Juan assumes a much greater width, and the Juanillo, with a width of one chain, and a depth at ordinary high water of 5 feet, passes from the main river, and, with many meander- ings, flows in a general direction northwesterly a dis- tance of about 23 miles, where, with a width of 4 chains, and a depth of 9 feet, it again unites with the San Juan 2.31 miles above the harbor. The canal, in crossing the head of this branch, will cut off the flow from the river ; the line thence passes over the gen- erally uniform surface of the flats along the San Juan 4.05 miles, to. nearly opposite the Colorado branch, where leaving the margin of the river, it is traced 0.80 miles in rear of some conical hills occupying a slight bend in the river directly opposite the Colorado, and with favorable cutting again approaches the river. From this point the line traverses a widely extended and uniform plain 13,58 miles to the point of crossing the Juanillo, 35 chains above its connection with the San Juan, The surface of this plain opposite the Colo- rado, is about 8 feet above the surface of the river, and by a quite uniform inclination descends to Ij feet above the surface of the Juanillo, which has here about the same elevation as the gan Juan. The canal is to cross in the channel of the Juanillo, with an average excava- tion of 3j feet below its bed, and a new channel is to be cut on the upper side, and nearly parallel with the 6 42 line, through which the stream is to be conducted to the harbor. From the Juanillo the line is extended in a northwesterly direction 1.79 miles, and with the ex- ception of an intervening lagoon, requiring about Sj feet depth of excavation | of a mile, it passes over a low though generally uniform surface, varying in eleva- tion from a few inches below to 1^ feet above the sur- face of the ordinary high water of the river, to the location of the lower, or lock No. 14, connecting the canal with the artificial harbor. From the junction of the Juanillo, the San Juan, with many windings, takes a northerly direction 2.07 miles to where it changes to the north, and by several channels enters the easterly end of the harbor. I The excavation at the surface of the short canals passing the dams at Castillo, Balas and Machuca, will be in earth ; at the bottom the material is rock ; at all of the remaining dams the material is a loamey clay witli a small proportion of fine gravel. The peculiar contour of the surface, along the line fram dam No. 7 to the divergence of the Juanillo is such as to require but few culverts, and no aqueducts will be necessary below the latter point ; with the San Juan on one side, and the Juanillo on the other, the country maybe drained from the canal in either direc- tion to these streams, tonsequently these structures will not be required on this part of the line. 43 HARBOR OF SAN JUAN. The principal branch of the river, at the point of discharging its waters into the harbor, changes from a northerly to a westerly direction. A short distance above this point there are on the left several islands, between which divergent branches from the river pass a considerable portion of its waters into the more southerly side of the harbor, and on the right, between the harbor and the sea, a mole of sand, vary- ing in width from three to twenty chains, extends westerly about 60 chains ; thence gradually curving to the left, bounds the northerly side of the harbor, 0.85 miles to its termination at a point 0.58 miles from the main land, bounding the southwesterly side of the harbor. This natural basin below the entrance of the river, has a water surface 1.68 miles by 1.18 miles in extreme length and breadth, and an average of about 1.45 miles by 0.95 miles in length and width, cover- mg an area of 881 acres, of which about 250 acres has a depth of 18 feet of water, with an extreme depth of 26 feet at low tide. This harbor is connected with the sea by a channel, at the time of making the soundings, September, 1851, 24 feet in depth, and about 1,300 feet in width. On the outer side of the channel, and about 800 feet below the termination of the natural mole, a sand bar, with a top width of 350 feet, rises to within from 5 to 8 feet of the surface of the sea, and being subject to the ac- tion of the waves and the currents of the river, is changeable in its position. The frequency and extent 44 of its changes were not, owing to the want of observa-| tions during the various stages of flow in the river, ascertained; it has not, however, been such as to prevent the largest steamers plying between Europe and the United States, and Chagres, from passing, and ; so far as is known, without difiiculty, through this channel to and from the harbor. To give greater stabil- ity and uniformity of depth in the channel, the expense of constructing two arms of a jetty or breakwater is included in the estimate, the one to extend from the termination of the mole before described 330 feet, and the other at right angles from the main land- 1,188 feet,; towards the channel, leaving an entrance 1,584 feet inl width. This work, when constructed, will, as is be-jj lieved, with the requisite light, at all times furnish to ij vessels a practicable and safe communication between the harbor and the ocean. The artificial portion of the harbor is to be formed by a cut 150 feet in width, to extend from the foot of the lower lock obliquely through a small lake, 7 chains wide, requiring 9 feet depth of excavation in its bed ; thence 0.66 miles to 17 feet depth of water in the har- bor at low tide, the average cutting is about 16 feet. This cut is to connect with the natural harbor on its southerly side, and at the central portion of its deepest water; its sides are to be»protected with a vertical dock- ing, and that portion between the lock and the natural harbor is to be surmounted with a wall of hydraulic masonry. The artificial harbor will contain an area of 13.40 acres, this added to 250, the number of acres of 18 feet depth of water in the natural harbor, makes an aggregate of 263 4-10 acres. There are facilities for obtaining additional harbor room, by excavations in the bed of the jlake, extending southwesterly in rear of the town, whielj has an aver-- Missing Page 45 age of about 6 feet depth of water ; by excavations at points the most favorable in the natural harbor, also by a cut, varying from 1 to 7 feet in depth, and about 1.25 miles in length, through a bar above the entrance of the river by which a communication would be opened to an area of over 275 acres with 17 feet depth of wa- ter. The area here alluded to is a stagnant pool, bounded by very low grounds on its westerly side ; the entrance to it would require protection. For a view of the plan of this harbor, see accompa- nying sketch. 46 MATERIALS NECESSARY IN THE CONSTRUC- TION OF THE CANAL. TIMBER. The timber of the native or original forests of Nicara- gua, as compared with that of the original forests of this country, is of inferior size. Trees of suitable form and height to furnish the ordinary timber required for the mechanical structures of the canal, and for general pur- poses of sawing, are also less in number on the same extent of surface ; the difference is supposed to be considerable. Between the summit level and the Pacific, the line traverses a section of country probably as heavily tim- bered as any other of equal extent in the State. The section of country upon either side of the San Juan River, extending from the Toro Rapids to a few miles below the divergence of the Colorado, a distance of over 65 miles, has also, with very inconsiderable ex- ceptions, its original forest, and for that country is heavily timbered. All of the timber found in that State is wholly unlike that of the productions of the higher latitudes. Mr. H. Woniger, an intelligent gentleman, formerly of Pennsylvania, and for the last 10 or 12 years a resi- dent of Nicaragua, kindly presented several specimens of the most useful timber of the State, accompanied with remarks, from which the following are extracts : " No. 1, Cedar. This is the best for building purposes ; it is strong though not heavy, and is very durable above ground." 47 There is one place, Salinas, where it is found in large quantities, and where it has not been cut away, in con- sequence of the difficulty in passing a high ridge, which occurs between that and the inhabited part of Nicara- gua. This supply of Cedar is found on a flat country, and will not exceed six miles from the harbor of Brito. It grows to a very elevated height and will produce tim- ber from 36 to 40 feet long, and 12 to 18 inches square. " No. 2, Roble. This, like the former, is a very firm wood ; it is a very elevated tree ; and the one from which the sam- ple was taken, produced a stick of timber 45 feet long and 18 inches square." " No. 3, Nispero. This is a very common forest tree, and grows to a great height ; it will produce timber 45 to 50 feet long, by 18 inches square. It is very durable above ground, but is not much used on account of its weight." " No. 4, Laurel. A very firm and durable wood above ground. Tim- ber 30 feet or more in length, and proportionably large, may be obtained from it." " No. 5, Madeira Negra. This is an exceedingly durable wood ; it is much used for posts set in the ground, which will last from 40 to 50 years. Timber from this tree can be procured 25 to 30 feet long, about 11 inches square ; of shorter sticks an almost unlimited supply may be obtained." " No. 6, Niambaro, or Rosewood. This, like the former, is a very strong and durable wood, even under ground, and will produce timber of 48 greater length than the Madeira Negra. Gonsiderabie quantities may be obtained in the flats near Brito." " No. 1, Tiguilote. This, though a light wood, will last many years under ground. It is occasionally found large enough to furnish timber from 30 to 35 feet long. The prin- cipal localities are on the borders of the lake." " No. 8, The Guachipilin Is a very heavy, hard and tough timber, grows large, and is lasting in the ground." " No. 9, The Caoio, or Mahogany. This is an inferior wood for furniture, but excellent for building purposes, being very similar to cedro, and a little heavier ; it will produce timber 30 feet long, and 12 inches square." " No. 10, The Palo de Arco Is a firm and durable wood both above and below ground ; it is found large enough to produce heavy posts from 15 to 20 feet long." " No. 11, The Guanadillo. I add this, as it is thought the handsomest timber for furniture." " No. 12, The Fenisaro. A very large tree, and is good for all timber pur- poses." The comparative strength and specific gravity of the above specimens, including a specimen of close straight grained well seasoned white oak, and white pine of this country, were tested in the following manner : 49 The specimens were each reduced to precisely i of an inch square and 12 inches in length, and their strength tested by placing them in a horrizonal position, on supports precisely 10 inches apart, and carefully noting the weight suspended at the centre with which each piece was broken; and their comparative specific gravities was ascertained by allowing them to float in a' vertical position in a vessel of water, and noting the length immersed. The following are the results : 1 2 3 4 5 6 1 8 9 10 11 12 13 14 N'ame ofWood boa . a if ^ Cedar, Roble. Nispero Laurel Madeira Negra. Rosewood .... Tiguilote Guachiipilin . . . Mahogany .... Palo de Arco . . Grandillo FemBaro White oak .... " pine .... if ■S-n S S ffl 14.06 8.19 35.00 18.13 29.07 31.94 10.13 19.13 17.13 33.06 12.13 27.06 10.81 > 4> bo ^ • 0.52 0.30 1.29 0.67 1.07 1.18 0.37 0.70 0.63 1.22 Omit 0.44 1.00 0.39 0.87 0.82 1.64 1.11 1.56 1.58 0.66 1.32 1.13 1.48 ted. 0.92 1.00 0.62 .3 9 • .9 S Q 1. 0.95 1.25 1.50 1.75 1.60 1.70 1. 1.25 1.08 1.80 1.08 Kemarks. Broke sudden with short fibres, do do do {Fibres coarse, frac- ture 6 inches long, sank slowly, speci- fic gravity estim'd. Fibres short. Fibres coarse & long. Broke sudden, fibres short. Fracture long with coarse fibres. Furniture timber. Bj-oke sudden, fibres short. Fine brushy fibres at fracture f in. long. 50 The results of the experiments, although in some degree defectiv^e for the want of a larger number, are nevertheless considered sufficient to furnish a general practical view of the strength of the several kinds of timber as compared with oak, the timber, of which lock gates and Other parts of the wood work of the me- chanical structures of the canals of this country, requir- ing strength and durability, are principally constructed. The Nispero is well known to be among the most com- mon timber of that country, and, as appears from the experiments, is 29 per cent, stronger than white oak ; it may be obtained of sufficient size, and if durable, it is believed may with safety be relied on as a good substitute for all of the purposes of the canal to which oak is usually applied, and that there are other kinds of timber from which plank and other lumber may be sawed, among which may be named " Roble," " Cedar," " Tignilote/' Fenisaro," and others, probably sufficient in the aggregate, to produce all the lumber required for use in the construction of the canal. STONE. Detached irregular angled stone was found on the surface of nearly all of the hills approaching the San Juan River, and in some of them, rock in place was discovered, from which there probably may be ob- tained stone of a suitable quality for the construction of the locks and dams. The rock consists principally of trap, grey wacke and shale, which, although at some of the localities is of so friable a texture as to be un^t for use, at others there probably exists a good material for the purposes of the canal. Among these localities may be named that at the Balas Rapids, on the 51 bank of the river about 1 mile below Machucg,, and several others between the San Carlos River and the location of dam No. 7 ; below the latter point no stone suitable for the mechanical structures were discovered. On the west side of the lake, limestone was found in the table lands at several localities, one about 2i, and another about 9 miles distant from the lake, and both within three miles of the line across the summit. Kilns are in operation at these quarries, producing lime ; it was also found in the dividing ridge on the transit road, presenting a vertical face of some 20 feet in jieight in the bed of the Chirarar, a small stream on the western slope of the dividing ridge. Old lime works were noticed near the base of the easterly slope of the same range of hills, near the Rio Grande, some 4 or 5 mUes southerly from the western termination of the summit level. A short distance west of these works, in a much more elevated position on a branch of the Rio Grande, was also noticed a mural escarpment, or cascade, of some 80 feet in height. The character of this rock was not ascertained. Near the westerly end of the summit level, a low short spur from the hill containing limestone is crossed by the line ; although at the surface, this material ap- pears to be of too thin strata to be useful in the work, thicker courses at greater depths may be found. The hills on the southerly side of the " Rio Grande" between this point and the Pacific, have more or less stone on their surfaces, and excepting the sand beach fronting the valley of this stream, tlie coast for many miles in either direction from Brito harbor, has an elevated irregular rocky face. No quarries having been opened in the immediate vicinity of the line, the distance it may be necessary to haul a large portion of the stone for the locks, and the rectangular wall in the 52 jettie, is rendered less certain. In the estimate it is assumed that the stone for the moles of the jettie may be obtained within 3 miles, and that for the rectangu- lar wall and the masonry of the locks, the average dis- tance of haul may be as great as 10 miles. Several specimens of the stone in the vicinity of the line were obtained, and with reference to more reliable information as to their associations, they were forwarded to Professor James Hall of Albany, an eminent geologist, for examination. In his communica- tion relating to them, he remarks': " The character of many of the specimens indicates that you have within your reach durable materials for any structures that may be required in the undertaking in which you are engaged. I would direct your attention to masses like Nos. 4 and 5, as being in their character well suited to your purposes if found in masses of sufficient thick- ness, also to No. 7 as before mentioned. The lime- stones are of a character to be durable if you can find the beds of sufficient thickness." " No. 9 is almost entirely pure carbonate of lime." Nos. 4 and 5 are a species of trap which prevails extensively on the west side of the lake, and to a con- siderable extent in the valley of San Juan. No. 4 was taken from the Island of Ometepe, more with reference to ascertaining the general characteristics of the rock of the country, than to immediate use. No. 5 was ob- tained from the Granada quarries, where a similar rock underlies a large extent of country, and from which the base of columns in buildings, curb stone and flagging for side walks, &c., in Granada, are obtained. These stone are easily wrought, and it is believed that blocks of any desirable dimensions might be readily obtained. This quarry would only be resorted to in case the stone in the valley of the river should prove unsuitable, a cir- cumstance considered very improbable. The cut on 53 the easterly portion of the summit level will probably be in a similar rock, and it is believed to exist in the hills between that level and Brito. No. 9 is a specimen of the rock forming the cascade on the Chirarar be- fore alluded to, from which stone in any quantity and dimensions that may be required can be quarried. If on opening a quarry on either side of the valley of the Rio Grande, the stone should prove defective, and suitable stone could not be found at any more conve- nient locality, stone from the Chirarar might be hauled on the transit road about 4 miles to the Harbor of San Juan del Sur, and boated thence 11 miles to Brito ; although the necessity of obtaining suitable stone under disadvantages so great, is regarded a contingency quite remote ; it is not deemed prudent to adopt prices below an equivalent to those required for obtaining at this quarry the larger blocks required in the work on the westerly portions of the canal, and from the limestone quarry before alluded to about 4j miles south of the summit, for the residue of the work west of the summit. From information derived from citizens of San Juan del Norte, it appears probable that stone might be obtaine(ton the Atlantic coast, at Monkey Point, about 42 miles northerly from San Juan, at Frenchman's Key, 15 miles south of Blewfield, and at Little Corn Island, some few miles off the coast from Blewfield. There being no harbor at the two former places, they could only be approached by vessels some 4 or 5 months in each year ; at the latter, there is said to be a good harbor, where stone of an excellent quality might be obtained. Should this prove correct, of which there appears to be much probability, stone for the work on the lower end of the line might be more conveniently obtained from this point than from any other. 54 WATER LINE, No stone from which water lime can be manufac- tured, of a quality suitable for the more exposed parts of the masonry required on the canal, was discovered; although this material may exist in the country, the opening of quarries has not, so far as is known, been sufficiently extensive to disclose it. Specimens of the stone from which lime is manufactured, and quite ex- tensively used in the construction of vats for the ma- nufacture of indigo, were procured, two of which have been subjected to analysis by Professor Hall, and the following shows their composition, together with that of the stone from which water lime is manufactured in the counties of Ulster and Madison, in this State, and used in the construction of the New York waterworksj the enlargement of the Erie canal, and in other States of the Union ; also an analysis of the sheppy stone, understood to produce a cement among the best used in England. Constitttents in 100 parts. «8 '"' R, d w. C8<^, CS ^ ^1 ^6 AW. a. I| w Cai'hoTiift 9.o,id "1 36 89 38 73 29 00 59 70 66 00 47 51 7 13 6 81 1 12 trace II 49 80 3 13 3 62 4 21 trace ti (( 09 35 00 Silica « . . . • 15 37 11 38 12 35 8 95 6 65 16 70 17 7s Alumina and Tvnn ■••. ........ 12 75 50 Soda Chlorine. ..«..4k.k. Sulniiuric Acid .*••• Water 1 20 1 70 3 00 1 00 99 46 99 58 100 00 100 00 99 00 55 From a comparison of the foregoiag analysis, it appears that the Nicaragua stone contains a larger proportion of lime, and less silica and alumina than either of the others ; the larger proportion of magnesia in the Ulster and Madison county stone is rather an evidence of less proportion of lime in the carbonates than of utility to the cement made from those stones ; the magnesia being in this respect, to a great extent, a neutral sub- stance in the composition. A larger proportion of alum-- ina and silica in the Nicaragua lime would therefore probably improve its hydraulic properties. On this subject. Professor Hall, in his communication, remarks " that by burning with this lime a clay, in proportions that could be determined by a few trials on a small scale, you may produce a cement ; the clay No. 1 4 I would recommend for this purpose." The specimen of clay alluded to, was taken from the bottom of the lake, within the limits of the pro- posed cut, about 1 1-2 miles from the outlet ; it is of exceeding fineness and would probably be used, as above recommended, if none other equally good, and in a more convenient locality, could be found. The Nicaragua lime is used in that country in all wet and dry masonry, such as the stoning of wells, which in many instances is done with hydraulic masonry from the bottom, and forms the curbing at the top, for plas- tering both the inner and outer sides of the adobe walls of dwellings, &c,; it is quite extensively used in the construction of indigo works, which consist of some two or three vats, each about 20 feet square, and some 6 or 8 feet in depth ; these adjoin each other and have different elevations, they are located by the side of permanent streams, the waters of which are raised by dams of hydraulic stone masonry, usually some 10 to 15 feet in height, from the top of which the water, in a 56 square trench cut in earth and lined with masonry, is conveyed to the upper vat, from which it is passed through the series. Among these works were noticed some, said to have been standing over 80 years, and notwithstanding their exposure to the action of severe currents, and usage, are now in a very perfect condi- tion ; although the mortar in these works is more friable than that made with the best cements of this country, it has sufficient strength, to render it evident, that a ce- ment of equal hydraulic properties, will be suitable with a trifling increase to the thickness of walls, for a large proportion of the masonry in nearly all of the structures required on the canal. In view, however, of the uncertainty of finding in that country a better material for cement, and of sufficiently improving that known to exist there, the expense of a good article from this country for the more exposed parts of the ma- sonry is provided for in the estimate. Missing Page 57 DIMENSIONS AND FORM Of the Transverse Section of the Canal in Earth. The water in the canal is to have a depth of 17 feet, and a bottom width, except in cases of turnouts, of 50 feet ; 9 feet above the bottom, or at the base of the slope wall, the width is to be 86 feet ; 17 feet above, or at the surface water line, the width is 118 feet; 21 feet above the bottom, or at the top of the slope wall, the space between the banks is 128 feet ; at the inner top angle of the banks, 22 feet above the bottom, the width is to be ISOj feet. The inner face of the banks rise from the bottom angle 9 feet, with a slope of 2 feet horizontal to one of vertical height ; at this elevation a horizonta!l offset 6 feet in width is made in the face of each bank, from which a slope of Ij feet horizontal to one foot vertical rise is carried to the top of the banks. The top of both banks to be 14 feet wide, and finished with a slope descending Ij feet from the front to the rear angle. An additional height is to be given to the banks in all cases of the connection of levels with the river. Form of Transverse Section of Canal in the Rock portions of the Summit Level. The canal is to have a bottom width of 50 feet ; it is to be 77 feet wide 9 feet above the bottom, and 78.33 feet in width at the surface water line. The inner faces of the rock on either side^ are to rise from the 8 58 bottom angle 9 feet high, with slopes of Ij to 1 respec- tively of base and vertical height, thence to 32 feet above the canal bottom, the faces of the rock to be cut to a batter of one inch to the foot rise ; at this eleva- tion offsets are to be made forming benches 9 feet wide, to serve the purpose of a toWing path, and to prevent deposits of earth in the canal; above the benches, the rock portions are to be cut to a slope of 3 inches to the foot rise, and the earth overlying the rock to a slope of U feet base to one of vertical rise. The spoil banks of rock to be laid with uniform slopes and elevation. To enable vessels moving in opposite directions to pass each other, the bottom width of the canal in earth is to be increased to 90 feet, and in rock to 105 feet. An enlargement of the prism is to be made at the head of all of the locks, and at other places, at least one in every mile of length of the canal. The bottom width of that portion of the canal occupying the Rio Lajas will be 100 feet ; at all of the cuts through bars in the river, the width at bottom is to be 150 feet. The locks, as designed for the canal, are 60 by 250 feet in dimensions of chamber, with 17 feet depth of water on their mitre sills. Appendix marked B, contains speci- fications of the manner of constructing the banks of the canal, also of the locks and other mechanical struc- tures. Herewith is presented a portfolio volume containing drawings of all the plans described in the specifications, also maps and profiles of the line of the canal in sec- tions drawn to a scale of 4 chains to an inch ; also a map 16| feet in length by 4j feet in breadth, upon which is delineated the profile and line of the canal on a scale of 64 chains to an inch, and showing in a more explicit manner the line and plan of the proposed communica- tion between the two Oceans. 59 PRICES. We come next to consider the prices to be adopted in the estimate of the cost of the canal. That they should be greater than would be required for similar work located in an improved section of this country it is supposed is already conceded ; the excess will in part consist, in the cost of transporting laborers and every description of tools necessary for their use in prosecuting the work ; several of the staple articles of food for the subsistence of workmen, among the more prominent of which may be included salted pro- visions and flour ; the machinery of mills for sawing timber, and carriages with which to transport it from place to place ; this excess will also probably be further enhanced by the greater price to be paid for the same amount of mechanical and other labor. The country along the river being with some incon- siderable exceptions uninhabited, and that along the line between the lake and the Pacific very sparsely populated, the erection of houses for the protection of property, and the residence of workmen will be necessary. The roads in the improved portions of this latter section are in a condition very unfavorable for use with lumber carriages, and the streams crossed by them are wholly destitute of bridges ; the construction of new roads for hauling lumber, stone, and other materials, will be extensively required in the more rough and uninhabited districts ; these, together with the construction of boats for transporting materials on the river, and elsewhere, the erection of cranes and other fixtures necessary in prosecuting the work, which must be principally done upon the line, will be attended with much greater expense, and will require more time than similar preliminary work in more favorable localities. 60 In Nicaragua carts with wheels carved from solid sections of timber, are usually drawn by 4 oxen, con- nected in pairs with rudely formed bars of wood lashed to their horns ; altogether a method of haul illy adapted to the heavy work required in the construction of the canal. The horses and mules of the country, although quite numerous in the more populous portions, are entirely unaccustomed to the harness, and carriages of every description, excepting ox-carts of the very rude con- struction above indicated, are wholly unknown. Al- though the timber in the valley of the San Juan river in the immediate vicinity of the location of the dams, and locks, also on the western slope in the valley of the Rio Grande, is of as large size, and as abundant as in any other equal portions of the country; the large quantities to be used in these structures will re- quire in most cases a large area to furnish it ; this, in connection with the hauling of the required quantity of stone from the quarries, will create the necessity of an extensive use of animal power in the transportation of materials. Oxen of good form and size may be obtained in the country in sufficient numbers, and when made submis- sive to the yoke, will fully serve the purposes of this kind of animal power. Although the horses are less abundant, and of inferior size, they are generally of firm build; the requisite number, together with the first class of mules, could be procured in the country, at reasonable rates, and when broke to the harness, would probably furnish a supply nearly equal to the balance of the demand for ordinary hght teams that would be caused by the construction of the canal. The remainder, for the more heavy work, would probably be imported. 61 The foregoing remarks have reference to the com- parative increased expense and delays, considered un- avoidable, in the preliminary preparations for com- mencing the work, and attributable only to the remote uncultivated and sparsely populated country, in which the canal is located. There is yet a contingency of more importance, and liable by possibility to produce a much greater in- fluence on the cost of the canal than any above named. I allude now to the contingent physical inability of the working classes to perform the ordinary daily labor necessary to a successful and rapid progress of the work, as compared with that ordinarily accomplished in the construction of similar works located in colder and more variable climates. Apprehending the neces- sity of relying mainly on the labor of foreigners to perform the work, a knowledge of the effects of a con- tinued temperature, varying throughout the year some- thing above that during the months of July and August in this country, upon their health, was considered as among the essential elements that should constitute the basis of a fair and reliable estimate of the cost of the canal. The grave consideration to which this subject was deemed to be entitled, induced an early attention to all existing or perceptible causes that might be regarded as liable to affect unfavorably, the health and vigor of workmen, upon which the progress and ultimate cost of the work so essentially depend. It is not known that any more extensive works than the erection of large church edifices and some small fortresses, have at any former period been constructed in the country. These furnish some example of the ability of the resident citizens to perform labor; if, however, the labor performed in constructing these 62 works was conducted with the same degree of moder- ation, as is the present common labor of the country, it would give but little evidence of value connected with the information sought. Although the laboring classes, when under compul- sory circumstances, are capable of great activity and of enduring much fatigue, in their ordinary avocations their movements, so far as observed, generally appear- ed to be tardy, and the times of their employment irregular ; an exception, however, was found in a class of boatmen, numbering about 400, engaged in the trans- portation of freight on the river and lake ; in these we have an example of physical labor and of exposure to the elements scarcely equalled in any country, and endured by them, with no perceptible prejudice, but apparently with benefit to their health. The boats used are generally of rude model, without covering, except for the protection of their food and some small portion of freight; they are about 40 to 50 feet long and of some 6 or 8 tons, and in some cases of greater burthen. In an ascending trip on the river, each boat is propelled solely by the muscular power of from 8 to 10 men, and in a passage to the lake, are forced up an ascent on the length of the river of over 100 feet. The men retire at night on a narrow plank athwart the boat, with no other protection than that afforded by a single blanket. These men are of a very athletic form, and as a class, notwithstanding their exposure and ap- parent indifferent attention to the means of health, there are none more capable of hard service, or that are more robust and healthy. However favorable the general health of the native born citizens of the country may be, and however great their capabilities for manual labor, it may be said that it does not follow that like capabilities can be invaria- 63 bly claimed for foreigners accustomed to a different climate and habits of life ; the fact of the ability of the native citizens to perform the most severe exercise, and that not only without detriment but rather vs^ith advantage to health, is regarded at least as some evi- dence that foreigners, already accustomed to hard la- bor, may, when thoroughly acclimated, and with no unnecessary exposure, be capable of some labor in this, if not of the ordinary amount usually performed on public works in other countries. A feature worthy of remark exists in the fact, that no swamps or pools of stagnant water was found in the country, west of the lake, nor is it believed that there are any between the lake and high tide on the Pacific, for a distance of some 25 miles in either direction from the line. The permanent streams contain soft water, apparently of the greatest purity ; and with the excep- tion of the distance between San Carlos and the Toro Rapids, and a section in the vicinity of San Juan del Norte, no swamps worthy of note were discovered oh the San Juan River. Of the party engaged in the survey, west of the lake, nine were unaccustomed to the climate. After a few months, a slight fever, followed by ague, pre- vented some of the number from continued daily exer- cise in the field; the disease being entirely under the control of medicine, was in all of the cases of short duration ; during a stay of some 7 months in this part of the State, illness in the party at no time inter- rupted the organization so far as to prevent a daily pro- secution of the survey. On the San Juan river some additions to the party of northern men were made, some of whom had been several months in the country ; it "here consisted of 12 persons, exclusive of some native citizens. During 64 the survey of this part of the canal, which occupied about 6i months, or from March to September, the party generally enjoyed good health, and no individaal was prevented by indisposition beyond a day or two from full service during the entire period. Of those engaged as axemen in clearing the line, two were northern men, whose daily exercise exceeded that usually practiced by laborers employed in constructing canals, and with no deteriorations to health or constitution. Having through inadvertence omitted to obtain from Doctor Lovejoy, the physician appointed to accompany the expedition, his opinion previous to his leaving the service of the company on our return in October last, and attaching much importance to any views he might entertain on this subject, the following correspond- ence was had. EDgineer's OflSce of tlie American Atlantic and Pacific Ship Canal Co. Syracuse, January 12ih, 1862. To Wm. J. Lovejoy, M. D., &c. Sir, — Being desirous of arriving at conclusions as correct as under the circumstances is possible in regard to the effect, whether favorable or other- wise, that the climate of that portion of the State of Nicaragua, embracing the line recently surveyed for the construction of a ship canal from San Juan del Norte on the Atlantic to the port of Brito on the Pacific, will have upon the physical energies of the laborers to be employed in the con- struction of that work ; in other words, the extent of the unfavorable influ- ence of the climate, if any, upon the ability of the laboring classes both of Europe and this country to perform continued, or the ordinary daily labor necessary in the construction of the canal ; and you sir, having accompanied the party as physician and surgeon, also as rodman assisted in making the exploring surveys of all the routes examined, also the survey of the fines revised for adoption, and having pursuant to instructions taken meteoro- logical observations, and notes of other existing conditions essentially con- nected with a truthful developement of the information desu-ed, I would thank you in aid of the object above stated, to favor me at your earfiest convenience with the views you may entertain on this subject. Veiy Eespectfully, &c., 0. W. Childs. 65 0. W. Childs, Esq., Dear Sir, — ^Yours of the 12th ult. is received ; I hasten to reply. During the term of my employment in Nicaragua, a period of 13 months, there were few foreigners residing in the country, and only a small proportion of these being of the laboring classes, but little opportunity of observa- tions of practical tests of the question alluded to in jonrs was afiforded, if I except that of the party with which I was connected ; beyond these, therefore, the opinions I may express are to be regarded as founded mainly in hypotheses. In addition to drought, humidity and salubrity, physical climate compre- hends the degree of heat and cold prevailing in any country. The sub- stances most deleterious to health, especially in sections unimproved, being produced by the decomposition of vegetable and animal matter, the rapidity of this decomposition, and consequent amount of malaria set afloat in the atmosphere, much depends upon the degree of heat and moisture, elements essentially connected as well with the growth as the rapid decay of vegetation. The extent to which the atmosphere may be- come impregnated with this substance, consequently the extent of its eflfects upon the health of the people of the country are also subject to great modi- fications by the currents of air or the degree of the prevalence of the winds, and by the quantity and period of the rains ; as the former cause will pro- bably produce a material and highly favorable influence to health, upon the line of the canal in Nicaragua, it is somewhat to be regretted that more full and careful observations on this subject were not made. The following statements show the average temperature, and the highest and lowest during each month, from Sept. 1st., 1850, to Sept. 12th, 1851, as observed each day at 6 o'clock A. M., and at 2 and 9 o'clock P. M., at several localities in the State of Nicaragua. Also the average, and the highest and lowest temperature during the months of June, July and August, at Lansingburgh lat. 40q 41', and the two latter months at Jamaica, Long Island, in lat. 40o 41', as taken from the annual report of the Regents of the University of this State for the year 1850 ; also the average of the same months in 1845, at thirty-five localities ; being all at which observations were taken in this State, as per Eegent's report for that year ; which is given for the reason that none of later date is at hand. 66 Year. Months. State of Mcaragua. ^1 ■*^ o « a 2 P □0 Q 3^ bo § Pi Remarks. Prevailing Winds, 1850. 1861, September... October . . . . November. . December... January . . . . February . . . March. April Jime July August Sept. (12)... Total mean. 18" 12 11 18° 42 1" if 16" 40 16" 11" 18" 83 78° 29 11'' 12 76° 98 76" 20 19" 10 86° 86° 84° 87° 84° 84° 8° 1° 88° 86° 71° 70° 74° 72° 69° 70° 72° 72° 68« 71° 71= 71° 74° 17° 16° 12° 12° 18° 14° 12° 16° 23° 17° 15° 15° 12° Between Lake and Pacific. Fort San Carlos. Ifear head of River. " Castillo Rapids. Las BaJos Rapids. Near Colorado Branch. At San Juan del Norte. 77° 42 86° 45 71° 15 15° 30 State of New York. 1860. June July August Total mean. 71° 02 73° 34 70° 16 71° 60 1850. 1846. July i\ugust. Total mean. 76° 65 73° 61 75° 15 July . . . August . 69° 22 72° 38 Total mean. 70° 80 95° 94° 46° 66° 42° 93° 66 47° 33 93° 95° 50 95°» 91° 60° 61" 60 49° 60 50° 26 49° 93 50° 39° 50° 46° 33 34° 45° 50 40° 74 43° 07 Lansingburgh. Long Island. 36 Localities. South East. East. N. Easterly. Easterly. 67 It appears from the above statement, that the mean annual temperature of Nicaragua is about 6" higher than the average of the months of June, July and August in Lansingburgh, and 2° higher than July and August at Jamaica, Long Island, and about 6^ above that of the same months throughout this State in 1845 ; that the average of the highest temperature of each month is for the year in Nicaragua about '7'' less than that of the 3 months at Lansingburgh, and about 9° less than that for the 2 months at Jamaica, and 6*? less than that averaged for the 2 months throughout the State in 1845 ; also, that the average of the range in Nicaragua is 31? less than in Lansingburg, 30? less than at Jamaica, and 28° less than the average in this State at the times as before stated, and that the average of any one month in Nicaragua is also less than either of the othere given in the statement ; thus showing a material difference in uniformity of tempera- ture in favor of Nicaragua, and comparatively a small difference in average temperature against it; the 'former requires a constant effort on the part of the human system to accommodate itself to these changes, and the latter also demands of the system efforts to enable it to sustain itself under the debilitating iufluences of the greater heat. Dryness and humidity, however, as also heat and cold, affect the human constitution very much in proportion as they are constant and uniform, or as they are fluctuating and in extremes. Although the heat at a given locality might not of itself be so great as sensibly to prejudice health, yet, as an agent, when sufficient to favor a rapid growth and decay of vegeta- tion, would, with a humid atmosphere, and subject to no mitigating cir- cumstances, be productive of disease. In Nicaragua the degree of heat and its uniformity is shown in the statement ; the amount of its action with humidity upon the other elements producing primary causes of disease, is only inferable in degree, from observations of the profusion or paucity of these elements, and of the effect of their continued operation upon the health of the people subjected to their influence. Doctor Johnson, English surgeon in India, and author of a work on the influence of the tropical climates on Europeans, says, "That although in India, under the influence of exposure and neglect of temperance in diet, result ardent fever with some serious local determinations to the cerebral organs and to the liver, yet it is to be admitted, that with the practice of the pro- per precautionary measures, or such as were dictated by common sense and experience, at the stations, the very hottest have proved the healthiest of the seasons." " From the result of my observations in active field service in Bengal and in Ava, I am led to conclude that mere heat, unless combined with intemperance in drink and other excessive habits of the people, is very rarely the direct cause of disease." "The troops from Bengal and Madras, in crossing the desert of Kosseir, were exposed to a temperature ranging from 80° to 95<» in the shade, and 68 from 100 to 110 in the sun, yet with no indulgence in excesses, they en- joyed excellent health." " In Bengal, with all its vicissitudes of climate, the English have, hy dint of prudent management, accommodated themselves to the climate." In Nicaragua, as in other warm climates, the equable determination to the surface consequent on the higher temperature, produces a favorable in- fluence on the general health. This remark is also applicable to the foreigner, by whom this augmentation of the sensible perepiration is borne, not only without injury to the constitution, but rather with an agreeable sensation. This view of its effects is fully sustained by the robust and hardy constitution of the native boatmen on the river, and by the improving health of those of our party, when their labors were most severe and per- spiration excessive, during the last five months of our operations in the country. In that part of the State with which I became familiar, the quantity of decaying Vegetable matter on the surface appeared very much less than in the forests of the north. This I attributed to a less fall of foliage, owing perhaps to its perennial character, and to its being borne off by the much heavier showers which occur in that country, and to its destruction by the numerous ants which subsist upon it. The malaria produced by the de- composition of these substances, is, to a great extent, diluted and dissipated by the high and almost constantly prevailing winds from the northeast and east, during the dry season, which very much lessens the effect this substance would otherwise have in producing intermitting and remitting fevei-s, and tends to render these diseases less frequent and of a milder form. There appeare to be no swamps or stagnant waters west of the lake, and excepting near San Juan, on the Atlantic, I discovered none in the vicinity of the line on the river, where, as I understand it, there is much work to be done. The water of the country, though warm, is generally good. The diseases most common in the country, are intermitting and remit- ting fever, and, as I was informed, diarrhoea and dysentery occur to some extent in some seasons, though very little fell under my observations. The fevers seem to arise more from a depressed nervous system, combined with checked perepiration and bihary secretion, than from the malaria of the country ; if the latter is the prime agent, it appeared not to act with great force in the cases I saw : to restore these functions, appeared to be all that was necessary to restore the patient to health. The first sickness in the engineer party, commenced about two months after their arrival in the country. It was remitting fever, lasting from ten to fourteen days uncom- plicated and easily controlled, yielding readily to febrifuge remedies, after a little previous preparation ; this, in most cases was followed by ague. Fever to some extent prevailed in the party, through November and De- 69 cember, after which, with some little exceptions, the party remained healthy. From my observations, while in the country, of its climate, of the habit and health of the native citizens, and of foreigners, of whom there were a few residing in the city of Rivas, Granada and other parts of the State, I am of the opinion that it is as healthy as many sections of equal extent and improvement in our Western States, and that Americans and Euro- peans may reside there with at least as good health as is enjoyed by the people of those districts ; that all would not suffer in becoming acclimatsd is also more than probable. Of the northern men comprising the engineer party there were four, of whom myself was one, who, although equally exposed with the others, was not prevented by any disease of the country from continued daily service. In the general views I entertain of the salu- brity of the climate, I believe I have the concurrence of Dr. Clark, of Pennsylvania, for many years a resident in the practice of medicine in Ni- caragua, and of other intelligent gentlemen, the latter now residing there, with whom I conversed ; I have also the authority of Dr. Clark in stat- ing, that no case of yellow fever ever occurred in Nicaragua, and that the country, with some little exceptions, has ever been free from epidemic disease. Dr. Drake, author of a work on the diseases of the valleys of North America, remarks, "that it was formerly beheved that white men were in- capable of enduring the heat to which they would be exposed in culti- vating the field below 33" of latitude," a popular error of pubhc sentiment long since exploded, leaving behind it evidence of the more modem im- provements in the science of Physiology and of the enterprise and per- severance of the people. In constructing the canal the degree of eiposure to disease will proba- bly be different at different localities ; with few exceptions, however, there will, in this respect, be much uniformity ; the difference will be mainly pro- duced by the difference in the amount of vegetable matter contained in the earth to be exposed (by excavations) to the air. The analysis of a specimen of earth, obtained from the borings near San Juan, gave of ve- getable matter 16|- per cent.; the analysis of another specimen, obtained a httle more distant, gave llf per cent. These specimens were obtained from localities supposed to contain a much larger proportion of vegetation than any other upon the line. The latter, however, from ordinaiy inspec- tion, appeared quite a pure earth, and probably did not vaiy much in com- position irom many of the alluvial formations of the valleys of the country. Notwithstanding that an equable temperature, averaging something higher than that of the hottest months in this country, may not alone be productive of disease, and although the disease most common in such Countries may be less malignant, less frequent, and less in variety than 70 those of a colder and more fluctuating climate, yet I am aware there is a prevailing opinion, that the uniformly higher temperature is productive of that degree of lassitude and general depression which disqualify m'en for active service, and renders them incapable of much physical exercise ; that this conclusion, if correct as a general principle, is applicable to the line of the canal in Nicaragua only in a very Umited degree, is strongly indicated, if not rendered certain by the strong constitution, uniform good health, and great physical powers, of the boatmen and of many othera of the la- boring classes in the countiy, and the beneficial effects attending those of the party whose daily exercise, while surveying the river, exceeded that of any common laborer on public works. The idea that the heat of Nicaragua is of itself sufficient to produce dis- ease, is not entertained. The large annual fall of rain, by frequent and heavy showere, bears with its waters in passing from the surface much of the elements of disease, and being accompanied with winds, tends to the coolness and salubrity of the atmosphere during the wet portions of the season. In the dry season, the temperature through the day is rendered agreeable by almost constant high winds ; the nights of . both seasons are generally cool. The prevalence of sickness among the workmen will much depend on the degree of temperance they practise in eating and drinking, their ex- posure, and the general care and attention they give to the means of health. That some, with the practice of all reasonable precautions, will, in becoming acclimated, to some extent, be sick, is quite probable, and others, with whose constitution the climate is better adapted, will reside there with uniform good health ; this is the effect in cases of emigration in this latitude from, the eastern to the western States, and of foreigners to this country. On carefully considering the causes of disease as they exist in Nicaragua, I can discover no good reason for apprehending more sickness in construct- ing the canal in that State, than has been experienced on some portions of the public works in this and some of the western States ; and that men with temperate and industrious habits, being well provided with comfortable lodgings and a diet adapted to the climate, and subject to no unnecessary exposure, will, after becoming acclimated, do nearly as much labor as was formerly done on similar works in the new or unsettled portions of the State of New York. A peculiar feature on the Isthmus between North and South America, is the valley extending from ocean to ocean along the line as surveyed for the canal, and through which there is almost at all times an invigorating cur- rent of air, which will be increased as the improvements on the river be- come extended. The construction of the canal through some of the valleys of this State was attended with much sickuesa and loss of lifC) that might have been 71 avoided by a judicious system of medical police. It is to be hoped that the company, in constructing that canal, 'will, &om considerations of phil- anthropy, if not- from motives of interest, pay more attention to this subject. On that canal, as on most others in new or uncultivated districts, the health of the workmen, consequently their ability to perform labor, will, as before remarked, much depend upon correct regimen, regular exercise with proper guards against exposure, while intemperance and general indulgence in excesses will result in crippled energies, disease and death. West of the lake the uniform temperature and delightful breezes which sweep across the country from lake to ocean, produces a salubrity of climate scarcely excelled in any country, In the immediate vicinity of San Juan, on the Atlantic, for reasons before given, I think the country less healthy. Very respectfully, Lake at San Carlos minationof summit level. | i West coast of Lake at Klo San Carlos V Lajas I Head of Lock No. 1, at Latter point >■ western termination of ) summit level 37 151 56 500 7 779 Total length of summit level 108 480 Zevels East of Summit. Head of Lock No. 1. Head of Look No. ' 10. ■ 11. ' 12. 18. 14. ' 10. 11. ■ 12. ■ 13. ' 14. [ 17 feet depth water in San ] I Juan Harbor. | Levela Weat of Summit. Head of Lock No. 1, at Buen Betiro. Head of Lock No. 2. Ii tl 2. » tt " 3 It u 8. <« tl " 4 t( u 4. It tt " 5 (t u 5. it tt " 6 U 11 6. '• II " 7 it *( r. (( " 8 ii » 8. tl « " 9 " " 9. II « " 10 it n 10. " tl "11 it tl 11. tt tl " 12 tl tl 12. ft tl " 13. It ii 18. It " " 14 It ^ 14. 17 feet deptii of water in | Brito Harbor. f 0,125 7,308 8,921 0,162 20,049 7,588 8,600 13,281 5,760 1,740 7,000 4,040 1,940 0,745 0,500 0,425 0,675 0,337 0,863 0,900 0,550 1,175 0,600 0,562 0,988 0,187 0,250 0,847 7,428 11,849 11,511 81,560 89,098 47,698 60,929 66,689 68,429 75,429 79,469 81,409 82,154 0,925 1,600 1,987 2,800 8,700 4,250 5,r- 6,025 6,587 7,575 7,712 7,962 8,809 8,00 8,00 8,00 6,50 8,00 8,00 8,00 8,00 8,00 8,00 8,00 8,00 8,00 6,23 8,00 8,00 8,00 8,00 8,00 8,00 8,00 8,00 8,00 8,00 8,00 8,00 8,00 7,47 8,00 16,00 24,00 80,50 88,50 46,50 54,50 62,50 70,50 78,50 86,50 94,50 102,50 108,73 8,00 16,00 24,00 82,00 40,00 48,00 66,00 64,00 72,00 80,00 88,00 96,00 104,00 111,47 SUMMARY OP ABOVE TABLE. Length of Summit Level 108,430 miles. •' " Levels East of Summit 82,154 " " " " West " 8,809 " Total length of canal to 17 feet water in either ocean . 194,393 " Whole fall from High lake to low tide in the Pacific Ill 47-100 ft. " " " " " Atlantic 108 73-100" Total rise and fall 220 20-100 " 79 For statement in tabular form of the length of the levels, lockage, and the distances, fall, &c. of the San Juan river, see tables C and D, appended to Mr. Fay's report. SUPPLY OP WATER. The quantity of water required for the canal consists in that to be used for lockage, and in the amount lost by leakage at the locks and dams, and filtration and evaporation from the prism of the canal. In estimating the quantity necessary for lockage at both ends of the summit level, it is assumed that three locks full may be required per hour at each lock, amounting to 12,000 cubic feet per minute. Taking the leakage of an 8 feet lift lock of the original size on the Erie Canal at 900 cubic feet per minute, which is the largest known to have occurred, and increasing this quantity in proportion to the increased surface pressed by the water, (excluding the side walls,) and it gives for the quantity required to supply the loss by leakage at the two summit locks 16,682 cubic feet per minute. The loss by filtration and evaporation during the hottest months of the season, or period of the greatest drought on the original Erie Canal as ascertained from the most authentic data, is 85 cubic feet per mile per minute ; increasing this quantity in proportion to the square root of the depth of the water, and the area of its surface in contact with the earth, shows the amount required per mile per minute to be 80 433.30 cubic feet; this multiplied into 11.23 miles, the sum of the distances in both direc- tions to be supplied from the summit, and it gives for the whole quantity required to supply loss by filtration and evaporation - - 4,868 cubic feet per minute. To this add 10 per cent, of the mininum flow of the San Juan river, the amount estimated to be required to supply the loss by leakage at the dams equals 71,580 cubic feet per minute, and we have - 105,130 cubic feet per minute as the quantity to be drawn from the lake during the driest portions of the seasons to sustain the navigation, and give full employ to the locks. RAIN. The fall of rain from September 9th, 1850, to Sep- tember 25th, 1851, a period of twelve months and seventeen days, was carefully ascertained by means of an ombrometer, or rain guage. The observations were in all cases taken by a member of the party, except during a term of thirty-four days in September and October, 1850, when they were taken by Don Fruita Chomorro, then Prefect of that department of the State, a gentleman of high scientific'attainments, whose accuracy in the performance of this voluntary service, is entitled to the fullest confidence. The observations were taken at Rivas de Nicaragua, from September 9th, 1850, to March 11th, 1851, and from the latter period to September 25th of the same year, they were taken on the San Juan River. The following are the results of the daily observa- tions : 81 Statement of the Rain in the State of Nicaragua from September 9th, 1850, to September 25th, 1851, showing the amount in inches and decimals of an inch, for each day in each month in which rain fell ; the aggregate for each month, and the total during the above period. u . b! ii Si .-1 f^ 2I 1851. July. \a a, 00 a 1 110 020 '"eoo 1.950 490 720 ( 700 |'i."230 2.650 270 070 220 580 j 780 1 "190 520 030 090 " 960 1.320 770 \ 2 8 4 6 6 1 8 9 10 11 12 13 14 16 16 17 18 19 20 21 22 23 24 26 26 27 28 180 2.720 030 290 210 2 710 4.710 190 460 920 240 640 310 600 1.270 010 350 "730 66f 060 240 160 t .... 1.260 1.510 540 680 040 300 ( oio 270 660 660 440 060 750 "'"26O 260 310 1.030 090 930 290 190 1.300 090 1.900 2.230 2.790 290 1.150 040 140 010 020 1 110 490 180 1.380 1.820 160 "350 '"990 ""710 490 640 050 530 040 840 140 ( "926 270 8.030 120 ""iso 350 470 1 720 190 120 1.340 240 270 080 1.740 1 560 1 ' ' '450 5.920 410 ("520 2.290 510 1.010 500 610 090 500 080 140 090 100 830 2.770 30( 1.39C 070 "m 170 1.600 385 2.040 '645 760 425 5o0 130 27r 250 470 29 30 31 070 690 600 180 7.006 17.860 1.395 3.2U 380 .... 1.410 430 9.14t 14.211 22.640 11.810 13.240 11 Total 101 .735 inches. 82 The following condensed statement shows the monthly fall of rain in the State of Nicaragua, embracing a period of one year, from September 9th, 1850, to September 8th, 1851, inclusive : Months. 1850 — September . October. . . November . December.. 1851 — January. . . February.. March.. .. April May June July August . . . September. Total for the year. Times between which it rained. From To 9 2 5 7 4 1 21 9 11 4 1 1 9 30 30 30 26 21 28 24 18 31 30 31 29 8 O o if ^t 16 19 6 8 2 3 2 16 49 23 20 5 139 14 12 24 24 29 28 28 28 15 11 8 11 4 226 °-s I 7 17 1, 3, 0, 1. 9, 14, 22, 11. 8, OOi 21 38 00 41 43 14^ 21 64 81 22 97.71^ From the above, it appears that in a period of one year the whole number of days in which rain fell, was 139, and the whole number of dry days was 226; that during the six months from May to October, inclusive, the period distinguished as the wet season, the whole fall was 90.89 inches, and during the remaining six months, distinguished as the dry season, the fall was 6.82j inches ; the greatest fall in any one month, was 22.64 inches, in July, and that there was one month only, February, in which no rain fell. It would have been interesting as affecting the daily progress of work on the canal, to have made a distinction in the amount of fall in time of day and night ; this not having been 83 done, it can only be observed that the largest propor- tion of the fall is supposed to have occurred in the night. The fall is almost invariably by showers of short duration, which mostly occur in the latter part of the day and in the night. The average annual fall of rain and snow, in the State of New York, during the period of ten years preceding that of 1846, as appears from the annual report of the Regents of the University of that year, is 34.14 inches, and the greatest fall in any year, during the same period, was 37.04 inches, and the least 32.10 inches. Although the aggregate fall of rain in the month of May, 1850, as appears from the above statement, was 9.14 inches, there was no sensible rise in the river or lake until the 5th of June. The quantity of water that passed from the lake when at its greatest depression on the 4th of June last, as ascertained from a careful guage of the river at its minimum flow, was 11,930 cubic feet per second. The flow in the San Juan, immediately above the junction of the San Carlos River, as guaged on the 15th of July, was 19,300, in the San Carlos at the same time, 16,447, making the whole quantity flowing in the San Juan, below the San Carlos, 35,747 cubic feet per second. On the 8th of August, the quantity passing in the San Juan, above the Serapiqui, was 39,526, and in the Serapiqui 13,266, giving to the San Juan, below the Serapiqui, 52,792 cubic feet per second. The flow in the San Juan, immediately above the Colorado, as guaged on the 20th of August, was 54,380 cubic feet per second, of which 42,056 passed through the Colorado branch to the ocean, and 12,324 through the San Juan. Subsequent to the 5th of June, the river was more affected by rains, and on the 19th Sep- tember, at the taking of the last observations previous 84 to leaving the country, the lake was found 2.55 feet above its lowest stage, or the level it occupied the pre- ceeding May ; it probably continued to rise until the following November, the usual termination of the wet season. Owing to the subsequent rise in the river, the above quantities were correspondingly increased to those given in a preceding table. The lake fell from its greatest elevation on the 23d December, 1850, to its lowest, on the 27 th of April, a period of 125 days, 3.43 feet, and continued about at this latter stage to the 5th of June. The quantity discharged from the lake, when ele- vated 343 feet above its lowest stage, as estimated from the guages, is 18,059 cubic feet per second, and allowing the discharge gradually to diminish to 11.930 at the end of the above 125 days, would give a mean flow for this period of 14,995 cubic feet per second, or 899,700 cubic feet per minute, from which deduct the amount before shown to be required for the canal, 105,130, and it gives 794,570 cubic feet per minute, or for the whole period of 125 days, 143,022,600,000 cubic feet as the quantity that passed from the lake, in excess of that required during the same time for the canal. If the average area of the lake be taken at 110 miles in length by 25 in breadth, which probably would not vary essentially from the truth, this quantity in passing from the lake reduced its surface 1 .87 feet, which de- ducted from 3.43 feet, the whole fall, leaves 1.56 feet as the amount of its reduction by evaporation, in which is also included the whole supply by drainage from the surrounding country during the same period ; thus show- ing, that it will be necessary to commence at the close of the wet season, with an excess of surface elevation of the lake, of 1.56 feet above that which it must neces- sarily have at the close of the dry season, an amount 85 that may very readily be held in reserve, and the flow regulated by means of gates on the crest and in the body of the dam. It is not known that this would to any very great extent prove injurious at any locality : between the Castillo and Toro Rapids some lands would be flowed that would otherwise be susceptible of cultivation ; the immediate valley being narrow, the amount that would be thus occupied by water is quite small. Between the Toro Rapids and the lake, the low flats lying between the river and upland, occupy a large portion of the distance, and alternately varying from a few rods on one, to say half a mile on the opposite side in average width, and having an elevation varying from Ij to 2j feet above the surface of low river, they are entirely submerged during most of the wet season, and are principally covered with an aquatic plant, of a light spongy texture, known as the Coroza, a species of wild palm, growing some 30 or 40 feet in height. These wet lands have now no value, and were they permanently flowed to the depth contemplated, the facilities for communication between the river and upland by boats in the channels of the lateral streams would be improved, and the atmosphere rendered more healthy. The banks bordering the sides of the lake so far as observed, are sufiiciently high, and whatever may be their elevation at other places, it is not per- ceived that injury could result from continuing the surface of the lake at the elevation it now occupies so large a portion of the year. It is certain that no im- provements would be disturbed, and the means of access at numerous points on the lake for purposes of commerce would probably not be impaired. No land worthy of note would be flowed by dams from Nos. 2 to 7 inclusive ; the country along the river 86 is hilly and the banks are generally elevated above that of the level, to which it is proposed to raise the water by these dams. In the preceding table before given of inclina- tion of surface, &c. the inclination of that portion of the river above the Toro Rapids is stated at 0.12 of a foot per mile; this multiplied into the length in miles of that portion of the river, gives 3.26 feet as the inclination of its surface in time of maximum flow, an amount that would be too great to admit of a convenient control of the flow from the lake, by means of the Castillo dam. It should be stated, that in the calculation of all of the inclinations and velocities given in the table, no allowance is made for enlargement of volume by a flow beyond the im- mediate channel of the river. In the case under con- sideration, this enlargement will be quite sufiicient to bring the inclination within such limits, as will render the flow from the lake perfectly controllable by the method before stated, and usually adopted in such cases. 87 CAPACITY OF THE CANAL. From information obtained from the most popular builders and others skilled in the science of the model and tonnage of steamers and other vessels, the opinion is ascertained that steamers of from 1800 to 2,400 tons, and merchant sailing vessels of a somewhat greater burthen, may be so constructed as to be well adapted to the passage of the locks, for movement in the pro- jected canal and for sea service. The former in navi- gating the canal would be propelled by their own power, and the latter would necessarily be tracked by steamers, especially constructed for that purpose, ex- cepting that portion west of the lake, and on that, inland, between Dam No. 7 and the harbor of San Juan del Norte, where, owing to the additional delays that would be caused by a propelling steamer in pass- ing the locks, animal power might probably be used with more advantage. The canal would also probably be navigated by brigs, and other coasting vessels of a smaller class, which, if admitted, would of course re- duce the movement of the maximum tonnage of which the canal would otherwise be capable. The average time required for steamers and other vessels to pass a lock, is estimated at 24 minutes, or 60 per day — the steamers requiring something less, and the larger class of sail vessels a little more than that above stated. The average rates of speed with which the steamers may safely move in the inland portions, without injury to the vessel or the banks of the canal, is estimated at 88 two and a half miles per hour, on the river portions, seven miles per hour, and on the lake the same speed may be attained as on the ocean, say eleven miles per hour. Sailing vessels propelled by horse power, might move on the canal at the rate of two miles per hour, and by steam-tugs in the river and lake, with an aver- age speed of say four miles per hour. The time, then, occupied in making a passage from ocean to ocean, would be for the steamers, 47.09 miles of canal navigation, at the rate of 2j miles per hour, 18.83 90.80 miles of river navigation, at the rate of 7 ' miles per hour, 12.97 56.50 miles of lake navigation, at the rate of 11 miles per hour, 5.14 Passage of 28 locks, at the rate of 20 minutes per lock, 9.33 Total, - - - 46.27 say two days. Time occupied hy Sail Vessels. 47.09 miles of canal navigation, at the rate of 2 miles per hour, 23.54 147.30 miles of river and lake navigation, at the rate of 4 miles per hour, - - . . 36.82 Passage of 28 locks, at the rate of 30 minutes each, .-.--.. 1400 Passage of 8 locks by steam tugs, at the rate of 20 minutes each, 2.67 Total number of hours, - - 77.03 or, say Z\ days. 89 The establishment of lights at several points on the river, and at the cuts on either side of the lake, in ad- dition to those required at the locks, will be indispen- sable to a practicable navigation in time of night. The improvement of rivers above tide water, for pur- poses of navigation in connection with that of inland canals of ordinary dimensions, is, except under peculiar circumstances, regarded with disfavor. The objections to adopting the channel of a river as part of a canal, arise mainly from too great current in time of flood, and the difficulty and expense attending the repairs of the mechanical structures connecting the inland with the river portions of the navigation. On the San Juan River, the former will, to a great extent, be remedied by the large increase of volume produced by the dams on the river below. In cases of substituting rivers for inland canals of large dimensions, where high dams are practicable, the double advantage of saving the expense of construct- ing a large prism, and of avoiding excessive currents, is attained, and the navigation of the river portions with steamers, and with sail vessels tracked by steam- tugs, would be more practicable ; these advantages will, to a very great degree, be realized by the adoption of this river upon the plan projected ; although the substitution of an inland canal migjit by some be con- sidered practicable, the expense, owing to causes already stated, would be very great. It is to be admitted, that high dams are more liable to failure than low ones ; the fall, however, in the cases under consideration, being so much reduced by the elevation of the river below them, by succeeding dams in all of the cases of earth foundation, excepting No. 7, very much tends to their security. With the proper precautions in constructing the latter, and ordinary care 12 90 in the others on the plan proposed, it is believed that these dams can scarcely he regarded as liable to the contingency of serious failure. Upon that canal, the effects of frost, an agent the most destructive of masonry and other parts of the canals in this country, and to which a large proportion of the sudden breaches that occur may be attributed, will not be experienced ; and so far as known, all of the conditions connected with permanancy a nd un- interrupted navigation, will be much more favorable than would attend a canal of the same dimensions and character of workmanship, located in this country. The instructions of your board require the survey and estimates to be for a canal of sufficient depth for vessels of the largest class. It will be seen by reference to the profiles of those portions of the river occupied by the canal, that the increase in the length of the cuts through the bars which a greater depth than that upon which the estimates are based would involve, consequently the ratio of increase of the expense of the canal, would bp very great. Any considerable increase to the depth would require under-water excavations between the lake and the Toro Rapids, a distance of about 27 miles, to be almost continuous ; it would very much lengthen the cuts on other portions of the river, and the liability of these artificial channels to receive deposits of earth to such extent as to obstruct the navigation, would be very much greater. On the inland portions of the canal a depth of 22 feet of water, which is about equal to the greatest draught of the largest merchant sailing' vessels, would, with 50 feet bottom width, give a trans- verse water section about 45 per cent, greater than a depth of 17 feet with the same bottom width ; and the expense of the inland portions would also, by 91 reason of the greater depth of excavation, be increased in a still higher ratio. The advances in improvements of model are such as are deemed sufficient to justify the belief that vessels of a burthen as great as before stated, may be so con- structed as to navigate the canal. The steam ship Northern Light, recently built of the greatest strength, for general sea service, is of recent improved model, and excellent finish ; the dimensions of this splendid steamer are such as would permit her to pass with full freight through the locks and the canal, and her bur- then, as stated by the proprietor, is about 2,200 tons. It is not known that there are any steam ships plying between the Atlantic States and the eastern coast of the Pacific, that have a draught as great as 17 feet. Of 261 steam vessels, princi^jally English, the largest portio n with side wheels, and the remainder, screw propellers, as given in Murray's treatise on marine engines and steam vessels, only 15 draw over 17 feet of water, 21 have 17 feet draught, and 225 draw less than 17 feet, each at load line. To construct the canal of dimensions capable of ad- mitting the passage of vessels of the ' largest draught now in use, of which there are comparatively so few, or by which it would be so little used, and under circumstances of so much greater cost, while, as is believed, merchant vessels of equal tonnage and of less draught may be so constructed as to be well adapted to sea service and the passage of the canal, would appear to be an injudicious application of means, which, as is supposed, your company would scarcely favor, or the interest of commerce require. The di- mensions before given were therefore planned and made the basis of the estimates with due consideration 92 of the disparity in cost and general utility* of a canal of larger dimensions, and with a view to practicability as referable to cost of construction, usefulness, and a fair remuneration for capital invested. This canal, as projected, is of much greater dimensions than any hitherto constructed in this country. If we except that of the Chesapeak and Delaware, which has 10 feet depth, the largest known on this side of the Atlantic, and most similar to that under consideration in respect to connecting natural with artificial naviga- tion, are those in Canada East, by which the naviga- tion is extended past the rapids on the St. Lawrence River, and the Welland canal in the Western Province, connecting the navigation of lakes Ontario and Erie, The canals connecting the navigable portions of the St. Lawrence with each other are 7 in number, vary- ing in length from 3-4 to 11 1-2 miles, with an aggre- gate length of 41 miles. They are 60 feet wide at bot- tom, and 90 feet at surface water line, excepting that at Beauharnois 11 1-4 miles in length, which is 80 feet at bottom, and 120 at top, and that at Cornwall 111-2 miles long, having a bottom width of 100 feet, and a surface width of 150 feet. The locks are 27 in num- ber, of which 20 are 200 feet in length between the gates, and 45 feet in width of chamber, and 7 on the Cornwall canal, have the same length and 55 feet width of chamber. All of the locks have 9 feet depth of water on the mitre sills, excepting 2 which have a depth of 16 feet. The Welland canal is 28 miles long, 35 feet wide at bottom, and 71 feet at top, excepting a small portion, which is 45 feet in bottom width, and 81 feet at the surface. The locks on the former portion, 24 in number, are 150 by 26 1-2 feet, and on the latter portion, 3 in num- 93 ber ; they are 200 by 45 feet in dimensions of chamber, all have 9 feet depth of water on the sills. The whole fall from Lake Erie to tide water at ThreeRivers on the St. Lawrence is 564 1-2 feet, of which 536 3-4 is made by 54 locks, the remainder 27 3-4 by the natural descent of the river. The aggregate length of inland canal is 69 miles, and the whole distance from Lake Erie to Three Rivers is about 430 miles. Sea going vessels, carrying 350 tons, pass these ca- nals. Although steamers and other sea going vessels of much greater burthen pass on the St. Lawrence ca- nals, yet owing to the want of a greater depth of water, they are understood to be limited to the above burthen. The extreme load of vessels adapted to the navigation of the Welland canal and the lakes is 400 tons of freight. The Caledonian Canal, forming a navigable connec- tion, for ships, between the east and west side of Great Britain, probably approaches in its dimensions and ca- pacity, nearer to those proposed for the ship canal between the Atlantic and Pacific oceans, than any other. This communication extends across the central portions of Scotland from Loch-Eil, connecting with sea on the westerly side, to Loch-Beauly or Murray- frith, an arm of the sea on the easterly side. It has a length of about 59 miles, of which 21j is constructed inland, and 37i is a navigation through the four lakes named in the order they occur, from West to East Lochy, Oich, Ness, and Doughfour, originally of dif- ferent elevations. The surfaces of Loch-Oich, and Loch-Lochy, now conform to the surface of the summit level of the canal; in construction, the former about 3| miles in length, was extensively dregded to obtain the requisite depth for navigation, and the surface of the latter about 9 miles in length, was raised 12 feet to lessen the depth of excavation tlirough the summits 94 between that lake and the western termination of the canal. Extensive dredgings were also made in carry- ing the canal through Lake Doughfour. The canal is 50 feet wide at bottom, 110 feet at the surface water line, and 20 feet deep. It has 24 locks, with chambers 40 feet wide, and 172 feet in length. Its summit is 90 feet above the west, and 94 feet above the east sea, and the descent is made by 12 locks on either side. Lake Ness has a length of about 20 miles, and to- gether with the two lakes on the summit level are subject to changes of some 6 to 8 feet in their eleva- tion by flood and drought. These flood waters are without difficulty retained for use, or otherwise dis- posed of as the circumstances of navigation require. This canal is similar then to that projected in Nica- ragua, in its summit lake, from which in both direc- tions it derives its supply of water, in the amount of its lockage, its dimensions, and in its frequent changes from inland canal to the adoption, for purposes of navi- gation, of larger waters, and as also indicated from its history, (see Encyclopsedia Brittannica,) the country, if we except climate, presented physical features, in- volving greater difficulties in its construction. That canal was constructed previous to the intro- duction of steam as a motive power for sea-going vessels, and was designed for merchant vessels and vessels of war, of the dimensions of a 32 gun frigate. The locks as designed for the Atlantic and Pacific Ship Canal, are large in their horizontal dimensions ; they will admit of the passage of a large class of steamships, which, as a means of transit, from their annually increasing numbers, appear to be rapidly growing in public favor. The main advantages to be realized by the use of 95 the Nicaragua canal is the saving of distance and time, in making a passage between the two oceans ; these being primary causes of the extension of commerce, will, in the present instance, produce benefits to be partici- pated in by a large portion of the people of the globe. A knowledge therefore of this saving, to be effected by a passage through the ship canal, in making voyages between important commercial ports of the two conti- nents, as well as between those on opposite sides of this, becomes interesting. The following statement shows the distances be- tween the several places named as measured on Mitchell's map of the world, Mercator's projection, and the difference in the distances between said places, by the way of Cape Horn and the proposed canal ; also the time estimated to be required to make the voyages by steam and sail vessels, and the estimated difference between the two routes, in the time of making said voyages, admitting the speed to be uniform (except on the canal) throughout the several parts of the route, and to be for the steamer at the average rate of 260 miles, and for sail vessels 1 10 miles per day, and on the canal at rates the same as before stated. m Time oc- Time oc- 1 1 cupied by cupied by sail ves'ls Name of Boute. 1 steamers Between what Places. "S In' o .g i o 1 11 65^ St 155 ■3g> id > NewTork and California, Via Cape Horn, 17.063 l( iC " Proposed Canal, 5.690 11.378 23J 42i 63J lOlf " Valparaiso, " Cape Horn, 10.648 41 96« " Proposed Canal, 5.811 4.8S2 23i m 54i m " Sandwich Is- lands, " Cape Horn, 16. 784 64* 152-i (1 K « " Proposed Canal, 7.178 9.611 28i 36i .66f 85f 96 The sailing distances, and the times occupied by sail vessels in making outward and homeward voyages, v^ould, on ^account of prevailing winds and currents, be liable to differ widely from each other, and from those given in the above statement, which are intended to represent the time averaged for the outw^ard and homeward voyagies, rather than the actual time of either. In the case of steamers, the difference would be much less, and the time estimated to be occupied by both steamers and sail vessels, averaged, as above slated, for the out and return voyage, is, upon the basis assumed, believed to be nearly correct. The following are the results of a " comparison be- tween voyages to be made through the canal of Nicaragua and those actually made via Cape Horn and the Cape of Good Hope," taken from " Rep. No. 143," made by Hon. John A. Rockwell, chairman, &c., be- fore referred to, with such slight modifications as were made necessary by assuming the western termina- tion of the canal to be at Brito, on Pacific, instead of Realego, as assumed by the author of the com- parison . 97 1 a ;^ N=>. .H mcQ Iz; « •■3 to § O 13 .S' 2 -s .2 I n ■■i a CQ CO CO rH '4ar- ^t^QO CO, os^oa^cQ eo o»ojooou3oooa^»oooooco^io os" (»" » j> o xr^ o « CO oo" ^" CO »o" w ^ ■^" CD »o M*" eo ;i I p o ja o a o la o p o •« o T3 o t) o T3 o -g O §•« SI! ol! o"^ S-a g-a g-c g-o g-o g-a B |tS gl |lS SW go g(§ go si |0 I 0) Q.g 0.0 B.S a.2 Q-S Q." 0.2 o 30c. cub. ft 154,193 40 94,407 ft. board meas. plank, $35 m. ft. . . . 3,304 24 2,010lbs. wrought iron, 12c. lb 24120 $393,062 64 Dam No. 7. OyVo ^'^^^ ^"*' "f '■*"^'' Serapequi, 8QI feet in length. 34,869 cub. yds. excavation of earth a $1 cub. yd. . 34,869 ,00 embankment 30o. " . 2,570 70 puddling, 20c. " . 837 20 masonryin abutments, $12 " . 24,960 00 stone filling in cribs, $2 " . 115,552 00 brush, stone and gravel, on upper side of dara, |1 cub. yd 9,910 00 517,928 cub. ft. timber in crib work and foundation, 30c. cub. ft 155,378 40 128,918 ft. board meas. plank, 135 m. ft. . . . 4,512 13 2,900 lbs. wrought iron, 12o. lb 348 00 8,569 11 4,186 II 2,080 (1 57,776 11 9,910 (1 $348,937 43 Composite Culvert of 2 spaces. Each 21 /^ X 2 ft. square. 4,777 cub. yds. excavation of earth a 35c. cub. yd. . $1,671 95 660 " puddling between timbers, and in sheet piling trenches, 30c. cub. yd. . . 198 00 4,449 cub. ft. timber in foundation and trunk, 30c. cub. ft 1,334 70 16,713 ft. bd. meas. plank in do., $35 r&. ft . . 584 95 508 cub. yds. masonry in breast wall, wings, and parapet, $9 cub. yd 4,572 00 For one culvert , . . . . 8,361 60 4 For four $33,446 40 133 Look No. 9, at Felipes. 8 fett lift. Walls 34^ feet in height. 35,114 cub. yds. of earth, at 35c. per cub. yd. . , $12,289 90 22,850 " embankment, at 30c. per cub. yd. . 6,855 00 2,020 " puddling in rear of lock walls, at 20o. per cub. yd 404 00 24,210 cub. ft. timber in foundation, at 30 c. per cub. ft. . 7,263 00 6il59 " » in lock gates and mitre sills, at $1 50 per cub. ft 7,738 50 190,506 ft, board meas, plank in foundation, sides, chamber and gates, $40 per m. ft 7,620 24 60,682 lineal ft. bearing piles, at 25c. per lineal ft. . . 12,663 00 9,424 cub. yds. masonry in lock walls, at $17 per cub. yd. 160,208 00 1,761 " concrete masonry in sheet piling trenches, at $8 per cub. yd 14,088 00 1,527 cub yds. rubble masonry under upper mitersill plat- form, and at head and foot of lock, and for sluice around lock, at $7 per cub. yd. . . . 10,689 00 44,575 lbs. wrought iron, at 12c. per lb. ... 5,349 00 17,850 " cast iron, at 90. per. lb. .... 1,606 50 $246,774 14 Lock No. 10, opposite the Colorado. Sfeet lift, wall 2^^ feet in height. 25,962 cub. yds. excavation of earth, at 35c. per cub. yd. 18,093 " embankment, at 30o. per cub. yd. 1,695 " puddling iu rear of lock walls, at 20c. per cub. yd 24,210 cub. ft. timber in foundation, at 30c. per cub. ft. . 4,396 " " in lock gates and mitre sills, at $1 60 per cub. ft 188,300 ft. board meas. plank in foundation, sides, chamber and ga^s, at $40 per m. ft. . . . 60,652 lineal ft. bearing piles, at 25 c. per lineal ft. . 7,700 cub. yds. masonry in lock walls, at $17 50 per cub. yd 134,750 00 1,761 cub. ydsi concrete masonry in sheet pihng trenches, at $8 per cub. yd 14,088 00 £9,086 70 5,427 90 339 00 7,263 00 6,694 00 7,532 00 12,663 00 134 1,475 rubble masonry, under upper mitre sill platform, at head and foot of lock, and for sluice around rock, at 17 per cub. yd 10,325 00 44,575 lbs. wroiight iron, at 12c. per lb. . . • 5,349 00 17,850 " cast " at 9c. per lb. ... 1,606 50 $215,024 10 Lock No. 11. 8 ft. lift. Walls 29 J feet in height. •34,907 cub. yds. excavation of earth at 50c. per cub. yd. 16,938 " embankment, at 30c. " 1,695 " puddling in rear of lock walls, at 20c. per cub. yd 24,210 cub. feet timber in foundation, at 35o. per cub. foot, 4,396 " do in lock gates and mitre sills, at $1 60 per cub. foot 7,033 60 188,300 ft. board meas. plank in fourdation, sides, chamber and gates, at $40 m. ft 7,532 00 50,652 linl. ft. bearing piles, at 25c. linl. ft. . . 12,063 00 7,700 cub. yds. masonry in lock walls, at $18 per cub. yd. 138,600 00 1,761 " concrete masonry in sheet piling trenches, at $0 per cub. yd 15,849 00 1,475 cub. yds. rubble masonry under upper mitre sill platform, at head and foot of lock, and for sluice around lock, at ^8 per cub. yd. . . . 11,800 00 44,575 lbs. wrought iron, at 12c. per lb 6,349 00 17,850 « cast « at 9c. " . . . . 1,606 50 $17,453 50 5,081 40 339 00 8,473 50 $231,780 50 Look No. 12. Sfeet lift. Walls 29ifeet in Mght. 25,962 cub. yds. excavation of earth, at 50c. per cub. yd. 18,095 " embankment, at 30c. " 1,695 " puddling in rear of lock walls, at 20c. per cub. yd 24,210 cub. feet timber in foundation, 35c. per cub. ft., 4,396 " do in lock gates and mitre sills at $1 60 per cub. ft 188,300 ft. board meas. plank iu foundation, sides, chamber and gates, at $40 per m. feet, .... $12,981 00 5,428 50 339 00 8,473 50 7,033 60 7,532 00 135 60,652 linl. ft. bearing piles, at 25c. per linl. ft. 7,700 cub. yds. masonry in lock walls $ 1 8 50 per cub. yd. 1,761 " concrete masonry in sheet piling trenches at $9 per cub. yd. ..... 1,475 cnb. yds. rubble masonry under upper mitre sill platform, at head and foot of lock, and for sluice around lock, at |8 per cub. yd. . . . 44,675 lbs. wrought iron, at 12c. per lb. ... 17,850 " cast " at 9c. " . . . , 32,732 16,989 1,695 24,210 4,396 188,300 50,652 7,700 1,761 1,475 44,675 17,850 Lock No. 13, near the River Juanillo. 8 feet lift. Walls 29^ fat in height. cub. yds. excavation of earth, at $1 00 cub. yd. , " embankment, 35 " " puddling in rear of lock walls, . . • . 25 cub. ft. timber in foundation, 35 cub. ft. . " " in lock gates and mitre sills, , . 1 60 " ft. board in. plank in foundation, sides, chamber and gates, 40 00 m. ft. linl. ft. bearing piles, . . 25 linl. ft. cub. yds. masonry in lock walls, 19 50 cub. yd. . " concrete masonry in sheet piling trenches, . .9 60 " . cub. yds. rubble masonry under upper mitre sill platform, at head and foot of lock, and for sluice around lock, . . 8 50 " lbs. wrought iron, . . . 12 lb. " cast "... 9 " 12,663 00 142,460 00 16,849 00 11,800 00 5,349 00 1,606 50 $231,605 10 $32,732 00 5,928 65 423 75 8,473 50 7,033 60 7,632 00 12,663 00 150,150 00 16,729 50 12,637 50 5,349 00 1,606 60 $261,159 00 Lock No. 14, a tiTTLE south of Sheppard's Lagoon at San Juan. 6 ^J_ feet lift. Walls '2^1 feet in height. 50,052 cub. yds, excavation of earth, at $1 00 cub. yd. $50,052 00 16,236 " embankment, 36 1,695 " puddUng in rear of lock walls, 26 5,682 60 423 75 136 24,210 cub. ft. timber in foundation, 40 cub. ft. 9,684 00 4,396 " " in lock gates and mitre sills, 1 70 " 1,413 20 188,300 ft. board in. plank in foundation, sides, chaml)er and gates, 40 00 m. ft. T,532 00 50,652 linl. ft. bearing piles, 25 linl. ft. 12,663 00 7,700 cub. yds. masonry in lock walls, 20 00 cub. yd. 154,000 00 1,761 " concrete masonry in sheet piling trenches, 10 00 " 17,610 00 l,47o cub. yds. rubble masonry under up- per mitre sill platform, at head and foot of lock, and for sluice around lock, 9 00 " 13,275 00 44,5'75 lbs. wrought iron, 12 lb. 5,349 00 17,850 " cast " 9 « 1,606 50 $285,351 05 Recapitulation of Eastern Division, Length, 119f'5V5- '>niles. '€3 8 7 4 6 4 Kind of Work. SLACK WATER NAVIGATION" ON THE SAN JUAN RIVER. RemoTal of bars in the San Juan, be- tween the Lake and foot of Machuca Rapids Canals around Dams Nos. 1 to 6, inclu- sive Locks at Dums from Nos. 1 to 6 inclu- sive Dams across the San Juan Amount. INLAND CANAL. Sections Locks Culverts. ., ■ Artificial harbor extending from foot of Lock No. 14, to 17 feet depth of wa- ter in the Harbor of San Juan Breakwaters or Jetties Light House Total. $792,383 81 444,179 7i 1,983,965 5-. 1,572,021 4( 4,651,970 3( 1,471,593 81 33,446 41 890,145 1( 635,640 (M 25,000 Of 14,794,550 47 $7,707,795 74 $12,51.2,346 21 137 General Summary of all th,^ Divisions. Total Length, 194^^^^ miles. 'J 3 •si TTind of "Work. Amount. 8 $12,440,861 14 l,025,6'r6 16 "792,388 80 444,179 15 Excavations and Piers at the mouth of the River La- iaa, and excavation and piling at the outlet of the Bemoval of bars in the San Juan, between the outlet of the Lake and the foot of Machuca Bapida Oanal around dams Noa 1 to 6 inclusive 28 Locks 6,601,673 18 8 Dams 1,667,844 59 1 Waste Weir 70,776 94 6 ^ Culverts 60,610 24 fi Bridges 70,933 09 2 60,626 07 2 8,074,029 19 4 2 Breakwaters or Jetties 1,096,241 96 60,000 00 $27,424,626 70 BEOAPITITLATION'. Western Division $18,896,608 84 Middle, or Lake Division 1,026,676 15 Eastern Division '. 12,602,346 21 $27,424,626 70 Add for contingencies, 15 per cent 4,113,693 88 Total estimated cost of the Canal $31,588,319 58 18 138 Tabular Statement of the length of the several levels, and their total lengths, to 17 feet depth of water in either ocean at hw tide ; the fall at the ter- mination of the several levels ; the number of feet of lockage descending east and west of the summit, and the total of the same : also the fall from high Lake to low tide in the Atlantic and Pacific Oceans. Length in Mile: . Lockage in Feet. Fall in ft. from high Lake to low tide. Levels. .ij «J *i t w a Total. ^ SS H ^ ^ Total. 4 1 i Ct-I o ■3 o 2i « U 1 (2 1 West of Lake. 9,779 Across the " 66,60 East of the " 37,151 0.126 7.303 3.921 162 20 049 7.638 8.600 13.231 5.760 1.740 7.000 4.040 0.60 0.425 0.675 0.337 0.863 0.900 0.650 1.176 0.600 0.562 0.988 0.137 1 2 3 4 6 6 7 8 9 10 11 12 13 8 8 8 6.60 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 1.940 0.250 192.801 14 6.23 7.47 220.20 108.73 103,430 81.409 7.962 108.73 111.47 111.47 In Harbors. . . 0.745 0.847 1.692 Totals 103,430 82.154 8.809 194.393 108.73 111.47 220.20 108.73 111.47 139 D. Statetnent of the distances and fall in the San Juan Kiver, from place to to place, and the total distance and fall from high Lake to low tide in the Atlantic. Dist. in Miles. FaU in Feet From Place to i-iace. 1 1 Total. % TotaL From To High. Low Lalce. 6.00 2.24 6.67 2.30 5.86 4.64 7.03 6.65 7.21 6.91 7.44 9.30 5.91 32.87 Fort San Carlos Head Toro Rapids Foot " " Head Castillo Rapids... Foot Head Mico " Foot Balas Head Machuca " Foot Dam No. 4 27.228 1.819 7.650 0.529 5.173 2.256 3.056 1.028 19.98" 7.568 8.603 6.220 28.200 27.228 29.047 36.697 37.226 42.399 44.655 47.711 48.739 68.719 76.287 84.890 91.110 119.310 7 24 Head Toro Rapids Foot " " Head CastiUo Rapids Foot " " Head Mico " Foot Balas " Head Macbuca " Foot " " 13.91 16.21 22.07 26.71 33.74 39.39 46.60 53 51 Dam No. 4 " « 6 fo.gs " " g " " 6 70 25 " " 6 (( a t7 76.16 " " 7 To 1 7 feet depth of water in San Juan Harbor. . 108.73 140 B. The following specifications are designed to be giv- en in sufficient detail, to show the general character of the work upon which the estimates are based. They embrace nearly all of the kinds of structures required on the canal. The plans of the locks together with those of some others of the structures may, on more mature deliberations, be deemed to require some modi- fications in their proportions and otherwise ; this it is not supposed will be necessary to an extent that will materially vary the cost. The apology offered for any errors that may exist in the plan or location of the breakwaters, is the absence of experience in the construction of maritime works. If previous to the commencement of the canal, circum- stances shall render it expedient to modify these works to some extent, both in plan and location, which is considered more than probable, a better opportunity than at present will be afforded for careful study, and more correct conclusions in regard to the more minute details of the plans and system of works that should ultimately be adopted at these harbors. If this shall not result in the immediate necessity of more extended, and expensive works, than those for which provision is made in the estimate, the present chief object will be attained. It will be seen that the specifications require no or- namental or other work not necessary to permanency ; the resolution of instructions received from your board, has, in this respect, as also that requiring the chamber walls to be faced with wood for the protection of ves- sels, been observed. 141 METHOD OF CONSTRUCTING THE PRISM AND BANKS OF THE CANAL. From the space to be occupied by the canal, all trees and brush are to be thoroughly grubbed up, and together with all vegetable substances, to be removed beyond the limits of the banks. Walls of puddled earth at least 10 feet in thickness are to commence in trenches, cut to such depth as will give them a connection with an imper- meable material, and be carried up in the central parts of the banks to within 4 feet of the top, at all places where the natural surface of the ground is below the surface water level of the canal ; during the progress of construction, the banks are to be kept from ridges, and be carried up in a regular form with the finer portions of the material placed contiguous to the puddle walls, to give them a uniform support. Except in cases of canal in rock, the upper portions of the interior face of the banks are to be covered with a slope wall 1:J- feet thick, commencing on a bench 8 feet below, and be carried up 4 feet above the surface water hne of the caaal, with a slope of IJ to 1, of base, and vertical height. The stone in the lower course to have at least a length of 1^ feet ; and all of the stone comprising the walls to be compactly laid with their lengths at right angles with the face of the banks, on a coating of gravel 6 inches thick. The spaces in the wall to be filled with the same material. The spoil banks to be placed contiguous to, and be carried up with the same slope as the canal banks, and the top finishing to be a uniform plane with sufiScient de- clivity to carry the falling water to the rear of the banks. LOCKS. The sides of the locks are to be composed of hydraulic stone masonry, and rest on a . foundation of timber and concrete covered with plank. The pit to be excavated to a depth of 2^ feet below the bottom plane of the lower level of the canal, and to be of the necessary horizontal dimen- sions to receive a foundation 86 feet in width by 350 feet in length. In cases of the occurrence of rock at the bottom of the pit, or of earth sufficiently compact and firm, ^ of the surface of the pit, after having been brought to a level, and made smooth and even, is to be covered with hewn timber, one foot in depth or thickness, of such length, and be so placed as to 142 terminate li feet in rear, and alternately 26i, and 1^ feet within the inner face of the walls, and be firmly attached with iron bolts to 4 lines of mud sills placed longitudinally, two on each side of the centre, securely anchored in the following manner. Trenches shall be cut 5 feet deep, and 4 feet wide, upon lines at the centre, and intermediate the centre and face of the side wall, extending from the upper mitre sill foundation to the lower end of the apron floor. In the bottom of the trenches, a line of anchor tim- bers, each of a length equal to the length of the trenches, at least 12 inches square is to be placed and be firmly connected with the mud sills by vertical dovetailed ties, and the space filled with rubble or concrete masonry. When practicable, suitable rows of piles shall be driven in place of the anchor timbers and be connected with the mud sills by dovetailed tenons, straps, and bolts. In cases of earth at the bottom of the pit not being snflBcient to sustain the superincumbent weight, the necessary number of bearing piles of suit- able dimensions are to be driven under that portion of the foundation to be occupied by the walls, and at such other places as may be required in con- nection with the sheet piling, of which there shall be at least 18 rows, pro- perly placed in trenches cut across the pit and spiked to the foundation tim- bers. The sheet piling trenches and the spaces between the foundation timbei-s to be thoroughly filled with concrete masonry, and the whole covered with three inch plank well treenailed to the timbers. Upon this floor the walls of the lock are to be constructed ; they are to have an ex- treme length of 356 feet, of which 56 feet is to extend above the upper, and 50 feet below the lower hollow quoin, leaving from quoin to quoin a length of 250 feet. The side walls to be placed 52i| feet apart on the floor, and, excepting the recesses, to be llf feet thick at the base, exclusive of the buttresses, which are to be 6 feet long, project 2^ feet from the rear of walls, and be placed 15 feet apart. The rear of the walls to be carried up plumb and the face to batter 2 inches to one foot rise, to a height of 16i ft. ; thence 1 inch per foot rise to the top of the walls 29| feet above the floor, where the space between the side walls is to be &Ofy feet. A timber frame work, covered with two courses of plank, and secured in its place by iron screw bolts, 1 inch square, reaching through the walls, is to occupy a recess formed in the face of both chamber walls, from 10 feet below the upper gates to 10 feet above the lower gate recesses, said frame work to occupy 13 feet in width of the upper portion of the face of the walls. The side walls to be composed of coursed masonry laid in mortar, made with first quality hydrauhc cement and clean sharp sand. The courses shall not be less than one foot in depth or thickness, and in that portion of the face in the rear of the timber facing, the courees may be composed 9l- 143 ternately of 1 and 2 stones, but no stone in the face course shall be less than 9 inches thick, 2 feet length of face, and a width of bed equal to If its thickness. A header at least 4^ feet in length to be placed one in every 10 feet in every alternate course, and intermediate the headers in the preceding course ; the beds and vertical joints of the face courses to be so dressed with full comers, as to form when laid in the work, a mortar joint, not exceeding | of an inch thick, to a width alternating in the courses If and 3 feet back from the face of the walls. The beds and vertical joints of the face stone in other parts of the side walls are to have a width alter- nately of 2 and 3-^ feet dressed to -J^ of an inch joint, and to be well bonded to the backing, in courses of the same thickness, and number of headers as other parts of the face of the walls. The quoin stone to be at least equal in thickness to the courses in which they are placed and to be alternately 3f by five feet, and 5 by 5^ feet in horizontal dimensions. The hollow of the quoin to be smoothly cut to a curve of 10 inches radius, and bevelled back to the vertical face of the recess, and the nose to be cut to a bevel to confoi-m to the face of the walls. The beds of the quoin stone, recess corners, and capstan walls, to be cut to f^ of an inch mortar joint. The backing shall have headers of the same dimensions as the face, and be placed in the rear couraes successively to the back of the wall, interme- diate the headers in the adjoining courses vrith which they shall break joints at least one foot. The other principal stone in the backing shall be at least 9 inches thick of good form and size, and shall, together with the headers, be hammer dressed to fair beds, and be compactly laid with good bond, in hydraulic mortar, and the vertical joints well filled with grout. The quoin coping, and the two contiguous pieces, to be at least 15 inches in depth and 5 by 7 feet square, and be connected together by clamps of iron, and to the walls, by bolts well leaded. The coping on other parts of the side walls, excepting opposite the timber facing, to be at least one foot thick, 3 feet length of face, and 4i feet width of bed, that opposite the tim- ber facing to be 9 inches thick and 5 feet width of bed. A mitre sill foundation wall is to be constructed across at the upper termination of the chamber 38 feet wide, and to a height when covered with a floor of timber and plank 15 inches less than the lift of the lock ; the timbers of the floor to be bolted to other bed timbers firmly anchored in the masonry. The breast wall is to be 5 feet thick, it is to extend across at the head of the lock, and be carried up from the floor to the bottom of the upper level, leaving a space 5 feet wide above the mitre sill foundation. The cop- ing to be at least one foot thick, 3 feet wide, and a length equal to the width of the breast, and. to be anchored with iron bolts. The floor be- 144 tween the side walls, to be lined with two inch plank well spiked and treenailed to the foundation timbers. The gates are to be of the usual form, 36 feet in length ; they are to be operated by means of chains and captans, and move on a circular tram rail of iron, and on a pivot placed at the centre of motion under heel posts formed from timber 20 feet by 24 inches square. The frame of the gates is to be of wood, strengthened with iron screw bolts, plates and braces, and the quoin posts are to turn in collars fastened to anchors secured to the coping by clamps and bolts. An apron floor is to extend from the lower termination of the wing walla 50 feet, on which is to be constructed substantial walls of quarried stone, laid in hydraulic mortar, on a bevel line, forming a proper connection with the slope wall on the face of the banks below. Similar walls are to be constructed at the head of the locks. In all cases of locks connected with the river, an additional height is to be given to the side walls, and gates to guard against any injurious influx of the streams in time of high water. All of the locks connected with the river, and others so located as not to admit of being drained, are to have suitable recesses formed in the face of the side walls, at the head and foot of the lock, to receive the ends of an iron caisson to be placed across, and fill the space between the walls, forming a tight barrier, and rendering it practicable, when necessary, to dis- charge the water from the locks, for the purposes of repairs. The embankments in rear of the walls, a length of 60 feet from the ' head of the locks, are to be formed with puddled clay and gravel, the re- mainder with common earth, carried up in a level and compact manner. DAMS. The plan upon which the estimates of the dams are based, consists' of cribs formed of well flattened timber, locked together and treenailed, and where necessary to give greater security to the work, ragged bolts of iron are to be driven at the crossings, and the spaces of the cribs to be filled with stone. The dam is to be carried up with a series of oflFsets towards the centre, from the upper and lower sides. Proceeding up from the base, those upon the lower side of the dam are to have a horizontal width vary- ing from 12 to 8 feet, with intermediate vertical ascents of from 6 to 4 feet, thus forming a succession of aprons from the top of the dam to its base. The aprons are to be covered with squared timbers, extending back into the body of the dam, and be thoroughly treenailed and bolted to the crib work on which they rest. 145 The upper side of the dam being reduced by ofifeets to the necessary width, at 6 feet below the top the remainder is to be finished up in the proper form, to receive a sloping covering of tapered plank, respect- ively, 6 and 3 inches thick at the ends, and 26 feet long, to be firmly spiked and treenailed to the range timbers, forming a tight plank covering 26 feet in width the whole length of the dam ; the vertical face extending from the lower edge of the plank covering to the first offset to be covered with two inch plank, well spiked to the timbers of the dam. Abutments of i-ubble masonry are to be constructed at each end of the dam ; they are to be 6 feet thick at the top, and increase in thickness downwards, by a batter on the face of 1 inch in every foot of vertical de- scent, and are to consist of large well shaped stone, laid with good bond in hydraulic mortar. They are to rest on a foundation of timber and plank placed as low as the bottom of the dam, and where no rock occurs secui'ed with sheeting and bearing piles. That portion of the face of the walls in contact with the current, is to be laid in alternated courses of 2 and 3 feet width of bed dressed to f of an inch joint, and be well con- nected with the backing with suitable headers in every alternate course. The upper side of the dam to be thoroughly embanked with gravel, and below the lower apron, where no rock occurs, with stone of sufficient size to withstand the action of the current. The rear face of the abutments where not carried up in contact with the vertical face of a rook bank, are to receive a thick coating of hydraulic mortar, and be embanked with well assorted materials. In the centre of the bank a puddle wall of clay and gravel 10 feet thick is to be carried up from the floor to the top of the abutments, and extend in cases of earth on the southerly side of the river, in a deep trench to the hill, and on the north side in a similar trench, to, and connect with the puddle walls in the embankment of the canal. STONE DAM ACEOSS THE KIO GRANDE AT THE WESTERN TERMINATION OF THE SUMMIT LEVEL. The foundation of the dam to consist of two courses of hewn timber; each course to be formed with sticks 12 inches square, and 35 feet long. The timbera forming the Ist coui-se across the stream, are to be placed longitudinally side by side on a surface of rock previously made smooth and level to receive it, and on transverse sills so let in and bolted to the rock as to present an even bearing, and to which each stick in the couree is to be firmly secured by ragged bolts and treenails. The 2nd coui-se to break back from the lower termination of the first, forming an apron 8 feet 19 146 wide, and be secured in like manner to transverse sills, and to the timbers in the firet course. 11 feet in -width of the up stream side of the 2nd course to be covered with plank, well treenailed to the timber?, upon this floor the masonry of the dam is to rest. The masonry over which "the water is to pass, is to have a length of 290 feet, it is to be 16 feet thick at the base, and be carried up 33 feet with a batter on the face of 4 inches to the foot rise, giving a top width of 5 feet, which is to be finished up with a bevel, and coped with tapered plank 6 and 3 inches thick at their respective ends, well secured with bolts and treenails to longitudinal tim- bers, firmly anchored in recesses at the top angles of the wall, and to mud sills anchored in the puddle wall filling on the upper side of the dam. Abutments of masonry of the proper form and dimensions, are to be constructed at each termination, and be carried to a height of 6 feet above the crest of the dam. An arched culvert of 4 feet chord is to be con- structed of cut masonry in the north abutment, through which, by means of iron gates, a portion of the surplus water in time of floods, and if for any purpose it should become desirable to do so by shutting oflf the water near the lake in the dry season, the summit level might be drained. The masonry of the dam to be laid up in courses not less than 1 foot in thickness, the beds of the face stone to be alternately 2 and 3 feet in width, and together with suitable headere to be dressed to |- of an inch mortar joint. The remainder of the walls to be well bonded and hammer dressed, and the whole laid in good hydraulic mortar, and the vertical joints well filled with grout. Such portions of the abutments as do not abut against a face of rock in place, are to be embanked with similar materials, and in like manner, as is described for the embankments in rear of abutments connected with timber dams. RECEIVING WEIRS. A receiving weir with a breast full, of 20 feet in height, and 184 feet in length, over which the waters of the Rio Grande, are to be received into the Canal ; it is to be constructed across the stream in a recess, cut back 2 chains from and upon a level with the bottom of the Canal. The receiving weir to be composed of hydraulic stone masonry, resting on a timber and plank foundation. The foundation timbers are to cover -J of the area, the spaces between them are to be filled with concrete, and the whole covered with plank. The surface of the floor is to conform to the level of the bottom of the Canal, and be 22 feet in width, and 119 feet in length. A row pf sheet piling is to be placed in a trench alongthe lower side of the floor. 147 and be spiked to the foundation timbers and the space filled with concrete or rubble masonry. The breast wall is to be placed on the up stream side of the floor, leaving an apron 10 feet wide ; it is to be 11 feet thick at the base, and be carried up with a batter on its lower face, and be 6 feet thick at the top, and coped with 4 inch plank, 6 feet long, treenailed to timbers, secured on the top of the wall by anchors, and by ties 15 feet in length, extending into the pud- dle wall filling at the upper side of the breast. Abutments of stone masonry of suitable form and dimensions, to be con- structed at the ends and be carried up from the floor to 12 feet above the top of the breast, the whole to be formed with large well shaped quarried stone well bonded and compactly laid in hydraulic mortar. The face . stone to be laid in courses at least 1 foot thick, with beds alternately 2 and 3 feet width, dressed to f of an inch joint. Substantial slope walls of dry masonry are to be constructed on the face of the banks above, and below the weir. WASTE WEIR. A waste weir of hydraulic stone masonry with a discharge way 300 feet in length is to be constructed on a foundation of plank and timber in the berm bank opposite the entrance into the Canal of the River Tola. The surface of the floor to be on a level with the bed of the creek, and 5 feet below the bottom of the Canal, and is to rest on bearing piles to which the floor timbers are to be firmly attached. The floor is to have a width of 44^ feet, and be 316 feet in length, and be secured with sheet piling placed in trenches along its upper and lower sides, and the spaces in the trenches and between the foundation timbers, to be filled with concrete. The breast wall to be 12 feet thick at the base, and 6 feet at top, and be built up with a batter on both sides, to a height of 22 feet, and be coped with stone at least 1 foot thick, and 3 feet wide, and of a length equal to the width of the top of the wall. Abutments with suitable wings and buttresses are to extend from the floor, 6 feet above the top of the breast wall, and be covered on their rear - faces with a thick coat of mortar, with which the embankments and puddle walls of the Canal banks are to be connected. Retajning walls 4f feet thick, and 8 feet high, are to be constructed on the lower edge of the apron floor, and extend from the face of each abut- ment 120 feet towards the centre of the weir. That portion of the apron floor not occupied by masonry to be covered with two courses of plank 3 inches thick, well spiked and treenailed to the foundation timbers. 148 The masonry to be laid up in courses at least one foot thick, the face stone on both sides of the breast wall, to have alternately in the courses 2 and 3 feet width of bed, with headei-s 4 feet long placed 12 feet apart in every alternate course. The beds and end joints of all the face stone to be dressed to J of an inch mortar joint ; the centre and backing of the Avails to be composed of large well shaped stone, dressed to half an inch joint, and the whole to be laid with good bond in hydraulic mortar, and the vertical joints iiUed with grout. The coping to be secured in its place with iron bolts well leaded. The bed of the creek below and adjoining the apron floor, is to be lowered and the space to be filled with large stone. CESS POOLS. For receiving into the canal the water draining from the country cess pools, are to be constructed with hydraulic stone masonry of such dimensions as may be required to give them full capacity for this purpose at the various localities at which they may be required. Those of medium size are to be formed with a vertical semi-circular well, 4 feet in transverse diameter, ex- tending from the surface of the ground in rear of the bank, to the level of the bottom of the canal, and connect with a horizontal trunk of masonry of a square form, resting on a timber and plank foundation, and leading under the bank to the bottom inner angle of the canal. SWING BRIDGE. Bridges are to be constructed to swing on a centre pivot, resting on a pier of hydraulic stone masonry, placed at the centre of the canal. They are to span a clear width of 65 feet of water-way on either side of the centre pier, and close on to abutments of masonry located at the banks of the canal. The centre pier is to be 16 feet thick, and where no rock occurs, it is 'to commence at the bottom of the canal on a foundation of timber and plank, and, together with the abutments, are to be carried to a height correspond- ing with the surface of the country continuous to the canal where the bridges are located^ except where it is below the top banks. The abutments are to be laid up with a batter on the face and in courses not less than 9 inches thick. The face stone to have a width of bed in al- 149 ternating courses, 1 J and 2i feet, and be dressed to -J- an inch mortar joint ; it is to be well bonded to good hammer dressed backing, and the whole compactly laid in hydraulic mortar. The superetructure to connist of a light truss frame of wood 17J feet in height, and 171 feet in length, and of sufficient width to admit of a clear road way 12 feet wide, supported by the trass and by iron tension braces. In addition to the pivot at the centre, the truss is to turn on iron wheels, 20 inches in diameter, placed on the periphery of a circle of 13| feet in diame- ter, and made to track on a circular tram plate of iron, secured to a frame work of wood, resting on the centre pier. The bridges are to be turned by means of a crank operating upon wheels. JETTIE OR BREAKWATER AT BRITO HARBOR. The plan upon which the estimate of the cost of this work is based, con- sists of a mole, formed with large stone promiscuously thrown in ; it is to have a width of 7T feet at the surface of low tide, with a slope on the inner side of 2 feet, and on the opposite or sea side of 3 feet horizontal to one foot vertical. The surface of the mole having been made compact and level, a vertical rectangular wall 12 feet, thick is to commence at the surface at low tide and b? carried up 17 feet high ; the courses of the first 9 feet in height, to be 15 inches, and in the remaining 8 feet at least 20 inches thick ; the beds of f of the stone in the first 8 feet below the coping, to be hammer dressed to half an inch joint. They are to be laid with good bond, and be of sufficient size to cover an area of at least 10 feet. The coping to be dressed to half an inch vertical joint ; each stone to cover an area of not less than 15 feet, and be firmly anchored with iron bolts to the masonry on which they rest. The outer face of the mole to be continued Up to the top angle of the centre wall, and be composed of stone at least of sufficient weight to withstand the action of the sea. They are to be placed in the most compact manner, with the largest beds vertically, and at right angles with the line of the jettie. The inner face of the mole to be carried 7 feet above the base of the centre wall, and finished in like manner as the outer slope. The termina- tion of both wings of the jettie to be enlarged and finished in a circular farm. The rectangular wall is to extend from the coast line of low tide to the termination of the jettie, and that portion of the moles between the goast lines of high and low tide to be carried 8 feet above high tide, and be 12 feet wide at top, and be finished with hke slopes and in the same man» ner as other parts of the jettie. 150 Breakwater at San Juan IIarbor. To be in all respects similar to those above described for the Brito Har- bor, except that the rectangular wall is to be omitted and the outer slope is to be 2^ and the inner slope IJ feet horizontal to one foot vertical, and 12 feet wide at top. PEOTECTION PILING AT THE OUTLET OF LAKE NICARAGUA. Piles 1 foot in diameter, and averaging 23 feet in length, are to be worked to a straight line on two sides and be driven in two rows, in close contact in each row. The piles to be driven 12 inches below the surface of high Lake, and properly capped with a line of timbere 12 inches square, and 20 feet long, and secured with spikes and treenails to the top of each pile. The distance between the rows to be nearly equal to the width of the river at the outlet, from which at either side they are to extend upon nearly parallel lines 5 miles to 17 feet depth of water in the Lake. Side bracing piles of similar dimensions are to be driven one in every 20 feet to give additional support to the principal row to which they are to be secured at top with iron bolts. PIERS AT THE CONNECTION OF THE CANAL WITH THE WEST SIDE OF LAKE NICARAGUA. The piers to extend upon convergent lines from the shore of the Lake Upon either side of the cut, 1650 feet to 17 feet depth of water. They are to be composed of continuous Hues of crib work placed 500 feet apart on the shore and 300 feet at their termination in the Lake. That portion of the docks below the surface of the water, to be formed with 2 lines of flattened timbers, and above the surface, with timber 12 inches square, laid close, with an even bearing and connected together with treenails, and to each other with cross ties, and filled with stone. They are to have a width of 14 feet, and a height of 6 feet above the suiface of the water. DOCKS AT SAN JUAN. Docks at San Juan are to be constructed on both sides of the canal, or artificial harbor, and extend from It feet depth of water in the natural harbor at low tide, to the foot of the first or lower lock No. 14, a distance " of OfjV miles. 151 They are to be formed with timber cribs filled with stone, and extending from the bottom of the canal to the surface of the water at low tide, and that portion between the line of the coast and the lower lock to be sur- mounted with a wall of hydraulic stone masonry. The front and j-ear tiers of the cribs to consist of longitudinal courses of well flattened timber, so laid with an even bearing as to break jbints, and be firmly connected together with tree nails, and the tiers with each other by suitable cross ties, with dovetailed tenons let in and treenailed to the timbers. Timber piles, 30 feet in length, are to be driven one in eveiy 8 feet of the length of those portions of the dock surmounted with walls, on the inner side of the front tier, and project 1 feet above the top of the crib. The cross ties are to be arranged with reference to giving the greatest strength to the cribs and a regular form to the spaces, which are to be compactly filled with stone, and by means of land ties, to be well secured to the banks. The walls are to be placed upon a line in rear of the projecting piles ; they are to be 5^ feet thick and 6 feet high, and to consist of substantial rubble masonry laid in ranges with large well shaped quarried stone, well hammer dressed and bonded ; it is to be coped with stone at least 9 inches thick, 3 feet in length of face, and 4 feet width of bed, and the whole laid in the first quality hydraulic mortar. DOCK AT BRITO. A dock of the same form, and plan of construction as described for that at San Juan is to be located on the northerly and a portion of the southerly side of the artificial harbor at Brito ; it is to extend from the foot of the lower lock on the northerly side to the present coast line of high tide, a distance of 3060 feet, and on the lower portion of the southerly side, a distance of 600 feet; it is to have a thickness of 22 feet at the bottom of the harbor, and be built with a batter of 4 feet on the face, and be 18 feet wide at top at the surface of low tide. The piles are to be 38 feet in length, and project 17 feet above the top of the crib work. The wall is to commence on the previously prepared surface of the stone filling of the crib, with a width at the base of 8 feet, be built 15^ feet high, with a bat- ter of 24 inches on the face, and be 6 feet wide at top ; so much of the upper portion of the wall as may be practicable, to be laid in hydraulic mortar. 152 [Copy.] Wae Department, Washington, March 12, 1852. Sir, — In compliance with your request of the 8th instant, the President has designated Col. J. J. Abert, and Lieut.-Col. W. Turnbull, of the Corps of Topographical Engineers, to inspect and give opinions on the report of the survey and location of an inter-oceanic canal in Nicaragua, provided these officers can perform the duty in this city. Very respectfully. Your obt. servt, (Signed) C M., Conkad, L. White, Esq.', Counsel to the Atlantic and Pacific Ship Canal Co., Washington City. Secretary of War. [Copy,] Bureau of Topographical Engineerb, Washington, March 20, 1852. Sir. — In conformity with your desire, and the directions of the Secretary of War, we have examined the project of the Nicaragua Canal, as present- ed in the drawings, reports, and estimates of the chief engineer of your company, 0. W. Childs, Esq. Wherever we have differed from Col. Childs, we have stated herein. There are two laethods of reporting upon this matter : one, of its gene- ralities ; the other, of i^s details. By tha first, we can submit our views in a short time and in a short paper, the second would involve much time, and a very long paper. Under these considerations, we have preferred, in the first instance, to follow the first method, holding ourselves subject also to follow the second, at any future day, should it be desired. We think that the plan, as proposed by Mr. Childs, practicable ; there being an abundant supply of water in the Lake summit level alone, apart from other supplies bfelow it. From our investigations of this subject, we are not of the opinion that any other route is as adequately supplied with water. 153 Second, we think that the work can be done at the amount stated, upon his exposition of quantities and labor. It could be done for much less in this country, but the per centage added by Mr. Childs to the prices of labor of this country, in order to meet probable contingencies of the locality of this canal, are very liberal. Also we think that the two jetties at the harbor San Juan of the At- lantic can be dispensed with, and one, and probably both, of those at Brito Harbor, on the Pacific ; and also we think that the proposed pile work in the Lake, near Fort San Carlos, can be advantageously dispensed with, a single row of guide piles or buoys, about 100 feet apart, would, we think, be sufficient at that place to designate the channel. These considerations will diminish the estimate materially. As the work progresses, we recommend that additional surveys be made from Casa de Felipe, by the valley of the Juanillo River to San Juan harbor, to determine if a more dh-ect and shorter line for the canal cannot be had. Drawing a direct Une between these two points, and reasoning upon the reputed character of the ground, we are disposed to think that a shorter canal trace may be found near such a line, or between it, and the present trace of the canal, which would materially lessen the canal trace, and thereby diminish the cost of the canal, and also the time in passing it. Kespectfully, Sir, Your ob't serv't, (Signed,) J. J. Abert, Col. Corps T. Engrs. W. TURNBULL, Major Top. Engrs., Bvt, Colonel. J. L. "WniTB, Esqr., Counsel to the Atlantic and Pacific Ship Canal Co., Washington City, 20 ;ii..i._.l'-=..i|SS; . ..,."1. KlW Ttrj>.-iiirii!lKriiU*Btl