Cost of five dams, giving a total elevation of 35 feet, $542, 276.10.

The locks attached to the movable dams, having a less lift by 3 feet than those in the permanent dams, will cost about one-fifth less than those used with the permanent dams so far as the superstructure is concerned. The foundation will be unchanged. Hence we shall have for cost of the foundation of the lock, $43,316.15; for the superstructure, $68,173.44. The cost of the abutment will remain as before.

Total cost of improvement....

Total cost of improvement by permanent locks and dams..

Or the improvement by movable dams will cost more than that by permanent dams by....

1,308, 405 77 688,023 21

620,382 56

But in this connection we must notice that by the permanent dams we only reach a height of 30 feet above the surface of the second pool of the Monongahela slack-water, whereas by movable dams we reach a height of 35 feet above the same surface. The cost per foot of lift with the movable dams is.. And for the permanent dams it is

Or....

$37,383 02 22, 934 11

14,448 91 in favor of the improvement by permanent dams per foot of rise. Hence the cost per foot of rise by the system of permanent dams is approximately only two-thirds of what it would be by movable dams.

In view of the above figures, I would most certainly recommend that the permanent dams be adopted for the improvement of the Youghiogheny River. Very respectfully, your obedient servant,

Maj. W. E. MERRILL,

F. A. MAHAN,

First Lieutenant of Engineers, U. §. A.

Corps of Engineers, U. S. A.

APPENDIX O.

ANNUAL REPORT OF MAJOR G. WEITZEL, CORPS OF ENGINEERS, FOR THE FISCAL YEAR ENDING JUNE 30, 1874.

(Letter of transmittal under Appendix D.)

IMPROVEMENT OF THE FALLS OF THE OHIO RIVER AND LOUISVILLE AND PORTLAND CANAL.

The operations on this work are fully set forth in the report of Capt. M. B. Adams, Corps of Engineers, my assistant, who was, under my direction, in immediate charge of the work. The following is a copy of his report:

Report of Captain M. B. Adams, Corps of Engineers.

UNITED STATES ENGINEER OFFICE,
Louisville, Ky., June 30, 1874.

GENERAL: In accordance with your instructions, I have the honor to make the folowing report of operations on the Louisville and Portland Canal enlargement, and the mprovement of the falls of the Ohio, for the year 1873-1874:

During the past year the work carried on under the above heading was done in part by contract and partly by hired laborers. That by contract was done by the firms, Boyle & Roach, (contractors for constructing the guide-wall and for excavating below the new locks;) Sheehan & Loler, (contractors for completing the retaining-walls and grading the slopes;) and M. S. Lord, (contractor for constructing outer protectionwall.) M. S. Lord completed his contract in August, 1873; Boyle & Roach completed theirs in October, 1873; and Sheehan & Loler theirs in November, 1873. The entire amount of work done under each of these contracts was as follows, viz:

Within the fiscal year, under each contract, the following amount of work was done:

The work that was done by hired laborers consisted in the excavation of a channelway through a rock reef below the new locks out into the main river-channel; the excavation of a portion of a rock reef along the apron-dam at the head of the canal, and the construction of the dam at the crest of the falls. This work was advertised three times, and, the bids in each case being considered high, it was finally decided to do the work by hired laborers.

The following extracts from the monthly report for October, 1873, will, it is thought, explain the progress and results of the work under the labor-system, viz:

"During the month a coffer-dam was finished, which in all extended a distance of about 1,150 feet along the apron-dam leading into the canal, and at a distance from that dam of about 100 feet in the extreme. The amount of stone that would require removing within this area, in order to reach grade, is [was] about 4,600 cubic yards. The area was divided into three rooms, by cross or partition walls of earth, in order to make the power of our pumps more sure, and to better provide against accident from a break in the dam. The first section of 400 feet was entirely surrounded with an earth dam, which was not found to be as economical a structure as one of earth and timber combined, even when built in 5 feet of water, and when the earth was costing only 25 cents per cubic yard, (in dam.) All the stone within the first, and about half of that within the area of the second, room was removed during the month, making a total of about 1,600 cubic yards removed.

Six hundred feet of the crib-work for the dam along the crest of the falls was constructed, and about 500 feet of this was filled with the stone from the excavation, the rest of the excavated stone being used to replace the riprap in front of that portion of the dam already constructed. This riprap was carried away by the ice-flood of last winter,

(1872,) and in order to secure the new riprap, the outer layer of stone was placed on edge, (or paved,) the stone fitting in close to each other and being further secured by resting some of the largest stones from the excavation against the last course at the bottom of the slope.

It was the intention to have had this work all made secure in the manner as described above before the close of the season, but the very sudden rise in the river left it only in part done. There remains about 100 feet of crib-work to be filled with stone, and there was not more than 300 feet of the paved riprap that was secured with the large stones along the lower course.

At the foot of the canal, during the month, a coffer-dam was constructed of timber and earth, surrounding an area of 200 feet by 400 feet, from within which it was the intention originally to bave removed about 3,000 cubic yards of stone, making a “150-foot channel" through the rock reef that extends across the steamboat channel out into the river from the new locks. Within this area the work of excavating the stone was commenced on the 17th of the month, and between that time and the morning of the 26th there were 1,500 cubic yards of stone removed. The water then broke into the dam and prevented any further work. The channel resulting from this work gives a clear passage-way down to grade of 90 feet in width in the narrowest place.

Total expense on upper excavation.

Cost per yard of stone removed.
Total expense of lower excavation.
Cost per yard of stone removed.
Total cost of dam...

Cost per foot.....

$14, 138 29 8.83

13,977 49 9 32

7,058 48 11 76

As the river remained up, all further work on the dams, filling of crib-dam and the like, was prevented. The coffer-dam surrounding the upper excavation was allowed to remain through the season, but the lower one was taken up through the kind assistance of the superintendant of the canal, who sent his dredge-boat to our relief. The material was caught and brought to shore, and afterward taken to the Jeffersonville yard and stored there. About half of the coffer-dam left in over winter was carried away by the high water. The material saved from the other one will be all that is required for the next season's work, (to surround and complete the upper piece of excavation.) The riprap dam has again been carried away where it was not well secured with paved face and heavy stones at the base of the slope.

The dam between the head of Sand Island and the Indiana shore will require repairs, as reported in my monthly report for May, 1874. There being nothing further to report,

I remain, very respectfully, your obedient servant,

General G. WEITZEL,

Major of Engineers, U. S. A.

M. B. ADAMS, Captain of Engineers, U. S. A.

As stated in my last annual report, the sum of $100,000 is still needed to complete this work as originally designed. The delay in making this appropriation has already done harm to the unfinished parts of the work, and will continue to do so if this appropriation is not made at once. It is needed to complete the rock excavation at the head and foot of the canal, to complete the dam on the crest of the falls, and to raise the protectionwall at the upper end of the canal.

The original estimate for the cost of this work, as stated in my annual report for the fiscal year ending June 30, 1870, was $1,243,500. There has been allotted and appropriated for the work as follows:

Of this amount $1,335,983.60 has been expended. As above stated the additional sum of $100,000 will be required to complete the work, making its cost $1,463,200, instead of $1,243,500. The difference is,

in round numbers, about $220,000, and this excess in cost is entirely due to the manner in which the appropriations were made. If these had been made as I recommended, I am certain that I could have built the work in three summers, and for a sum less than my estimate.

The total amount of work done during the fiscal year was as follows, viz:

Dry wall built, cnbic yards

Earthwork, (excavation and filling,) cubic yards

Rock excavation, cubic yards

Stone filling, cubic yards

Masonry, cubic yards....

6,292 47, 354 +

5,396 1, 128 180

The amount that can be profitably expended on this work during the next fiscal year is $100,000.

The work is located in the third collection-district of Kentucky. The nearest port of entry is Louisville.

The amount of revenue collected at this port during the last fiscal year was $2,054.44. The commerce and navigation of the Mississippi River and all its branches will be benefited by the completion of this work.

Financial statement.

Balance in Treasury of United States July 1, 1873

Amount in hands of officer and subject to his check, (including $20,889.17,

percentage due on contracts not yet completed)..

Amount expended during the fiscal year ending June 30, 1874.

Amount available July 1, 1874

Amount required for the fiscal year ending June 30, 1876..

APPENDIX P.

ANNUAL REPORT OF MAJOR WALTER MCFARLAND, CORPS OF ENGINEERS, FOR THE FISCAL YEAR ENDING JUNE 30,

1874.

UNITED STATES ENGINEER OFFICE,

Chattanooga, Tenn., September 12, 1874.

GENERAL: I have the honor to transmit herewith my annual reports for the year ending June 30, 1874.

Very respectfully, your obedient servant,

WALTER MCFARLAND,

Major of Engineers.

Brig. Gen. A. A. HUMPHREYS,

Chief of Engineers.

P 1.

IMPROVEMENT OF THE TENNESSEE RIVER.

This improvement, as in the preceding year, has been carried on exclusively by the use of hired labor, and with the usual good results. No time has been wasted through inadequacy of outfit or supplies, and the work has been well done, the dams particularly offering a marked contrast to those built under the contract system, the stone being larger and more compactly placed, which enables them to resist better the

shock of floating bodies, while their greater tightness gives a better depth of water in the channels which they are designed to improve.

In both the upper and the lower river work has been carried on only at the points where it had previously been begun, the appropriations not being large enough to justify the commencement of new work, although this is greatly to be desired.

On the 13th of January, the building in which was situated the United States engineer-office at this place was destroyed by fire, and with it were destroyed a number of instruments, books, records, and maps; amongst the latter were the results of seven months' work on the detailed surveys for the Muscle Shoals Canal, consisting of sketches and detailed estimates needed for beginning the repair of this work. This was the most serious of our losses, as it involves the necessity of going over all this field-work again, and produces a delay of several months at a season when we ought to be at work. It is hoped that this loss will be repaired in time to admit of the beginning of the work early in the fall.

TENNESSEE RIVER ABOVE CHATTANOOGA.

The works are mentioned in their order, beginning at the one nearest Chattanooga.

Sanda Shoals.-The dams here are completed; aggregate length, 4,984 feet; 9 feet wide at top, and averaging 4 feet in height. The effect has been to give 12 inches more water at the head of the shoals, which is at the foot of Sanda Island; the gain diminishes, however, to nothing at the foot of the lower dam. A small amount of excavation remains to be done at the foot of the island; and in order to gain a sufficient depth of water in that part of the channel which is not affected by the dams already built, it will be necessary to build here an additional dam, at a probable cost of $6,000. Steamboats have, however, passed this obstruction regularly all this spring and summer, the river having been sometimes within 6 inches of the lowest stage.

The name of this obstruction has been misprinted in previous reports Sandy instead of Sanda.

Kelly's Shoal.-Very little done; about 30 cubic yards of rock removed from the channels.

Watts's Bar.-Only a small amount of rock-excavation has been done here this year. About one-quarter of the whole amount remains to be done.

White's Creek Shoals.-This work, as ordered, has been completed. The whole length of dam constructed here is 3,910 feet; variable width in some places, 12 feet; and in one place built in 13 feet depth of water. Some of the stone used in this dam were much exposed to the impact of drift-logs; weight from two to three tons apiece.

This improvement is completely successful, there being now 3 and 4 feet depth in the channel where formerly there was a depth of but 18 inches and 2 feet. Three years ago this was the most serious obstacle in this part of the river, being the first to close navigation when the river fell. A sand-bar appears to be forming at the foot of this shoal, and if we find that the scour of the river is insufficient to remove it, it will be necessary to extend the lower dam some 500 feet further down stream, at a probable cost of $2,500.

Half-moon Shoals.-The improvement at the head of Half-moon Shoals is complete. About 2,000 linear feet of dams have been built, the effect of which has been to give 34 feet of water in what were formerly the