ment, it is assumed that this examination is to be limited by the mouth at Waterford, above the State Dam at Troy.

Having sent to Mr. F. J. Rodgers, overseer upon the improvement of the Hudson River, under this office, for certain information upon which to base an estimate of the cost of a preliminary examination, I was furnished in reply with a report upon this part of the river, which he was able to make without cost to the United States, which contains much more information than could be obtained by an ordinary preliminary examination. A copy of this report, with tracings, is inclosed herewith.

The navigation of the river above the dam is evidently good enough to supply all the present demands of commerce, particularly as the ruling depth in the river is greater than that allowed to enter the canal. Should any additional depth be required between the dam and the mouth of the canal at Waterford, it could be obtained most readily and probably most economically by raising the dam.

Below the dam and above the Congress Street Bridge the river is rocky and dangerous to general navigation. Good maps of the river from the Congress Street Bridge to the State Dam, made under direction of this office, exist. A survey sufficiently accurate for making estimates for the improvement of the river from Troy to Waterford could be made for about $500.

The river from Troy to Waterford has always been considered a part of the State system of canals, and all constructions and improvements have been made under the supervision and at the expense of the State of New York. Any comprehensive improvement of the river would be at large expense, and would probably give rise to a complication of the works and interests of the State and General Government, owing to the intimate relations existing between the river and the Champlain Canal. The commerce to be benefited now or in the immediate future is small, and is very well provided for with the river in its present condition. Under the circumstances the river is not, in my judgment, worthy of improvement by the United States. Respectfully submitted.

The CHIEF OF ENGINEERS, U. S. A.

JAS. MERCUR, Captain of Engineers.

REPORT OF MR. F. J. RODGERS, OVERSEER.

No. 55 NORTH PEARL STREET,
Albany, N. Y., August 16, 1884.

SIR: I have the honor to transmit, in separate package, a tracing of map of survey of the Hudson River from Troy to Waterford, made in 1867, on file in the office of the State engineer and surveyor, together with tracings of the profile and cross-sections between the State dam at Troy and Waterford, as constructed therefrom, from which may be developed, probably, all the information necessary for the requirements of a preliminary examination as contemplated and referred to in your communication of the 9th instant.

The Champlain Canal connects Lake Champlain with the Hudson River at Albany. The distance between the two points is given as 73 miles.

At Waterford, 12 miles north of Albany, it is connected with the Mohawk and Hudson by a "side cut." At a point 7 miles above Albany it joins the Erie Canal, and at West Troy, just below this point, the river is again reached by two “side-cuts" about 1 mile apart. Finally it empties into the basin at Albany, which is part of the canal

system of the State, but at present, owing to neglect, the greater part is not navigable. The lower end of the basin is used as landings for steamers and as harbor during the winter.

Of the four entrances and outlets to the Champlain Canal, the one at Waterford is least used, the greater bulk of the carrying trade entering and leaving the Hudson at West Troy and Albany.

The greatest draught permitted to enter the canal is 44 feet. The yacht upon which I made the trip was tipped to 4 feet, but while under way probably drew the limit of 4 feet. In many instances she touched bottom, and occasionally was compelled to await the passage of a canal-boat coming from the opposite direction and having the right of way, owing to the narrowness of the navigable section of the canal.

The width of the yacht was 13 feet, and of the canal-boats from 13 to 174 feet. The locks are single, designed to be 18 feet in the clear, and the prism of the canal 45 feet on top, 35 feet on bottom, and 5 feet deep.

Returning by railroad from Whitehall, I stopped at Waterford, and from thence proceeded to the sloop lock or State dam on a steam-tug. Before leaving the "sidecut" I made a sounding on the miter-sill of the lower lock and found a depth of 5 feet, and others at the shoalest point in the river, the least of which was 64 feet.

It is the opinion of the master of the tug that the river above the dam has shoaled somewhat on the west side, especially at the point where the small island designated Whale Island is located on the map. This island has disappeard, and is now said to be a middle ground, with a depth of 14 feet of water upon it. Another noticeable changeh since the map was made is the bridge at Lansing street, Lansingburgh, which I have drawn upon the tracing.

The "pond" between the State dam at Troy (which is about 18 feet in height) and Waterford is called 3 miles in length, and is referred to as part of the Champlain Canal, upon which tolls were collected up to last year, when the canals were made free by constitutional amendment. There is little, if anything, necessary to be done between the sloop lock and the mouth of the "side-cut" at Waterford to give a depth of 6 feet, which is the greatest draught possible to be moved through the canal in its present shape.

The condition of the river below the dam and sloop lock has been accurately determined by the surveys made from time to time by the United States Engineers, These surveys indicate a rocky and dangerous bottom between the dam and the Congress Street Bridge. If this section were improved and navigation made safe through it the number of canal-boats entering and leaving the Champlain Canal at Waterford would be largely increased and the time of each trip from and to Albany diminished two hours at least.

I have not sought to collect any statistics of the amount of commerce to be benefited by any contemplated improvement at this locality. I learned, however, from casual inquiry, that the average number of canal-boats locked into the river from the canal during the first eleven days of August was 4 per day, and the number locked into the canal from the river, for the same period, averaged 10 per day.

The boats coming from the canal were laden with ore, stone, lumber, &c., while the boats going into the canal, as well as those consigned to Upper Troy and Lansingburgh, were loaded generally with coal.

Very respectfully, your obedient servant,

Capt. JAMES MERCUR,

Corps of Engineers, U. 8. A.

F. J. RODGERS.

APPENDIX E.

REMOVING OBSTRUCTIONS IN EAST RIVER AND HELL GATE, NEW YORK.

REPORT OF BRIGADIER-GENERAL JOHN NEWTON, CHIEF OF ENGINEERS, BVT. MAJ. GEN., U. S. A., OFFICER IN CHARGE, FOR THE FISCAL YEAR ENDING JUNE 30, 1885.

UNITED STATES ENGINEER OFFICE,

New York, August 12, 1885.

SIR: I have the honor to transmit herewith the annual report upon removing obstructions in East River and Hell Gate, New York, for the fiscal year ending June 30, 1885.

Very respectfully, your obedient servant,

The CHIEF OF ENGINEERS, U. S. A.

JOHN NEWTON,
Brig. Gen., Chief of Engineers.

REMOVING OBSTRUCTIONS IN EAST RIVER AND HELL GATE, NEW YORK.

Capt. James Mercur, Corps of Engineers, was on duty in connection with this work until October 1, 1884, when he was appointed Professor of Engineering at the Military Academy, West Point; since that date Lieut. Col. Walter McFarland, Corps of Engineers, has been on duty connected with this work, and Lieut. George McC. Derby, Corps of Engineers, has been in superintendence of the operations at Flood Rock and of the steam-drilling scow during the year.

The appropriation of July 5, 1884, of $360,000, being limited in its application to "removing the reef at Hell Gate," no work has been done under this appropriation at any other locality under the project for the improvement of East River and Hell Gate.

The whole amount appropriated will be applied to the removal of Middle Reef (Flood Rock).

At the close of the last fiscal year work had been suspended on Flood Rock since May 31, 1883, owing to the failure of the river and harbor bill in March, 1883.

Work was resumed on Flood Rock in August, 1884, and the operations were confined to extending the galleries in the northeastern sec

tion of the rock, comprising about three-quarters of an acre, and drilling the holes in the roof and pillars for the final blast.

The work of extending the galleries has been completed and all the holes for the final charges have been drilled. In order to determine the practicability of using rackarock powder for the final blast at Flood Rock a series of experiments under water was necessary, and as the temperature of the water in the East River and vicinity would not be sufficiently high until very late in the spring, and as it was important to have the results known as soon as possible, I directed LieutenantColonel McFarland and Lieutenant Derby to proceed to Jacksonville, Fla., as a suitable place to make these experiments. For details of experiments see accompanying report.

On June 20, 1885, proposals were opened under circular letters for furnishing explosives and copper cartridge cases for the final blast, and contracts were made with the Rendrock Powder Company to furnish about 225,000 pounds rackarock powder, and with R. W. Warren to furnish about 50,000 pounds of dynamite No. 1. Contract will be made with the Rendrock Powder Company to furnish about 37,500 copper cartridge-cases 24 inches in diameter and 24 inches long, and 15,000 cases 24 inches in diameter and 15 inches long. Owing to some modifications in the specifications this contract was not executed before the close of the fiscal year.

The cartridge-cases are to be delivered to the parties furnishing the explosives and by them filled and the tops sealed and then to be delivered at Flood Rock ready for charging the holes.

The delivery of the explosives will be at the rate of 5,000 pounds of rackarock daily and 3,600 pounds of dynamite weekly.

The charging of the holes will be commenced during the month of July, and it is expected will be completed about October 1, 1885, at which time the blast will be fired.

The steam-drilling scow was taken from Gowanus Creek in August, 1884, and put on the dry dock and thoroughly calked, after which she was placed upon the rock off Nineteenth street, East River, known as Pilgrim Rock, and by drilling and blasting removed it to 24 feet mean low water. For the details of this work I would refer to the report of Lieutenant-Colonel McFarland.

The expenses for the removal of this rock were paid from the balance on hand of the appropriation of August 2, 1882.

After completing the removal of Pilgrim Rock the drilling scow and other floating property were laid up alongside the dike between Great and Little Mill rocks where they lay securely during the winter.

As reported last year a reef with 21 feet at low water exists about 150 yards northeast of the place occupied by Diamond Reef previous to its removal, constituting a serious obstruction to large vessels coming to the wharves of New York and Brooklyn.

I append herewith report of Lieut. George McC. Derby, Corps of En gineers, who has been in local charge of the works.

In its original condition the channel of East River and Hell Gate contained many large and dangerous rocky obstructions to navigation. The depth over Diamond Reef at mean low water was 173 feet; over Coenties Reef, 14. 3 feet; over Frying Pan, 11 feet; over Pot Rock, 20 feet; over Heel Tap, 12.1 feet; over reef at the North Brothers, 16 feet; Hallet's Point, from the shore at Astoria, projected under water 325 feet, to the contour line of 26 feet at mean low water, and embraced an area of about 3 acres. The Middle Reef, with an area of about 9 acres, lay in the middle of the channel at Hell Gate, having a small back