I

to the east, with or without corresponding motion in the end of the west jetty. The aggregate length of the jetties proposed by the Board is somewhat less than that of Plan B, and less dredging will probably be required.

(6) As to the height of the eastern jetty, it may be said that by keeping the outer end of the eastern jetty at mean-tide height another element of flexibility is added to the plan, and as it allows an easier filling of the tidal basin, the Board would recommend that beyond 2,500 feet from Coatue Point the eastern jetty be kept at half-tide height until experience shows there is too much loss of stone by ice, or that the concentration of the escape over this part of the jetty is needed for scour between the jetties.

The section used in the recent parts of the western jetty seems to have sufficient strength, and, with the addition of finer material to reduce loss of water through the jetty, and the danger of settling when effective contraction of the water-way is obtained, can be used for the eastern jetty.

(7) Lieutenant-Colonel Elliot gives an estimate indicating that over half of the 30,000 vessels passing annually through Nantucket Sound draw less than 12 feet of water. Of those drawing over 12 feet, few would be able at once to take refuge in this harbor after the improvement. Respectfully submitted.

J. C. DUANE,

Col. of Engineers and Bet. Brig. Gen.
C. B. COMSTOCK,

Lieut. Col. of Engineers and Bvt. Brig. Gen.

Brig. Gen. JOHN NEWTON,

Chief of Engineers, U. S. A.

LETTER OF THE CHIEF OF ENGINEERS.

OFFICE OF THE CHIEF OF ENGINEERS,
Washington, D. C., July 21, 1885.

SIR: Your letter of the 6th ultimo, submitting report upon the subject of improving the harbor at Nantucket, Mass., and also project for the application of the appropriation of $10,000 made by the river and harbor act of July 5, 1884, for continuing its improvement, was duly received, and referred to the Board of Engineers for Fortifications and River and Harbor Improvements, who have returned it with a report, of which the inclosed copy is furnished for your information and guidance. The views of the Board are concurred in by the Acting Chief of Engineers.

The map accompanying your report, marked Plat A, with the modification proposed by the Board marked thereon, is herewith returned, and should, after such record as may be necessary has been taken, be returned to this office.

By command of the Acting Chief of Engineers.

Very respectfully, your obedient servant,

Lieut. Col. GEORGE H. ELLIOT,

H. M. ADAMS,

Captain of Engineers.

Corps of Engineers.

C 3.

IMPROVEMENT OF WOOD'S HOLL AND HARBOR OF REFUGE AT WOOD'S HOLL, MASSACHUSETTS.

The name "Wood's Holl" is applied to a strait connecting the waters of Buzzard's Bay and Vineyard Sound, and also to a harbor situated on the strait. This harbor is divided into Great Harbor and Little Harbor. The mean rise and fall of the tide is about 2 feet.

ORIGINAL CONDITION.

Before the commencement of the improvement the channel of the strait, which was obstructed by bowlders that covered the bottom, was very narrow and crooked, and the tidal currents were from 4 to 5 miles an hour. Even with steam only small vessels of about 8 tons draught could pass it at all times, and for them it was dangerous. In Little Harbor there was a bar which obstructed the approach to the wharf of the United States Light-House Establishment, and on which there was but 7 feet at mean low water, or 5 feet at extreme low water.

PLANS OF IMPROVEMENT.

In 1853 and 1854 $2,482.76 was expended in the construction of a breakwater on the northern side of Great Harbor, to close a passage through which water passed in storms between it and Buzzard's Bay. The amount was insufficient for the work, and the remainder of the cost was borne by private parties. In the years 1879 and 1881 there was expended $14,094.26 in cutting a channel through the bar into Little Harbor, 130 feet wide and 10 feet deep at mean low water, and in widening and deepening the strait into Buzzard's Bay.

The present approved project consists in the construction of retaining-walls, a hollow pier, and wharves for the use of the United States Fish Commission,and to serve also as a coaling station for the revenuemarine and other branches of the public service, and as a harbor of refuge. A plat of Great Harbor, containing a plan of the works in progress, was published in the Annual Report of the Chief of Engineers for 1884, page 598.

AMOUNT EXPENDED AND RESULTS TO JUNE 30, 1884.

The amount expended on the project under which we are now working, at the close of the fiscal year ending June 30, 1884, including liabilities outstanding at that date, was $36,817.82, and the result was the completion of all the retaining-walls and the excavation of the trenches for the pier-walls. The riprap foundation of the east pier-wall had been wholly, and that of the south pier-wall nearly completed. About onefourth of the masonry of the east pier-wall had been completed, and the masonry of the south pier-wall had been commenced.

OPERATIONS DURING THE LAST FISCAL YEAR.

At the beginning of the last fiscal year work was in progress under the contract with Isaac A. Sylvester, of Atlantic, Mass., for building the retaining and pier walls, which was described in the last Annual Report. With the approval of the Chief of Engineers, the time of completing this contract was extended to October 1, 1884, and the amount

of work to be done by the contractor at the contract prices was made to include the stone-work of the pier that remained after the amount of work covered by the contract was completed, it being considered that a new advertisement, printing of specifications, and letting of contract for this small amount of work could not be made without injury to the public interest. The amount of work done during the year under this contract and its extension was 548.32 tons of riprap laid in the foundations, and 1,906.93 cubic yards of granite masonry laid in the retaining and pier walls. On the 18th of September, 1884, advertisements were issued for proposals for a small quantity of riprap stone for protecting the foot of the eastern retaining-wall, which the extension of the east pier-wall into deep water exposed to a run of the sea. The following proposals were received, and were opened September 24, 1884:

The contract was awarded to Charles H. Edwards, the lowest bidder, for the estimated entire amount of stone required, dated September 24, 1884, to be commenced within ten days after award of contract, and completed November 20, 1884. Work was commenced under this contract on October 15, 1884, and finished November 22, 1884. The amount of stone delivered under the contract was 20 tons of chipstone and 221.25 tons of riprap. Advertisements inviting proposals for dredging in the pier-basin and for berths for vessels at the wharves were issued October 16, 1884. The following proposals were received, and were opened October 31, 1884:

Mr. Symonds proposed to do the work at 70 cents per cubic yard if the contract for excavation in Wareham Harbor should be awarded to him; but his proposal for the Wareham work was the highest received for that work. The lowest price having been named by two responsible bidders (Mr. J. H. Fenner and Mr. Augustus B. Martin), by an agree ment between themselves and with the approval of the Chief of Engineers the contract was awarded to Mr. J. H. Fenner, contract dated November 18, 1884, to be commenced within ten days after signing contract, unless otherwise agree, and completed within forty days from date of commencing work. Work was commenced under this contract on November 19, 1884, and finished on January 2, 1885. The pierbasin, about 270 by 150 feet in area, was dredged to the depth required,