The rollers are of cast iron, 5 inches wide, 4 inches thick, and with 1-inch flanges one-half inch deep. They rest upon an iron rail (a band of iron 3 inches wide and one-half inch thick, spiked to the center and running the full length of the upper face of lower timber of each set of ways), and are kept in position by the frame, and on the rail by the flanges. The frame is free, and is kept in position by its own weight and the weight of the upper timber, which has a rail similar to that of the lower timber attached to its under face and resting in and upon the rollers. The platform is prevented from rising at the upper side, when run out, by round iron bands, one at either end of the platform, which pass through the upper timber and loosely around the lower timber of the ways (shown at c). The deck planking of the platform is nailed directly to the upper timbers of the ways, and is protected from the sliding stone by iron bars of an L-section, inverted, and running the width of the platform at intervals of about 16 inches. These bars, by reducing the friction, greatly facilitate the sliding of the stone, and are kept greased. The ways have a pitch of 9 inches in 21 feet, and the lower timber of each set is bolted to the deck of the scow or upon blocking. The lower ends of the sbore-spurs d are strongly but loosely bolted, allowing free swinging action to the lever. The lower bumper b is bolted to blocking or the deck of scow. The upper bumper b is bolted to the upper timber of ways and to the platform. There are three sets of shore-spurs and bumpers, one at either end of platform and one in the middle. The plan of the lever is shown in Fig. 2, at l. The distance from fulcrum to the connecting rod is 74 inches; from fulcrum to end of lever 6 feet. The scow Enterprise, to which this invention is applied, is 66 feet long and 21 feet wide. The platform is 32 feet long and 21 feet wide, and a full cargo averages about 75 gross tons. Mr. Edwards, the inventor of this scow, has applied for a patent. B 2. IMPROVEMENT OF MERRIMAC RIVER, MASSACHUSETTS. The object of this work is the improvement of the channel of the river from its month near Plum Island Light to the head of the Upper Falls, a distance of 21 miles. Previous to its commencement the channel was narrow and crooked in several places, and much obstructed by bowlders, ledges, shoals, and the remains of old crib-work and piers. The present project was adopted in 1870, and modified in 1874. It provides for a channel of navigable width, its various parts having the following depths at high water of ordinary stages of the river: From the mouth near Plum Island Light to Deer Island Bridge, 163 feet; from the Deer Island Bridge up to Haverhill Bridge, 12 feet; thence to the foot of Mitchell's Falls, 10 feet; thence to the head of the Upper Falls, not less than 44 feet with the mill waters at Lawrence running. The estimated cost of the improvement under the amended project of 1874 was $147,000. The following appropriations have been made by Congress, to wit: By acts from July 11, 1870, to June 18, 1878.... Total..... The total amount expended to June 30, 1884, is $166,911.27. $132,000 5,000 12,000 9,000 9,000 3,500 170, 500 In consequence of the relocation and reconstruction of the draw-bridge at Rocks Bridge the channel was cleared above and below the new draw for a width of 60 feet and to a depth of 12 feet at mean high water. In this work, 1,056.95 cubic yards of bowlders, gravel, and clay were removed by dredging at a cost of $2.18 per cubic yard (scow measurement), under contract of September 27, 1884, with Mr. John McDermott, of Cohoes, N. Y. The present condition of the work is as follows: The channel from the mouth to the head of the Upper Falls has been completed in accordance with the adopted project. The excess of expenditure over the original estimate in the execution of this work is $15,670.09. This excess is explained by the fact that about $16,000 have been expended in the removal of rocks and other obstructions whose existence was unknown or whose removal was not contemplated when the original estimate was made, and in the making of an examination of the upper part of the river, at an expense of $800. In the further improvement of this part of the river the following work is recommended: 1. Removing sunken rocks and shoals from the falls above Haverhill.... Total. $1,500 8,750 1,250 11,500 To complete the improvement so that the depth of water obtained through Mitchell's Falls can be carried to Lawrence (distant 5 miles from the head of the falls) additional work is required, which was estimated for in 1882 by Col. George Thom, Corps of Engineers, as follows: Dredging channel through Gage's Ferry Shoal and Andover Bar, and removing bowlders and ledges.... To recapitulate: $11,000 For the improvement of the channel from its mouth at Plum Island Light to Lawrence, a distance of 263 miles, the amount required is as follows: From the mouth to head of the falls Total. $11,500 11,000 22,500 Under the projects above mentioned this amount can be expended to advantage during the fiscal year ending June 30, 1887. This work is located in the collection district of Newburyport, Mass., of which Newburyport is the nearest port of entry. The nearest light-house is on Plum Island, at the mouth of the river. Money statement. July 1, 1884, amount available.... Amount appropriated by act approved July 5, 1884. $88 73 3,500 00 July 1, 1885, amount expended during fiscal year, exclusive of outstanding liabilities July 1, 1884 3,588 73 2,999 54 July 1, 1885, amount available........... 589 19 harbor acts of 1866 and 1867. Amount (estimated) required for completion of existing project 22,500 00 22,500 00 B 3. IMPROVEMENT OF SCITUATE HARBOR, MASSACHUSETTS. This harbor is situated on the west shore of Massachusetts Bay, midway between Boston and Plymouth lights, distant about 14 miles from each and about 25 miles from Race Point, in a direction north 220 west. The object of its improvement is to create a harbor of refuge for vessels seeking Boston from the eastward, the intermediate coast being densely studded with shoals and sunken rocks. Before the commencement of the work this harbor had a low-water area of 57 acres, over 6 acres of which there was a depth of at least 3 feet. It was much exposed to the action of easterly winds. The project adopted in 1880 is to build two breakwaters, one from Cedar Point, on the north side of the entrance, and the other from the point of the First Cliff on the south side, and to deepen by dredging the area inclosed and in front of the entrance. The breakwaters are to be of rubble-stone, with a width of 20 feet at top, and are to be carried to a height of 4 feet above mean high water, except at the channel ends, which are to be raised to a height of 10 feet so as to afford a conspicuous guide to the entrance. The total amount of excavation proposed is 500,000 cubic yards, giving a depth of 15 feet at mean low water in the channel outside the breakwaters, from 12 to 15 feet between them, 12 feet immediately in rear of them, and 10 feet for the main basin within the harbor. The estimated cost of the breakwaters was $100,000 and of the dredg ing $190,000, making the total estimated cost $290,000. In furtherance of this project the following appropriations have been made by Congress, viz: By the river and harbor act of June 14, 1880 Total ...... $7,500 10,000 10,000 10,000 37,500 The total amount expended to June 30, 1884, is $27,500. Under contract of October 7, 1884, with Boynton Brothers, of Boston, Mass., 22,724 cubic yards of sand and shingle were removed from the harbor by dredging. A channel 1,600 feet long, 100 feet wide, and 5 feet deep at mean low water was cut through the inner bar to the "Deep Hole," and this basin was deepened to 7 feet at mean low water over an area of 200 by 160 feet. The present condition of the improvement is as follows: The north breakwater has been constructed to a height of about 4 feet above mean high water, and for a length of 720 feet, 14,977123 tons of rubble stone having been put in place. A portion of the beach between Cedar Point and the land has been protected by a brush-and-stone bulkhead for a total length of 450 feet, in front of which a stone apron, 10 feet wide and 385 feet long, has been constructed. An examination made during the month of April, 1885, shows that the dredged area above described has not been affected by the winter storms. No material has been driven into the anchorage, and in some places the cuts of the bucket have not been obliterated. Harbor Rocks, situated 130 yards southwest from the head of the north breakwater, and near the southern edge of the dredged channel, are a serious inconvenience to navigation, as vessels entering the har bor are now compelled to keep further to the south than formerly. Their removal is desirable. They are estimated to contain about 108 tons of stone, and their removal to cost $648. It is proposed to apply further appropriations to continuing the im provement under the approved project, as delineated in the map accompanying the Annual Report of the Chief of Engineers of 1881. To this end $75,000 can be profitably expended during the fiscal year ending June 30, 1887, which, if appropriated, it is proposed to expend as follows: To place 20,000 tons of stone in south breakwater, at $2.15 $43,000 00 648 00 To enlarge the basin to 9 acres, by dredging 80,000 cubic yards, at 30 cents. 24,000 00 Engineering and contingencies.. Total... 7,352 00 75,000 00 This work is located in the collection district of Plymouth, Mass. The nearest port of entry is Plymouth. The nearest light-house is Minot's Ledge Light, distant about 5 miles. Money statement. Amount appropriated by act approved July 5, 1884... July 1, 1885, amount expended during fiscal year, exclusive of outstanding liabilities July 1, 1884. July 1, 1885, amount available $10,000 00 9,608 54 391 46 = 252,500 00 Amount (estimated) required for completion of existing project. harbor acts of 1866 and 1867. B 4. IMPROVEMENT OF BOSTON HARBOR, MASSACHUSETTS. The improvements in this harbor undertaken by the General Government since 1866 were projected from time to time as the interests and necessities of the harbor demanded, being in general conformity with the recommendations of the United States Commissioners, whose labors terminated with that year. The objects of these improvements have been (1) The preservation of the islands and headlands by permanent seawalls or aprons and jetties of rubble-stone, for the purpose of protecting the channels against encroachment, controlling the resultant tidal scour, and securing shelter to vessels in roadsteads. (2) The widening, straightening, and deepening of the main shipchannel by dredging, and the removal of dangerous sunken rocks, thereby securing a channel of not less than 600 feet in width, with a depth of 23 feet at mean low water. (3) The widening, deepening, and straightening of the channel in Hingham Harbor, and the removal of sunken ledges, for a width of 100 feet and depth of 8 feet at mean low water. (4) The opening of a channel at the mouth of the Mystic River for a width of 400 feet and depth of 23 feet at mean low water. (5) The widening, deepening, and straightening of the channel from the mouth of Charles River up to the dam at the head of tide-water, as follows: (a) From its mouth up to Western Avenue Bridge for a width of 200 |