by two rubblestone aprons, one between the northern and eastern sea walls, 1,440 feet long, and the other south of the east sea wall, 1,330 feet long.

No operations were in progress during the fiscal year.

The condition of the work on June 30, 1892, was as follows: The sea walls and the ripraps on the eastern shore were in good order; the western shore riprap had been undermined in places and had fallen down, but it needed no immediate repairs.

Gallops Island.-The western, northern, and eastern shores of this island are protected by a granite sea wall 2,085 feet long, completed in 1889, and by a rubblestone apron, completed in 1884, 3,050 feet long, which also covers the foundation of the sea wall.

During the fiscal year the extension of the sea wall 300 feet to the southeast was completed.

On June 30, 1892, the wall and ripraps are in good order.

Deer Island.-Three prominent bluffs of this island are protected by granite sea walls, originally built about 1827. The north head wall is 1,740 feet long, the middle head wall is 840 feet, and the south head wall is 380 feet long. In 1865 and 1869 these walls were partly rebuilt and in the weakest places were backed with concrete. They were all originally built dry, and from time to time have required repairs.

No operations on these sea walls were in progress during the fiscal year, and at the date of this report they are in fair order.

Long Island. The north head of this island is protected by a granite sea wall 2,0813 feet long, completed in 1874. Part of the foundation of the sea wall and of the beach at both its ends are protected by a rubblestone apron, aggregating 1,375 feet in length. This apron was built in 1874 and extended in 1884.

During the fiscal year 1,100 tons of rubblestone were landed on the beach at the southwest end of the sea wall, and considerable of it has been hauled in to form a riprap protection for the beach west of the sea wall. This work will be continued during the next fiscal year. At the date of this report the sea wall is in good order.

Rainsford Island. The north head of this island is protected by a dry granite sea wall 1,500 feet long, originally built about 1840, and extensively repaired in 1884-'85. No work was done during the fiscal year, and on June 30, 1892, the wall was in good order and needed no repairs.

Castle Island.-The north and part of the east and west shores of this island are protected by a dry granite sea wall, 3,300 feet long, built in 1835. A light riprap extends along the east shore 300 feet from the end of the wall; this was built in 1865. No work was done during the year ending June 30, 1892, and at that date the riprap was in good order. The sea wall needed repairs on the north face a short distance west of the wharf, where the foundation has been undermined and the wall has settled. About 100 running feet of the wall has been thus injured, and this length of the wall needs taking down and rebuilding, at a cost of $1,000.

Governors Island.-The shore line of this island has never been protected. The east and south bluffs, however, should be covered by sea walls to prevent additional abrasion, not only to secure the sites of the important heavy batteries which occupy these bluffs, but also to prevent injury to the main ship channel.

The east bluff wall should be 500 feet long, and is estimated to cost $30,000; the south bluff wall should be 1,800 feet long, and will cost $50,000.

ENG 92-37

WORKS OF IMPROVEMENT.

The main ship channel.-Before improvement it had a least width of 100 feet and a least depth of 18 feet at mean low water. The general project for its improvement was submitted in 1867. It proposed to dredge the channel 23 feet deep at mean low water, 1,000 feet wide at the upper and lower middles and 685 feet at the Narrows.

In 1870 the proposed width at the narrows was reduced to 625 feet, and at the anchorage shoal, in the inner harbor, increased to 1,100 feet. In 1887 it was proposed to straighten the passage through the "Narrows," by cutting off a spur that projected from Lovells Island, which was estimated to contain 20,000 cubic yards.

On June 30, 1891, the condition of the main ship channel was as follows: It was 23 feet deep at mean low water, 1,100 feet wide west of the Upper Middle, 750 feet wide at the Upper Middle, 1,000 feet wide at the Lower Middle, and at least 625 feet wide elsewhere, except off Brewster Spit, where it was 550 feet wide approximately.

In effecting this improvement, dredging or blasting was done at the following places:

At Nashs Rock Shoal, during the years 1876-'78, 365 cubic yards of ledge were removed.

At Kellys Rock and Shoal, during the years 1869-'79, 222 cubic yards of ledge were removed.

Tower, Corwin, and Channel Rocks were removed during the years 1867-75; they aggregated 6083 cubic yards.

From the west end of Brewster Spit, during the years 1874-76 and 1891, 45,666 cubic yards of sand and gravel were dredged, and 95 cubic yards of ledge were removed.

At Lovells Island, from the southeast and southwest points, 267,294 cubic yards were dredged during the years 1867-77, and from a spur between these points 3,430 cubic yards were dredged in 1888.

At Castle Island Bar and Shoal, opposite the Lower Middle, during the years 1880-'83, 36,957 cubic yards were dredged and 20 tons of rock were removed.

At the Lower Middle, in 1874-75, State and Palmyra rocks were removed; they aggregated 62 cubic yards. In 1887-'89, 71,892 cubic yards were dredged from this shoal, and 375 cubic yards of ledge removed.

At the Upper Middle, during the years 1870-76, 268,2784 cubic yards were dredged and 118 cubic yards of ledge were removed; in 1880-'90, 146,182 cubic yards were dredged and 111 cubic yards of ledge were. removed.

At Anchorage Shoal, during the years 1879-'82, 65,327 cubic yards were dredged.

At Man-of-War Shoal 85,917 cubic yards were dredged in the years, 1878-'80.

At Mystic River Shoal, during the years 1879-'82, 82,082 cubic yards were dredged.

During the fiscal year 12,070 cubic yards were dredged from the west end of Brewster Spit, under a contract with Mr. A. R. Wright; 28,510 cubic yards were dredged under this contract, and the main ship channel at this point was made 625 feet wide.

One hundred and thirty thousand nine hundred and sixty-two cubic yards were dredged under a contract with Mr. A. R. Wright, from the extension of the main ship channel towards Jeffreys Point. This channel is now 275 feet wide, 18 feet deep at mean low water from Grand Junc

tion Wharf to just east of Simpson's Patent Dry Docks, and thence gradually narrows to 250 feet and shoals to 15 feet, to a junction with the same depth off Jeffreys Point.

On November 10, 1891, an advertisement was issued calling for proposals for dredging to widen the main ship channel at the upper middle bar. The bids received were opened December 10, 1891, and an abstract of them will be found in the annexed table.

On December 19, 1891, a contract was entered into with Mr. A. R. Wright to dredge 211,764 cubic yards from the upper middle bar.

Operations under this contract were commenced in April, 1892, and during the fiscal year 74,779 cubic yards were dredged and this part of the main ship channel is, at the date of this report, 800 feet wide.

On June 30, 1892, the main ship channel is 23 feet deep at mean low water, 1,100 feet wide west of the upper middle, 800 feet wide at the upper middle, 1,000 feet wide at the lower middle, and at least 625 feet wide elsewhere.

The following tributary channels have been improved by dredging or blasting.

1. CHARLES RIVER.

This river empties into the inner harbor near the navy-yard at Charlestown.

Before improvement the natural channel had, as far up as Western Avenue Bridge, 43 miles from its mouth, 7 feet depth at mean low water, except in several places, covering about 14 miles in extent below Brookline Street Bridge, where the depth varied from 4 to 7 feet.

From Western Avenue Bridge to Arsenal Street Bridge (24 miles) there was a depth of 4 feet at mean low water; thence to Market Street Bridge (mile) 24 feet at mean low water; and thence to the dam at the head of tide water (13 miles) a depth varying from 0 to 9 feet above mean low water. The mean rise or fall of the tides is 10 feet. A sketch showing the river was published in the Annual Report of the Chief of Engineers for 1884, page 512.

The project for the improvement of this river consists in straightening, widening, and deepening the natural channel, so that it should be from its mouth to Western Avenue Bridge 7 feet deep at mean low water and 200 feet wide; from Western Avenue Bridge to Market Street Bridge, 6 feet deep at mean low water and 80 feet wide; thence to the dam at the head of tidewater, 60 feet wide and 2 feet deep at mean low water.

The estimated cost of this improvement was originally $85,000. A revised estimate was submitted in 1881 of $125,000.

The total appropriations for this improvement to date have been $77,500.

The expenditures to June 30, 1891, were $57,500. No operations were in progress during the fiscal year, and the condition of the improvement June 30, 1892, is as follows: The projected channel has been completed from the mouth of the river to Arsenal Street Bridge (74 miles); work was stopped at this point for the reason that the piers and draws of this bridge do not conform to the projected channel above, it. In effecting this improvement 127,971 cubic yards were dredged during the years 1880-1884.

2. FORT POINT CHANNEL.

This channel is situated between the eastern shore of Boston proper on the one side and the reclaimed and improved flats of South Boston

on the other side. It connects the tidal basin of South Bay, which has an area of 250 acres, with Boston Inner Harbor, is fast becoming the center of the city's most extensive shipping trade, and is the most important branch of the main ship channel. Fort Point Channel is 14 miles long.

Before improvement the least depth at mean low water was 12 feet at its entrance and 17 feet above Congress Street Bridge.

That part of it which it is proposed to improve is spanned by bridges at Congress street, Mount Washington avenue, and at an intermediate point. These bridges have conveniently located draw openings, but the draw piers of the railroad bridge must be strengthened or reconstructed before the improvement can be extended past them, and the width of the draw increased to that of the other bridges above and below it.

The project for this improvement was submitted January 27, 1885 (Annual Report, Chief of Engineers, 1885, page 545).

It proposed the excavation of a channel 175 feet wide and 23 feet deep at mean low water from the entrance to near Federal Street Bridge, a distance of 4,100 feet, and was estimated to cost $100,000, the railroad bridge to be reconstructed at the expense of the owners.

By the river and harbor act of August 5, 1886, the sum of $18,750 was appropriated for the improvement of that part of the channel lying below Congress Street Bridge.

The total expenditures to June 30, 1891, were $18,750.

No operations were in progress during the year, and the condition of the improvement June 30, 1892, is as follows: The channel had been dredged as proposed from its entrance to Congress Street Bridge, a distance of 1,900 feet; 94,211 cubic yards were removed in effecting this improvement during the year 1887.

To complete the improvement as proposed to Federal Street Bridge will cost $60,000, and this sum could be expended to advantage during the fiscal year ending June 30, 1894, if the railroad draw shall have been properly reconstructed.

(See separate report.)

3. HINGHAM HARBOR.

4. NANTASKET BEACH CHANNEL.

This is a small channel along the east side of Hingham or Hull Basin. It leads to a wharf on the west side of the heel of Nantasket Beach, about 12 miles from Boston.

Before improvement it was approximately 100 feet wide, and had a depth of at least 11 feet, except at the eastern end 1,500 feet from the wharf, where the width was reduced to from 40 to 50 feet and the depth to less than 8 feet. It was circuitous and obstructed by bowlders at the mouth of Weir River, and by a ledge near the wharf.

The project adopted in 1880 was to widen and deepen the channel from the mouth of Weir River to the steamboat wharf so that it would be 100 feet wide and 94 feet deep at mean low water, to remove a few bowlders at the mouth of Weir River, and to remove the ledge near the wharf.

The total appropriations and allotments for this work to date are $21,067.80, of which $19,523.83 had been expended to June 30, 1891. On June 30, 1891, the channel was at least 150 feet wide, 9 feet deep

at mean low water, except over a ledge uncovered by the dredging near the wharf, which is estimated to contain 150 cubic yards.

No operations were in progress during the fiscal year and the condition of the improvement at the date of this report is the same as on June 30, 1891.

This is a channel through the bar which extends from the north head of Long Island to Nixs Mate Shoal. Previous to the improvement there was 4 feet depth of water on the bar at mean low tide.

The project for the improvement was adopted in 1883. It was to dredge a channel 200 feet wide, 12 feet deep at mean low water, and about 550 feet long. In 1887 it was recommended that the axis of the cut be shifted 30 degrees to the westward and that it be widened to 300 feet, 15 feet deep at mean low water. The original project was estimated to cost $9,000. The project of 1887 was estimated to cost $25,000 additional. No specific appropriation has been made for this work. The expenditures on it to June 30, 1891, from the appropriations for improving Boston Harbor were $9,709.77.

On June 30, 1891, the project of 1883 had been completed, and a contract was in force to complete the project of 1887.

Operations under this contract were commenced in September, 1891, and completed in January, 1892. Seventy thousand six hundred and seventy-four cubic yards were dredged at a cost of $15,273.20.

At the date of this report the channel is 300 feet wide, 15 feet deep at mean low water.

6. BROAD SOUND.

An obstruction called Barrel Rock, lying on the north side of the Broad Sound Channel, was removed in 1869. It contained 116 cubic yards.

Recapitulation of amounts which could be expended to advantage during the fiscal year ending June 30, 1894.

The several works completed and projected for the improvement of this harbor are located in the collection district of Boston and Charlestown, Mass. Boston is the port of entry.

The accompanying commercial statistics for the fiscal year ending June 30, 1892, have been furnished by the collector of customs at Bos ton, Mass.