DEFENSES OF SAN FRANCISCO, THE NAVY-YARD AT MARE ISLAND, AND THE ARSENAL AT BENICIA continued. in 1870, form the defenses of the south side of the Golden Gate, the entrance to San Francisco Harbor. The main work is garrisoned. The disintegration of the mortar in the joints of the scarp and in the soffits of the arches continues, particularly on the faces of the work exposed to the prevailing summer winds. In general, the casemates are in good condition. The sea-wall is in good order. The apron at the foot of the wall has changed but little during the year. The magazines are in good condition. The state of the work is much as it has been for several years past. Earthen barbette batteries exterior to the fort.-There being no special appropriation for these, the watchman has repaired the steps to the overseer's quarters and to wagon house; rebuilt fence about overseer's quarters, replaced portions of underpinning to mechanic's quarters, the framework of upper tank and some 58 linear feet of redwood pipe for water supply; made repairs to the windmill and drains; mowed por. tions of slopes of parapet and traverses and lacquered 'iron work of mortar platforms. The exterior of the buildings has been whitewashed. Two platforms, in addition to those which are mounted, are ready to receive their guns. Six others have been constructed, but, owing to the settlement of the terre-pleins in deep filling, two of these are not in condition to have the guns mounted. The pintle-blocks for eight platforms are in position, and the concrete foundations for six more have been built. "Three positions for heavy guns are ready for platforms, and fourteen more have been begun. Twelve traverse magazines are ready, and sixteen in addition can be used. Twelve timber platforms for heavy mortars are in position. The timber of these is decayed. To complete the batteries for their armament of heavy guns will require, it is estimated, about $130,000. The plans require revision. No appropriation baving been made, no work was done at this fortifica tion during the last fiscal year beyond its protection, preservation, and repair, as far as was possible with the general appropriation made for this purpose, and no other work is contemplated during the current fiscal year for the same reason. No appropriation asked for next fiscal year. Fort at Lime Point, San Francisco Harbor, California, in charge of Lieut. Col. G. H. Mendell, Corps of Engineers.-The northern shore of the entrance to San Francisco Harbor, extending from Point Cavallo westward to Point Bonita, a distance of more than 3 miles, is known as Lime Point. The shore is bold. The position is indispensable for defense. The defenses projected on this shore consist of a casemated battery on Lime Point proper, and detached barbette batteries on the cliff above the point, at Gravelly Beach, at Point Diablo and Point Bonita, and at Point Cavallo. The site for the casemated work yet requires a large amount of excavation. No work has been done upon it since 1868. The batteries at Point Diablo and Point Bonita have not been begun. The Gravelly Beach battery is the only one completed. The revetments and platforms of this battery are of wood, and not entirely serviceable. DEFENSES OF SAN FRANCISCO, THE NAVY-YARD AT MARE ISLAND, AND THE ARSENAL AT BENICIA—continued. The batteries have been under the care of keepers during the year who have kept the parapets, slopes, platforms, and buildings in good order. The magazines are all dry and in condition for service. The wharf and large tank for water supply are much decayed, and it will be necessary to rebuild them when operations shall be resumed. Twenty-four gun platforms and breast-height walls for seven guns are required to complete the batteries, the construction of which has been begun. The plans of the batteries require revision. No appropriation having been made, no work was done at this fortifica tion during the last fiscal year beyond its protection, preservation, and repair, as far as was possible with the general appropriation made for this purpose, and no other work is contemplated during the current fiscal year for the same reason, No appropriation asked for next fiscal year. Fort on Alcatraz Island, San Francisco Harbor, California, in charge of Lieut. Col. G. H. Mendell, Corps of Engineers.—The position of Alcatraz Island gives it command of the channels leading to San Francisco and of much of the anchorage ground which might be occupied by a hostile fleet. During the year two stone platforms were completed by the addition of the necessary irons. With this exception no construction has been in progress during the past nine years. The defenses are incomplete. The batteries and buildings are under the charge of a keeper, who, with the assistance of military prisoners, keeps them in good condition. The work of the keeper was applied during the year to painting torpedoes, embrasure irons, magazine doors, ventilators, and office; to cutting grass and clearing out weeds on parapets and slopes; repairing ramps, policing batteries, clearing drains, and lime-washing buildings. The magazines are all dry and serviceable. The forms of the parapets and slopes are as well preserved as is possible under the peculiar climatic conditions which prevail on the California coast. The plan of the work requires revision. tion during the last fiscal year beyond its protection, preservation, and Fort Mason, San Francisco Harbor, California, in charge of Col. C. S. Stewart, Corps of Engineers. During the late civil war two temporary earthen batteries were built on this point. In the east battery the timber platforms are decayed as well as the Food-work of the magazines, part of which has caved in. This battery is unserviceable. Projects for new earthen batteries of heavy guns and mortars for the occupation of this important point in the second line of defense for the bay and harbor of San Francisco have been prepared by the Board of Engineers for the Pacific Coast. No appropriation was made for the fiscal year ending June 30, 1886. No appropriation asked for next fiscal year Batteries on Angel Island, San Francisco Harbor, California, in charge of Col. C. 8. Stewart, Corps of Engineers.--The three earthen batteries on this island were built during the late civil war for temporary use. DEFENSES OF SAN FRANCISCO, THE NAVY-YARD AT MARE ISLAND, AND THE ARSENAL AT BENICIA-continued. The timber platforms and the timber magazines are decayed, and nearly all the gun-carriages have been condemned. The batteries are practically inserviceable. Barbette earthen batteries for the heaviest guns have been planned by the Board of Engineers for the Pacitic Coast, to occupy the most valuable positions on the island which bear on the channels leading to the upper part of the bay, to the navy-yard at Mare Island, and to the arsenal at Benicia. No appropriation was made for the fiscal year ending June 30, 1886. No appropriation asked for next fiscal year. DEFENSES OF THE COLUMBIA. Defenses at the mouth of the Columbia River, Oregon, and Washington Territory, in charge of Capt. C. F. Powell, Corps of Engineers. The defenses consist of Fort Stevens, an inclosed earth work at Point Adams, Oregon, on the south side, and the earthen batteries at Fort Canby, Cape Disappointment, Washington Territory, on the north side. The works command the channels at the entrance, the ship-channels leading to Astoria, and the anchorage in Baker's Bay under the lee of the cape on the north. The chamels to the river bare natural depths of 19 to 24 feet at low water, and a mean rise of tide above this plane of 7} feet. These defenses are field works in character; they were built hastily during the late civil war in anticipation of complications with foreign powers. On account of increased penetration of present orduance, and the decay of the greater part of the wooden platforms and magazine timbers, the works are of little value in their present condition except for drill purposes. Fort Sterens, Oregon.—During Augnist and September the repairs to the magazine were complete and minor repairs maile about the fort. Fort Canby, Washington.—The service magazine and two gun-platforms at the left battery were repaireil, and ininor repairs made in the center battery and to the powder house. A building was constructed for use as store, lodging, and mess house. The roads leading to the center and left batteries were graded, ditched, and macadamized. No appropriation was made for the fiscal year ending June 30, 1886. No appropriation asked for next fiscal year. BOARDS OF ENGINEERS. THE BOARD OF ENGINEERS. The Board of Engineers stationed in New York City consisted of Col. J. C. Duane, Lieut. Col. Henry L. Abbot, Lieut. Col. Cyrus B. Comstock, and, when so ordered, the officer in charge of the work under consideration. During the fiscal year the Board has considered the questions referred to it by the Chief of Engineers, and has prepared and submitted reports thereon, of which the following is a brief summary: Upon the subject of fortifications.—1881, August 30. Submitting estimates for the construction of defensive works for the principal harbors of the United States. December 1. Submitting plan and estimate for a barbette battery for sea coast defense. December 1. Plans and estimates for the masonry emplacements for two revolving iron turrets located on an artificial island or a bare rock; also for masonry emplacement of a single turret on land. December 1. Recommending the purchase of an additional fish tor: pedo. 1885, January 6. Submitting project for reorganization of the Engineer School of Application at Willets Point; also programme of instruction, &c. January 27. Supplemental report on above. February 17. Upon details of a proposed 5-inch siege breech-loading rifle. March 3. Recommending the building of a steam barge for use in operating torpedoes. March 24. Project for expenditure of appropriation for torpedoes, 1885–86. April 7. Upop question of condition and protection of storage magazines at Fort Schuyler and fort at Willets Point, New York. April 14. Relative to military value of Castle Island, Boston Harbor, April 14. Relative to publication of reports of Captain Bixby. Upon the subject of Rivers and Harbors.--1884, September 3. On Senate bill 2176, providing for an appropriation for improving the bar at Sandy Hook by methods proposed by Mr. H. F. Knapp. December 1. Upon project of Capt. Thomas Turtle for improvement of Sabine Pass, Texas. December 23. Upon project of Major Gillespie for the deepening of Gedney's Channel; and recommending a general plan for improving the entrance to New York Harbor so as to give 30 feet from New York to the ocean. 1885, January 24. Upon project of Lieutenant-Colonel Robert for a breakwater at Rouse's Point, New York. June 23. Upon project of Major Adams for a break water at Rouse's Point, New York. June 25. Upon project of Major Raymond for a pier at Avery's Ledge, Massachusetts. In addition to their duties with the Board of Engineers, the individual members have been otherwise engaged, as follows: General Duane has continued in charge of his light-house duties, as engineer of the third district, and has also served on special board for the examination of officers of engineers for promotion; as member of Board of Visitors for Engineer School at Willets Point; on board to examine and report upon the condition of the electric light plant of the Wasbingtou Monument, and on board to determine the various calibers, &c., of guns and projectiles. General Abbot has remained in command of the Engineer Battalion and School of Application at Willets Point, also in charge of torpedo experiments and construction of the works of defense at the eastern entrance to New York Harbor. For the greater part of the year he con tinued upon the joint gun foundry board of Army and Navy officers has served on board for the examination of officers of engineers fo promotion; as member of Board of Visitors for Engineer School a Willets Point; on board to examine and report upon the condition of th electric light plant of the Washington Monument, and as member o the board of officers and civilians to examine and report at what port fortifications or other defenses are most urgently required, &c. General Comstock has served throughout the year (as president t November 26, 1884) upon the Mississippi River Commission, also o special board for examination of officers of engineers for promotion, an as member of Board of Visitors for Engineer School at Willets Poin Coast defense. This subject having been fully discussed in former r ports of the Board, and as the matter has recently been committed b Congress to a special board, further reference to the condition and r quirements of our sea-coast fortifications is considered unnecessary. Torpedo defense.-The act of Congress providing for fortifications, &c for the fiscal year 1884-'85 provided as follows: For the purchase of such submarine movable torpedoes propelled and controlle by power operated from shore stations as may be recommended by the Board of E gineers of the Army of the United States and approved by the Secretary of Wa $50,000; for the improvements and tests of motors for movable torpedoes, $25,000; f the purchase of submarine mines for harbor defense, $5,000; for a continuation torpedo experiments, and for practical instruction of engineer troops in the details the service, $30,000; in all, $100,000. By the wording of this law three-quarters of the whole sum appr priated was restricted to the purchase and improvements of the Sin movable torpedo, to which alone its language is applicable. But, a stated in our last Annual Report, this torpedo is still in the experimen stage. Trials made during the summer and autumn of 1884 with th new 2-mile war pattern developed difficulties which had not arisen the 1-mile pattern, and which, although giving no ground for anticipa ing ultimate failure, were of a character to indicate that the details a not yet sufficiently perfected to warrant the purchase of numbers these torpedoes to be put in store. One 1-mile boat and three 2 mi boats were already owned by the Government; another, to embody a improvements to date, was ordered in March, 1885, but was not receiv in time for testing. Further trials, made during the spring of 1885, wi the old 2-mile boat failed to meet the expectations of the Board in c tain details; and on June 18 it recommended that the unexpended b ance of the $50,000 be allowed to revert to the Treasury under the pi vision of law restricting the expenditure to the current fiscal ye Subsequently Mr. Sims offered to assume all risks in meeting a specifi standard deemed serviceable by the Board, and upon its recommend tion a contract for five boats was awarded to him, subject to meeti these conditions prior to July 1, 1886, when, if not disbursed, the fun are finally covered into the Treasury. The appropriation bill for the current fiscal year (1885-'86) also c tains an item of $50,000 for the purchase of these torpedoes. It is probable that contracts for their delivery can be judiciously made fore the latter part of the fiscal year. No very large number of mova torpedoes will be required for the defense of the coast, and all deta of construction should be finally settled before it will be expedient place a larger number in store. For these reasons no appropriation the purchase of these torpedoes is recommended for the coming fis year. Investigations to perfect them should of course be continued. With fixed mines for obstructing channels the case is quite differe Their details have been thoroughly studied, and large numbers |