promotion; on Illinois and Michigan Canal and proposed Hennepin Canal; on harbor of refuge at Atlantic City, N. J.; and in personal inspection of works of harbor improvement along the coast of Texas. On leave of absence since April 6, 1887. Lieutenant-Colonel Houston has conducted the various works of river and harbor improvement and of fortifications under his charge, and has served as member of Board of Visitors for Engineer School of Application, and represented the General Government in erection of the pedestal to receive the statue of Liberty, New York Harbor. He Lieutenant-Colonel McFarland, in addition to conducting the works of river and harbor improvement and fortifications with which he is charged, has served as member of the Board of Visitors for the Engineer School of Application; of board for examination of officers of Engineers for promotion; and on harbor of refuge at Atlantic City, N. J. Major King was assigned as member of the Board April 4, 1887. has commanded the Battalion of Engineers, and since April 5, 1887, the Post and Engineer School of Application at Willets Point, and in charge of Fort and Engineer Depot at Willets Point; torpedoes for harbor defense, and of experiments with torpedoes. He has also served on boards for plans of locks and dams for improvement of Black Warrior River, Alabama; on reconstruction of Aqueduct Bridge across Potomac River; on plans and estimate for a lock at or near the lower island at Nashville, for improving Cumberland River, Tennessee. Sea-coast fortifications.-The works upon which the defense of our coasts depends have been so fully discussed in former annual reports of the Chief of Engineers, as well as in the recent report of the Board on Fortifications or other Defenses, appointed by the President under a special act of Congress, 1886, that no further remarks seem to be either necessary or appropriate. From the facts presented in these reports bearing upon the condition of our sea-coast defenses, it must be evident that immediate action is demanded to place them in a proper condition to resist the attacks of an enemy. From the difference of opinion which exists among certain non-military experts as to the character of armor to be used in land defenses it has been argued that the whole subject of sea-coast defense is in an unsettled and tentative condition and that the policy of inaction now existing should still continue. But the facts will not warrant this conclusion, as more than nine-tenths of the armament recommended for our sea-coasts is not to be mounted behind iron protections, but in rear of earthen covers surmounting and shielding the masonry magazines, bomb-proofs, and store-rooms. Particularly is this true of the rifled mortars, which must hereafter play an important part in the defense of our channels and fairways, and there is no reason why the erection of the batteries required for them should be delayed a single month. Neither is armor required for guns mounted on lifts or disappearing carriages; in a word, proper sums may judiciously be expended and much progress toward placing our coasts in a defensive condition may be made, indeed must be made, before the question of armor demands consideration. Torpedo defense.-Congress having failed to pass a fortification bill at its last session, no funds have been available for torpedo expenditures since July 1, 1886. Submarine mines, in the present condition of our coast defenses, constitute our chief reliance in case of war. They require time for fabrication and safe positions from which to operate them by electricity. For these reasons appropriations should at once be made (1) to provide submarine mining material, and (2) to construct the casemates, shafts, and galleries needful for the reception of the batteries, electrical apparatus, cables, etc. Last year the annual appropriation failed to pass, and in the two preceding years the funds were nearly all restricted to the item of movable torpedoes, for which there is no urgent necessity. Several of them are now on hand, but their function is a subordinate one, and the purchase of mines should not be interrupted on their account. At present we have nothing modern to oppose the entrance of hostile fleets into our chief ports, except a few incomplete mines in store at four of them. But submarine mines belong to a complex system, every part of which must be ready or the whole fails. As well expect a chronometer to keep time with one wheel missing as to expect mines to bar a channel without cable-shafts or casemates, and all the other appliances which enter into the system. After years of experiment the details of our system have been perfected; the cost is sma!!; the material when properly stored is imperishable; careful work and time are indispensable in its fabrication; hence there should be no further delay in providing an adequate supply for this defense of our entire coast. The total cost of such a supply was estimated by the Board ordered by Congress to report "at what ports fortifications or other defenses are most urgently required, and the character and kind of defenses best adapted for each, with reference to armament, utilization of torpedoes, mines, or other defensive appliances." Including everything except electric lights, the grand total was $3,134,000, and this covers the entire coast. The Board presents the following as its consolidated estimate for the purchase of submarine mining material, etc., for the fiscal year 1888-'89. It will be applied to the ports most urgently requiring fortifications or other defenses: For the purchase of submarine mining material.... Making a total of........................ $300,000 1,560,000 30,000 1,890,000 Respecting the progress of certain investigations connected with submarine mining material, with which he is charged, Colonel Abbot reports: Trials during the past year have been directed to improving the old pattern of the self-acting mine and to designing apparatus for more perfectly controlling the ignition of locomotive torpedoes governed from the shore. Four different patterns of miniature firing cells have been under test to determine their permanency when standing on open circuit. Several cells of each pattern, some of them very small in size, have remained under observation continuously for six months. One of the patterns has shown gradual deterioration, but every cell of each of the other three patterns has remained without the slightest indication of loss of power. Researches have been made to determine the chemical composition and best mode of constructing certain soluble rings needed for the apparatus, and these matters, with the proper dimensions and other details, have been definitely determined. Devices for readily transforming the service pattern of electrical mine into the selfacting type have been made and experimentally tested with satisfactory results. The rendering of these classes interchangeable is important, not only to reduce the original outfit, and hence its cost, but also to facilitate the defense of a mined zone against the counter operations of the enemy. Nothing now remains to be done to effect this object in the United States service. Progress has been made in devising improved apparatus for controlling the explosion of movable torpedoes, but no definite conclusions have been reached. The matter remains under study, The draught of an official manual for submarine mining, including the material and its service, has been submitted to the Chief of Engineers, and has received his approval and that of the War Department. The work is now in press, together with a new and extended edition of my Notes on Electricity, for use in the military and civil duties of the Corps of Engineers. Major King, in charge of experiments with torpedoes at Willets Point, reports the following progress during the past year: During the past fiscal year three more of Sims's fish torpedoes have been tested and finally accepted and paid for, thus closing the contract for five torpedoes made under the last appropriation for movable torpedoes. Several trial runs were made with each torpedo, as follows: No. 8.-Three runs, giving curves of 236 to 274 feet radius in steering, and speeds of 8.674 miles per hour, 9.520 miles and 10.037 miles. No. 9.-Six runs, giving curves of 183 to 300 feet radius, and speeds of 9.68, 9.65, 9.81 over distances of a mile and a half, as required by contract. This torpedo was, however, accepted by authority of the honorable Secretary of War on my recommendation, the speed being only about two per cent. less than called for by the contract, and the torpedo being in all other respects equal to those already accepted. No. 10.-Had five trials, with the following results: First, the torpedo dived to the bottom; second, it failed in speed; on the third the steering gear failed, and it ran ashore; the fourth trial failed from a burn in the cable; and the fifth made the required speed and a little more, viz, 10.177 miles per hour, for 1.69 miles. No diving trials were required. On the 29th of March, 1887, the Board of Engineers was instructed to prepare plans for the defense of our more important harbors, and in compliance therewith submitted the following report: THE BOARD OF ENGINEERS, Army Building, New York, August 2, 1887. GENERAL: In accordance with your instructions of March 29, 1887, the Board has undertaken a thorough revision of the plans for the defense of our chief ports by submarine mines, and a study of the precise locations for the new armament rendered necessary by modern modes of attack. Good progress has been made; but it will be impracticable to submit final reports, with detailed drawings, in season for your annual report. The Board has considered each of the chief ports on the seaboard named by the Endicott Board as most urgently requiring fortifications or other defenses; and has the honor to submit the following estimate for sums which can be profitably expended upon their construction during the fiscal year 1888-'89. No iron armor is included in these estimates, because a more extended defense can be obtained by investing these funds in other preparations equally necessary and less costly. Such works are mortar batteries, disappearing-gun batteries, lifts, and the casemates, shafts, and galleries needful to establish a defense by submarine mines. The Board has prepared two typical designs for mortar batteries, including all modern requirements, constructed of sand, covering masonry and bomb-proofs. No armor is now or ever will be required for such batteries. Mortars constitute more than half the total armament proposed for the defense of our sea-coast; their construction is much less difficult than that of guns, and the fabrication of a serviceable pattern of breech-loading mortars should not be beyond the present capacities of our own manufacturing establishments. For these reasons the Board submits estimates for beginning work at once upon this class of defenses in our principal ports. Positions for disappearing guns may also be provided without any necessity for armor. Types for these carriages have been designed, which have endured severe tests, and the Board entertains little doubt that carriages can be procured that will be suitable for 12-inch rifles of 50 tons. An appropriation is therefore recommended for constructing batteries to mount a few guns of this caliber at each of our principal ports. If impossible to procure 12-inch guns, a smaller caliber might be mounted temporarily in these batteries should any emergency arise. No wiser or more economical expenditure of funds to provide for our urgent necessities can be made. The type of battery adopted in the estimates is that submitted with the report of the Board dated December 1, 1884. It is a matter of no little importance to construct at least one lift platform at the Narrows entrance to New York Harbor. The plan is that proposed by General Duane, and distributed to the Corps December, 1886. The necessity for preparing casemates with shafts and galleries for use in submarine mining is extremely urgent. Without them our only present hope of delay ing the entrance of an cuery into our ports by torpedoes would be vain. Estimates for such of them as are necessary in our ten chief seaports are accordingly submitted. The following is the estimate for the construction of gun and mortar batteries during the fiscal year 1888-'89: The following is the estimate for preparing mining casemates and cable-shafts and galleries for the coming fiscal year: At New York, 5; at San Francisco, 5; at Boston, 5; at Hampton Roads, 2; at Philadelphia, 2; at Washington, 1; at Baltimore, 1; at Portland, 3; at Narragansett Bay, 2; making a total of 26 casemates, at $60,000, $1,560,000. Respectfully submitted. THOS. LINCOLN CASEY, Colonel Corps of Engineers. Colonel Engrs., Brt. Brig. Gen'l. Lt. Col. Engs., Bvt. Col. Lieut. Col. of Engineers. W. R. KING, Maj. of Engrs. The CHIEF OF ENGINEERS, U. S. A., Washington, D. C. POST OF WILLETS POINT, NEW YORK-ENGINEER SCHOOL OF APPLICATION-BATTALION OF ENGINEERS-ENGINEER DEPOT. At the close of the fiscal year ending June 30, 1887, the garrison of the post consisted of 21 commissioned officers and 342 enlisted men. The Quartermaster's Department has commenced the execution of several long-needed improvements, such as the supply of water from the Flushing works, new quarters for officers, and a new hospital. A telegraph line to Whitestone and a steam-tug have facilitated communication and travel for the post as well as for Fort Schuyler, N. Y. Improvements recommended are: A new set of barracks; a change in the location of the quartermaster's and commissary store-houses; to clean out and deepen the lagoon and ditch between the post and mainland; the reconstruction of the soldiers' laboratory, destroyed by fire last November; a building to contain the collection of engineer models, and beginning to replace the present temporary buildings by those which will be of more permanent character. The health of the garrison has been satisfactory (but four deaths in a population of 600, being only 6.7 per thousand), and it is thought will be improved as the sewerage and water are improved as contemplated. SCHOOL OF APPLICATION. During the past year six officers of engineers completed a three-years course and three artillery officers a seven-months' course, and have been relieved. The library of the school has received accessions, and $1,000 is asked for the next year. (See Appendix No. 2.) It is suggested that the course of study be made as practical as possible, and instruction obtained from things instead of text-book description of them, thus leading to a habit of personal investigation. Circumstances have made it possible to offer accommodations for a detail of eight or ten artillery officers, and the suggestion is offered that a detail of officers from other arms of the service might be useful and desirable. EXPERIMENTS. Owing to there having been no appropriation for two years for continuing experiments with torpedoes, but little has been attempted. Small charges of dynamite have been exploded, and a group of mines placed near Sandy Hook and information gained thereby. Three of Sims's fish-torpedoes have been tested and purchased during the year. No. 8 had three runs, No. 9 had six runs, and No. 10 had five runs. BATTALION OF ENGINEERS. The legal strength is 752 enlisted men, in five companies; the allowed strength is 450. Companies A, B, and C are stationed at Willets Point; Company E at West Point. A roster of officers and changes is given in the report. Recruiting has been done by a sergeant detailed at New York reildezvous and by assignment from the general depot at David's Island, New York Harbor. During the year the losses have been 120 and the gains 113. A detachment of three officers and nine men have performed the usual field-survey duty, and the battalion has been drilled and instructed in the various subjects pertaining to their duties as Engineer troops, |