needed for the defense of the coast. At present they constitute our chief dependence for excluding hostile fleets from our ports. An appropriation of $300,000 for their purchase is strongly recommended for the coming fiscal year. Even if a proper supply of mines were on hand they could not be served without the construction of operating casemates, shafts, and galleries for the introduction of the electrical cables into the fortifications. This work could not be completed in time after the outbreak of war; and an appropriation of $200,000 is urgently recommended for the coming fiscal year to provide for these essential constructions. For continuing the torpedo investigations at Willets Point, including the study of new explosives and other material, and trials with movable torpedoes, &c., and for instructing the engineer troops in the practical details of the service, the sum of $30,000 is recommended. In accordance with the above views, the Board presents the following consolidated estimate for the service of torpedoes during the fiscal year 1886-87: For the purchase of submarine mining materials to close the channels leading to our principal sea-ports against the entrance of hostile fleets.... For the needful casemates, cable galleries, &c., to render it possible to operate submarine mines in the defense of the principal ports on the Atlantic and Gulf coasts.. For continuing torpedo experiments and for the practical instruction of engineer troops in the details of the service.... Making a total of... $300,000 200,000 30,000 530,000 The following extracts from General Abbot's report exhibit the progress made in these matters at Willets Point during the past year: Much work was done in testing new explosives by the usual ring method. One hundred and eighty-four shots were fired with different grades of Judson powder, rackarock, forcite, and explosive gelatine imported from Scotland. An addendum (No. II) to Professional Papers No. 23 of the Corps of Engineers was printed on the press of the battalion and distributed to the officers of the corps, reporting these tests in detail and stating conclusions which seemed to be warranted. The more important results were the following: (1) A judiciously selected explosive base adds enormously to the energy developed by the nitro-glycerine alone; (2) each particular kind of base requires a definite percentage of nitro-glycerine to yield the best work. There is an economic loss in increasing this percentage; (3) partially gelatinizing the nitro-glycerine before absorption is advantageous; (4) the chemical composition of the base is very important. As to the practical value of the new explosive, rackarock, consisting of potassium chlorate and a fluid hydro-carbon, joins absolute safety in transportation and storage to a strength nearly or quite equal to that of dynamite No. 1. Explosive gelatine, approximately represented in our market by forcite gelatine, is the strongest of known explosives. Judson powder, costing about the same as potassium nitrate blasting powder, has an intensity of action equal to about 40 per cent. of dynamite No. 1, although it contains only 5 per cent. of nitro-glycerine. All these remarks apply to explosives under a considerable depth of water and well removed from the bottom. Various experiments under ice, and others to determine tendency to explosion upon impact or by sympathy, were made during the year at Willets Point; also a few preliminary trials with the new explosive, panclastite. The experiments with extra sensitive low-tension fuzes mentioned in the last annual report have been continued, and samples have been fabricated ranging in sensitiveness from those exhibited at Vienna in 1883 by the Royal Danish Torpedo Corps to a standard requiring only half their igniting current. No final conclusions as to the practical utility of this class of fuzes have yet been reached. The following is a brief statement of the trials with the Sims movable fish torpedo. The new 2-mile pattern was first put in the water on July 18, and experiments were continued until November 7, chiefly to determine the best dimensions of propeller and to discover mechanical defects. The increased size of the boat developed many of the latter. Much delay and trouble grew out of the insulated cable for carrying the electrical current, and finally a shunt in the armature of the Siemens motor put a stop to the work until the season was too far advanced for resump During the winter the Siemens motor was repaired and a new motor was ordered from the Edison Machine Works in New York, exact and full data as to the electrical requirements being furnished by me. This motor has not yet been tested at Willets Pont; but the preliminary trials at the shops of the company promise a high degree of success. Much interest has been taken in the matter by the general manager, Mr. Charles Batchelor, who has worked out many details where computation affords only an uncertain guide. I shall be much disappointed if this new motor does not prove superior to the one constructed by Siemens, which, in its turn, was a great advance upon the one designed by Mr. Edward Weston. During the winter Mr. Sims received an order for another 2-mile boat, to embody all improvements and correct all defects discovered to date. This was completed too late for trial before the close of the fiscal year. Experiments with the old boat were resumed early in May and continued to the end of the year. Their chief objects were to test its steering qualities, to determine its speed, and to learn whether the truss uniting the torpedo proper to the float possessed sufficient strength to resist, when moving at full speed, a shock against a heavy floating boom. The latter object was successfully accomplished, but the results as to steering and as to speed were unsatisfactory. The chief trouble arose from defects in the apparatus supplied by Mr Sims for putting the reversed turns in the cable preparatory to inserting it in the boat for a rub. With the 1-mile pattern this necessary work has always been done by hand; but the weight of 11,000 feet of cable renders automatic action indispensable, and the compound reel designed for the purpose proved defective. The whole supply of new cable was ruined by this ma chinery, and no satisfactory results, either as to steering or as to speed, were secured. For full details of the trials with this torpedo during the year I would refer to previous reports now on file with the Board. They sufficiently show the laborious and disappointing character of the work; but I by no means regard them as suggesting ultimate failure. Much has been learned by them, and in attempting to perfect an invention of this kind it is idle to expect uninterrupted success. BOARD OF ENGINEERS FOR THE PACIFIC COAST. During the year ending June 30, 1885, this Board has consisted of the following officers of the Corps of Engineers: Col. Charles S. Stewart and Lieut. Col. George H. Mendell. No special subjects have been laid before the Board for its action. BATTALION OF ENGINEERS AND ENGINEER SCHOOL OF APPLICATION. The strength of the battalion of engineers on June 30, 1885, was 21 commissioned officers and 383 enlisted men, commanded by Lieut. Col. Henry L. Abbot, Corps of Engineers. The battalion was stationed as follows: The field staff and band and Companies A, B, C, and D (the latter only existing on paper) at Willet's Point, New York Harbor; Company E at West Point, N. Y. The troops at Willets Point guard the public property of the depot and fort, carry out experiments with new explosives, fish torpedoes, and other matters connected with the development of the Submarine Mining Service; remodel ponton trains, print confidential documents, &c. At West Point, besides its ordinary garrison duty, the company aids in the instruction of the cadets in practical military engineering. The whole battalion is equipped and drilled as infantry, and is always ready in an emergency for military service in that capacity as well as for the duties pertaining directly to its own arm-sapping, mining, pontoniering, mili tary map making, submarine mining in the defense of the coasts, &c. The legal strength of the battalion is 752 enlisted men, but the force allowed to be recruited at the date of my last Annual Report was fixed at 200 men. In July, 1884, this number was authorized to be increased to 450 men by the honorable Secretary of War, after a personal visit and inspection of the establishment at Willets Point. The soldiers at Willets Point constitute the only body of men in the United States instructed in the details of defensive torpedo warfare, and the necessity for this increase has long existed. Advantage has been taken of their service with the troops to afford young officers on joining the corps an opportunity of supplementing their West Point course in matters where it is not sufficiently extended in respect to the special duties of the engineer service. A school of application has thus gradually developed, of much value to the corps, not only for study, but also for original research. During the past year it has been reorganized and placed on a more substantial basis by the approval of the honorable Secretary of War to a project presented by me in February, 1885. (See Appendix No. 3.) ENGINEER POST AND DEPOT OF WILLETS POINT, NEW YORK HARBOR. All materials pertaining to sapping, mining, pontoniering, field fortification, the torpedo service, and other military duties of the Corps of Engineers as well as all surveying and astronomical instruments not actually in use by its officers, are stored at Willet's Point, which is our only engineer depot. The post is garrisoned by three companies of engineer soldiers, who, in addition to their other duties, receive, guard, and issue the property in store. The usual appropriations of $3,000 for the incidental expenses of the depot, of $1,000 for the purchase of materials for the instruction of these troops, and of $2,000 for purchase and repairs of instruments for issue to officers of the corps engaged on civil works, are requested. Also of $1,000 for supplying the library of the engineer school of application with professional works of recent date, treating of military and civil engineering, and of $12,000 for the construction of a new officers' mess building, also to contain the library, draughting-room, &c., of the school of application. Total, $19,000. For further information as to this depot and the appropriations requested above, I would refer to the appended report of the officer in command. (See Appendix No. 4.) RIVER AND HARBOR IMPROVEMENTS. The funds with which the works for the improvement of rivers and harbors were prosecuted during the past fiscal year were derived from appropriations of the act of July 5, 1884, together with such few balances as were on hand from previous appropriations. A brief statement, taken from the reports of the district officers, is given below, setting forth the condition of each improvement, the extent of work performed during the fiscal year, the amount of money expended, and, in compliance with the provisions of the river and harbor act of March 2, 1867, estimates of the amount that can be profitably expended during the fiscal year ending June 30, 1887, and of the prob able cost of completion. Although, as a general rule, regard is necessarily had in the preparation of these estimates to the more intimate acquaintance of the Engineer officer in charge with the requirements of each locality, they have in a few instances been revised and amended in this office, and it is proper to state that they are made in compliance with the require ments of the above mentioned act, and are not to be considered as ca rying with them a recommendation of the officer in charge of the dis trict or of this office in respect either to the commercial value of th improvement or to the amount to be appropriated, other than for th most economical administration of the works, the prosecution of whic had already been approved by Congress. The reports of the officers in charge of the various improvements wi be found in the Appendix, and to these reports special reference shoul be made whenever detailed information is desired concerning the prog ress and condition of each work. The examinations and surveys required and provided for in the rive and harbor act of July 5, 1884, have been completed. Reports of thei results will be found in the Appendix of this report. They were, with a few exceptions, transmitted to Congress from time to time during it last session. The act provides that no survey shall be made until th local engineer has reported, after a preliminary examination, that th locality is worthy of improvement, and, further, that the Chief of Eu gineers shall direct the making of such survey only in the case wher in his opinion the river or harbor proposed to be surveyed is worthy o improvement by the General Government. Of the one hundred and thirty-nine localities enumerated in the abov act, fifty-three were reported as not worthy of improvement. Examinations were made during the fiscal year of such plans and locations as were submitted by the parties interested of bridges pro posed to be built over navigable waters, under authority of Congress subject to the approval of the Secretary of War. A brief statement is given below of the action had in each case, the detailed reports of which will be found in the Appendix. A statement is also given of the work accomplished in the removal of wrecks obstructing or endangering navigation, general provision for which is made in the river and harbor act of June 14, 1880. Section 2 of the river and harbor act of July 5, 1884, requires the Secretary of War to report to Congress all instances in which piers. break waters, or other structures built by the United States in aid of commerce or navigation are used, occupied, or injured by a corporation or an individual, and the extent and mode of such use, occupation, or injury; and, further, to report whether any bridges, causeways, or structures, now erected or in process of erection, do or will interfere with free and safe navigation, and if they do or will so interfere, to report the best mode of altering or constructing such bridges or causeways so as to prevent any such obstructions. And, also, by section 8 of the same act, the Secretary of War is directed, whenever there is reason to believe that any bridge over navigable waters of the United States, or of any State or Territory, is an obstruction to navigation by reason of difficulty of passing its draw openings or raft-spans, to require the owners of or persons controlling or operating the same to cause such aids to the passage of the bridge as may be deemed necessary to be erected by them at their own expense. To comply with these requirements of law instructions were given to officers of the Corps of Engineers in charge of river improvements to prepare and submit to this office, for the information of the Secretary of War, all facts that might be deemed necessary for compliance with the terms of the act. These reports, and other information relating to the subject that is received, will be duly submitted in a separate communication. ATLANTIC COAST AND GULF OF MEXICO. IMPROVEMENT OF RIVERS AND HARBORS IN THE STATES OF MAINE AND NEW HAMPSHIRE. Officer in charge, Col. Charles E. Blunt, Corps of Engineers. 1. Lubec Channel, Maine.-The following appropriations have been made for this thoroughfare: The project for its improvement was based upon a survey made in 1878, the object being to make it navigable in all stages of the tide by giving it a width of not less than 200 feet and a depth of 12 feet at mean low water. This required the deepening of several bars between the head of "The Narrows" and "Western Bar Beacon" (a distance of about 23 miles), the shoalest of which had a depth of not over 5 feet at mean low water. This channel was completed in 1883. A stone jetty on Gun Rock, Lubec Narrows, 259 feet long, began in May, 1884, was finished in July. Its object was the stoppage of a troublesome tidal current at that point. Part of a ledge at Eastport, much in the way of steamers, has been removed during the past year. The remainder of last year's appropriation is now being expended in widening the channel at the southern bend. The officer in charge submits a modification of last year's estimate for an increase of width and depth to this channel, and recommends that the proposed increase of depth be, for the present, abandoned. The tidal rise being 17 to 18 feet, it may be doubted whether the advantage of an increase of depth from 12 feet to 15 feet at low water would counter balance the cost. This will reduce last year's estimate for completion from $113,000 to $45,000, and deducting the widening made this season, as above stated, will leave the cost of completing the dredging of the whole channel to a general width of 275 feet increased to 300 feet in the bends, at about $32,000. This modification is approved. July 1, 1884, amonnt available................. Amount appropriated by act approved July 5, 1884 $11, 115 16 10, 000 00 21, 115 16 July 1 1885, amount expended during fiscal year, exclusive of outstanding liabilities July 1, 1884.. $16, 121 02 July 1, 1885, outstanding liabilities.... 1,954 85 18, 075 87 July 1, 1885, amount available... 3,039 29 Amount (estimated) required for completion of existing project... 32,000 00 32,000 00 (See Appendix A 1.) 2. Bangor Harbor and Penobscot River, Maine.-Under successive ap. propriations made by Congress between the years 1870 and 1879, inclu |