Corps of Engineers.-These defenses consist of Fort Stevens, on the south side, and three detached earthen barbette batteries at Cape Disappointment, on the north side of the entrance. They were built during the late war, and the materials used in their construction being those chiefly used in temporary works, they require frequent repairs. The revetments of all the interior slopes and traverses, and the timbers of the magazines at Cape Disappointment, are rotten and fallen in many places. They should all be replaced the coming year. No appropriation was made for fiscal year ending June 30, 1872. The only operation carried on during the past year at these works, was the erection of a picket fence around Fort Stevens. Sea-coast mortar batteries.-The appropriations of 1870 and 1871, for sea-coast mortar batteries, amounted, in all, to the sum of $175,000. This sum has been apportioned between the important ports of Portland, Boston, New York, Philadelphia, and San Francisco, as follows: At Portland, for the emplacement of 4 mortars Boston... ..do .......do.......14...do.... $5,000 34, 000 Making a total of ninety-two mortars in all. Projects for the batteries for nearly all these mortars have been prepared and approved, and the constructions have been commenced at some points. The fire from mortars is an important part of the defense of our harbors against iron-clads, and a further appropriation for batteries of this description is recommended. Amount appropriated for fiscal year ending June 30, 1872, $100,000. Appropriation asked for next fiscal year, $100,000. Examinations of tidal currents.-Careful surveys and examinations to determine the strength and direction of the tidal currents in the channels opposite to and near the works of defense for our sea-ports on the Atlantic, Gulf, and Pacific shores have been made, or are still in progress, under the direction of the several officers charged with the supervision of the fortifications at the respective points, except upon the Pacific coast, where the observations were under the direction of Lieutenant Colonel B. S. Alexander, Corps of Engineers. BOARDS OF ENGINEERS. The board of engineers for fortifications, stationed in New York City, consisting of Colonel J. G. Barnard, Colonel G. W. Cullum, Lieutenant Colonel Z. B. Tower, and Lieutenant Colonel H. G. Wright, have been engaged during the past year upon the plans for the modifications of the sea-coast defenses and the decision and investigation of questions connected therewith. The board of engineers for the Pacific coast, consisting of Lieutenant Colonel B. S. Alexander and the officers in charge of the construction of fortifications in San Francisco harbor, with Lieutenant Thomas H. Handbury as recorder, have been occupied with projects for the defense of the Pacific coast. BATTALION OF ENGINEERS AND DEPOTS. Battalion of engineers, commanded by Major Henry L. Abbot, Corps of Engineers, headquarters' Willet's Point, eastern entrance to New York Harbor. The strength of the five companies constituting the battalion of engineers on the 30th of June, 1871, was 12 officers and 303 enlisted men; 51 recruits were needed to complete the reduced organization fixed by General Orders No. 122, series of 1870, from the War Department. This organization, in accordance with the act of July 15, 1870, was determined to be as follows: Companies A, B, C, and E, 83 enlisted men each; Company D, 20 enlisted men; non-commissioned staff of battalion, 2 men; making a total of 354 enlisted men of engineers. The companies of the battalion were stationed and commanded as follows: At Willet's Point, Company A, Captain Mackenzie; Company B, Captain Wm. R. King; Company C, Captain C. W. Raymond; and Company D, (a skeleton organization) under charge of the adjutant of the battalion. Detachments of one sergeant and five first-class privates of Company D were stationed at Yerba Buena Island, California, and Jefferson Barracks, Missouri, for the purpose of guarding and caring for engineer property at those points. The detachment heretofore kept at the Military Academy for the purpose of aiding in the instruction of cadets in practical engineering, signaling, &c., was increased to a full company, and Company E selected for that purpose. Company D having been practically disbanded by the reduction of the battalion, as mentioned above, the four companies of the battalion are now stationed at two points only-Willet's Point and West Point. During the past year the battalion has, in common with infantry and artillery troops, been occasionally called upon for active military service, for escort duty, and to aid in enforcing the revenue and other civil laws. Careful instruction is required in the duties of its special arm to keep the engineer battalion always ready for field service; and, notwithstanding many interruptions arising from the reduction and moving of the troops, good progress has been made in field fortifications, pontoning, mining, military maneuvers, signaling, infantry drill, and in the use of torpedoes. The duties required of the officers and troops serving at Willet's Point have been so combined and arranged that the post is rapidly acquiring the character of a school of practice for engineer officers, and is thereby adding materially to the efficiency of the service. I would respectfully recommend that an appropriation of $1,000 be asked for the purchase of the stock used in the fabrication of siege and mining materials, and for a simple photographic apparatus for copying maps, &c., and again renew my recommendation of past years that the battalion be allowed two principal musicians, and that the seventh section of the act of July 13, 1866, taking from engineer troops the per diem paid to other soldiers when engaged in continuous labor, be repealed. Engineer post and depot at Willet's Point, New York Harbor, commanded by Major Henry L. Abbot, Corps of Engineers.-At this post is the principal engineer depot of the Army; large quantities of bridge equip age and engineer tools and material are stored and guarded by the engineer battalion, and issued, from time to time, as required for use on public works. The old temporary buildings (originally designed for the Grant General Hospital) in which much of the property is stored have become so ruinous as to no longer serve their purpose, and a new building to replace them is now constructing. It is desirable that the ponton-boats belonging to the bridge-trains should be covered with a light roofing of boards to protect them against, the weather; and also that certain parts of the bridge equipage on hand should be modified to correspond with the new pattern adopted in 1869, after thorough study of the experience gained in the war. For these objects, and for the current expenses of the depot, an appropriation of $5,000 is requested; the labor will be performed by the engineer soldiers without cost. Work upon the public buildings has been pushed forward as fast as▾ the funds on hand have allowed. Three new barracks have been completed, almost entirely by the labor of the engineer soldiers, thus reducing the cost nearly to that of the material used. This work will be continued during the coming year. An appropriation of $5,000 for further repairs, and one of $5,000 for a suitable chapel, is requested. During the past year this depot has been extended to include the instruments (astronomical, geodetic, reconnoitering, &c., &c.) in use by the officers of the Corps of Engineers, all of which are now stored and issued at Willet's Point. There are many on hand which require repairs, and delay in issuing them often arises from the fact that requisitions cannot be filled until these repairs can be made at the cost of the special appropriation for which the instruments are needed. This delay will be obviated by an appropriation for "repairs of instruments," and $10,000 is requested accordingly. It will be expended from time to time, as needed, to keep a proper supply on hand suitable for issue. This post having been constituted, by order of the Secretary of War, the torpedo school of the Army, an elaborate course of experiments was begun in 1869 with a view to determine the best and most economical methods of employing this new auxiliary in harbor and land defense. The project was drawn up by the board of engineers for fortifications, after due deliberation, and has been actively carried on by the engineer troops at very small cost to the Government. It comprises a careful experimental investigation of the whole subject. The results already arrived at are entirely satisfactory. Use has been made during the past year of the instruments and methods to settle certain questions arising in practical sub-aqueous blasting now in progress. An appropriation of $10,000 is requested to continue the investigations. Engineer post and depot of Jefferson Barracks, Missouri, commanded by Captain P. C. Hains, Corps of Engineers.—In accordance with General Orders No. 122, series of 1870, from the War Department, Company E, stationed at this post, was reduced and reorganized, and left this post for West Point on the 1st, and arrived at its new station on the 3d of March, 1871. The engineer property at the post is still retained there under the care of a small detachment of engineer soldiers. By General Orders No. 41, series of 1871, from the War Department, dated April 24, 1871, this post, with all the lands appertaining thereto, was transferred to the Ordnance Department. Engineer post and depot of Yerba Buena Island, California, commanded by Captain S. M. Mansfield, Corps of Engineers.-In accordance with General Orders No. 122, series of 1870, from the War Department, Company D, battalion of engineers, stationed at this post, was reduced and the skeleton ordered temporarily to Willet's Point. In compliance with this order the reduced company left this post on the 11th, and arrived at Willet's Point on the 21st of March, 1871, leaving behind a small detachment of men to care for the engineer property still remaining on the island. In accordance with the orders of the honorable Secretary of War, as conveyed in letter of the Adjutant General of the Army to the commanding general Division of the Pacific, this post was on the 30th of June, 1871, turned over by the Engineer Department to the Quartermaster's Department, to be occupied for depot purposes or quartering troops, as circumstances might require. RIVER AND HARBOR IMPROVEMENTS. The appropriations with which works for the improvement of rivers and harbors have been prosecuted during the past fiscal year have been derived from the act approved July 11, 1870, in connection with such balances of former appropriations as were available for the fulfillment of contracts and the liquidation of obligations made prior to the beginning of the fiscal year. The amounts appropriated by this act for works in course of construction were applied in the continuation of these works, in accordance with previously approved plans. In the case of new works of improvement provided for by the act, steps were at once taken to prepare projects, and on their being approved the officers in charge were directed to commence operations with as little delay as possible. For a general understanding of the condition of these improvements, and also of the progress made during the year, I beg leave to refer to the summary of operations at each locality, contained in my annual report dated October 25, 1870, and to the corresponding summary submitted herewith. These summaries, together with the detailed reports of the officers in charge of works will, it is believed, furnish full and complete information in regard to the progress and condition of each improvement at the close of the fiscal year ending June 30, 1871. These detailed reports are transmitted herewith. The examinations and surveys directed by Congress to be made at certain localities specified in section 2 of the act approved July 11, 1870, have, with a few exceptions, been completed. The reports on the greater portion of them were transmitted to Congress during the sessions of 1870-71. Copies of these reports, together with those since received, are transmitted herewith. By an act approved March 3, 1871, Congress made additional appropriations for the repair, preservation, and completion of certain public works on rivers and harbors, and in the fourth section of the act it was provided "That any part of the appropriations made by this act may, at the discretion of the Secretary of War, be applied during the current fiscal year." In accordance therewith the officers were instructed that in all cases of necessity, and wherever it was manifestly to the public interest, the amounts appropriated were made available at once, and applicable to the works of construction and improvement therein specified. The execution of the examinations and surveys directed to be made at the localities named in the third section of the act were at once distributed among the officers of the corps, and on their submitting projects for surveys or examinations, with estimate of probable cost of each, certain portions of the appropriation for examinations and surveys, and for contingencies of rivers and harbors, were allotted, and suitable instructions issued. Many of these surveys and examinations have been made, and the reports have already been received, some of which are herewith transmitted. It is believed that the field-work of all will be completed during the present working season, and the reported results will be received in time to be submitted to Congress during the next session. HARBORS ON LAKE SUPERIOR, AND ON THE WEST AND SOUTH SHORES OF LAKE MICHIGAN. Officer in charge, Major D. C. Houston, Corps of Engineers, having under his immediate orders Captain J. W. Cuyler and Lieutenant A. M. Miller, Corps of Engineers. 1. Du Luth Harbor, Lake Superior, Minnesota.-The appropriation for the harbor ($60,000) is being applied to the extension of the breakwater built by the Northern Pacific Railroad Company. This work was 400 feet long, and, with the addition of 500 feet to be completed this season, will be 900 feet in length. The total length proposed for it is 3,000 feet. The city of Du Luth is now cutting a canal through Minnesota Point, from the lake to the bay of Superior, in order to form an interior harbor or basin, having its entrance protected by the breakwater. The opening of such a water-way through Minnesota Point would divert some of the volume of discharge of the St. Louis River from the natural entrance of the bay of Superior, and also a part of the inflow and outflow of the reservoir volume of Superior Bay and St. Louis Bay, derived from the incessant variations in the level of the west end of Lake Superior. The depth of the entrance channel is closely dependent upon the volume of its discharge. Measures, therefore, have been taken to secure such a construction of the inner harbor of Du Luth and its canal as will prevent injury to the natural entrance, the improvement of which by the construction of parallel piers extending into the deep water of Lake Superior is in process of execution. Amount appropriated by act of March 3, 1871.... $60,000 00 Amount required for fiscal year ending June 30, 1873..... 100, 000 00 (See Appendix A 1.) 2. Superior City Harbor, Lake Superior, Wisconsin.-The work during the year has consisted in the extension of the Minnesota pier 768 feet, and of the Wisconsin pier, 96 feet. At the close of the fiscal year the Minnesota pier was 1,888 feet, and the Wisconsin pier 736 feet in length. The work is now rapidly progressing on both piers, and it is anticipated that by the end of the season they will be extended (up to the water surface) over the bar to a depth of 12 feet water in the lake. Amount on hand July 1, 1870..... Amount appropriated by act of July 11, 1870. Amount expended during the fiscal year ending June 30, 1871 .... Amount available July 1, 1871..... Amount required for fiscal year ending June 30, 1873.. (See Appendix A 2.) 3. Ontonagon Harbor, Lake Superior, Michigan.-A contract was made in September, 1870, for the extension of the west pier. This work will be completed the present season, making an extension of 224 feet, and exhausting the available funds. No appropriation was made for this harbor at the last session of Congress. The completion of the improvement in accordance with original plans involves the extension of the east pier 1,220 feet, and the west pier 1,896 feet. This harbor is well situated for a harbor of refuge, and in view of the increasing commerce of Lake Superior, it is recommended that the work be continued. Amount on hand July 1, 1870.... Amount appropriated by act of July 11, 1870. Amount expended during the fiscal year ending June 30, 1871 ... $4,409 88 10, 000 00 349 92 |