REPORT OF THE CHIEF OF ENGINEERS. OFFICE OF THE CHIEF OF ENGINEERS, SIR: I have the honor to present for your information the following report upon the duties and operations in the Engineer Department during the fiscal year ending June 30, 1874. OFFICERS OF THE CORPS OF ENGINEERS. The number of officers holding commissions in the Corps of Engineers, United States Army, at the end of the fiscal year, was 105 on the active list, and 5 on the retired list; the latter, however, under the law of January 21, 1870, not being available for duty. In the duties devolving upon the corps by law, and its organization, the employment of a number of scientists and assistant engineers has been necessary. Since my last report the corps has lost by death and retirement three officers, namely: First Lieut. Eugene A. Woodruff, who died at Shreve port, Louisiana, September 30, 1873, of the yellow fever, contracted while devoting himself to the care of the sick during the epidemic of that year; Brig. Gen. Richard Delafield, late Chief of Engineers, (retired,) who died in Washington November 5, 1873; and Colonel George W. Cullum, who was retired, January 13, 1874. On the 30th of June, 1874, the officers were distributed to duties as follows: On duty, Office of the Chief of Engineers, including the chief On duty, projection and construction of fortifications On duty, construction of fortifications and light-house duty On duty, construction of fortifications and river and harbor works, and surveys for same On duty, construction of river and harbor works, and surveys for same. On duty, construction of river and harbor works, and light-house duty, and surveys for same .. 22 On duty, construction of fortifications and river and harbor works, and light-house duty, and surveys for same.. 4 15 5 6 10 1 On duty, survey of northern and northwestern lakes.. On duty, explorations of country west of one hundredth meridian On duty, public buildings and grounds, District of Columbia.. Total....... The officers detached were on duty as follows: Col. I. C. Woodruff, engineer third light-house district Lieut. Col. William F. Raynolds, engineer fourth light-house district Lieut. Col. R. S. Williamson, engineer twelfth light-house district Maj. G. L. Gillespie, on staff of Lieutenant-General commanding military division of the Missouri Capt. Asa H. Holgate, on staff of commanding general Department of Texas.. Capt. William Ludlow, on staff of commanding general Department of Dakota... Capt. William S. Stanton, on staff of commanding general Department of Platte.. First Lient. E. H. Ruffner, on staff of commanding general Department of the Missouri First Lieut. J. G. D. Knight, on staff of major-general commanding Military Divis ion of the Pacific... 1 1 1 1 1 1 Capts. William J. Twining, J. F. Gregory, and First Lieut. F. V. Greene, on duty under Department of State, upon joint commission for the survey of the boundary line along the forty-ninth parallel......... First Lieut. R. L. Hoxie, chief engineer of the District of Columbia, under the direction of the board of commissioners. 1 3 Capt. C. W. Raymond, First Lients. E. W. Bass, and S. E. Tillman, on duty under the superintendent of the United States Naval Observatory in connection with observation of the transit of Venus 3 Capts. A. M. Miller, T. H. Handbury, First Lieut. J. C. Mallery, and Second Lieut. C. F. Palfrey, on duty at the Military Academy.. 4 24 Total.... The following principal civil engineers and geologists were employed on the 30th of June: General J. H. Wilson, member of board of engineers upon improvement of the Des Moines and Rock Island Rapids, and improvement of the Illinois River; Clarence King, geologist, in charge of geological exploration of the fortieth parallel; and S. Thayer Abert, in charge of river and harbor improvements on Potomac River and Chesapeake Bay. SEA-COAST AND LAKE-FRONTIER DEFENSES. The progress during the past year, of the works for the defense of our harbors from naval attacks, has been satisfactory, and some of the works for the protection of the harbors of our principal cities, are approaching completion. As has been mentioned in my previous annual reports, the class of works now in progress are mainly earthen barbette and mortar batteries, having great thickness and height of parapets, and thorough protec tion from enfilade and reverse fires, by massive traverses and parados. The barbette-batteries for guns are being arranged for the new ordnancecarriage of increased height, but will also be available for the depressing-carriage when that shall have been provided. Every step taken in the location, construction, or modification of our sea-coast defenses is in accordance with the general conclusions and principles agreed upon by the board of engineers in 1869, which received the approval of the Chief of Engineers, the General of the Army, and the Executive, and which have repeatedly commended themselves to the intelligence of Congress. In comparison with the large number of harbors and anchorages along our coasts, but a limited number are being fortified, and appropriations are asked only for those having sufficient depth of water to admit the entrance of the enemy in iron-clad vessels carrying the pow erful rifled modern armaments, and where interests covering millions of dollars would be sacrificed by a successful invasion. But a small number of our works are what could be called new; that is, planned entirely in accordance with the requirements for resisting |