REPORT FRANCISCO OF THE CHIEF OF ENGINEERS. OFFICE OF THE CHIEF OF ENGINEERS, Washington, D. C., October 20, 1879. SIR: I have the honor to present, for your information, the following report upon the duties and operations of the Engineer Department for the fiscal year ending June 30, 1879. 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 Jannary 21, 1870, not being available for duty. In the duties devolving upon the corps by law and by its organizations, the employment of a number of scientists and assistant engineers has been necessary. Since the last annual report the corps has lost, by death and retirement, four of its officers: Col. Henry Brewerton (retired), who died at Wilmington, Del., April 17, 1879; Col. I. C. Woodruff, who died at Tompkinsville, N. Y., December 10, 1878; Lieut. Col. B. S. Alexander, who died at San Francisco, Cal., December 15, 1878; and Brig. Gen. A. A. Humphreys, Chief of Engineers, who was retired June 30, 1879, at his own request, after more than forty years of continuous active service. There have been added to the corps, by promotion of graduates of the Military Academy, three second lieutenants and two additional second lieutenants, whose commissions date from June 13, 1879, but who did not become available for duty till after the close of the year, and are, therefore, not included in the strength of the corps. On the 30th June, 1879, the officers were distributed as follows: On duty, office Chief of Engineers, including the chief. On duty, Public Buildings and Grounds, District of Columbia. On duty, fortifications. On duty, fortifications and light-house duty On duty, fortifications and river and harbor works. On duty, fortifications, river and harbor works, and light-house duty. On duty, river and harbor works... 27 On duty, river and harbor works, and light-house duty 6 On duty, survey of Northern and Northwestern lakes and Mississippi River.. On duty, explorations of country west of one hundredth meridian On duty with Battalion of Engineers... 8 On duty with Battalion of Engineers and fortifications 2 On staffs of generals commanding divisions and departments, and on river and harbor works 2 Detached on duty with the General of the Army, generals commanding divisions and departments, Light-house Establishment, Military Academy, Department of State, and the Board of Commissioners of the District of Columbia.... 22 Total 105 SEA-COAST AND LAKE-FRONTIER DEFENSES. During the past fiscal year work upon our sea-coast defenses has been limited, in accordance with the terms of the act of March 23, 1878, to their protection, preservation, and repair. These works are subject more than any other national structures, with the exception, perhaps, of light-houses, to the destructive and deteriorating effects of the sea, and the amount heretofore appropriated for the above-mentioned objects has proven insufficient, many necessary works of repair and protection remaining unexecuted at the close of the fiscal year, for want of funds, No progress whatever has been made for several years past in the construction of new, or in the modification of our old works (built before the inventions of modern ordnance and armored ships), for want of appropriations therefor, and I beg to renew the remarks and the recommendations of the last annual report from this Department in relation thereto, as follows: The system to govern the future construction of our works was elaborated in 1869 and will be found stated in detail in Executive Document No. 271, House of Representatives, Forty-first Congress, second session, where it will be seen the system received the approval of the General of the Army and the Secretary of War, and since then has been repeatedly indorsed by the action of Congress. The main features of this system are the use of heavy earthen barbette batteries, with parados and traverses, of heavy mortar batteries, and of obstructions in the channels (mainly electrical torpedoes) to hold vessels from running past the batteries and reaching the cities or depots beyond them. The modification of the casemates of our masonry forts was at that time deemed premature, it being then thought preferable to await the further development of iron-clad fleets and their armaments, and to take advantage of the experience of foreign nations. From 1869 to 1875, while appropriations for coast defense were granted by Congress, much progress was made in earthen barbette batteries for heavy guns and mortars; and further, a system of defense by torpedoes-a subject of continuous study up to this time-has been developed which only requires a sufliciency of material and trained men to put it into practice when needed. But torpedo defense, however efficient in itself, cannot stand alone; the torpedoes must be protected by shore batteries. Unfinished earthen batteries, however, provided with a small fraction only of the number of guns for which they were designed, and those of insufficient caliber, and mortar batteries without mortars, though aided by torpedoes, will form but a feeble defense against the powerful fleets prepared and now being prepared to take the high seas. The great powers of Europe do not place their reliance on barbette batteries. They believe in, and are constructing, casemated forts, some of which are provided with wrought-iron scarps and others with iron casemate-shields to protect the gun, and gunners serving it, both from direct and curved fire. This department, while recommending and urging the construction of barbette batteries as an initiatory means of obtaining by comparatively small expenditures a partial defense for the numerous exposed harbors of our coast, has always insisted that the efficient service of the large guns mounted in them would require high parapets and depressing or counterpoise carriages. It has also, from the beginning, looked forward to the ultimate conversion of some of our casemated forts, which would admit the change, for the reception of guns of the largest caliber, and to the possible construction of new works. Within the past two years, in furtherance of these views, a large casemated fort has been designed to take the place of old Fort Lafayette at the Narrows entrance to New York Harbor. Plans also have been prepared for modifying the casemates of Fort Schuyler on the East River, and for completing Fort Carroll on the approaches to Baltimore. The modification of other casemated works is now a subject of study. It will require much time and large expenditures to make the foregoing modifications, and to complete our barbette and mortar batteries and furnish them with suitable armaments. It would be but an act of prudence to make the beginning without delay. The disasters of the first three months of a war under the present condition of our defenses might cost the nation tenfold the expenditure that would be needed to thoroughly protect our coast against attack. Our great cities, New York, Philadelphia, Boston, San Francisco, New Orleans, Baltimore, and Washington, should they fall into the hands of an enemy, would suffer ten times more than the cost of all the forts necessary to secure them against such disaster. But such reverses would also be great calamities to the nation, crippling its war power. When the great change in ships and their armaments was initiated, Great Britain did not hesitate to appropriate $40,000,000 for the defense of its most important harbors, and in addition she has already expended about $60,000,000 upon her iron-clad fleet. We may well profit by her example. There is nothing so costly to a nation as a lack of preparation for war. In fact, to be prepared for war will often prevent it; and though we may not feel the daily imminence of war with great foreign powers, as England did, yet with incomplete or inadequately armed defenses for our great sea-port cities, even the attitude of belligerency, which we not unfrequently have to assume, has not the imposing effect it should have, nor is it accompanied with a justly founded self-confidence on our own part. The neglect of suitable preparation cost France many millions of treasure, a portion of her territory, and a great humiliation. The same must inevitably happen to the United States if it does not push forward its coast defenses and provide them with guns like those possessed not only by the great powers, but even by smaller nations. That our forts should be efficient we must have guns of power not inferior to those that will be brought to contend with them. These guns must have a protectionwhether by earthen parapet and depressing carriage or by iron armor-no less efficient than that which protects the hostile gun. Our system of torpedo defense must rely upon forts for protection, otherwise it would be rendered harmless. It would be speedily destroyed by an enemy if one of its ironclad fleets were suffered to approach it unopposed. It is, therefore, by the combination of the two systems, viz, the torpedo defense and shore batteries, that our harbors can be made secure against the powerful iron-clads of the present day in the event of a war with a maritime nation. It concerns the honor of the United States, when involved in controversy with other powers, to be able to appeal to the sword, but that appeal should be accompanied by the consciousness that the weapon appealed to would not be inferior to that held by the adversary. This relation of inferiority may at present exist though the adversary be a comparatively weaker power. We have the assurance that iron plates can be manufactured in this country equal in magnitude and not inferior in quality to those which fifteen years of experience have enabled the English rolling-mills to turn out. During the past fiscal year plans have been prepared for the modification and completion of two more very important casemated works, viz, the fort at Sandy Hook, the outermost of the works for the defense of the southern approaches by sea to the harbor and city of New York; and Fort Wool, designed to command the entrance to Hampton Roads and defend the passages from sea to the city of Norfolk and its navyyard. These works, with the three important casemated works especially mentioned in last year's report, viz, Fort Schuyler, commanding the East River approach from sea to the harbor and city of New York; the work designed to replace old Fort Lafayette at "The Narrows" entrance to New York Harbor; and Fort Carroll, which commands the approach from sea to the rich and important city of Baltimore, await appropriations for their construction. Their plans, which have been carefully prepared in the light of full information respecting the recent great improvements in ordnance and armor, provide for mounting the heaviest of modern rifled guns, and for resisting the projectiles of cannon of the immense calibers now possessed by nearly every maritime nation of Europe. Plans for similar modifications of the more important of the other casemated defenses of our harbors will be made as rapidly as practicable, and in the mean time it is urgently recommended that appropriations be made by Congress for the works just mentioned and for the earthworks recently designed for many of our harbors for mounting heavy rifled guns and mortars, which have been already partially constructed, or for which the plans are ready for execution, as will be observed in the synopsis of the reports of the several officers in charge. It is certain that in our present condition, injuries to our citizens abroad and insults to our flag, could not be resented with that vigor and promptitude demanded by the dignity and honor of the nation, and justified by a knowledge that our fine harbors, important navy-yards rich commercial cities, and depots for military and naval stores were guarded by impreg |