SURVEY OF NORTH AND NORTHWESTERN LAKES.*
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OPERATIONS OF THE YEAR.
The expenditure for carrying on the war has been of first necessity, and the appropriations heretofore have in general absorbed the full amounts, while for permanent defense of the sea-coast a large amount remains unexpended and available for the future.
The work done on the several forts and batteries is particularized in the accompanying statement, as derived from the reports of the superintending engineer. The great end in view has been to hasten to completion such parts of the works as would soonest enable the armaments to be introduced, and the progress made continues to be for all description of guns greatly in advance of the ability of the Ordnance Department to provide the required artillery while arduously engaged in providing the armies in the field with their necessary munitions.
The Board ordered by you in January, 1864, to examine the system of our sea-coast defenses as then being constructed, & c., entered upon its duties and proposed several modifications called for by the introduction of increased calibers in guns, the rifling of heavy artillery, and the use of armor-clad vessels as combatants.
Earth as an opposing mass to resist artillery, while it is also used to cover and protect masonry, has from the earliest period of permanent fortifications been considered the most reliable material and least subject to injury from an enemy's artillery, whether large or small, rifled or smooth-bore, and all exposed masonry has been and continues to be objectionable as liable to certain demolition where fixed batteries of sufficient power can be brought to act against it. These views the Board emphatically recommend to be steadily kept in view, and point out several instances where masonry parapets have been designed for works in progress where these can and should be substituted by earthen ones.
The Board was dissolved by its members being called into the field before time had been given for maturing detailed special plans for carrying their ideas into effect for the several works indicated for modification. The several superintending resident engineers have been called upon for designs to modify their respective works so far as their present condition will permit, while in other cases special boards will have to be organized to mature detailed plans for the proper modifications. The great pressure for engineer officers with the armies is now such that the requisite experience cannot be commanded for the organization of such board.
For the defenses of the California coast and to carry into effect the intention of Congress in fortifying the land approaches to San Francisco, a special board has been ordered and is now engaged on that duty, keeping at the same time in view the recommendations of the late Board created by your order of the 27th of January, 1864.
All the supplies of engineer material required for our great armies in the field, whether of bridge equipage, supplies for siege operations, or for the construction of field-works and defensive lines, have been provided and distributed promptly as called for. The principal depots for these supplies have been that of Washington, in charge of Colonel W. H. Pettes, New York Volunteer Engineers, for the armies operating in this vicinity; the depot at Cincinnati, in charge of Lieutenant