HDQRS. ARMY OF THE POTOMAC, ENGINEER DEPT.,
December 3, 1864.

SIR: I have the honor to submit the following report of the engineering operations in this army for the week ending to-day:

Captain Harwood was in command of the Battalion of U. S. Engineers, and, assisted by Lieutenant D. P. Heap, inspected the line from Fort Bross to Fort Davison. The latter officer also assisted Lieutenant Howell on a reconnaissance with the cavalry division commanded by General Gregg. Lieutenant W. H. H. Benyaurd had charge of the repairs at Fort Stedman. These repairs will be finished on the 5th instant. Lieutenant C. W. Howell inspected the line from Fort Howard to Fort Dushane, and was on a reconnaissance with the cavalry division. Lieutenants Phillips and Lydecker were also on a reconnaissance with cavalry division. Colonel Spaulding, commanding detachment Fiftieth New York Volunteer Engineers, with the officers of his command, was engaged in superintending the overhauling and repairing of the pontoon trains and the putting up of stables for the public animals.

In the topographical department, the maps of the battle-fields at Spotsylvania Court-House and Cold Harbor are being constructed, and an additional section of the map captured from the enemy is being copied. The information obtained by the assistants who accompanied the cavalry division on the late reconnaissances has been added to the one-inch map, a copy of which is respectfully forwarded.

I am, sir, very respectfully, your obedient servant,

J. C. DUANE,

Major of Engineers, U. S. Army.

Major General J. G. BARNARD,

Chief Engr. Armies operating against Richmond, City Point, Va.

HDQRS. ARMY OF THE POTOMAC, ENGINEER DEPT.,
December 12, 1864.

GENERAL: I have the honor to submit the following report of the engineering operations in this army for the week ending on the 10th instant:

Captain Harwood was in command of the Battalion of U. S. Engineers, and, assisted by Lieutenants Howell and Phillips, examined and inspected the line from Fort Wadsworth to Fort Dushane. On the 9th instant, in compliance with the orders of the commanding general, Captain Harwood marched the battalion of engineer troops on the Vaughan road and joined the Second Corps troops as infantry. Lieutenant Benyaurd had charge of repairs at Fort Stedman until ordered on a reconnaissance with the Fifth Corps. Lieutenant Howell had charge of the building of a magazine at Battery 26, and, in addition to the assistance rendered Captain Harwood in the inspection already referred to, was with the battalion with Second Corps. Lieutenant Lydecker inspected the line from Fort Howard to Fort Rice, and was with the battalion when it joined the Second Corps troops. Lieutenant Heap was on a reconnaissance with the Fifth Corps. Colonel Spaulding, commanding detachment Fiftieth New York Volunteer Engineers, is absent on an expedition, and made no report of the operations of his command for the last week.

In the topographical department, the assistance were engaged in delineating the several routes by which the army marched during the