late campaign, and constructing maps of the battle-fields of Spotsylvania Court-House and Cold Harbor. The information on the reconnaissance of the 26th of October is also being added to the eight-inch map west of the Weldon railroad, and the copying of the last section of the photograph map captured from the enemy is nearly finished.

Very respectfully, your obedient servant,

J. C. DUANE,

Major of Engineers, Brevet Colonel, 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 20, 1864.

SIR: Since the date of my last report of the 12th instant I have the honor to report the following engineering operations of this army for the week ending December 17, 1864:

Brevet Major Harwood was in command of the Battalion of U. S. Engineers. Brevet Captain Benyaurd and Lieutenant Howell returned from reconnaissance with Fifth Army Corps; Brevet Captain Howell inspected the line from Fort Howard to Fort Sedgwick; Lieutenant Lydecker inspected the line from Fort Howard to Fort Dushane, and Lieutenant Phillips examined and inspected the line from Fort McGilvery to Fort Howard. The following extracts from the report of Colonel Spaulding will show the nature and extent of the engineering duties performed by his command from the date of his last report to me of November 25, 1864:

At the date of my last report all the field pontoon trains of the army were in park near Fort Stevenson, to which point they were moved on the night of the 18th of November. During the week ending December 2 nearly all the men in my command were engaged in clearing ground near my present camp for parking pontoon trains and corralling the animals. About forty acres of ground were cleared, corrals built and fenced in for over 2,000 animals, and gateway and gates put in at the entrances of the several corrals. On the 1st of December all the pontoon trains were moved to the ground prepared for them and the animals placed in the new corrals. In compliance with your orders, I sent on the morning of the 4th instant, a detail of one sergeant, two corporals, and twenty men, to report to Captain Davis, signal officer at Fifth Corps headquarters, for the purpose of constructing a signal tower. Captain Davis returned the men with a message that he was not yet prepared to commence the work. He called on me on the 5th and requested that I would furnish an officer to superintend the construction of the tower. I replied that with your approval I would furnish an officer and men to build the tower, provided I could control the design, but I was not willing one of my officers should be held responsible for a work put up at haphazard, which might or might not be successful. After Captain Davis had seen you on the subject it was arranged that I should do as I proposed, he undertaking to furnish all the material. I accordingly detailed Captain Hine with his company to build the tower and furnished him with the plan. Up to this time, owing to the late movement of the several corps, but little has been done toward furnishing material. Colonel Fisher, signal officer, who now has charge of delivering the material, undertakes to furnish it as speedily as practicable, so that the work will be probably commenced in a few days.

On the morning of the 5th I sent Captain Folwell with two companies to repair the works in front of the Ninth Corps, on the right of the Norfolk railway, and on the morning of the 6th I sent a detail of two more companies, Captain Dexter commanding, to repair the works on the left of the Norfolk railway. Captain Folwell reports that during the night of the 5th and day and night of the 6th the revetments, damaged scarps, and damaged abatis were repaired at all points from Fort McGilvery to the Norfolk railway. Two new doors were also placed on the magazines at Fort Morton.