HDQRS. DEPT. OF VIRGINIA AND NORTH CAROLINA,
CHIEF ENGINEER'S OFFICE,

August 1, 1864.

GENERAL: I have the honor to submit the following report of engineering operations in the department for the month of July:

The isolated batteries on the right flank along the James River have been completed and have had good, commodious bomb-proofs erected near them for the shelter of the men. The works at Deep Bottom were completed about the middle of the month. Those at Fort Powhatan have been carried on to near completion, requiring but a few days more to finish them. Another pontoon bridge was thrown across the river below Four-Mile Creek at Deep Bottom for the passage of the Nineteenth Army Corps to the left bank of the river. The roadway leading from the pontoon bridges across the Appomattox to those across the James were cleared, widened, and repaired for the use of the Second Corps on the 26th. During the sojourn of this corps on the left bank of the James a survey was made of the topography of that section of the country, which is embodied in the accompanying photographic maps. During the month photographic views have been taken of the principal batteries along the line of intrenchments, copies of which are sent with this report. A copy of the department orders naming the batteries is sent to designate the location of each battery on the tracing sent with the previous report. A photograph of the general map of the country, as far as our troops hold in this vicinity, is also forwarded. This embraces all topography surveyed by our own officers and in addition to that obtained from rebel maps found on prisoners of war.

Captain Farquhar reports the engineering operations of the Eighteenth Army Corps for the month of July as follows, viz:

I have the honor to submit the following report of the engineering operations of the Eighteenth Army Corps for the month of July, 1864, together with a tracing of the line of intrenchments occupied by it. I was assisted by a battalion of the First New York Volunteer Engineers, under the command of Major Graef, and by First Lieutenant C. B. Phillips, U. S. Engineers, who reported for duty July 9:

From the 1st to the 10th of the month nothing was done save the strengthening of our position by means of abatis.

On the 10th I received a leave of absence of ten days. During my absence Battery Numbers 5 (see accompanying tracing), for two 20-pounders; Battery Numbers 9, for two 8-inch mortars; Battery Numbers 10, for five Coehorn mortars, and Battery Numbers 11, for one Napoleon gun, were constructed under the direction of Lieutenant Phillips. The sap a b was also commenced for the gaining of a better position for sharpshooters, and should the position near the railroad prove favorable for a battery the mortar batteries were to keep by their fire the enemy from massing his troops in the low ground in front of our left, and to annoy his working parties. The Napoleon gun was to sweep the head of the sap. It being reported by officers that the enemy was mining our line between Batteries Nos. 4 and 5, a shaft was sunk on the 23d, but the nature of the soil and the proximity of water presented so many difficulties to mining that no galleries were run. A shaft was sunk at C, near Battery Numbers 8, and a listening gallery commenced on the 25th, running in front of Batteries Nos. 6 and 7. The shaft was sunk twelve feet deep; the soil was a sticky clay, containing a great deal of water, so that by the 30th the gallery was only about forty feet long. During the night of the 26th Battery Numbers 8. was commenced and Battery Numbers 9. was enlarged to make room for four Coehorn mortars. This increase of mortars was necessary to keep down the mortar fire of the enemy concentrated on the batteries near the Hare house. These batteries were all half sunken.

Before closing I will testify to the hearty co-operation and energy of Major Graef and his command.

Lieutenant W. R. King, U. S. Engineers, chief engineer of the District of North Carolina, reports the engineering operations there as follows, viz:

At New Berne laborers have been employed in completing Forts Dutton and Amory and in reveting of Fort Chase, sodding superior and exterior slopes of same work,