calibers within his defenses, he made but slight use of artillery fire in delaying our approaches, the defense being almost entirely by musketry. Lack of ammunition was assigned as the reason for this by some of the Confederate officers, but we captured over 40,000 rounds of artillery ammunition, as reported to the Chief of Ordnance. Night sorties were made on our left by the enemy with some loss to ourselves and interrupting to the work, while in front of the Thirteenth Army Corps great friendliness prevailed at night, the enemy's pickets and our guards for working parties being within 10 yards of each other at times, without a shot being fired during the night. On one occasion, indeed, in the anxiety of each party to get all the ground possible, the opponents became completely intermixed, and the lines were only arranged after quite a discussion on mutual right, by the opposing officers. From the lack of educated engineer officers, the approaches and parallels were in some places badly located and much unnecessary work done. The boyaus were often sunk to the depth of 5 even 6 feet where the enemy's fire was heavy, largely increasing the amount of labor. The sap-roller was used in all close approaches, one of cane with a central cavity being found best. Canes with their joints crushed were found, 89, with 220 guns in position on June 30, as stated by the chief of artillery. Batteries were usually reveted with gabions, and also portions of the approaches. After Captain Prime's departure, the only officers of engineers present on engineer duty were Captain M. D. McAlester and First Lieutenant P. C. Hains. Captain McAlester reported June 28, and was assigned to the charge of operations on the left, where he rendered efficient assistance till relieved on July 5. Lieutenant-Hains was in immediate charge of the engineer operations of the Thirteenth Army Corps during the siege, and deserved the highest praise for his untiring energy and devotion to his work.

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

JOHN M. WILSON,

Captain of Engineers.

For C. B. COMSTOCK,

Captain Corps of Engineers.

Brigadier General John A. RAWLINS.

Number 6. Report of Lieutenant Peter C. Hains, u. S. Corps of Engineers, chief Engineer Thirteenth Army Corps. HDQRS. ENGINEER DEPT, THIRTEENTH ARMY CORPS, Vicksburg, MISS, July 30, 1863.

SIR: I have the honor to make the following report concerning the engineering operations performed under my charge in front of the Thirteenth Army Corps: The corps arrived in front, or in rear, of Vicksburg, as it is sometimes