accompany General Sherman on the expedition to Jackson and that on my return, after finishing the maps of that vicinity, I was taken sick, so as to be entirely unable to write, and have but just returned to duty from sick leave.

I have the honor to remain, very respectfully, your obedient servant,

W. L. B. JENNEY,

Captain and Aide-de-Camp on Engineer Duty.

Captain C. B. COMSTOCK, u. S. Engineers, Vicksburg MISS.

Number 8. Report of Captain William Kossak, additional aide-de-camp, U. S. Army, acting Engineer Officer. CAMP AT Vicksburg, MISS. near City Hospital, July 13, 1863.

SIR: I have the honor to submit to you the following report: According to copy of orders, annexed to this report,*I took charge of the trenches on and along the Graveyard road on the night of June 19. A part of the pioneer detachment of the SECOND DIVISION, Fifteenth Army Corps, under command of Captain Ashmead, furnished my saps with sap-rollers, gabions, fascines, and sap-faggots. Company I, Thirty-FIFTH Missouri Volunteer Infantry, lieutenant C. Lochbihler commanding, acted as sappers and miners, and an infantry detail of 50 men, for day and night, constituted the force that I used in the approach against the main bastion in front of Brigadier-General Ewing's brigade. To my right lay Brigade-General Lightburn's work, in charge of Colonel Malmborh, commanding FIFTY-FIFTH Illinois, attacking a stockade with advanced rifle-pits, situated in front the enemy's left; re-entering angle of the main bastion attacked by me. To my left was Colonel Giles A. Smith's work commanding Eights Missouri Volunteer Infantry, whose approach was directed to a more retired and smaller bastion on the enemy's right. When I took charge of the work approaching the main bastion, I found the work advanced with 20 feet of the enemy's counterscarp, with such obstructions in front of the sap-roller as to make it impossible to move the roller one inch without having the party engaged in the moving killed outright. I therefore branched off to the right and left, trying to raise trench cavaliers parallel to enemy's counterscarp and get a plying fire into his ditch. The sap-roller I left in its position, crowing it with gabions and sand-bags, so as to offer the pickets supporting working party a proper shelter. These trench cavalier I built during the 20th and 21st of June, when I discovered by the dull, deep sound of tamping to the left, that the enemy was mining to blow up the head of my sap. Immediately after this discovery I had counter ditches dug at the reserve slope of the ditch of my trench cavaliers t right angles to the direction of the mines of the enemy, hoping to strike either their chambers or their powdehole. This work took up the 23rd, of June, day and night. I found now that I could not strike the enemy's mines, having gone already to a depth of 10 feet the natural surface, where the enemy's mines could not be, his netraces lying much higher. I therefore started two counter-mines-one to the right, the other to the left

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*Omitted, as unimportant.

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