the three battalions of a corps forming a regiment, the commanding officer being chief pioneer of the corps. From this force details could be made for he columns of troops and wagon trains; the later would be efficient train guards. During the operations around Petersburg I often left the need of such organization to supply the place of heavy, untrained, shiftless infantry details. With a force of this kind I could have secured expedition and uniformity of construction, and could have kept that portion of the line under my charge in much better repair. Such a regiment could have been camped at some central point, and in case of necessity would have answered all the purpose of a reserve. Infantry details, with some few exceptions, I have found slow, careless, and, worse than all, stupidly ignorant of what was required of them, both in throwing up fortifications and in improving roads.

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

C. W. HOWELL,

First Lieutenant, Corps of Engineers, Brevet Captain, U. S. Army.

Bvt. Colonel J. C. DUANE,

Chief Engineer, Army of the Potomac.

Numbers 17. Report of Lieutenant Charles B. Phillips, U. S. Corps of Engineers.

HEADQUARTERS U. S. ENGINEER BATTALION, April 21, 1865.

COLONEL: In accordance with your instructions, I have the honor to report the service upon which I have been engaged during the recent campaign.

On the 28th of March last I was directed by you to report for temporary duty to Major-General Parker, commanding Ninth Army Corps. On the 29th, 30th, nd 31st ultimo I was engaged on the line then held by the Ninth Army Corps (in front of Petersburg, Va.), repairing the damages done to a portion of our line at various times by the enemy's shell, the principal injury being at Fort Haskell, where several embrasure had been destroyed. Changes were also being made in the armament, as at Fort Davis, where 30-pounders were to be placed in position.

On the 1st instant I also (by direction of General Parker) selected at several points along the line positions for trous-de-loup, which obstructions General Parke proposed having placed in our line.

On the morning of the 2nd instant (just before daylight) an attack was ordered upon the enemy's works in front of Petersburg. The main point of attack selected was Fort Mahone, on the plank road, opposite Fort Sedgwick, on our troops, nd met with a correspondingly stubborn resistance form the enemy (considering their strength), the latter not appearing to be in very great force at that point. The work was carried, and the guns which were taken (and which were uninjured by he enemy) were immediately turned on the enemy's line, being supplied with ammunition carried by hand form Fort Sedgwick. These guns, although not rendering the line untenable to any great extent on either side of Fort Mahone (on account of the arrangement of traverses on the line) yet proved to be of great service in repelling he assaults of the enemy, who repeatedly in the course of the day made