HEADQUARTERS FIFTH ARMY CORPS, August 2, 1864-2.30 p. m.

Major-General HUMPHREYS:

I was at the front redoubt on the plank road this morning at 10 a. m., and it was reported to me that the sound of picking as if a gallery was being dug underneath had been heard there since yesterday morning; this was reported yesterday, I am told, to the engineer officer and to Colonel Tilton, commanding the brigade, who did not think it worth notice. No report of it came to me. I however went into the magazines and the sound of picking is constant and distinct; as many as three picks at work. I listened carefully and am satisfied the sound was not made by our troops. I at once ordered three pits to be sunk at different points and a gallery begun to the rear. I think we should settle the question in the shortest possible time and request that the engineer troops assigned to my command be returned to me for the purpose. I would also request that I be consulted in the location of the new defensive works, and have the power to decide upon the order and necessity for their construction, and that the engineer officers employed thereupon for the time report to me and camp with my command that they may then have the deepest personal interest in their work; there has already been a good deal of unnecessary labor spent and I cannot afford more. I have 1,500 men on picket and all the rest on line except Ayres' division. One thousand of this division I wish to put at once constructing a second line behind the salient threatened, so that the place will become untenable to the enemy even if his mining operations succeed, and so that I can withdraw most of my men from it. With this preparation made, [it might] be advisable to allow the enemy to go on, and let him try an assaulting column if he wishes. At any rate I shall endeavor to ascertain for a certainty what is going on underneath, if anything. I have necessarily other work and ideas of defense than engineer officers, and if they cannot work under my orders they are more of an injury to me now than a benefit.

Respectfully,
G. K. WARREN,

Major-General.

HEADQUARTERS ARMY OF THE POTOMAC, August 2, 1864-5.15 p. m.

Major-General WARREN,

Commanding Fifth Corps:

Your dispatch relative to mining, &c., is received, and the major-general commanding directs me to say your operations of counter-mining, &c., are approved, and that any additional means you require will be furnished. The engineer detachment is ordered to be returned to you temporarily. While the commanding general cannot accede to your proposition to place the engineers under your command, yet he is ready to receive any suggestions you may have to make in regard to their operations and to decide all points of difference that may arise. The chief engineer was directed to confer with corps commanders.

A. A. HUMPHREYS,

Major-General and Chief of Staff.