HEADQUARTERS ARMY OF THE POTOMAC, July 26, 1864.

Major-General BURNSIDE:

What length of fuse is required for the mine?

E. R. WARNER,
Lieutenant-Colonel,&c.

HEADQUARTERS NINTH ARMY CORPS, July 26, 1864.

Lieutenant-Colonel WARNER,

Headquarters Army of the Potomac:

We require enough to make four lines of 600 feet each.

A. E. BURNSIDE,

Major-General.

CITY POINT, July 26, 1864.

Major-General BURNSIDE:

Is there any reason to suppose the enemy have found your mine?

HEADQUARTERS NINTH ARMY CORPS, July 26, 1864.

There are no indications that the enemy had discovered the location of the mine, but I am satisfied that they know that we are mining, and that they have sunk shafts with a view to ascertaining where our galleries run, because they were heard at work there day before yesterday. But the rain of night before last has evidently filled their shafts, which has delayed them in their work, and we have heard nothing of them either yesterday or to-day, except the ordinary work on the surface, laying platforms,&c. The placing of the charge in the mine will not require us to make any noise, so that I hope we will escape discovery until such time as it may be deemed advisable to use the mine. I am just sending to General Meade, by his order, a statement of my proposition for exploding the mine and the operations to follow it.

A. E. BURNSIDE,
Major-General.

CONFIDENTIAL.] HEADQUARTERS, ARMY OF THE POTOMAC,

July 26, 1864.

Major-General BURNSIDE,

Commanding Ninth Corps:

GENERAL: The major-general commanding directs me to inquire whether anything has transpired connected with your mine that leads you to believe that it is in danger from countermining? If it is your conviction that it is so endangered, then the commanding general authorizes you to make every preparation for springing it, but directs that you do not explode it earlier than to-morrow afternoon, Wednesday,