CONFIDENTIAL.] HEADQUARTERS ARMY OF THE POTOMAC,

July 26, 1864-8 p.m.

Major-General WARREN,

Commanding Fifth Army Corps:

I am instructed to inform you that General Hancock is moving his corps across the James River, and that General Sheridan, with two division of cavalry, is likewise moving across it. It is supposed that his movement will induce the enemy to send a considerable part of his force now in four front toward Richmond, and that an opportunity will be presented to attack him here. Should it occur, an assault will be made from Burnside's front, preceded by the springing of his mine, which is now being prepared for explosion. In such case you will be required to support Burnside's attack, concentrating your force on his left. This will require the abandonment of a part of the front you now hold. The commanding general desires you to have in view the arrangements necessary to carry out such project, and to be prepared to execute orders to that effect. The mine cannot probably by fully prepared before

to-morrow night.

A. A. HUMPHREYS,

Major-General and Chief of Staff.

HEADQUARTERS FIFTH CORPS, July 26, 1864.

Major-General HUMPHREYS:

If the picket-line is relieved on my left, east of the plank road, what line is it expected I shall picket?

Respectfully,
G. K. WARREN,

Major-General.

HEADQUARTERS ARMY OF THE POTOMAC, July 26, 1864-9.10 p.m.

Major-General WARREN,

Commanding Fifth Corps:

The infantry picket-line on your left, east of the plank road, was taken off this afternoon and had most replaced. The commanding general does not think that any material modification of your picket-line there is necessary.

A. A. HUMPHREYS,

Major-General and Chief of Staff.

HEADQUARTERS FIFTH ARMY CORPS, July 26, 1864.

Brigadier General S. WILLIAMS,

Assistant Adjutant-General:

I have the honor to report all quiet and nothing unusual transpiring on my front to-day. The following details been at work on the line to-day: First Division, 400 men; Second Division, 600 men;