HEADQUARTERS ARMY OF THE POTOMAC,
August 13, 1864-10.30 p. m.

Major-General WARREN,

Commanding Fifth Corps:

I am instructed to inform you that Major-General Hancock, with the Second Corps and other troops and Gregg's cavalry, is conducting an operation of the same character and with the same object as that undertaken by him on the 26th ultimo. The chief engineer, Major Duane, has been directed to stop the work on the intrenchments to-morrow, so that the requisitions for working parties need not be met. If Hancock's movement should lead to the almost entire abandonment of the enemy's intrenchments in our front, the commanding general will take advantage of it by withdrawing the greater part of the Fifth and Ninth Corps, or one of the corps and part of the other, leaving a thin line in the intrenchments, and undertake such operations as my seem best. The commanding general therefore directs the enemy's lines be closely watched and every arrangement be made with a view to the movements here indicated.

A. A. HUMPHREYS,

Major-General and Chief of Staff.

(Same to General Willcox, commanding Ninth Army Corps.)

HEADQUARTERS ARMY OF THE POTOMAC,
August 13, 1864-12 midnight.

Major-General WARREN:

I think, in view of contingencies to-morrow, you had better draw in any part of your command that may be on the Norfolk road, or between there and the redoubt in rear of the Chieves house, and not hold any farther to the left than that point after holding your line with the minimum force. Your available reserves had better be concentrated on your left ready for movement.

GEO. G. MEADE,

Major-General.

HEADQUARTERS NINTH ARMY CORPS,
August 13, 1864.

General WILLIAMS:

I have the honor to report that no changes or anything of importance occured on my front during the night. The picket-firing was quite heavy.

A. E. BURNSIDE,

Major-General.

HEADQUARTERS NINTH ARMY CORPS,
August 13, 1864.

Major-General HUMPHREYS:

We had on fatigue duty last night 1,000 men; to-day we have 1,200 men. To-night 1,000 have been ordered. An additional working party for to-night of 400 are now colles for. The details have been called for by Captain Harwood, of the engineers. I desire to know if they are authorized, and to state that the corps is not in condition to furnish