SEPTEMBER 21, 1863-10. 30 a. m.

Commanding Officer First Corps:

The major-general commanding desires you to examine Pony Mountain and vicinity, in view of the contingency that may arise requiring you to take position upon it with your corps. In such event, the Second and Twelfth Corps would be established between your corps and the Fifth Corps, which is now posted on the high ground in advance of Culpeper, and on the right of the railroad.

A. A. HUMPHREYS,

Major-General, and Chief of Staff.

SEPTEMBER 21, 1863-10. 15 a. m.

Commanding Officer Third Corps:

The major-general commanding desires you to examine the high ground upon the right of the Fifth Corps, with a view to establishing your corps in position upon it, in continuation of the position now occupied by the Fifth Corps. Major-General Sykes can indicate to you more exactly the high ground referred to.

A. A. HUMPHREYS,

Major-General, and Chief of Staff.

CONFIDENTIAL.] HEADQUARTERS ARMY OF THE POTOMAC,

September 21, 1863.

Major-General SLOCUM,

Commanding Twelfth Corps:

The major-general commanding directs me to inform you that a cavalry reconnaissance in force will be made to-morrow between Robertson's and Rapidan Rivers. The command is that which has been posted at Stevensburg.

A. A. HUMPHREYS,

Major-General, and Chief of Staff.

SIGNAL DEPT., HDQRS. ARMY OF THE POTOMAC,

September 21, 1863.

Major General A. A. HUMPHREYS,

Chief of Staff:

GENERAL: The following message has just been received, and is respectfully forwarded for the information of the commanding general:

SIGNAL STATION ON CLARK'S MOUNTAIN,

September 21, [1863]-12. 40 p. m.

Captain G.:

A body of cavalry, composed of about a brigade, moving from Stevensburg to Culpeper. Large wagon train coming up and parting at Mitchell's Station. Train of cars now at station.

WILLIAMSON.

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

L. B. NORTON,

Captain, and Chief Signal Officer.