HDQRS. FIRST ARMY CORPS, ARMY OF THE POTOMAC, October 17, 1863.

C. KINGSBURY, Jr.,
Assistant Adjutant-General, First Army Corps:

COLONEL: I have the honor to report that while at teh right of the picket line, to post orderlies, as instructed by you, a sergeant of the Eighteenth Pennsylvania Cavalry came in and reported the following; That he, with a small squad, was posted on the Aldie pike as a post of observation; that about 50 of teh enemy's cavalry came through the woods on the right, thus cutting off their retreat by the Aldie pike; that they retreated across the country to the Gum Springs road, to where their pickets were posted, and found a body of the enemy's cavalry had come down the Gum Springs road, and the pickets had retired toward the Stone Bridge in confusion, leaving everything behind them. The sergeant came down the Gum Springs road, and taking the Warrenton pike, returned to his command.

A citizen, residing near where the cavalry pickets were posted on teh Gum Springs road, states the enemy's force that came down the Gum Springs road was not over 20, and supposed they were White's men. None of teh enemy's force were seen by teh infantry pickets.

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

Lieutenant, and A. C. M., Second Div., First Army Corps.

HDQRS. CAVALRY CORPS, ARMY OF TEH POTOMAC, October 17, 1863-8 p. m.

Brigadier-General BUFORD,
Commanding First Cavalry Division:

Please one of your brigades at Fairfax Court-House and send the other to Chantilly, to look after teh enemy toward Frying Pan and on our right flank. Acknowledge receipt.

A. PLEASONTON,

Major-General, Commanding.

HEADQUARTERS ARMY OF THE POTOMAC, October 17, 1863.

Brigadier-General GREGG:

You will picket below Wolf Run Shoals and back as far as Occoquan, after General Buford withdraws his pickets, which he is directed to do.

A. PLEASONTON,
Major-General.

SIGNAL STATION, October 17, 1863.

Major General A. A. HUMPHREYS,

Chief of Staff:

The signal officer on Centerville Heights reports that he sees-

No indications of enemy's forces at Manassas. There are no guns in such works as he can see. Can distinctly observe camp smokes in rear of Bristoe. Too smoky to see into Bristoe Station.

L. B. NORTON,

Captain, and Chief of Signal Officer.