HEADQUARTERS ARMY OF THE POTOMAC,
November 1, 1862 - noon.

Brigadier-General BAYARD,

Willard's Hotel:

Your dispatch of this morning, from Fairfax Court-House, received. General Pleasonton, with his cavalry, will occupy Philomont to-day. General Reynolds' corps will occupy Purcellville and Hamilton. Reynolds' and Burnside's corps will advance to-morrow to near Aldie and Middlesburg. Under these circumstances, the commanding general directs that you march your command toward Aldie, keeping your scouts well out to the front, so as to warn you of any very large force of the enemy, and, if you find you are to encounter too heavy a force, you will turn to the right toward Leesburg, and pass around in the direction of the river, so as to form a junction with this army at the earliest practicable moment. Please send your wagons to Leesburg, from whence you can draw your supplies from White's Ford, or, perhaps, Edwards Ferry. General Stoneman received his supplies from white's Ford. You had better see that sufficient supplies are sent by canal-boats to opposite Leesburg before you leave Washington. Please acknowledge the receipt of this, and inform me when you will probably reach Aldie and Leesburg.

R. B. MARCY,

Chief of Staff.

NOVEMBER 1, 1862.

General R. B. MARCY,

Chief of General McClellan's Staff:

SIR: Your dispatch is received. I will be in Aldie to-morrow by 1 o'clock. I cannot tell when my train will be in Leesburg; I presume by night. I had yesterday a horse battery from General Sigel's corps. There is another in General Sickles' division. I sent back Sigel's battery this morning, and, therefore, will have to move without artillery, unless a battery is ordered to me. I should like to have the battery from General Sigel's corps.

GEO. D. BAYARD,

Brigadier-General, Commanding Cavalry.

HEADQUARTERS CAVALRY BRIGADE,
Camp at Rappahannock Station, Va., November 10, 1862.

GENERAL: I have the honor to report that last evening the enemy opened with two pieces of artillery at a private ford, just above the bridge. After firing about half a dozen shots at the picket there, they moved up to Beverly Ford, and opened there in the same manner, and then withdrew about dark. Nobody hurt. The picket at Beverly Ford reports that their carbines killed 1 officer. I moved up with cavalry and two pieces of artillery, but in both instances they were too quick for me, and withdrew before I could get the pieces in position.

General Taylor's brigade has only 1,000 effective men. I think there should be a brigade of infantry at Bealeton, as my left flank is entirely exposed.

I send down toward Fredericksburg a squadron of cavalry each day. The horses get better fed while they are away from here is the reason that I send so large a force.