Cannot see any force at Charlestown. Some general's headquarters were at Millwood. He moved at the head of the column that camped there.
Captain, Signal Officer.
L. B. NORTON,
Captain, and Chief Signal Officer.
HEADQUARTERS ARMY OF THE POTOMAC, July 21, 1863-10. 30 a. m.
Chief Signal Officer:
The major-general commanding directs me to acknowledge the receipt of the dispatch of 9 a. m. from the signal officer at Snicker's Gap, containing valuable information, and to say that it is highly important at the present time to know at the earliest moment everything that can be observed as taking place in the Shenandoah Valley, and to request that the signal officers report as frequently as practicable. Very respectfully, your obedient servant,
A. A. HUMPHREYS,
Major-General, Chief of Staff.
MIDDLEBURG, VA., July 21, 1863-12 m.
Chief of Staff, Army of the Potomac:
SIR: I have examined the ground in front of the town, and find an excellent position against forces coming from the direction of Ashby's Gap and from Warrenton, but it will require more than double my force to occupy it adequately.
The position I occupy at present in rear of the town has th disadvantage of presenting my left flank to the enemy if they come from the direction of Warrenton. I am limited to one or other of the two positions named, and cannot change one without taking up the other. If there are probabilities of an attack, I would prefer the position in front of the town, insufficient as my force is. I do not like to fatigue the troops by changing camp unnecessarily. I write this in hopes you may give me some information bearing on this point. Two squadrons of cavalry would be of great benefit to me. Very respectfully, &c.,
HEADQUARTERS FIRST CAVALRY DIVISION, One mile north of Salem, July 21, 1863.
Colonel C. ROSS SMITH:
I have the honor to state for the information of the major-general commanding that the Reserve Brigade encamped about a mile east of Manassas Gap last night, and undoubtedly will enter the Gap to-day. I have sent word to General Merritt to do all in his power to find out the enemy's position and movements. He encountered