HEADQUARTERS ARMY OF THE POTOMAC,
August 10, 1863-7 p. m.

Commanding Officer Cavalry Corps:

I am directed by the major-general commanding to acknowledge the receipt of Brigadier-General Gregg's report* upon the detachments sent over to establish the picket line south of the Aestham River, and to say that it was unsatisfactory; for it was reported by General Gregg that the enemy picketed the south bank in force, and apprehensions were expressed by him that his outposts or pickets might be captured; yet a detachment of merely 1 officer and 16 men is sent from Welford's Ford to communicate with the right of Buford's picket line, 4 miles distant. Why so small force was sent on this duty when Colonel [General] Gregg entertained the apprehensions referred to, in the opinion of the major-general commanding, requires explanation.

Very respectfully,

A. A. HUMPHREYS,

Major-General, and Chief of Staff.

[Inclosure.]

HEADQUARTERS CAVALRY CORPS,
August 10, 1863-8 a. m.

Major-General HUMPHREYS,

Chief of Staff:

GENERAL: The report from General Gregg, forwarded last night, is the latest received from him. General Kilpatrick reports all quiet along his picket line. A small squad of the enemy's cavalry showed themselves on the Falmouth road below United States Ford yesterday morning.

Two of Kilpatrick's men in disguise went into one of Mosby's rendezvous and found some 20 or 30 horses grazing. They made out they were Mosby's men. I have sent out a sufficient party to capture the concern. A second report from Kilpatrick just in states the squad of rebel cavalry captured a messenger; took him to Dumfries, and there paroled him. He sends in 6 prisoners; 2 are deserters from the rebel.

He (General Kilpatrick) further reports that scouts report that numbers of deserters from General King's command, and the commands at Fairfax and Manasses, are joining Mosby for the purpose of plunder. It is thought some of Mosby's men are in the commands referred to, in the character of spies, influencing our men to desert.

General Merritt reports no change in front of Colonel Devin, or in the immediate front, as regards the enemy. Colonel Huey reports no change or occurrence worthy of note.

Very respectfully,

A. PLEASONTONO,

Major-General, Commanding.

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*See McIntosh's report of skirmish near Welford's Ford, Part I, p. 67.

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