HEADQUARTERS ARMY OF THE POTOMAC, August 4, 1863.

Major-general Slocum:

It appears from the reports of the officer commanding the cavalry that you have misapprehended the position of Colonel Devin and his brigade. They were sent picket and scout the country in front of the Rappahannock, and particularly the roads from Kelly's Ford to Ley's, Germanna, and Stevensburg, with a view of ascertaining as far as practicable the position of the enemy and more particularly to notify you in the event of any movement threatening your position.

Under these circumstances, your withdrawal of the command to the south bank of the river, as reported, is not approved. Yo will please require Colonel Devin to carry out his original instructions received from General Buford, and, in case the enemy should think proper by superior numbers to drive him in, you will be prepared to support his retreat and withdrawal, if necessary, across the river, though this contingency is not deemed probable.

Please direct Colonel Devin to connect his pickets with those of Buford on his right, and I desire that you report to these headquarters with these headquarters.

Geo G. Meade,
Major-general.

HEADQUARTERS CAVALRY CORPS, August 4, 1863.

Major General George Stoneman,

Chief of the Cavalry Bureau, Washington:

General: I inclose for your information a copy of the trimonthly report of this corps for the 31st July, 1863.

The aggregate number of cavalry present for duty, not counting the horse artillery serving with it, is 12, 945; the aggregate number absent is 11, 922, and in case it is intended to fill up the regiments to their maximum standard of 1, 200 men to a regiment, 18, 333 more men will be required. There are 201 officers and 4, 228 men absent, sick, from the corps; allowing one-fourth to return in the next month, it will require 1, 000 additional horses to mount them. Including this number, it will take from 3, 000 to 4000 horses to supply deficiencies and keep the corps to its present standard with the ordinary duties of campaigning up to the 1st of September.

A very active campaign with a severe battle would greatly increase the number of broken-down and disabled horses. One of the most serious drawbacks in the injury of horses has been the loss of shoes, and the difficulty of having the horses shod before they become lame and are rendered unfit for service.

A great assistance in this respect would be to furnish a sufficient number of fitted shoes to the cavalry regiments in the field, to answer the campaign. The shoes sent to us have been such in many instances that could not be used or fitted on the march.

It is urgently recommended that the importance of keeping up the numbers of the officers in the different regiments be impressed on the Governors of States, to be given to those officers, non-commissioned officers, and men who have shown themselves most worthy of promotion.