HDQRS. THIRD ARMY CORPS, ARMY OF VIRGINIA,
Warrenton, Va., July 28, 1862.

Colonel DEVIN,

Commanding Sixth New York Cavalry:

SIR: You will proceed by the Falmouth road to Barnett's or Ellis' Ford; establish your at that place. Push out parties across the Rappahannock and across Ely's Ford and Germanna Mills, on the Rapidan, in such way as to keep under observation all the roads leading from the enemy's position, at or near Orange Court-House, across the Lower Rapidan and North Fork of the Rappahannock.

Immediately after your arrival you will report by letter to Brigadier-General King, commanding at Fredericksburg, and receive from him further orders for the performance of the duty hereby assigned to you. Make daily reports to General King, and such supplies as the country does not afford you under existing orders, and which may be necessary for your command, will be obtained from Fredericksburg. In procuring supplies from the country it must be done in the mode pointed out in orders, and not in indiscriminate by soldiers. Keep your men from strolling about the country in the neighborhood of your camp. For this purpose have a guard posted, and never allow a horse to be taken from a picket-rope except to go on some duty.

You are reminded that you are held responsible for the good order of your camp and the proper and soldierly conduct of your men. This can be best accomplished by keeping them always in hand and constantly engaged in acquiring a knowledge of their duties by drilling, &c. See also that the daily rolls calls prescribed by the Army Regulations are observed and absentees confined and punished.

Get all possible reliable information respecting the enemy's force and position by the employment of negroes and scouts and by putting yourself in communication with citizens in your neighborhood, especially a Colonel Morgan, a Union man, who will doubtless give you useful information.

Lieutenant Suter, of the Engineers, will accompany you. When he wishes to return please furnish him a sufficient escort.

By order of General McDowell:

ED. SCHRIVER,

Colonel and Chief of Staff.

WARRENTON, July 28, 1862.

Brigadier-General KING, Falmouth:

The Sixth New York Cavalry, eight companies, has been ordered to Barnett's Ford, above you, there to encamp. He is to report to you and to receive your instructions about the duty of observation and scouting he is ordered to perform, namely, to push out parties across the Rappahannock and across Ely's Ford at Germanna Mills, on the Rapidan, in such way as to keep under observation all the roads leading from the enemy's position, at or near Orange Court-House, across the Lower Rapidan and North Fork of Rappahannock. The force is to make daily reports to you.

ED. SCHRIVER,

Colonel and Chief of Staff.