You will excuse this private letter; an official one on this subject might by some be through out of place.

Very truly and sincerely, your obedient servant,

JOS. K. F. MANSFIELD.

HEADQUARTERS SEVENTH ARMY CORPS,
Fort Monroe, Va., September 7, 1862.

Brigadier General O. S. FERRY,

Commanding at Suffolk, Va.:

I wish to complete a reconnaissance in the vicinity of the Dismal Swamp. It will be under the direction of Captain William Heine, who is engaged in constructing military maps of the district south and west of Suffolk. It will be necessary to send with him two companies of infantry, with two mountain howitzers, under a discreet and efficient field officer. It will probably be necessary to pass around the Dismal Swamp, returning on the east side. The men must have rations for eight days, and they must take with them their tents and the smallest practicable amount of camp equipage. During the first two or three days it will be well to send two or three companies of cavalry out on the road nearest to the Blackwater, in the direction of Somerton and Winton, as a cove to the movement. A number of wagons, sufficient to carry the provisions, forage, and tents, will be sent with them, and an ambulance for the use of the engineers. At this season the men should be covered at night, and if possible their tents should be pitched under the shelter of trees and their march should be suspended during the heat.

The movement will conform to the requirements of Captain Heine, who is charged with the reconnaissance; but the command of the escort, and all that relates to the control of the men, will be under the direction of the senior officer, who will be enjoined to enforce the strictest discipline. The inhabitants of the country will be protected against all disturbance, and the least violation of their property will be visited with the most extreme rigor of the law. Should it be necessary to procure supplies from the district through which the movement is made the commanding officer will endeavor to obtain them by agreement with the parties, or, if, compelled to take them, he will give receipts on public account and render a return to me of the articles taken with the names of the owners.

Everything will be in readiness on Monday, so that the party will move early on Tuesday morning, and I trust to you to make such arrangements as to insure the object of the expedition, and at the same time to carry out my wishes, which will be creditable to those who are engaged in it.

If you have not mountain howitzers we can send them from here.

Answer immediately.

JOHN A. DIX,

Major-General.

WAR DEPARTMENT,

Washington, September 7, 1862.

Major-General DIX, Fort Monroe, Va.:

Send to Washington as promptly as possible the First Delaware and the Third and Fourth New York Regiments, now as Suffolk.

H. W. HALLECK,

General-in-Chief.