WASHINGTON, D. C., October 12, 1864.

Brevet Brigadier-General McCALLUM,

Washington, D. C.:

GENERAL: The Secretary of War directs that, in relations for the murderous acts of guerrilla bands, composed of and assisted by the inhabitants, along the Manassas Gap Railroad, and as a measure necessary to keep that road in running order, you proceed to destroy every house within five miles of the road which is not required for our own purposes, or which is not occupied by persons known to be friendly. All males suspected of belonging to, or assisting, the robber bands of Mosby, will be sent, under guard, to the provost-marshal at Washington, to be confined in the Old Capitol prison. The women and children will be assisted in going north or south, as they may select. They will be permitted to carry with them their personal property and such provisions as they may require for their own use. Forage, animals, and grain will be taken, for the use of the United States. All timber and brush within musketry fire of the road will be cut down and destroyed. Printed notices will be circulated and posted that any citizens found within five miles of the road hereafter will be considered as robbers and bushwhackers, and be treated accordingly. Copies of these instructions will be sent to General Augur and General Sheridan, with orders to give you all possible military aid for the accomplishment of these objects. The inhabitants of the country will be notified that for any further hostilities committed on this road or its employes an additional strip of ten miles on each side will ba laid waste, and that section of country entirely depopulated.

Very respectfully, your obedient servant,

H. W. HALLECK,

Major-General and Chief of Staff.

ALEXANDRIA, VA., October 12, 1864.

Lieutenant Colonel J. H. TAYLOR,

Assistant Adjutant-General:

The following dispatch received this evening:

The guerrillas attacked three men near wood-pile, killing one and wounding the others; one fatally. Will write particulars.

C. BARNES,

Colonel, Commanding .

W. M. GWYNNE.

SPECIAL ORDERS, HEADQUARTERS SIXTH ARMY CORPS, No. 215.
October 12, 1864.

7. In accordance with instructions from headquarters Middle Military Division, the Provisional Brigade of the Third Division of this corps, under command of Colonel Heine, is relieved from this command, and will remain at Front Royal upon the movement of this corps to-morrow and await instructions from the headquarters last named. The cavalry under Colonel Dotze will report to Colonel Heine.