4. The Sixth Army Corps will move on both sides of the pike, with its artillery on the pike, and will constitute the rear guard. Only such ambulances will be retained with the artillery as may be deemed necessary. Corps commanders will send a small escort with their trains.

5. General Custer's division of cavalry will continue on the Back road, and encamp to-morrow night on Tumbling Creek at the point that the Back road crosses said creek. The destruction of the forage, grain, &c., by the cavalry will be continued, in accordance with special instructions from the chief of cavalry.

By command of Major-General Sheridan:

JAS. W. FORSYTH,

Chief of Staff.

WASHINGTON, D. C., October 7, 1864.

General AUGUR:

I have directed General Wallace to send down from Ellicott's Mills a small cavalry force to try to watch the guerrilla robbers at Sandy Spring. A small force should be sent from here to cut off their retreat across the Potomac.

H. W. HALLECK,

Major-General and Chief of Staff.

WHITE PLAINS, October 7, 1864-11.20 a.m.

(Received 12.30 p.m.)

Major-General HALLECK,

Chief of Staff:

I arrived here at 7 this morning. The telegraph is just completed to this point. Mosby had possession of Salem for while, and is said to have destroyed a good deal of the track there. The construction train is now at Rectortown, with the Fifth Pennsylvania Heavy Artillery, well protected. It is said Mosby shelled awhile last night. Nothing is heard of him this morning. I have sent five companies from here to Salem, and requested the construction train to return there and repair the road. There is a large and heavy train off the track at Thoroughfare Gap, which will not be cleared away before this afternoon so that trains can pass. As soon as the cavalry arrives, all will be well here.

C. C. AUGUR,

Major-General.

SIGNAL STATION, D. C., October 7, 1864.

(Received 10.30 a.m.)

Brigadier-General HARDIN:

Last night a party of Mosby's men, two or three in number, robbed the store of Gilpin & Bently of property to the amount of $1,000. They have gone in a direct northwest course. The above report was given to the Eighth Illinois Cavalry; but as they were ordered in another direction they could not attend to it.

Respectfully, &c.,

THOS. ALLOCK,

Lieutenant-Colonel, Fort Reno, D. C.