HDQRS. ARMY OF THE POTOMAC, SIGNAL DEPARTMENT, July 12, 1864.

Major General A. A. HUMPHREYS,
Chief of Staff:

GENERAL: I have the honor to forward the following reports just received from the signal stations at Jordan's house and near plank road:

JORDAN'S HOUSE, July 12, 1864-6 p.m.

Same as usual along this line. Enemy are strengthening their works on the plateau opposite.

CLARK,

Captain.

NEAR PLANK ROAD, July 12, 1864-6 p.m.

No movement of troops sine this a.m. Trains have been seen on Weldon railroad near lead-works, but none south of that point. The enemy have been at work almost all day on their lines north of station.

DUFF,

Lieutenant.

I am, general, very respectfully, your obedient servant,

B. F. FISHER,

Captain and Chief Signal Officer, Army of the Potomac.

WALTHALL SIGNAL STATION, July 12, 1864-7.45 p.m.

Captain FISHER,

Chief Signal Officer, Headquarters Army of the Potomac:

A heavy smoke hangs over everything in view. Enemy very busy about Farley's this p.m. The steam reported in direction of Whitehead's has been visible all day and may be a steam-mill. Intercepted rebel message:

Colonel BRENT,

Assistant Adjutant-General:

No movements of troops in enemy's camp about Cobb's this p.m. Three gun-boats off Point of Rocks and one gun-boat above pontoon.

OPERATOR,

At C.

(Same to A. B.)

CHAS. L. DAVIS,

Captain,&c.

CIRCULAR.] HEADQUARTERS ARMY OF THE POTOMAC, July 12, 1864.

General headquarters is located near the Prince George Court-House road about half a mile west of Birchett's house.

S. WILLIAMS,

Assistant Adjutant-General.

SPECIAL ORDERS,
HDQRS. ARMY OF THE POTOMAC,

No. 185.
July 12, 1864.

* * * * * *

5. Brigadier General R. De Trobriand, volunteer service, is assigned to duty with the Second Army Corps, and will report for further instructions to Major-General Hancock, commanding that corps.

By command of Major-General Meade:

S. WILLIAMS,

Assistant Adjutant-General.