HEADQUARTERS DEFENSES OF WASHINGTON,
September 11, 1862.

Major-General HALLECK,

Commander-in-Chief, U. S. Army:

GENERAL: I have the honor to inclose to you a synopsis from the reports of the 10th instant of the forces in and near Washington for its defence. I t is as near to the exact strength as "reports" will bring us. The aggregate is probably somewhat larger than the actual number of troops ready for duty.

I have the honor to be, with much respect, your obedient servant,

N. P. BANKS,

Major-General, Commanding.

P. S.-The number of guns reported is one hundred and twenty; forty of these are heavy guns in garrison. The balance is doubtless field artillery.

Troops for defense of Washington.

CORPS D'ARMEE.

General Heintzelman's corps d'armee 16,000

General Porter's corps 21,000

General Sigel's corps 9,800

________

46,800

IN GARRISON.

General Abercrombie (Ethan Allen) 1,335

Lieutenant-Colonel Senges (Third New York Artillery) 266

Colonel Greene (Fourteenth Massachusetts, First

Wisconsin, Sixteenth Maine). 2,400

Colonel Tyler (First Connecticut Artillery) 1,056

Lieutenant-Colonel Haskin 6,458

General Woodbury 4,000

METROPOLITAN GUARD.

General Wadsworth 4,000

General Slough 2,500

______

6,500

PROVISIONAL BRIGADES.

General Casey 4,500

RECAPITULATION.

Three corps d'armee 46,800

Troops in garrison 15,500

Metropolitan Guard 6,500

Provisional brigade, Casey 4,500

_______

73,300

One hundred and twenty guns are reported.

WASHINGTON, September 11, 1862.

(Received 8.45 p. m.)

Major-General HEINTZELMAN, Commanding:

General Fitz John Porter's corps will be directed to move to-morrow morning to Brookville, via Leesborough, to report to General McClellan. The space left by this corps in the defense of Washington will be immediately filled by other troops under your command.

H. W. HALLECK,

General-in-Chief.