SEPTEMBER 18, 1862 - 3.30 p. m.

Major General GEORGE B. MCCLELLAN:

I communicate, for your information, the following telegrams, received this morning.

M. P. BANKS,

Major-General, Commanding.

[Inclosures.]

ARLINGTON - 12 m.

Captain RICHARD B. IRWIN,

Acting Assistant Adjutant-General:

Colonel Davies reports more definitely as to the enemy's force found at Leesburg. It was about 200 cavalry and 500 infantry; the latter composed of the force previously reported at Edwards Ferry and recovered sick and stragglers. They were intending to go to Harper's Ferry.

S. P. HEINTZELMAN,

Major-General.

ARLINGTON - 1.30 p. m.

Captain RICHARD B. IRWIN,

Acting Assistant Adjutant-General:

Colonel Davies reports no force of enemy at Centreville. The enemy have pickets at Groveton, and Sixth Virginia at Salem; also many sick and nurses at Centreville.

L. HUNT,

Acting Assistant Adjutant-General.

UPTON'S HILL, September 18, 1862.

Lieutenant-Colonel MCKEEVER:

I have a message from the expedition I sent out; will be back to-night. They, under Lieutenant-Colonel Kilkpatrick, found the passage of Goose Creek disputed ba a squadron of cavalry. This was dispossessed by artillery. They found at Leesburg one regiment of infantry and a battalion of cavalry, which they dove out of the town after a sharp action, in which the enemy's loss was considerable. One flag and a considerable number of prisoners were taken. Our loss was but slight. The Tenth New York behaved very gallantly. Colonel Kilpatrick reports there is no enemy between Harper's Ferry and Leesburg; none at Edwards Ferry, and but a few at Winchester.

J. M. DAVIES,

Colonel, Commanding.

HEADQUARTERS DEFENSES OF WASHINGTON,
September 18, 1862 - 1.10 p. m.

Brigadier General GEORGE STONEMAN, Poolesville:

Two telegrams received. Send down for rations. The commanding general thinks that, Harper's Ferry being almost beyond a doubt in the enemy's hands, and in the present uncertainty as to the result of operations of yesterday and the next day or two, concerning which some solicitude is felt here, it will be best not to detach any portion of the forces now here, for the present.

RICH'D B. IRWIN,

Captain, Aide-de-Camp, and Actg. Asst. Adjt. General