They chanced on a party of his cavalry toward Leesburg, which was evidently sent out by Stuart to reconnoiter toward Snickersville. Our party was only about 300 men, and accolade not go farther. I believe that the infantry spoken of was sent out to protect Stuart in his recrossing the Potomac. General Stahel reports also that during the last day a most vigorous pass system was kept up by the enemy near the Shenandoah against Unionists and Secesh without distinction. This may have been done to cover Stuart's raid, or a more general movement. A party just returned from Broad Run and found no enemy there.

I have ordered strong patrols to go out in all direction toward north west, and the main cavalry force from Centreville to Chantilly to stay there until further orders, as they are unable to make a long march to-night. I have also sent a regiment of infantry to Fairfax Station; two pieces of artillery will follow. In case of an attack, I will concentrate our troops where I think it best, and report.

F. SIGEL,

Major-General.

[Indorsement.]

Major General GEORGE B. McCLELLAN:

Respectfully forwarded.

N. P. BANKS,

Major-General, Commanding.

HEADQUARTERS DEFENSES OF WASHINGTON,
October 14, 1862-1 p.m.

Brigadier General S. WILLIAMS,

Assistant Adjutant-General Army of the Potomac:

General Stoneman's command concentrated at Poolesville, the general reporting to General McClellan; consists of Birney's brigade, Robinson's brigade, and Berry's brigade, augmented by several new regiments.

Whipple's division has not left Washington yet. Your question as to what force will be left here when all ordered have gone I will answer later.

RICH'D B. IRWIN,

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

HEADQUARTERS DEFENSES OF WASHINGTON,
October 14, 1862-12 p.m.

Brigadier General S. WILLIAMS,

Asst. Adjt. General, Headquarters Army of the Potomac:

Telegram received 11.25 p.m. I sent you list of Stoneman's troops by mail of Sunday. Have not means of repeating it to-night, but will in the morning.

Whipple's division consists of Piatt's brigade, in which are the Eighty-sixth New York, 462; One hundred and twenty-second Pennsylvania, 841, and One hundred and twenty-fourth New York, 950; total, 2,253. Carroll's brigade, Eighty-fourth Pennsylvania, 242; One hundred and tenth Pennsylvania, 234, and One hundred and sixty third New York, say 700; total, 1,176. Also the following unassigned: One company engineers