guerrillas. McKee, with the cavalry of your corps from Dumfries camp which could be gotten ready, is at the mouth of the Monocacy to-night, probably. Two regiments of infantry should be there tomorrow, as well as the battalion of regular engineers, with bridges (afloat on the canal). If you want assistance, you can send for McKee and the infantry, if within your reach. General Howard is at Goose Greek (Trappe Rock mill-dam and canal lock). See the McDowell map. Meade at Gum Springs. The advance of the infantry is suspended until further information of the enemy's movements. Two regiments of Stahel move early to-morrow morning to Warrenton, Sulphur Springs, Rappahannock Station, &c. The officers will be directed to communicate anything learned to you, as well as here. Captain [J. M.] Robertson's brigade, horse artillery, sent to Fort Runyon to refit, has been ordered to rejoin on the morning of 21st, via north shore of the Potomac. He is to join the army wherever it may be. If Lee's army is in rear of his cavalry, we shall move up by forced marches with the infantry. Give us any indications of it as soon as possible. Make the country forage your command as far as practicable wherever you go.

Very respectfully, &c.,

DANL. BUTTERFIELD,

Major-General, Chief of Staff.

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HEADQUARTERS ARMY OF THE POTOMAC, Fairfax Station, Va.,
June 17, 1863-12 midnight.

Commanding Officer Cavalry Corps:

Since writing your last dispatch, the inclosed have been received from Point of Rocks, or Sandy Hook. It may be that [E. V.] White is there, to cover Stuart's crossing, or vice versa. This should be prevented, or he should be caught. Slocum's corps has been ordered to march from Dranesville to Leesburg at 3. 30 a. m. I inclose copy of his order. * He ought to be up by 9 a. m. to-morrow (or to-day, 17th).

Very respectfully, &c.,

DANL. BUTTERFIELD,

Major-General, Chief of Staff.

[Inclosures.]

SANDY HOOK, MD., June 17, 1863.

(Copy received, War Department, 11 a. m.)

GENERAL SCHENCK:

Our scouts report the country clear of any masses of rebel troops. Our information as to the route of the rebel forces in inconclusive. The best inference is that they have gone through Rommey, via Oldfield, toward Staunton. Am expecting the arrival of the two regiments every moment. Milroy's men are still coming in, but in less numbers than I had hoped.

DAN. TYLER.

(Same, Schenck to Averell.)

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*See p. 178.

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