BALTIMORE, MD., June 17, 1863.

(Received 9. 50 p. m.)

Major-General HALLECK,

General-in-Chief:

Has General Heintzelman the country patrolled about Poolesville and in toward Annapolis Junction? It ought to be. I have no cavalry to send in that direction. Eight rebel cavalry come up from the Potomac last evening, and visited the railroad station next this side of Mount Airy, 40 miles from Baltimore. They alarmed the people, but only asked for news. They were evidently out on a scout to get information.

ROBT. C. SCHENCK,

Major-General.

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JUNE 17, 1863-10. 30 p. m.

General DANIEL TYLER,

Sandy Hook:

A force of cavalry, with two regiments of infantry and a bridge train, are ordered to the mouth of the Monocacy, via Washington, from this army. They will be there to-morrow morning. Fitz. Lee's brigade of cavalry were driven out of Aldie by our cavalry this afternoon. Stuart is reported at Middleburg. Their presence there may indicate Noland's Ford or that vicinity as a point of crossing. Please see that our infantry guard Noland's and Hauling Fords.

DANL. BUTTERFIELD,

Major-General, Chief of Staff.

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WASHINGTON, June 17, 1863-11. 45 p. m.

General SCHENCK,

Commanding, &c., Baltimore, Md.:

I have the country patrolled above Poolesville and along the Potomac as high as the Monocacy on this side, and have scouts out on the other toward Leesburg, but no patrols in toward Annapolis Junction. The railroad is guarded by a regiment of infantry as far as above the mouth of the Monocacy. I see no necessity for any patrols in the rear of my troops.

S. P. HEINTZELMAN,

Major-General, Commanding.

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BALTIMORE, June 17, 1863.

Colonel TRUEX, Monocacy:

The rebels are in possession of Harper's

Ferry. Our forces are on Maryland Heights. Approach with great

caution, and feel your way on to the Heights, sending scouts in advance, and when within range show your colors, so as not to be fired on from the Heights. General Tyler expects you.

By order:

DONN PIATT,

Chief of Staff.