Gap. Jackson's force is estimated between 25,000 and 30,000, composed of infantry, cavalry, and artillery, but principally of infantry. I will scout between the river and the mountains north and south of Ashby's Gap as far as possible.

With high respect, your obedient servant,

JNO. W. GEARY,

Brigadier-General, Commanding.

HDQRS. DEPARTMENT OF THE RAPPAHANNOCK,
Rectortown, Va., May 31, 1862.

Major General JAMES SHIELDS,

Commanding Division:

GENERAL: The major-general commanding has received with the greatest satisfaction, as well as the War Department, to which it was at once telegraphed, the report of your dash upon the enemy at Front Royal. It was most opportune, and its effects will be felt by them, as it will be inspiriting to our own troops.

The general is doing everything possible to send forward re-enforcements, prepared for the field in every way. King's division is to leave Catlett's this morning; his infantry by way of Manassas by rail, and Colonel Haupt promises to have his wagons up by to-night. Ord's whole division was encamped 5 miles in advance of this last night, and was to go forward to-day, and by 5 o'clock a. m. Bayard's cavalry brigade is at Thoroughfare Gap, and is coming forward.

Have you heard from General Geary? If the railroad does not fail us, and we have no accidents, you will be heavily re-enforced to-day.

Major-General Fremont telegraphed he will be at Strasburg by 5 o'clock p. m. to-day. Get your division well in hand to go forward to his support.

Corinth is evacuated by the enemy.

Very respectfully, your obedient servant,

ED. SCHRIVER,

Lieutenant-Colonel and Chief of Staff.

HDQRS. DEPARTMENT OF THE RAPPAHANNOCK,
Piedmont, Va., May 31, 1862.

General JOHN W. GEARY:

SIR: General McDowell has received your communication of the 31st of May from Upperville, but knows nothing of the three reports alluded to as having been sent by you. But one has been received.

As to the occupation of the Vestal's and Keys' passes, the general says he does not with to divide your command so much, but you must merely have small mounted parties there to warn you of any approach to them.

Unless Aldie can be occupied in force, which your command will not allow, it is best not to do so at present.

Occupy Ashby's Gap in force, and keep your brigade well in hand. There was a successful dash on Front Royal day before yesterday by Shield's advance brigade, in which a quantity of property and a number of prisoners were taken.

The enemy was threatening Harper's Ferry last night.