Junction, and the infantry of the Twelfth Corps at Brandy Station. Both are in readiness to proceed to Alexandria the moment they are furnished with transportation. It is supposed the Eleventh Corps will probably all be taken to Alexandria during the day. So far as known, no trains have yet arrived for the Twelfth Corps.

The two corps have been instructed to provide themselves with two days' cooked rations, and they have been ordered to leave at Alexandria their small-arms ammunition, excepting 40 rounds per man, to be carried in the boxes. Both General Slocum and Howard have been instructed to report to you by telegraph.

S. WILLIAMS,

Assistant Adjutant-General.

SEPTEMBER 25,[1863]-1.30 p.m.

Major-General SLOCUM, Commanding Twelfth Corps:

The major-general commanding directs me to say that cars for your troops will not be provided to-day, and that as your movements have been observed by the enemy, you should move your whole command, including trains of every kind,to Bealeton Station to-night. The movement should not commence until after dark, and no preparation for it made or anything done previous to its being dark, so as to conceal the movement as far as practicable. The troops should be screened at or in the vicinity of Bealeton Station train the observation of the enemy's signal officer on Clark's Mountain. Watery Mountain will be cleared by our cavalry.

A. A. HUMPHREYS,

Major-General, Chief of Staff.

BRANDY STATION, September 25, 1863.

His Excellency ABRAHAM LINCOLN,

President of the United States:

SIR: I have just been informed that I have been placed under command of Major General Joseph Hooker. My opinion of General Hooker both as an officer and a gentleman is too well known to make it necessary for me to refer to it in this communication. The public service cannot be promoted by placing under his command an officer who has so little confidence in his ability as I have. Our relations are such that it would be degrading in made to accept any position under him. I have therefore to respectfully tender the resignation of my commission as major-general of volunteers.

Very respectfully, your obedient servant,

H. W. SLOCUM,

Major-General of Volunteers.

CHATTANOOGA, TENN., September 25, 1863.

(Received 5.40 p.m.,26th.)

Hon. E. M. STANTON, Secretary of War:

Arrived at this place at 5.30 p.m.; found your dispatch of 7.33 p.m., September 24, waiting my arrival.

The telegraph wires are cut,and I can give you little reliable information in regard to the equipment of the railroad from Louisville to