The trains will move with their corps, those at Westminster crossing to Middletown, via Frederick.

The Artillery Reserve follow, via Taneytown and Middleburg. Headquarters will be at Creagorstown to-night. The army will assemble at Middletown p. m. of the 7th instant. Headquarters train will move at once. All trains not filled with ammunition and supplies will be sent to Frederick.

The commissary and quartermaster's depots and supplies at Westminster will be transferred to Frederick.

The commandant at the Cavalry Corps will details a regiment to report to the provost-marshal-general, for the temporary duty of driving up all stragglers, and collecting all captured property, arms, ammunition, &c., on the recent battle-field. The medical director will establish a general hospital at Gettysburg for the wounded that cannot be moved with the army.

For the movement, and until the concentration at Middletown, General Sedgwick will, without relinquishing command of his corps, assume command and direct the movement of the corps forming the right-First, Sixth, and Third. General Slocum will, without relinquishing command of his corps, assume command and direct the movements of the corps, assume command and direct the movements of the corps forming the left-Twelfth and Second. General Howard will, without relinquishing the command of his corps, assume command and direct the movements of the corps forming the center-Fifth and Eleventh.

Staff officers will be sent to report at headquarters each night on all marches.

The battalion of regular engineers and other troops at Westminster will proceed to Middletown, via Frederick.

By command of Major-General Meade:

S. WILLIAMS,

Assistant Adjutant-General.

CIRCULAR.] HEADQUARTERS ARMY OF THE POTOMAC, July 5, 1863.

The movements of troops ordered to-day, and all arrangements dependent thereupon, are suspended until further orders.

By command of Major-General Meade:

S. WILLIAMS,

Assistant Adjutant-General.

HEADQUARTERS ARMY OF THE POTOMAC, July 5, 1863-10 a. m.

Commanding Officer Sixth Corps:

A scout just reports enemy's cavalry column four hours in passing-from 1 to 5 o'clock this morning. Passed from the Fairfield road on to the Emmitsburg road, via Moritz tavern, turning toward Emmitsburg. There were two guns. This may be a raid, or may be a movement to cover their flank. The point where this column turned into the Emmitsburg road was about 4 miles this side of Emmitsburg. Please communicate to General Warren.

Very respectfully, &c.,
DANL. BUTTERFIELD,

Major-General, Chief of Staff.