The withdrawal of Imboden from the lower valley is not, I apprehend, to send him south, but to hold the passes in the upper valley and resist such expeditions as we now propose, or perhaps to operate on my rear, should I advance.

It has been raining very had since last evening. This will render all roads, excepting the pike to Gainesville, impassable, and will swell all the small streams and branches. I shall make every preparation with the utmost expedition to advance, and in the meantime select a cavalry command, and arrange the details for the raid ordered.

GEO. G. MEADE,

Major-General, Commanding.

WASHINGTON,

October 24, 1863-6. 45 p. m.

Major-General MEADE:

Yours of 2 p. m. is just received. I shall not be able to see the President before to-morrow to learn his views on your report of the present aspect of affairs.

H. W. HALLECK,

General-in-Chief.

OCTOBER 24, 1863.

Lieutenant Colonel C. ROSS SMITH:

Report from the cavalry advance toward Bealeton Station:

Colonel Devin's brigade, of the First Division, encamped last night at Liberty, pushing one regiment as far as Bealeton Station. This morning Colonel Devin sent two regiments to drive the enemy's pickets toward or across the river at Rappahannock Station, in order to establish his line at that point. Colonel Devin's men succeeded in driving the enemy from the woods a mile on this side of the river, and close on to the works over the burned bridge, where the enemy had their infantry in line, and from whence they immediately pushed forward about 3,000 men with a force of cavalry, the infantry moving on the north and the cavalry on the south side. Colonel Devin fell back, being closely followed by the enemy's infantry, as far as Liberty, when the enemy halted, and in a short time fell back, followed by our forces, toward Bealeton. Colonel Devin did not engage the enemy, merely observing his movements, losing only 1 man killed and a few wounded.

Colonel Devin expects to have his brigade advance by sunset close to Bealeton, as the last reports from his advance guard say:

The enemy seem to be retiring to their previous position in the works at Rappahannock Bridge.

Colonel Gregg reports to have learned from a prisoner, or deserter, that Ewell's corps occupy the works at the bridge, two divisions being on this side. Both of our cavalry brigade commanders agree in saying that there is at least one division of rebel infantry on this side.

A locomotive was heard to approach the bridge last night from Culpeper.

Respectfully forwarded.

MYLES W. KEOGH,

Captain, and Aide-de-Camp.