Lee is merely preparing for an anticipated extension of our lines, I am unable to say; but the existence of these reports and the movements known have combined to produce caution on my part during your absence. I deem it proper to call your attention to the small force of cavalry under my command. For ordinary purposes, and were the enemy without cavalry, it would be ample, but in the presence of the enemy's superior forces, this arms of the service is unable to accomplish anything. In yesterday's operations the lowest estimate of the enemy's forces made by prisoners and deserters is 6,000, and called suddenly, as our troops were, without time to draw in pickets and detachments, I question whether the combined commands that went in pursuit amounted to 3,000. With this superiority, a knowledge of the country, and preparations made to meet pursuit, it is hardly fair to expect much more than what was accomplished, though I hoped the difficulty of driving the cattle and the chances of war might prove more favorable to us. These is nothing else to report up to this hour.

GEO. G. MEADE,

Major-General, Commanding.

P. S.-General Birney has just telegraphed that a deserter, in this morning, reports Hoke's division withdrawn from his front, and that it has gone to General Lee at Reams' Station. This may mean General W. H. F. Lee, commanding cavalry, and to cover the withdrawal of the cavalry, or it may be part of an offensive movement.

[Inclosure.]

CITY POINT, September 17, 1864-1 p.m.

Major-General HUMPHREYS:

Yesterday evening the battalion of Government employes in Richmond were ordered to assemble this morning with the understanding that they would be sent to Petersburg. Reports will shortly be sent you.

SHARPE,

Colonel.

SEPTEMBER 17, 1864.

Colonel SHARPE,

City Point:

Deserters to-day from Wise's and Ransom's brigades, of Johnson's division, corroborate fully the information received yesterday of the movement of Hoke's division to the right - supposed to Reams' Station; also movement of other troops from Hill's corps. A large force of infantry, at least four or five brigades, from some point north of the Appomattox, passed through Petersburg on Wednesday eye and Thursday morning last. Eight prisoners sent in to-day from cavalry - representing that W. H. F. Lee's and Butler's division of cavalry and two battalions of artillery comprised the late raiding party, Hampton in command and W. H. F. Lee holding plank road to save their being cut off.

J. C. B.[ABCOCK].