moved west. I have sent a small party due north to try to reach the pike, and when it returns think I shall feel in that direction myself, as being the speediest and surest way to ascertain what has been or is going on. The cavalry picket on this road is now placed at Cabin John's, two and a half miles above. Everything quiet.

Yours, respectfully,

C. R. LOWELL, JR.,

Colonel Second Massachusetts Cavalry.

Lieutenant Colonel JOSEPH H. TAYLOR,

Assistant Adjutant-General.

FORT RENO, July 13, 1864.

The following I have just received from Colonel Lowell, dated four and one-half miles from Rockville, 9.15 a. m.:

Their first picket was about one mile from here. Have sent out to try and take it, but fear it has already withdrawn. Their rear guard left the Bethesda Church about 4 a. m. The main body (McCausland's cavalry brigade) fell back about midnight. Have sent a company to move up the roads to the left, and have now sent another to go to the right, to the old city turnpike, from Leesborough to Rockville, to see what is there and to pick up stragglers.

C. R. LOWELL, JR.

M. D. HARDIN.

Lieutenant Colonel J. H. TAYLOR,

Assistant Adjutant-General, Twenty-second Army Corps, and

General McCOOK.

FORT RENO, July 13, 1864.

(Received 12.35 p. m.)

The following has just been received:

ONE AND ONE-HALF MILES FROM ROCKVILLE--10.15 a. m.

There seems to be no force till within a quarter and a half mile from Rockville. They have been passing on the old city road certainly ever since daybreak. The last passed about half an hour ago. Captain Rumery, who took his company on that road, reports from citizens that Breckinridge and Early passed during the night. He also reports that a part of their column passed an hour since. Citizens here report their trains moving on that road when they went to bed last night, and columns of dust seen and noise heard all this morning. The rebels talked to the citizens as if they were going to cross the river the first opportunity. It might be well to have the section of artillery to advance when we find where they are crossing and try to annoy them. From the River road on the left I last heard half an hour ago; the party then a mile from Offutt's Cross-Roads; nothing seen or heard of them since. Any serious attempt against them with infantry must, I think, be made soon. Three prisoners taken from Early's old division of Early's present corps confirm the above. They left the line before the infantry soon after sundown. They say they have been rn to death. They think Early and Breckinridge and all are going west from Rockville. My advance is within a half mile of Rockville.

10.30 a. m.--Captain Rumery, on the right, saw their infantry column, one on right and one on left of Poolesville road, moving back a little, diverging apparently. This may be their train. Rumery is moving up. Their rear guard, or some large force of infantry and cavalry guard, are reported by citizens seven and a half miles from Rockville, on the Leesborough old city road, in line. My company must then be in their rear. Possibly they are our own men. This last report comes from a scout sent on the extreme right.

LOWELL,

Colonel, Commanding Cavalry.