As soon as I heard of it I telegraphed to Captain Reed at Fort Ethan Allen to take his 80 men toward Dranesville, and directed Captain McKendry to follow as soon as he could see the trail.

Major Hall, Sixth New York Cavalry, with 70 men - part his own, part furnished from this command - having already started on a scout toward Gum Springs and Aldie, he could not be communicated with, but I relied on him to stop the main roads to the west. From Major Hall I learn force, and fact that Mosby and White had joined, and left Aldie on Monday.

From Captain McKendry I learned the force, and the route taken by Mosby on Tuesday. From Captain Reed I have not heard, but hope that he may yet give some account of the party that went toward Dranesville. He had 80 men with him and an excellent guide.

From other facts collected by Major Hall, I think it is Mosby's intention to leave the country round Gum Springs to White's men, and himself to move his headquarters to near Dranesville.

With your approbation, I propose to establish a regular escort of 30 to 50 men over the pike from Centreville to some point near Alexandria, once each way at irregular hours, all sutlers and stray wagons to be halted and compelled to come with this escort. This will be less fatiguing to my horses, and will, I think, with the detachments going to the front, afford all necessary protection to the sutlers.

I would call your attention to the necessity of having good officers in command of all detachments going to the front of cattle guards. With so many sutlers on the road anxious for escort, whisky is very easily obtained, and it is not uncommon to see both officers and men drunk.

I think most of the wagons broken down or left by Mosby have been plundered by our stray cavalrymen. I would also suggest that some more systematic method be adopted for encouraging citizens to bring in information. When citizens bring in valuable and reliable information, is there any fund from which I can rely upon their getting some reward?

I sent in 61 horses on Monday, and 55 more to-day, most of them United States horses, some captured, some collected to the northwest of here, and some near Maple Valley.

The party sent Sunday to Maple Valley remained two days scouring there, and has just returned from there. Kinchiloe left a week ago, according to last information. His men are again returning by twos and threes.

I am, colonel, respectfully, your obedient servant,

C. R. LOWELL, JR.,

Colonel Second Massachusetts Cavalry, Commanding.

Lieutenant Colonel J. H. TAYLOR,

Chief of Staff.

Numbers 2. Report of Major John S. Mosby, C. S. Army.

CULPEPER,

August 20, 1863.

GENERAL: On Tuesday, August 11, I captured a train of 19 wagons near Annandale, in Fairfax County. We secured the teams, and a