to the country between the Bull Run Mountains and Blue Ridge, for the purpose of hunting up and driving out guerrilla parties known to infest that region. On Sunday night [August 2], at 12 o'clock, I received information that Lieutenant-Colonel [E. V.] White, with 400 men, were encamped at Landmark, near Middleburg. I at once saddled up and started to attack him. Arriving at the point, found his deserted camp, and learned that he had moved a few hours before, but in what direction I could not learn. It being yet dark, I was not able to take trail. However, I moved rapidly on in the direction supposed by citizens to be the trail taken. At 5 a. m. [August 3] I learned that I was on the wrong road, and, believing that he had gone toward Leesburg, I struck across the country in that direction. Not finding his trail, I rested in the mountains until Tuesday morning, when I again started toward Snicker's Gap, striking the trail of Mosby, who had gone toward Chester Gap, with some 80 mules and 50 prisoners, captured with a train near Alexandria. I at once took this trail, and pursued with all vigor to Cobler Mountain, and although too late to overtake the train, I captured some dozen of Mosby's men. Mosby having escaped, I at once returned, by way of Upperville, to look again after White. At Middleburg I learned that White was near Leesburg, preparing to accomplish the original design that had brought him to Landmark, i. e., a raid with his force, combined with Stringfellow's and other straggling guerrilla parties, on Alexandria, to plunder and destroy Government stores there. He was reputed to have now assembled 600 men. I rested at Middleburg five hours, my horses being much exhausted, and then set out to find White, and prevent this expedition. Going down the Catoctin range, I again came upon his camp, deserted but a few hours, and learned that he had again taken fright, having heard that I was returning with a large force, and gone to Snicker's Gap. I pursued some distance, but getting information that he had undoubtedly crossed into the Shenandoah Valley, I considered farther pursuit with my jaded horses impracticable. I returned to Aldie, and at night sent the body of my command, under Lieutenant-Colonel Litchfield, to camp here, and, with 30 picked volunteers, I set out for Dranesville and Frying Pan, whither I learned Stringefellow, with some 40 men, had gone. On Friday [August 7], at 2 p. m., I ran into this party, and, giving them a volley, they broke in all directions through the thickets. We chased some squads across Goose Creek, but most of them escaped. I then returned to this camp, arriving at 5 p. m. to-day. The results of the expedition are 20 prisoners, mostly Mosby's and White's men, generally taken with arms and horses, some 40 horses, 84 head fat cattle, and a quantity of contraband goods, cottons, and blankets, which property I have directed to be turned over to the provost-marshal, and, most important of all, the prevention of the contemplated raid to Alexandria, which, in the present state of our line of defense, would, I fear, have been successful, and attended with great damage to us. Further, I have gained such information of the haunts and habits of these guerrillas as will be of great use in future expeditions, should it be the pleasure of the commanding general to send me again in search of these fellows. The command took but little forage or rations with them, but were