alarmed the enemy, he fell back toward the ford before we could get rounds to his rear. We, however, with our dismounted men, attacked him in flank on rough ground, and had a sharp carbine engagement, taking about 511 prisoners, 61 of whom, together with 300 stand of arms, were turned over to an officer of Kilpatrick's division by mistake; also 3-inch Parrott gun, captured from the enemy by the Eight New York Cavalry, which was afterward sent by General Kilpatrick to the camp of this brigade, wherever it properly belong.

NEAR CHESTER GAP, VA., JULY 21 AND 22.

In obedience to orders, this brigade marched from near Rectortown Va., to Chester Gap(about 20 miles), arriving in that vicinity at 3. 30. p. m. July 21. About a mile from the Gap our advance line of skirmishers encountered the enemy's pickets. I dismounted six squadrons, and drove the enemy's pickets to the crest of the Gap on their reserve, which was found to consist of Pickett's division of infantry, one regiment of Jones' cavalry, and a battery of six guns, occupying the Gap, on the crest of the mountain. Upon obtaining this information, and not having a sufficient to drive enemy from the Gap, having no support nearer than 20 miles, we fell back 1. 1/2 miles from the Gap, and took position so as to cover the two roads leading from the Gap, one toward Barbee's Cross-Roads, the other to Little Washington and Sperryville; placed the guns in battery, and a strong line of pickets in front and flanks. We captured to-day 23 prisoners 84 horses, 12 mules, 654 beef cattle, 602 sheep, all purchased and on the way to be delivered to the rebel army at the Gap, in charge of a commissary agent and his son, who were also captured. July 22, at 8. a. m., my pickets reported the enemy advancing in column with skirmishers on the road from the Gap toward Sperryville. When the head of the enemy's column came within early range, we opened fire on it with artillery and the carbines of the dismounted men so effectually that his column, with his wagon train, halted and fell back out of our range, his advance guard and skirmishers being still engaged with ours, and continued firing, we holding our position and preventing the head of Longstreet's corps from moving forward from the Gap from 8 a. m. till 6 p. m., when the enemy bought five regiment of infantry around out of sight in the woods, and, approaching my left flank, drove in our skirmishers, and only by overwhelming numbers compelled me to fall back slowly toward Barbee's Cross-Roads, keeping my vedettes and pickets watching the enemy. I think it proper to state that our battery, under Lieutenant Heaton, Second U. S. Artillery, had the very worst kind of ammunition, and consequently could do but comparatively little execution. About one shell in twelve would explode, and then it would be prematurely, over the heads of our own men. A tabular recapitulation of killed, wounded, and missing is herewith appended, the usual list of casualties by name having previously been forwarded, according to orders.

All of which is respectfully submitted.

WM. GAMBLE

Colonel Comdg. First Brigade, First Cavalry Division.

Captain T. C. BACON,

Assistant Adjutant-General, First Cavalry Division