_Sunday, June 21._--At Gainesville. A battle is going on between Pleasanton's and Stuart's cavalry near Ashby Gap. Our cavalry pickets near Gainesville, were driven in this afternoon. Three companies of infantry, and the right section, got ready for support. About seven o'clock P. M., General Stahl's division of cavalry, with three rifled guns and a four-pound howitzer, taken from Moseby, near Fairfax Court House, two weeks ago, passed through, going to Warrenton. A dangerous experiment was made by John Tyng this evening. Pounding on a round shell, lying there since the second battle of Bull Run, the shell exploded amidst a crowd of the battery, without hurting any one.
_Monday, June 22._--Gainesville. It was read in line that General Pleasanton, supported by Barnard's division of infantry, Fifth corps, gained a victory over Stuart's cavalry at Upperville and Ashby Gap, taking two guns and a quantity of small arms.
_Tuesday, June 23._--Gainesville. Trains came up from Alexandria this morning, bringing supplies. Stahl's cavalry came back from Warrenton.
_Thursday, June 25._--Gainesville. Orders came to pack up. Two trains arrived from Alexandria, bringing supplies, and the news that the telegraph line had been broken and several cars burned, between this place and Fairfax Station, by guerillas. We left Gainesville at noon, crossed the Bull Run, marched on the Winchester and Leesburg turnpike, passed Sudley's church, taking the same route we did under McDowell, going to and coming from the first Bull Run battle, until we turned off to Gum Spring, halting for the night. Marched eighteen miles in all. Battery B, lost a caisson and two men taken prisoners, coming from Thoroughfare Gap.
_Friday, June 26._--Gum Spring. Left at ten o'clock A. M., going to Edward's Ferry, where we arrived by eight o'clock P. M.--ten miles march. Two pontoon bridges are drawn across the Potomac. Troops are going over all the time. We halted for the purpose of camping. Tents were pitched, but the order came at ten o'clock P. M., that all the troops had to cross before daylight. General Hayes' brigade of Heintzelman's corps, consisting of the Thirty-ninth, One Hundred and Eleventh, One Hundred and Twenty-fifth, and One Hundred and Twenty-sixth New York regiments, was attached to the Second corps.