My pickets last night extended above Barnett's Ford, but were driven in. This morning, as I wrote you last night, I went out with the intention of extending them so that they should meet General Buford's pickets, with whom I had communicated that day. Colonel Karge before day started from camp with 160 men from the New Jersey Cavalry. He passed Elm Farm, and taking a road leading to Madison, got round the enemy between there and Liberty Mills, and his advance guard, Captain Janeway, captured some 20 men, who had gone into a house to get breakfast. They were infantrymen, and reported that Ewell had crossed the preceding evening in force. Colonel Karge, therefore, fell back after a large camp in his front was reported.

In the mean time I proceeded to the front with Major Beaumont's battalion, which passed Dr. Slaughter's, and the vedettes went in sight of the enemy's camp. Numerous tenets were seen, men lounging about camp, a large train parked, and the whole covered by numerous pickets. I therefore ordered the forces to fall back to the road which Colonel Karge had taken, which I held under a heavy fire until all Colonel Karge's forces had returned. Just before we reached Robertson's River they opened upon us with shell from two guns; I do not think there were more.

I think I am now 5 miles from Culpeper. I burned some blankets in the Pennsylvania camp, which, I believe, are our only loss. I sent an orderly to Captain Boyd, commanding the pickets below Robertson's River, to hold out as long as possible, like myself, and then fall back. He has not yet reported, but I sincerely trust he has fallen back on Colonel Duffie. He has 60 men and they surely cannot be all captured. They must have escaped some way.

The Jersey regiment left one portable forge, which Colonel Karge says the quartermaster shall pay for, as its loss was entirely useless.

One corporal is, I fear, mortally wounded, and 1 private severely.

I am, sir, very respectfully, your obedient servant,

GEO. D. BAYARD,

Brigadier-General, Commanding.

Colonel SCHRIVER, Chief of Staff.

HDQRS. CAVALRY BRIGADE, THIRD ARMY CORPS,
Camp five miles from Culpeper, Va., August 8, 1862.

COLONEL: I fell back to this point to-day, holding a line of pickets and vedettes 1 mile to the front, when General Crawford came up and encamped 1 mile in advance of my utterly exhausted troops.

Colonels Allen and Duffie reported this evening, and the latter to-night is on picket; and by order of General Roberts I have to-night ordered an advance of two squadrons to find the enemy. My pickets were all driven in, off, or captured.

I still hope to hear of Captain Boyd and his 60 men and that they are not captured.

To-morrow I shall re-establish my line of pickets if we are successful in driving off the enemy, and I will then send you the report you desire. The enemy are about 2 miles in advance of us.

I am, sir, very respectfully, your obedient servant,

GEO. D. BAYARD,

Brigadier-General, Commanding Cavalry.

Colonel SCHRIVER, Chief of Staff