HEADQUARTERS FIRST CAVALRY DIVISION, DEPARTMENT OF WEST VIRGINIA,
Charlestown, Va., August 19, 1864.

Captain GEORGE B. SANFORD,

Acting Assistant Adjutant-General,

Hdqrs. Chief of Cavalry, Middle Military Division:

SIR: I have the honor to state that an ambulance, with some wounded in it, was captured by guerrillas near Halltown about an hour or two since. The ambulance was without guard, and was passing to Harper's Ferry, having arrived just at the had of a wagon train, with a guard of five men coming in this direction. The five men failed to do anything on the pretense of being too weak. It is impossible for me to take the responsibility for the safety of Halltown and vicinity with the small force of cavalry which I have. I would call your attention to the fact that my reports show only 1,000 men for duty. I have 150 men constantly on picket; about 100 guarding trains at the present time, and about 150 men on scout and patrol duty. Add to this the necessary details for camp duty, and more than half my command is constantly on duty. It is impossible for me, under these circumstances, to insure safety from guerrillas at Halltown.

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

A. N. DUFFIE,

Brigadier-General.

P. S.-I have just received information that the men, six in number, have been retaken by my troops, but the rebels made off with the ambulance and horses.

I am, sir, very respectfully, &c.,

A. N. D.,

Brigadier-General.

HEADQUARTERS MIDDLE MILITARY DIVISION,
Charlestown, August 19, 1864-8 a.m.

Brigadier General W. W. AVERELL, Commanding Cavalry Division:

GENERAL: Your dispatch of 12 p.m. received. General Merritt is at Berryville, with four brigades of cavalry, picketing form Snicker's Ferry, via Stone Church, on Millwood pike, round to the Opequon. General Wilson is at Summit Point, picketing the Opequon country, his left connecting with Merritt. General Wilson has scouting parties on the east bank of the creek, scouting the country between Martinsburg pike and the creek; General Merritt also has scouting parties on the east bank of the creek, on the Berryville and Winchester pike. Latest report last night was that the enemy were moving toward Berryville. Our infantry line crosses the Charlestow pike at North Fork of Bullskin Run, and extends to Welch's Spring, on the Summit Point road. Did you receive dispatch of 1 p.m. yesterday?

JAS. W. FORSYTH,

Lieutenant-Colonel and Chief of Staff.

HEADQUARTERS MIDDLE MILITARY DIVISION,
Charlestonw, August 19, 1864-5 p.m.

Brigadier General W. W. AVERELL, Commanding Cavalry Division:

GENERAL: I want you to look out sharply for a movement of the enemy toward Martinsburg. All the reports from my front indicate a