MEDICAL DEPARTMENT.

Surg. George L. Pancoast, U. S. Volunteers, medical director.

Surg. R. W. Pease, Tenth New York Cavalry, medical inspector.

Asst. Surg. G. M. McGill, U. S. Army, assistant medical inspector.

First Lieutenant C. B. McLellan, Sixth U. S. Cavalry, provost-marshal.

Captain V. E. von Koerber, First Maryland, topographical engineer.

First Lieutenant Ferd. Theilkuhl, topographical engineer.

Colonel G. A. H. Blake, First U. S. Cavalry, commissary of musters.

First Lieutenant I. W. Trask, Eighth Illinois Cavalry, chief ambulance officer.

AIDES-DE-CAMP.

First Lieutenant C. Thompson, First New York Cavalry.

First Lieutenant G. W. Yates, Fourth Michigan Infantry Volunteers.

First Lieutenant James F. Wade, Sixth U. S. Cavalry.

First Lieutenant George H. Thompson, First Rhode Island Cavalry.

First Lieutenant E. B. Parsons, Eighth New York Cavalry.

First Lieutenant D. W. Littlefield, Seventh Michigan Cavalry.

First Lieutenant James G. Birney, Seventh Michigan Cavalry.

By command of Major-General Pleasonton:

C. C. SUYDAM,

Assistant Adjutant-General.

THOROUGHFARE MOUNTAIN, CULPEPER COUNTY, VA.,

October 3, 1863.

Captain L. B. NORTON,

Chief Signal Officer, Army of the Potomac:

SIR: In compliance with General Orders, Numbers 9, Signal Department, headquarters Army of the Potomac, I have the honor to submit the following report of the set under my charge during the month of September, 1863:

September 5, assumed charge of the signal station on Watery Mountain, near Warrenton, Va., relieving Captain Hall. Second Lieutenant W. H. Warts, with one flagman, reported to me for duty. At the time of taking charge, the station was in communication with the following points, viz: Near Germantown, with headquarters of the army and headquarters Cavalry Corps at Warrenton; headquarters Sixth Army Corps, at Catlett's Station: headquarters Eleventh Army Corps, near Jefferson; headquarters Second Cavalry Division, and near Warrenton with Colonel McIntosh's brigade, of the Second Cavalry Division. Communication with the last-named point was had by orderlies, a detail having been made by Colonel McIntosh.

September 8, reported to me for duty, Flagman Charles A. Griffin and James H. Smith. From the 5th to the 12th, inclusive, telescopic reconnaissances were made in direction of the enemy from three to six times daily, but without discovering anything of importance. The atmosphere decidedly unfavorable for observation during the entire period.

The movement of our cavalry upon Culpeper commenced on the morning of September 13. The progress made by it from the time of first engaging the enemy at Muddy Run, 5 miles from Culpeper, was noted and reported to General Sedgwick and yourself.