No. 6. Report of Captain B. F. Fisher, Acting Signal Officer, U. S. Army, of operations September 4-30.

SIGNAL CAMP, NEAR THE MOUTH OF ANTIETAM, September 30, 1862.

SIR: I have the honor to submit the following report of the manner in which the signal detachment of the Army of the Potomac has been employed since the 4th of September, upon which day I again resumed command of it, having been absent for a short time to recruit my health. For a detailed account of the messages sent and received and special services rendered, I refer you to the individual reports of the several officers composing this detachment.

The morning of the 4th September I joined the party, then encamped near Alexandria, Va. During the day I rode along the front, ascertained the manner in which our troops were stationed, and made the details for the next morning accordingly. Ordered Lieutenants Fralick and Kendall to Maryland Heights, and sent an order to Lieutenant Rowley to man Point of Rocks, Sugar Loaf Mountain, Poolesville, and Seneca with members of his party until I could send him assistance. Lieutenants Denicke and Daniels were ordered To Great Falls, Lieutenants Hebrew and Pierce to Fairfax Seminary, Lieutenants Jerome and Yates to Falls Church, Lieutenants Hill and Neel to Minor's Hill, Lieutenant Carey to Upton's Hill, Lieutenants Gloskoski and owen to hall's house, which was to be the center of all lines, to receive the reports and communications from all stations, and then transmit them by telegraph to Washington.

Friday, September 5, moved camp to the vicinity of Hall's Hill as being more central; ordered Lieutenants Hutchinson and Hall to Fort Pennsylvania. In the evening Lieutenant Herzog and I traveled over the hills in the neighborhood of Langley, to watch for the appearance of the signal torches of Lieutenants Denicke and Daniels upon the tower of Great Falls, according to prearrangements. Not discovering them, we returned to camp about 11 p. m. The next morning I rode up to Great Falls, and found that our lines were now extended to within a mile of our former station; was halted by Major-General Couch, and informed that it was not safe to go any farther in that direction; upon, however, being recognized by the general, I was permitted to use my own discretion, and proceeded to the station and opened communication with Lieutenant Spencer, then at Seneca, some 6 miles farther up the river, and learned through signals from him of the presence of the enemy in Maryland and the breaking up of the stations of Sugar Loaf and Poolesville and of the necessity to abandon Seneca for a short time. At 5 o'clock Lieutenants Daniels and Denicke arrived and occupied the station. Immediately upon giving my instructions, I rode rapidly back to Fort Pennsylvania, from which point communication was then opened with Great Falls.

Sunday, September 7 upon returning to camp, I learned that the troops generally were on the road to Rockville; whereupon I took steps to remove the camp at once to the north side of the potomac, and received your order to report with the party to headquarters of the Army of the Potomac at Rockville, Md. On Monday morning, at daylight, we were in the saddle and on the road for the Upper Potomac, and reported our arrival at Rockville to Colonel Colburn at 10 a. m., encamped