lower bridges. The pontoon which had been brought up from below were accordingly ordered back. Eight or ten, however, had been already landed and drawn up on shore. By your direction, I remained at the middle bridge, with instructions to dismantle it when all the troops had crossed over. Owing to a misunderstanding of your orders on the part of one of the officers of the pontoniers, the dismantling of the bridge was commenced about 6 o'clock. As soon as I discovered the error, I directed the cheeses to be replaced. The interruption to travel over the bridge was not more than ten minutes in duration; but as the same officer had sent one of his men into the town to turn the troops to the upper bridge, a brigade was turned back that otherwise would have crossed at this place. As I was not able to put myself in communication with the officer commanding the rear guard, I could have no certain information when the town was entirely evacuated. I therefore directed a few cheeses to be taken up, the lashings loosened over every fourth boat, and every preparation made to float the bridge off in sections at a moment's notice. About 8 a.m. a half regiment passed over the bridge, the officer in command stating that they formed the rear picket, and that all our troops had evacuated the town. As the tide was running out rapidly, and a heavy northwest wind blowing, I saw that it would be exceedingly difficult to take the boats up the stream with the small force at my command, and directed the lashings to be refastened, the connection with the shore loosened at each end, a cable made fast to the extremity of the bridge next the town, and then fastened down the stream to the shore on this side. The boats were also all connected by a cable, a half hitch being made around each stanchion; all but three of the anchors were weighed, and the bridge held by spring lines to these. At 9 a.m. Captain Sterling, of General Butterfield's staff, came upon the ground and stated that the town had been entirely evacuated. I accordingly directed the bridge to be swung round, leaving four boats with crews to bring over stragglers. The few balks and cheeses connecting the farther extremity of the bridge with the shore fell off into the water, the bridge swung easily round,, was drawn in and made fast to the shore on this side, the whole process occupying less than five minutes. There are at this point, including those on shore, thirty-four boats.

Very respectfully,

H. W. BOWERS,

Assistant Adjutant-General.

Brigadier General D. P. WOODBURY

Commanding Engineer Brigade.

Numbers 19. Reports of Major James A. Magruder, Fifteenth New York Engineers.

CAMP NEAR FREDERICKSBURG, VA.,

December 12, 1862.

GENERAL: I have the honor to report as follows:

December 10. at 8 p.m., I marched seven companies of my command to the pontoon park, and at ten minutes before 1 a.m. of the 11th fell in line of march with my train in rear of regulars' train. At 5 a.m., just before the signal guns heard higher up the river, the train was in position at the appointed place, and at once unloaded. At 7 a.m. the abutment was begun, and the bridge was nearly finished without interruption from