At the request of Admiral, commanding the South Atlantic squadron, an expedition was formed, under the command of Brigadier-, to co-operate with the Navy in the of a fort at Saint John's Bluff, about 7 miles above the mouth of Saint John's River. One of the transports engaged in the expedition has just come in for a supply of coal, bringing a report from General Brannan announcing the capture of the fort, which was evacuated by the enemy after an attack by your gunboats. The rebels seemed to have left tho work in very great haste, as their guns wee all mounted, loaded, and in good condition, the ammunition served, and everything in excellent fighting order. The magazine will be blow up and the works will be utterly destroyed. it is intended to bring off the guns, namely, two 8-inch columbiads, two 8-inch guns, smooth bore, two 8-inch howitzers, and two 4.6-inch rifled guns. The gunboats had proceed up the river some distance, and report a large amount of corn on the river, which will be either brought away or destroyed.

Very respectfully, your obedient servant,

O. M. MITCHEL,

Major-General, Commanding.

Major General H. W. HALLECK,

General-in-Chief, Washington, D. C.

Numbers 2. Report of Colonel William B. Barton, Forty-eighth New York Infantry.

HEADQUARTERS U. S. FORCES,
On the Savannah River, Fort Pulaski, Ga., October 4, 1862.

LIEUTENANT-COLONEL: I have the honor to report, for the information of the general commanding, that in accordance with the permission granted in his communication of September 26 I left this post at 1 o'clock on the morning of the 30th ultimo, with armed steamers Planter and Starlight, having on board five companies Forty-eighth New York State Volunteers, under command of Captain D. W. Strickland, and a detachment of Company G, Third Rhode Island Artillery, in charge of Captain John H. Gould. We arrived at the mouth of May-commonly called Bluffton-River, about three-quarters of an hour before daybreak, and proceeded as rapidly as possible up the river. My original design was to land the infantry force at a point 1 1/2 miles this sid of Bluffton, and by making a rapid march gain a point in the rear of the village to which all the roads leading from it converge, and thus cutting off a squadron of cavalry I knew to be stationed there. Unfortunately, however, when within half a mile of this point, in the thick fog which prevailed the Planter ran aground, and the noise of the engines in getting her off revealed us to the enemy's pickets, and rendered anything like a surprise impossible. I however landed the troops as soon after the steamer got afloat as possible, and directing Captain Strickland to communication with me through his signal officer, proceeded with the steamers directly up to Bluffton, keeping some half a mile ahead of the troops on shore. This village is one of the most defensible possible against an attack by water, as the river makes a sharp turn a short distance from it and the bluffs entirely command the narrow channel through which vessels necessarily approach bows on. We