Second Division of Ships—Pensacola, Morris; Portsmouth, Swartwout; Mississippi, Smith.
First Division of Gunboats, Captain T. Bailey—Oneida, Lee; Varuna, Boggs; Katahdin, Preble; Kineo, Ransom; Wissahickon, Smith; Cayuga, Harrison.
Second Division of Gunboats, H. H. Bell—Iroquis, De Camp; Sciota, Donaldson; Kennebeck, Russell; Pinola, Crosby; Itasca, Cauldwell; Winona, Nichols. Total, 18.
The mortar flotilla consisted of twenty-one brigs and schooners, and was divided into three squadrons of seven each. Besides these, five steamers, the Harriet Lane, (flag-ship,) Miami, Owasco, Westfield, and Clifton, were connected with the mortar flotilla, and these were afterwards joined by the Octorora, a new boat, commanded by Captain George Brown, of Indiana, which afterwards became Porter’s flag-ship.
The entire fleet, thus constituted, numbered forty-six vessels, carrying two hundred and eighty-six guns. On the morning of April 16th, it made a rendezvous in the river, at a distance of about four miles below Forts Jackson and St. Philip, the two formidable fortifications on the river, which it was necessary to pass before reaching the city of New Orleans. On the morning of the 16th, Commodore Porter brought up several schooners, and stationed them about two miles and a half from the forts, in order to ascertain the range of the mortars before opening the bombardment. After several hours of practice, in which the range was admirably obtained, and the execution on the works was plainly visible, Commodore Porter expressed himself fully satisfied, and suspended operations for the night.
Fort Jackson, which is by far the stronger work, is a regular pentagonal bastioned fortification, having two fronts bearing on the river, and three on the land side. The land fronts have each a glacis and covered way, and the channel is commanded by a battery of twenty-five guns. A wet ditch, from forty to seventy feet wide, and six feet deep, surrounds the main work on the river, and a similar ditch, one hundred and fifty feet wide, the land fronts. There is also a wet ditch, six feet deep, and thirty feet wide, around the channel-bearing battery. The two channel-bearing fronts have each eight casemated guns, which are the only casemated ones in the work. The ditches are defended by twenty-four-pounder howitzers at either flank. The parapet is carried across the gorge of the bastion, so that there is no flank parapet defence. The bastions are only arranged for musketry fire from the walls. The main work of the lower battery mounts in the aggregate one hundred and twenty-five guns, of which one hundred bear on the channel. There was a one-story brick citadel within the fort, having two tiers of loop-holes for musketry defence, the walls of which are five feet thick. The entrance to the work is by a wooden bridge on the west side, connected with a draw bridge ten feet wide.
Fort St. Philip consists of a main work and two attached batteries, which bear respectively up and down the river. The principal work is irregular in form, having seventeen faces. It is surrounded by a wet ditch six feet deep, and from twenty to thirty feet wide. At the foot of the glacis is a ditch from seventy to one hundred and forty feet wide. There is a glacis and covered way entirely around the fort. Outside of the principal ditch is another, which was dug to furnish earth for the levee, and this is twenty feet wide, and four feet deep. Fort St. Philip mounts one hundred guns, of which seventy-five bear on the channel. All the guns were mounted en barbette. The scarp works were strengthened by relief arches, which were pierced with loop-holes for musketry.
Both forts are built of brick. The guns of Fort Jackson are twenty-five feet above the level of the river, and those of St. Philip nineteen feet. The guns of the outer batteries of both forts are fourteen feet above the river. When the rebels took possession of these forts there were only thirty-six guns mounted, none of which were of larger calibre than thirty-two-pounders. All the carriages were poor. The plans for completing these forts were taken from the Custom house at New Orleans, just after the rebellion broke out, and the works were finished in accordance with the original intention. From centre to centre of the forts the distance is three-quarters of a mile, and the river between them half a mile in width.
On the 17th the rebels commenced their defence against the Federal fleet, by sending down the stream a fire raft. This incendiary messenger was a common flat-boat, about one hundred and fifty feet long, fifty broad and eight deep, filled with pine knots and other combustible matter, which burned fiercely, and sent a dense column of black smoke rolling heavily upwards as it was borne along by a fresh breeze that blew up the river. As soon as the raft floated near enough it was fired into and destroyed, without damage to the fleet, and then ran ashore. It was a timely warning to the squadron, for during the day the vessels were fitted up with grapnel-ropes, fire-buckets, axes and other appliances with which to attack other of these fiery islands that might be set adrift by the enemy.
The arrangements were scarcely completed, and the review made, when, about ten o’clock at night, a brilliant fire appeared on the river, flaming out from a heavy dense column of smoke, which rolled up and displayed another of the fiery pioneers of the rebel flotilla lying near the forts. It burned magnificently, and made a splendid pyrotechnic display for the sailors, who were waiting impatiently to reach the grand magazine whence it issued. Signals were made, and in a few moments a vast crowd of boats were launched upon the waters and moved rapidly toward the island of fire. The Westfield came plowing her way up and plunged her prow into the blazing mass, at the same moment opening her steam-pipes and pouring a heavy force of water into the hottest of the conflagration. Amid the steam and smoke and seething struggle of the flames, the men leaped upon the raft with their buckets, and completely extinguished the fire. Then the blackened and smoking mass of logs was sent contemptuously adrift to follow its companion.