Although Jackson was invisible from the decks of the mortar-boats and the direction given by sights fixed to the mastheads, the firing was so accurate and annoying as to attract a constant angry return from the fort. To draw off and divide this one of the corvettes and two or three of the gunboats took daily guard duty at the head of the line, from 9 A.M. one day to the same hour the next. The small vessels advancing under cover of the trees on the west bank would emerge suddenly, fire one or two shots drifting in the stream, and then retire; the constant motion rendering the aim of the fort uncertain. Nevertheless some ugly hits were received by different ships. Every night the enemy sent down fire-rafts, but these, though occasioning annoyance to the fleet, were productive of no serious damage beyond collisions arising from them. They were generally awkwardly started, and the special mistake was made of sending only one at a time, instead of a number, to increase the confusion and embarrassment of the ships. The crews in their boats towed them ashore, or the light steamers ran alongside and put them out with their hose. Mortar-firing, however good, would not reduce the forts, nor lay New Orleans at the mercy of the fleet. It was necessary to pass above. Neither the flag-officer on the one hand, nor the leaders of the enemy on the other had any serious doubt that the ships could go by if there were no obstructions; but the obstructions were there. As originally laid these had been most formidable. Cypress trees, forty feet long and four to five feet in diameter, were laid longitudinally in the river, about three feet apart to allow a water-way. Suspended from the lower side of these logs by heavy iron staples were two 21/2-inch iron cables, stretching from one side of the river to the other. To give the framework of trunks greater rigidity, large timbers, six by four inches, were pinned down on the upper sides. The cables were secured on the left bank to trees; on the right bank, where there were no trees, to great anchors buried in the ground. Between the two ends the raft was held up against the current by twenty-five or thirty 3,000-pound anchors, with sixty fathoms of chain on each. This raft, placed early in the winter, showed signs of giving in February, when the spring-floods came sweeping enormous masses of drift upon it, and by the 10th of March the cables had snapped, leaving about a third of the river open. Colonel Higgins was then directed to restore it. He found it had broken from both sides, and attempted to replace it by sections, but the current, then running four knots an hour, made it impossible to hold so heavy a structure in a depth of one hundred and thirty feet and in a bottom of shifting sand, which gave no sufficient holding ground for the anchors. Seven or eight heavily built schooners, of about two hundred tons, were then seized and placed in a line across the river in the position of the raft. Each schooner lay