The night of the 11th of April was fixed on for the enterprise. The fire-ships were ready, but one mortar-vessel, the _Etna_, alone had arrived. The _Imperieuse_, from whence operations were to be directed, anchored close to the inner end of the Boyart Shoal. The _Aigle, Unicorn_, and _Pallas_ frigates, brought up in a line to the northward of her, in order to receive the crews of the fire-ships and support the boats of the fleet, while the _Etna_ anchored off the north-east point of Ile d'Aix, covered by the _Emerald_ frigate and four gun brigs. Two others, with screened lights hoisted, were to act as pointers for the guidance of the fire-ships. They were to pass between the two light vessels, and then shape a course for the boom. A strong wind from the north-west enabled the fire-ships to run about two points free for the boom. At 8:30 p.m. Lord Cochrane, accompanied by Lieutenant Bissell, embarked on board the largest of the explosion vessels, on the perilous undertaking, the other fire-ships followed. He was accompanied by a boat's crew of four volunteers only, in addition to the lieutenant. Having nearly reached the boom, he ordered the lieutenant and his men to get into the boat while he ignited the port-fires. It was supposed that the fusees would burn fifteen minutes, by the end of which time the boat might be well out of the range of the grenades; but scarcely five minutes had elapsed ere a terrific explosion occurred, throwing up a huge wave which nearly swamped the boat, while grenades and rockets were darting round them on all sides, shells and missiles of every description rising in the air. The escape of Lord Cochrane and his companions was almost miraculous, for not one of them was hit. The fire-ship, too, had performed her destined work, if not as completely as had been desired, sufficiently so to enable the _Mediator_ fire-ship, Commander Woolridge, to force her way. In his eagerness to direct her against the enemy, he remained till the explosion actually occurred, when he, with two lieutenants, a seaman, and the gunner, who was killed, were blown out of the ship. So well directed were the six other fire-ships that two fell on board the _Ocean_, of 120 guns, and the _Regulus_, a 74, the former being compelled to cut her cables, and she soon afterwards, narrowly escaping the Pallas Shoal, ran on shore, where she again had a narrow escape from another fire-ship. So panic-stricken were the French crews that every effort to escape was made. The scene was indeed truly terror-inspiring, the darkness rendering the effect of the burning ships, the flight of shells and rockets, and the flashes of the guns awful in the extreme.