The Bronx continued to dart ahead at her best speed, and no sound came from the fort. It was only a question of minutes now before the steamer reached a point inside of the island where she could accomplish her mission by the capture of the Sphinx. The officers remained on deck, but they were protected by the bulwarks, the masts, and especially under the shelter of the top-gallant forecastle. Christy had earnestly warned the second and third lieutenants not to expose themselves needlessly to the musketry of the fort, and Mr. Flint was discreet enough to need no such warning. "Soldiers on the fort, sir!" shouted Vincent, when the Bronx was within less than a quarter of a mile of the works. Christy and the first lieutenant sprang from the shelter where they had been waiting the passage of the fort, and rushed up the steps to the bridge. The commander of the force on shore, with half a dozen men, was at work on one of the guns on the barbette; but it was impossible to make out what they were doing. Then there was a flash, a cloud of smoke went up, and a shot crashed into the deck directly under the pilot-house, tearing up the planks, and disappearing in the space below. "Wheel disabled, sir!" shouted the quartermaster. "Beat to quarters, Mr. Flint!" said Christy, trying to make out what mischief had been done by the shot; but he could only see that it had cut the wheel ropes. "Strike two bells, Vincent!" he called to the quartermaster. By this time the executive officer had beat the crew to quarters, and every man was at his station. "Strike three bells, Vincent," continued the commander. "Mr. Flint, open fire upon the fort with the midship gun. Have the carpenter report at once on the damage done by that shot. Strike two bells, Vincent." It was plain enough to all the officers and men that the commander knew what to do in the emergency, and every one was energetic in the discharge of his duty. Mr. Ambleton was fully alive to the peril of the moment, and he was careful to make his aim sure with the great gun. It had been loaded before with a solid shot, and presently the steamer was shaken to her keel by the concussion of its discharge. Christy was still on the bridge, and he watched with intense interest the effect of the shot. In a moment he saw the carriage of the only gun that seemed to be mounted on the barbette flying in pieces in every direction. He directed the gunner to use a shell next time; but the soldiers had hastened away from the place, bearing with them two of their companions, doubtless wounded by the splinters. "Let go the anchor, Mr. Flint!" shouted Christy.