On through the darkness they went, hitting the channel squarely, and steaming in under the frowning walls of the Morro through gloom and death-like silence. But the Spaniards were not asleep. A small picket-boat came gliding out under the collier’s stern and fired several shots at the suspicious craft. One of these carried away the rudder and spoiled one important item of the plans. The dingy, which was trusted to for escape, disappeared, perhaps hit by one of these shots. The picket-boat, having done this serious mischief, then hurried ashore and gave the alarm, and quickly the shore batteries were firing on the dark hull. The ships in the harbor echoed the shots with their guns. The Spaniards were alert. They thought that an American battle-ship was trying to force its way in, perhaps with the whole fleet in its wake, and were ready to give it a hard fight. Through the rain of balls the "Merrimac" drove on, unhurt by the bombardment, and even by a submarine mine which exploded near her stern. The darkness and her rapid motion rendered her hard to hit, and she reached the desired spot, in the narrowest spot of the channel, none the worse for the shower of iron hail. So far all had gone well. Now the critical moment had arrived. Hobson gave the signal fixed upon, and the men below reversed the engine and opened the sea connections. They then dashed for the deck. Those above dropped the anchor and set the helm. Only then did Hobson, to his bitter disappointment, discover that the rudder had been lost. The ship refused to answer her helm, and the plan of setting her lengthwise across the channel failed. The final task remained. Touching the electric button, the torpedoes went off with a sullen roar and the ship lurched heavily beneath their feet. The sharp roll threw some of the men over the rail. The others leaped into the sea. Down went the "Merrimac" with a surge at the bow, cheers from the forts and the ships greeting her as she sank. The gunners thought they had sent to the depths one of the hostile men-of-war. At the last moment of leaving the "New York" an old catamaran had been thrown on the "Merrimac’s" deck, as a possible aid to the crew in extremity. This float lay on the roof of the midship house, a rope fastening it to the taffrail, with enough slack to let it float loose after the ship had sunk. It was a fortunate thought for the crew, as it afforded them a temporary refuge in place of the lost dingy. We may let Lieutenant Hobson speak for himself at this point in our narrative. He says, "I swam away from the ship as soon as I struck the water, but I could feel the eddies drawing me backward in spite of all I could do. This did not last very long, however, and as soon as I felt the tugging cease I turned and struck out for the float, which I could see dimly bobbing up and down over the sunken hull.