This was Bushnell’s submarine boat, but it was only one feature of his invention. His other discovery, the torpedo, was ingeniously combined with his vessel. On the stern of the boat, just above the rudder, on the outside, was a large cask, made of two pieces of oak, carefully caulked and tarred, and bound together with iron. The interior was dug out and contained a charge of powder. Within was a gun-lock, which was arranged to strike fire whenever a clock-work attachment ran down. The magazine was fastened to the boat by a screw, which could be unscrewed from within. It was contrived so that when the magazine should be disengaged from the vessel the clock-work should be set agoing. The clock-work ran down in about thirty minutes, when the gun-lock went off and ignited the charge. A short cable attached the magazine to another screw in the top of the vessel. From within the operator could fasten this screw into the bottom of a vessel and fill his own boat at the same time. He could, therefore, sail safely away, leaving the magazine attached to the bottom of the enemy’s man-of-war, and await developments. There was no evident reason why the attempt upon the _Eagle_ should not have a satisfactory issue. Sergeant Lee was obliged to wait several nights for a favorable opportunity. Finally, at eleven o’clock one night in August, he embarked on his dangerous voyage. General Putnam was on the wharf when he pushed off, and kept a constant watch throughout the next few hours. Lee was towed by whale-boats as near the ships as the oarsmen dared to go, and was then cast off. He discovered that it was too early to make the attempt. The tide was running strong, and, in spite of all that he could do, it carried him far beyond the ships. He rowed aimlessly around until the tide slowed up, when he made directly for the man-of-war. He drew so near under the stern of the ships that he could see the British sailors and hear their voices. At a favorable moment he let the water into the reservoirs and sank. Everything up to this point worked splendidly. He had no difficulty in managing his boat under the water, and took up a favorable position directly under the keel of the man-of-war, near the stern. He at once proceeded to attach the screw to the bottom of the vessel, when he struck a formidable opposition. He had not figured on the copper with which the bottom of the ship was covered, and which resisted all his attempts to fasten the screw. At every attempt the boat rebounded from the vessel’s bottom. Lee finally moved to another part of the ship, and in so doing lost his hold completely, and rose with tremendous velocity to the surface. He came within two or three feet of the man-of-war, upon whose destruction he had been bent--a rather uncomfortable circumstance, especially as it was nearly daylight. He at once, therefore, filled the reservoirs and sank again. As it would soon be morning, however, and as he had four miles to row, he decided