Bushnell lost no time. In ten days the machine was ready. It was a peculiar-looking affair, justifying its name by its resemblance to a large ocean-turtle. In the head, or front portion, was an air-tight apartment, with a narrow entrance. It was claimed to be capable of containing fresh air enough to support life for half an hour. The bottom of the machine was ballasted with lead. Motion was obtained from an oar, adapted for rowing backward or forward, while a rudder under control of the operator served for steering purposes. In the bottom was a valved aperture, into which water could be admitted when it was desired to sink the machine; while the water could be ejected by two brass pumps when the operator wished to rise again. The torpedo arrangement consisted of two pieces of oak timber, hollowed out and filled with powder, the space containing a clock-work arrangement that could be set to run any time desired, and a contrivance for exploding the powder when the time expired. This torpedo was fixed in the rear of the vessel, and was provided with a strong screw, that could be turned by the operator, so as to fasten it under the bottom of a ship or in other desired location. So far as appeared, the contrivance was not unpromising. It failed in its purpose, but solely, if the word of the operator may be taken, from the absence of an indispensable article of supply. What this was will appear in the sequel. Captain Bushnell's brother had volunteered for the perilous enterprise. A sudden sickness prevented him, and his place was taken by a venturesome New London sergeant named Abijah Shipman, or, as rechristened by his companions, "Long Bige." He was an amphibious chap, half sailor, half soldier, long, thin, and bony, and not wanting in Yankee humor. He had courage enough to undertake any enterprise, if he could only be primed with rum and tobacco, articles which he deemed the leading necessaries of life. It was an early hour of a July morning. The sun had not appeared on the eastern horizon. By a wharf-side on the Hudson floated the strange marine monster whose powers were about to be tested. On the shore stood Putnam and many other officers. In their midst was Abijah Shipman, ready to start on his dangerous enterprise. It was proposed to tow the nondescript affair into the stream, set it adrift on the tide, and trust to Abijah's skill to bring it under the bottom of the "Eagle," Admiral Howe's flag-ship, which had been chosen for the victim. If the magazine could be attached to the bottom of this vessel, she must surely be destroyed. But certainly the chances seemed greatly against its being thus attached. Everything was ready. Abijah stepped on board his craft, entered the air-tight chamber, closed the cover, and was about to screw it down, when suddenly it flew open again, and his head emerged.