Of course, the boat was air-tight and water-tight, but it had a supply of fresh air that would last half an hour for one man. There was an oar for rowing and a rudder for steering. A valve in the bottom let in the water when the one-man crew wanted to sink his turtle-like boat, and there were two pumps to force the water out again when he wanted to rise.
There were windows in the top shell of the turtle, air pipes to let out the foul air and take in fresh air, small doors that could be opened when at the surface, and heavy lead ballast to keep the turtle level. In fact, the affair was, for the time, very ingenious and complete.
A very important part of it was the torpedo, with its 150 pounds of powder. This was carried outside, above the rudder. It was so made that when the boat came under a vessel the man inside could fasten it with a screw to the vessel's bottom, and row away and leave it there. Inside it was a clock, which could be set to run a certain time and then loosen a sort of gunlock. This struck a spark and set fire to the powder, and up—or down—went the vessel.
You can see that Dave Bushnell's invention was a very neat one; but, for all that, luck went against it. He first tried his machine with only two pounds of powder on a hogshead loaded with stones. The powder was set on fire, and up went the stones and the boards of the hogshead and a body of water, many feet into the air. If two pounds of powder would do all this, what would one hundred and fifty pounds do?
In 1776 the Turtle was sent out against a big British ship named the Eagle, anchored in New York Bay. The man inside rowed his boat very well under water, and after some time found himself beneath the King's ship. He now tried to fasten the torpedo to the bottom, but the screw struck an iron bar and would not go in. Then he moved to another place, but now he lost the ship altogether. He could not find her again, and he had to row away, for he could not stay much longer under water.
There is a funny story told about the man in the Turtle. He was a queer fellow named Abijah Shipman, but called by his companions "Long Bige."
As he entered the craft and was about to screw down its cover, he opened it again and asked for a chew of tobacco. All those present felt in their pockets, but none of the weed was on hand.
"You will have to go without it, old chap," said General Putnam, who was present. "We Continental officers can't afford even a plug of tobacco. To-morrow, after you have sent the Eagle on her last flight, we will try and raise you a whole keg of the weed."
"That's too bad," growled Bige. "Tell you what, Gineral, if the old Turtle don't do her duty, it's all along of me goin' out without tobacco."
After he had gone Putnam and his officers watched anxiously for results. Time passed. Morning was at hand. The Eagle rode unharmed. Evidently something had gone wrong. Had the torpedo failed, and was "Long Bige" resting in his wrecked machine on the bottom of the bay? Putnam swept the waters near the Eagle with his glass. Suddenly he exclaimed. "There he is." The top of the Turtle had just emerged, some distance from the ship.