"Boat o' some kind," he muttered; "but what kind? That screw's too small to make it go. Let's see the other end."
He launched it with difficulty, and noticed that when floating end on to the surf it ceased to roll and kept the T-shaped projection uppermost, proving that it was ballasted. Swinging it, he grounded the other end, which was radically different in appearance. It was long and finely pointed, with four steel blades or vanes, two horizontal and two vertical,—like the double tails of an ideal fish,—and in hollowed parts of these vanes were hung a pair of unmistakable propellers, one behind the other, and of opposite pitch and motion.
"One works on the shaft, t' other on a sleeve," he mused, as he turned them. "A roundhouse wiper could see that. Bevel-gearin' inside, I guess. It's a boat, sure enough, and this reverse action must be to keep her from rolling."
On each of the four vanes he found a small blade, showing by its connection that it possessed range of action, yet immovable as the vane itself, as though held firmly by inner leverage. Those on the horizontal vanes were tilted upward. Just abaft the T-shaped projection—which, fastened firmly to the hull, told him nothing of its purpose—were numerous brass posts buried flush with the surface, in each of which was a square hole, as though intended to be turned with a key or crank. Some were marked with radiating lines and numbers, and they evidently controlled the inner mechanism, part of which he could see—little brass cog-wheels, worms, and levers—through a fore-and-aft slot near the keyholes.
Rising from the forward end of this slot, and lying close to the metal hull in front of it, was a strong lever of brass, L-shaped, connected internally, and indicating to his trained mechanical mind that its only sphere of action was to lift up and sink back into the slot. He fingered it, but did not yet try to move it. A little to the left of this lever was a small blade of steel, curved to fit the convex hull,—which it hugged closely,—and hinged at its forward edge. This, too, must have a purpose,—an internal connection,—and he did not disturb it until he had learned more.
To the right of the brass lever was an oblong hatch about eight inches long, flush with the hull, and held in place by screws. Three seams, with lines of screws, encircled the round hull, showing that it was constructed in four sections; and these screws, with those in the hatch, were strong and numerous—placed there to stay.
Fatigued from his exertion, he moistened his hair, sat down, and watched the incoming tide swing the craft round parallel with the beach. As the submerged bow raised to a level with the stern, he noticed that the small blades on the horizontal vanes dropped from their upward slant to a straight line with the vanes.
"Rudders," he said, "horizontal rudders. Can't be anything else." With his chin in his hand and his wrinkled brow creased with deeper corrugations, he put his mind through a process of inductive reasoning.
"Horizontal rudders," he mused, "must be to keep her from diving, or to make her dive. They work automatically, and I s'pose the vertical rudders are the same. There's nothing outside to turn 'em with. That boat isn't made to ride in,—no way to get into her,—and she isn't big enough, anyhow. And as you can't get into her, that brass lever must be what starts and stops her. Wonder what the steel blade's for. 'T isn't a handy shape for a lever,—to be handled with fingers,—too sharp; but it has work to do, or it wouldn't be there. That section o' railroad iron on top must be to hang the boat by,—a traveler,—when she's out o' water.
"And the fan-wheel on the nose—what's that for? If it's a speed or distance indicator, the dial's inside, out o' sight. There's no exhaust, so the motive power can't be steam. Clockwork or electricity, maybe. Mighty fine workmanship all through! That square door is fitted in for keeps, and she must ha' cost a heap. Now, as she has horizontal rudders, she's intended to steer up and down; and as there's no way to get into her or to stay on her, and as she can't be started from the inside or steered from the outside, I take it she's a model o' one o' those submarine boats I've heard of—some fellow's invention that's got away from him. Guess I'll try that lever and see what happens. I'll bury the propellers, though; no engine ought to race."