r 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,--to