integrity indefinitely, and, as it circulates automatically through the
motor, the little engine will run for months at a time without a particle
of attention. Is that quite clear?"

"Perfectly," I lied.

"All right. Now I'll show you how she starts," smiled the inventor,
opening with a key a little door in the wash-boiler and lighting a match.

"Careful, Hawkins, careful," I ventured, backing toward the cabin.

"My dear fellow," he sneered, "can you not grasp that in an engine of this
construction, there is absolutely no danger of any kind of explo----"

Just then a heavy report issued from the wash-boiler. A sheet of flame
seemed to flash from the little opening and precipitate Hawkins into my
arms.

At any rate, he landed there with a violent shock, and I clutched him
tightly, and tried to steady the launch.

"Leggo! Leggo!" he screamed. "Let me go, you idiot! It always does that!
It's working now."

He was right. The launch was churning up a peculiarly serpentine wake,
and the motor was buzzing furiously.

Hawkins dived toward his machinery, tinkered it with nervous haste for
a little, and finally managed to head the boat down-stream just as a
collision with the Palisades seemed inevitable.