At noon a letter from Lieutenant Commander Kimball came aboard the
submarine, inquiring whether Captain Benson could make it convenient
to take him and several officers out to sea afternoon and give an
exhibition of the boat's diving powers.

"After we've taken the boat out ourselves, and tested her," was the
answer Captain Jack sent back. "With so many spies about we want to be
sure that the boat is in safe running order before we risk the lives of
half a dozen naval officers."

A luncheon was eaten, after which, the young submarine captain hastily
climbed the stairs to the conning tower.

"Throw on the gasoline, Hal," he called back over his shoulder. "And,
as soon as we get way, test all the electric connections, before we
attempt to do any diving. Be sure of everything old fellow."

Forward in the engine room the gas motors were soon moving merrily. By
the time that Eph had cast loose from moorings Jack signaled for slow
speed ahead, and the grim-looking little Benson moved on out of the
harbor.

Once out of the harbor Captain Jack rang, successively, for two higher
speeds. The "Benson" answered both like a charm.

"The gasoline part of the craft is working all right," declared the
youthful skipper to Eph, who had come up into the tower.

Fifteen minutes later Hal shouted up: