“If you give the speed-ahead signal, sir, I think you’ll feel as though
you had a live engine under your deck,” Hal assured him.

The signal was given, the “Pollard” immediately responding. She cut a wide
circle, at good speed, returning to her former position, where the
propellers were stopped.

“You suspect your own machinist, who was aboard?” asked the naval officer,
in a low tone, of the submarine boys.

“If you’ll pardon our not answering directly, sir,” Captain Jack replied,
“we want to have more than suspicions before we make a very energetic
report on this strange accident. But we shall not be asleep, sir, in the
matter of finding out. Then we shall make a full report to Mr. Mayhew.”

“Success to you—and vigilance!” muttered the naval officer.

The gunboat’s cutter came alongside, transferring Jack and Hal back to the
“Farnum.”

Hal went directly below to the engine room.

“You fixed the trouble with the ’Pollard’?” demanded Eph Somers, eagerly.

“Yes,” Hal admitted.

“What was wrong?”

“Why, I don’t know as I’d want to commit myself in too offhand a way,”