proper interval from the 'Dad' boat. Besides, I've been up there on
relief, for an hour while you slept, and Hal came down and sat with the
engines. Cheer up, Jack. No one misses you from the conning tower."

Benson laughed, though he said, warningly:

"I reckon we'll do as well to drop calling the gunboat the 'Dad boat'
instead of the 'parent vessel.'"

"Well, you needn't bother at all about the conning tower to-day," wound up
Eph, glancing at his watch. "It's after half-past three at this moment and
I understand we're to drop anchor about five o'clock."

So Skipper Jack settled back with a comfortable sigh. Truth to tell, it
was pleasant not to have any immediate duty, for his head throbbed, every
now and then, and he felt dizzy when he tried to walk.

"Who could have hit me in that fashion, last night, and for what earthly
purpose?" wondered the boy. "I've had some enemies, in the past, but I
don't know a single person about Dunhaven, now who has any reason for
wishing me harm."

Never a thought crossed his mind of suspecting Sam Truax. That worthy had
come with a note from David Pollard, the inventor of the boats. Sam,
therefore, must be all right, the boy reasoned.

Jack lay back on the upholstered seat. He sat with his eyes closed most of
the time, though he did not doze. At last, however, he heard the engine
room bell sound for reduced speed. Getting up, the young captain made his
way to the foot of the conning tower stairs.

"Making port, Hal?" he called.

"Yep," came the reply. "We'll be at anchor in five minutes more."

Jack made his way slowly to the door of the engine room.

"Eph," he called, "as soon as you've shut off speed, take Truax above and
you two attend to the mooring."

"Take this other man up with you," urged Sam Truax. "I don't know anything
about tying a boat up to moorings."

"Time you learned, then," returned Eph Somers, "if you're to stay aboard a
submarine craft."

"Take this other man up with you," again urged Truax.

Eph Somers turned around to face him with a good deal of a glare.

"What ails you, Truax? You heard the captain's order. You'll go with me."

"Don't be too sure of that," uttered Sam Truax, defiantly.

"If you don't go above with me, and if you don't follow every order you
get aboard this boat, I know where you _will_ go," muttered Eph,
decisively.

"Where?" jeered Sam.

"Ashore--in the first boat that can take you there."

"You seem to forget that I'm