ushed slightly, as he saluted the naval officer. Then the
cadet's jaws settled squarely. He remained silent.

A few more questions and the hour was up.

Lieutenant Commander Mayhew gave the order for the cadets to pass above
and embark in the cutters. He remained behind long enough to say to the
three submarine boys:

"You have done splendidly, gentlemen--far better than I expected you to do.
If you manage the sea instruction as well, in the days to come, our cadets
will have a first-class idea of the handling of the Pollard boats."

"I wish, sir," Jack replied, after thanking the officer, "that the cadets
were not required to say 'sir' to us. It sounds odd, and I am quite
certain that none of the young men like it."

"It is necessary, though," replied Mr. Mayhew. "They are required to do it
with all civilian instructors, and it would never do to draw distinctions
on account of age. Yes; it is necessary."

When the second squad of cadets arrived, in the afternoon, the three
submarine boys found themselves ready for their task without misgivings.
Eph took more part in the explanations than he had done in the forenoon.
Then came a third squad of cadets, to be taken over the same ground. The
young men of both these squads used the "sir" at once, having been
previously warned by one of the naval officers.

"That will be all for to-day, Mr. Benson, and thank you and your friends
for some excellent work," said Lieutenant Commander Mayhew, when the third
squad had filed away.

"Say, for hard work I'd like this job right along," yawned Eph Somers,
when the three were alone in the cabin. "Just talking three times a
day--what an easy way of living!"

"It's all right for a while," agreed Jack. "But it would grow tiresome
after a few weeks, anyway. Lying here in the Basin, and talking like a
salesman once in a while, isn't like a life of adventure."

"Oh, you can sigh for adventure, if you wish," yawned Eph. "As for me,
I've had enough hard work to appreciate a rest once in a while. Going into
the town to-night, Jack?"

"Into town?" laughed the young skipper. "I went last night--and some of the
folks didn't do a thing to me, did they?"

"Aren't you going to report the robbery to the police?" demanded Hal,
opening his eyes in surprise.

"Not in a rush," Jack answered. "If I do, the police may start at once,
and that mulatto and his friends, being on the watch, will take the alarm
and get away. If I wait two or three d