ne and shouted to Steve and Wink and the others
who were over on the rock near the inlet. By the time they got it
through their thick heads--"

"Thick heads be blowed!" exclaimed Steve disgustedly. "You were just
yelling a lot of words that didn't mean anything. If you hadn't kept on
pointing we'd never have known what was up. We all thought you had a
fit."

All's well that ends well, however, and an hour after breakfast the
incident was, if not forgotten, dismissed. Joe reappeared, looking
rather pale still, but announcing himself quite all right. "I was nice
and sick at my tummy," he explained, "and now I feel fine."

"Being sick at your tummy," remarked Perry unkindly, "is quite the best
thing you do, Joe. If you can't be sea-sick you go and try to drown
yourself!"

Of course "Brownie" was allowed to surmise that he had done something
rather big, and Joe thanked him very nicely, but Mr. Carnegie is still
in ignorance of his exploit!

The two boats floated out of the pool about ten and set off for Bar
Harbor. The barely averted tragedy somewhat modified their regret at
leaving Titania's Mirror and Mystery Island. Later, Steve and Joe tried
to locate that island on the charts but without certain success. There
were so many islands thereabouts that neither dared to more than guess
at the identity of the one they had visited. Looking back at it from a
distance of a half-mile they saw that it was in reality much smaller
than they had supposed, being scarcely more than a huge rock pushed up
from the ocean bed. Ossie, who had a leaning toward geology, furnished
the theory that Mystery Island was no more nor less than the top of an
extinct volcano and that Titania's Mirror was the crater.

"It probably sank, like lots of them did," he elaborated, "and the sea
wore away part of it and flowed into the crater. I'm pretty sure that
that rock we climbed out on this morning when we were swimming was
volcanic."

"Sure," agreed Perry. "It was pumice stone. I meant to bring a bit of it
along for you to clean your hands with."

"I didn't say pumice," replied Ossie haughtily. "It was more probably
obsidian."

"My idea exactly! In fact, it had a very obstinate feeling. It--it left
quite an impression on me!"

The _Follow Me_ developed engine trouble that morning and they lay by
for a half-hour or more while Tom Corwin toiled and perspired, argued
and threatened. It was well after two o'clock when they ran up the
eastern sh