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.