I need hardly say that nowhere is the labor of man apparent.

All this is the handiwork of nature, and it is not without wonder, mingled with awe, that I reflect upon the telluric forces capable of engendering such prodigious substructions.

The daylight from the crater in the centre only strikes this part of the cavern obliquely, so that it is very imperfectly lighted, but at night, when illuminated by the electric lamps, its aspect must be positively fantastic.
I have examined the walls everywhere with minute attention, but have been unable to discover any means of communicating with the outside.
Quite a colony of birds--gulls, sea-swallows and other feathery denizens of the Bermudan beaches have made their home in the cavern.
They have apparently never been hunted, for they are in no way disturbed by the presence of man.
But besides sea-birds, which are free to come and go as they please by the orifice in the dome, there is a whole farmyard of domestic poultry, and cows and pigs.

The food supply is therefore no less assured than it is varied, when the fish of all kinds that abound in the lagoon and around the island are taken into consideration.
Moreover, a mere glance at the colonists of Back Cup amply suffices to show that they are not accustomed to fare scantily.

They are all vigorous, robust seafaring men, weatherbeaten and seasoned in the burning beat of tropical latitudes, whose rich blood is surcharged with oxygen by the breezes of the ocean.