"I have my pickaxe, and I shall soon make my way through this wall.

Where shall I strike ?" "Here," replied the engineer, showing the sturdy sailor a considerable recess in the side, which would much diminish the thickness.
Pencroft attacked the granite, and for half an hour, by the light of the torches, he made the splinters fly around him.

Neb relieved him, then Spilett took Neb's place.
This work had lasted two hours, and they began to fear that at this spot the wall would not yield to the pickaxe, when at a last blow given by Gideon Spilett, the instrument, passing through the rock, fell outside.
"Hurrah! hurrah!" cried Pencroft.
The wall only measured there three feet in thickness.
Harding applied his eye to the aperture, which overlooked the ground from a height of eighty feet.

Before him was extended the sea-coast, the islet, and beyond the open sea.
Floods of light entered by this hole, inundating the splendid cavern and producing a magic effect! On its left side it did not measure more than thirty feet in height and breadth, but on the right it was enormous, and its vaulted roof rose to a height of more than eighty feet.
In some places granite pillars, irregularly disposed, supported the vaulted roof, as those in the nave of a cathedral, here forming lateral piers, there elliptical arches, adorned with pointed moldings, losing themselves in dark bays, amid the fantastic arches of which glimpses could be caught in the shade, covered with a profusion of projections formed like so many pendants.

This cavern was a picturesque mixture of all the styles of Byzantine, Roman, or Gothic architecture ever produced by the hand of man.