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.  And yet this was only the work of nature.  She alone had hollowed this fairy Aihambra in a mass of granite.

The settlers were overwhelmed with admiration.  Where they had only expected to find a narrow cavity, they had found a sort of marvelous palace, and Neb had taken off his hat, as if he had been transported into a temple!

Cries of admiration issued from every mouth.  Hurrahs resounded, and the echo was repeated again and again till it died away in the dark naves.

“Ah, my friends!” exclaimed Cyrus Harding, “when we have lighted the interior of this place, and have arranged our rooms and storehouses in the left part, we shall still have this splendid cavern, which we will make our study and our museum!”

“And we will call it?—­” asked Herbert.

“Granite House,” replied Harding; a name which his companions again saluted with a cheer.

The torches were now almost consumed, and as they were obliged to return by the passage to reach the summit of the plateau, it was decided to put off the work necessary for the arrangement of their new dwelling till the next day.

Before departing, Cyrus Harding leaned once more over the dark well, which descended perpendicularly to the level of the sea.  He listened attentively.  No noise was heard, not even that of the water, which the undulations of the surge must sometimes agitate in its depths.  A flaming branch was again thrown in.  The sides of the well were lighted up for an instant, but as at the first time, nothing suspicious was seen.

If some marine monster had been surprised unawares by the retreat of the water, he would by this time have regained the sea by the subterranean passage, before the new opening had been offered to him.

Meanwhile, the engineer was standing motionless, his eyes fixed on the gulf, without uttering a word.

The sailor approached him, and touching his arm, “Captain!” said he.