An hour passed. All went down through the rain to the sea. In these hours the tide had fallen fifteen feet. The top of the mouth of the opening rose eight feet above the water, like the arch of a bridge. Looking in, the engineer saw a black object floating on the surface. He drew it toward him. It was a canoe made of sheet-iron bolted together. It was tied to a projecting rock inside the cavern wall. A pair of oars were under the seats. “Get in,” said Smith. The colonists entered the boat, Neb and Ayrton took the oars, Pencroff the tiller, and Smith, in the bows holding the lantern, lit the way. The vault, at first very low, rose suddenly; but the darkness was too great for them to recognize the size of this cavern, its heighth and depth. An imposing silence reigned throughout this granite chamber. No sound, not even the pealing of the thunder penetrated its massive walls. In certain parts of the world there are immense caves, a sort of natural crypts which date back to the geologic epoch. Some are invaded by the sea; others contain large lakes within their walls. Such is Fingal’s Cave, in the Island of Staffa; such are the caves of Morgat on the Bay of Douarnenez in Brittany; the caves of Bonifacio, in Corsica; those of Lyse-Fjord, in Norway; such is that immense cavern, the Mammoth Cave of Kentucky, which is 500 feet high and more than twenty miles long! As to this cavern which the colonists were exploring, did it not reach to the very centre of the island? For a quarter of an hour the canoe advanced under the directions of the engineer. At a certain moment he said:—— “Go over to the right.” The canoe, taking this direction, brought up beside the wall. The engineer wished to observe whether the wire continued along this side. It was there fastened to the rock. “Forward!” said Smith. The canoe kept on a quarter of an hour longer, and it must have been half a mile from the entrance, when Smith’s voice was heard again. “Halt!” he exclaimed. The canoe stopped, and the colonists saw a brilliant light illuminating the enormous crypt, so profoundly hidden in the bowels of the earth. They were now enabled to examine this cavern of whose existence they had had no suspicion. A vault, supported on basaltic shafts, which might all have been cast in the same mould, rose to a height of 100 feet. Fantastic arches sprung at irregular intervals from these columns, which Nature had placed here by thousands. They rose to a height of forty or fifty feet, and the water, in despite of the tumult without, quietly lapped their base. The light noticed by the engineer seized upon each prismatic point and tipped it with fire; penetrated, so to speak, the walls as if they had been diaphanous, and changed into sparkling jewels the least projections of the cavern. Following a phenomenon of reflection, the water reproduced these different lights upon its surface, so that the canoe seemed to float between two sparkling zones.