Leaning forward, the engineer saw a black object floating on the water. He drew it towards him. It was a boat, moored to some interior projection of the cave. This boat was iron-plated. Two oars lay at the bottom.
"Jump in!" said Harding. In a moment they were in the boat. Neb and Ayrton took the oars, Pencroft the rudder. Cyrus Harding in the bows, with the lantern, lighted the way.
The elliptical roof, under which the boat at first passed, suddenly rose; but the darkness was too deep, and the light of the lantern too slight, for either the extent, or height of the cave to be ascertained. Solemn silence reigned in this basaltic cavern. Not a sound could penetrate into it, even the thunder peals could not pierce its thick sides. Did the cavern extend to the center of the island? For a quarter of an hour the boat had been advancing, making détours, indicated to Pencroft by the engineer in short sentences, when all at once, "More to the right!" he commanded.
The boat, altering its course, came up alongside the right wall. The engineer wished to see if the wire still ran along the side. The wire was there fastened to the rock.
"Forward!" said Harding. And the two oars, plunging into the dark waters, urged the boat onwards.
On they went for another quarter hour. A distance of half-a-mile must have been cleared from the entrance, when Harding's voice was again heard. "Stop!" said he.
The boat stopped, and the colonists perceived a bright light illuminating the vast cavern, so deeply excavated in the bowels of the island, of which nothing had ever led them to suspect the existence.
At a height of a hundred feet rose the vaulted roof, supported on basalt shafts. Irregular arches, strange mouldings, appeared on the columns, erected by nature in thousands from the first epochs of the globe. The basalt pillars, fitted one into the other, measured from forty to fifty feet in height, and the water, calm in spite of the tumult outside, washed their base. The brilliant focus of light, pointed out by the engineer, touched every point of rock, and flooded the walls with light. By reflection the water reproduced the brilliant sparkles, so that the boat appeared to be floating between two glittering zones.
