rocks leant over and united in a vaulted roof about 500 or 600 yards above us. At the top was a circular hole, through which I had caught that glimpse of daylight.
“Where are we?” I asked.
“In the heart of an extinct volcano,” replied the captain; “a volcano to which the sea was admitted by some great natural convulsion. While you were asleep the Nautilus entered this lagoon by a canal which opens about ten yards below the surface of the ocean. This is our harbour of refuge, sure, safe, commodious, and mysterious, perfectly sheltered. Can you find me any harbour in the world so completely out of the reach of all storms?”
“You are certainly in perfect safety here, captain—who could reach you in the centre of a volcano? But is there not an opening at the top ?”
“Yes, the crater, which now gives passage to the air we breathe.”
“But what is this volcano?”
“It belongs to one of the numerous islands scattered in this sea. A rock for all vessels save mine, for us an enormous cavern. I discovered it by chance, and in that fate befriended me.”
“But can no one descend through the crater?” I asked.
“No more than I can ascend it. For a hundred feet up the interior base of the mountain is practicable, but above the cliffs are perpendicular, and they cannot be scaled.”
“I see, captain, that Nature helps you everywhere, and in everything. You are in perfect safety here, and no one can intrude in these waters, But what is the good of it, after all? The Nautilus does not require a harbour.”
“No, but it requires electricity to move it, and the
