Much longer should I have remained at the window admiring the beauties of sea and sky, but the panels closed. At this moment the Nautilus arrived at the side of this high, perpendicular wall. What it would do, I could not guess. I returned to my room; it no longer moved. I laid myself down with the full intention of waking after a few hours' sleep; but it was eight o'clock the next day when I entered the saloon. I looked at the manometer. It told me that the Nautilus was floating on the surface of the ocean. Besides, I heard steps on the platform. I went to the panel. It was open; but, instead of broad daylight, as I expected, I was surrounded by profound darkness. Where were we? Was I mistaken? Was it still night? No; not a star was shining and night has not that utter darkness.

I knew not what to think, when a voice near me said:

"Is that you, Professor?"

"Ah! Captain," I answered, "where are we?"

"Underground, sir."

"Underground!" I exclaimed. "And the Nautilus floating still?"