They absorb the marine salts, they assimilate the solid elements in the water, and since they create coral and madrepores, they're the true builders of limestone continents! And so, after they've finished depriving our water drop of its mineral nutrients, the droplet gets lighter, rises to the surface, there absorbs more salts left behind through evaporation, gets heavier, sinks again, and brings those tiny animals new elements to absorb. The outcome: a double current, rising and falling, constant movement, constant life! More intense than on land, more abundant, more infinite, such life blooms in every part of this ocean, an element fatal to man, they say, but vital to myriads of animals--and to me!

When Captain Nemo spoke in this way, he was transfigured, and he filled me with extraordinary excitement.

There, he added, out there lies true existence! And I can imagine the founding of nautical towns, clusters of underwater households that, like the Nautilus, would return to the surface of the sea to breathe each morning, free towns if ever there were, independent cities! Then again, who knows whether some tyrant . . .

Captain Nemo finished his sentence with a vehement gesture. Then, addressing me directly, as if to drive away an ugly thought:

Professor Aronnax, he asked me, do you know the depth of the ocean floor?

At least, captain, I know what the major soundings tell us.

Could you quote them to me, so I can double-check them as the need arises?

Here, I replied, are a few of them that stick in my memory. If I'm not mistaken, an average depth of 8,200 meters was found in the north Atlantic, and 2,500 meters in the Mediterranean.