“True,” the captain put in.
“In the second place, because oxygen is the basis of life, and we know that the amount of oxygen dissolved in salt water increases rather than decreases with depth, that the pressure in these lower strata helps to concentrate their oxygen content.”
“Oho! We know that, do we?” Captain Nemo replied in a tone of mild surprise. “Well, professor, we have good reason to know it because it’s the truth. I might add, in fact, that the air bladders of fish contain more nitrogen than oxygen when these animals are caught at the surface of the water, and conversely, more oxygen than nitrogen when they’re pulled up from the lower depths. Which bears out your formulation. But let’s continue our observations.”
My eyes flew back to the pressure gauge. The instrument indicated a depth of 6,000 meters. Our submergence had been going on for an hour. The Nautilus slid downward on its slanting fins, still sinking. These deserted waters were wonderfully clear, with a transparency impossible to convey. An hour later we were at 13,000 meters—about three and a quarter vertical leagues—and the ocean floor was nowhere in sight.
However, at 14,000 meters I saw blackish peaks rising in the midst of the waters. But these summits could have belonged to mountains as high or even higher than the Himalayas or Mt. Blanc, and the extent of these depths remained incalculable.
Despite the powerful pressures it was undergoing, the Nautilus sank still deeper. I could feel its sheet-iron plates trembling down to their riveted joins; metal bars arched; bulkheads groaned; the lounge windows seemed to be warping inward under the water’s pressure. And this whole sturdy mechanism would surely have given way, if, as its captain had said, it weren’t capable of resisting like a solid block.
While grazing these rocky slopes lost under the waters, I still spotted some seashells, tube worms, lively annelid worms from the genus Spirorbis, and certain starfish specimens.
But soon these last representatives of animal life vanished, and three vertical leagues down, the Nautilus passed below the limits of underwater existence just as an air balloon rises above the breathable zones in the sky. We reached a depth of 16,000 meters—four vertical leagues—and by then the Nautilus’s plating was tolerating a pressure of 1,600 atmospheres, in other words, 1,600 kilograms per each square centimeter on its surface!
“What an experience!” I exclaimed. “Traveling these deep regions where no man has ever ventured before! Look, captain! Look at these magnificent rocks, these uninhabited caves, these last global haunts where life is no longer possible! What unheard-of scenery, and why are we reduced to preserving it only as a memory?”
“Would you like,” Captain Nemo asked me, “to bring back more than just a memory?”