It must have been about three o’clock when we reached a narrow valley, between high perpendicular walls, situated about seventy-five fathoms deep. Thanks to the perfection of our apparatus, we were forty-five fathoms below the limit which nature seems to have imposed on man as to his submarine excursions. I say seventy-five fathoms, though I had no instrument by which to judge the distance. But I knew that even in the clearest waters the solar rays could not penetrate further. And accordingly the darkness deepened. At ten paces not an object was visible. I was groping my way, when I suddenly saw a brilliant white light. Captain Nemo had just put his electric apparatus into use; his companion did the same, and Conseil and I followed their example. By turning a screw I established a communication between the wire and the spiral glass, and the sea, lit by our four lanterns, was illuminated for a circle of thirty-six yards. Captain Nemo was still plunging into the dark depths of the forest, whose trees were getting scarcer at every step. I noticed that vegetable life disappeared sooner than animal life. The medusæ had already abandoned the arid soil, from which a great number of animals, zoophytes, articulata, molluscs, and fishes, still obtained sustenance. As we walked, I thought the light of our Ruhmkorff apparatus could not fail to draw some inhabitant from its dark couch.