“I should think,” said she, speaking very slowly, “that if your sounding-lead had gone down into nothing, it would have continued to go down indefinitely. What was there to stop it if there is nothing there?” “Margaret,” said he, “I don't know anything about it. That is the crushing truth. I can find out nothing at all. When I look down through the earth by means of the Artesian ray I reach a certain depth and then I see a void; when I look down through a perfectly open passage to the same depth, I still see a void.” “But, Roland,” said Margaret, holding in her hand the view taken of the bottom of the shaft, “what is this in the middle of the proof? It is darker than the rest, but it seems to be all covered up with mistiness. Have you a magnifying-glass?” Roland found a glass, and seized the photograph. He had forgotten his usual courtesy. “Margaret,” he cried, “that dark thing is my automatic shell! It is lying on its side. I can see the greater part of it. It is not in the hole it made itself; it is in a cavity. It has turned over, and lies horizontally; it has bored down into a cave, Margaret--into a cave--a cave with a solid bottom--a cave made of light!” “Nonsense!” said Margaret. “Caves cannot be made of light; the light that you see comes from your electric lamp.” “Not at all!” he cried. “If there was anything there, the light of my lamp would show it. During the whole depth of the shaft the light showed everything and the camera showed everything; you can see the very texture of the rocks; but when the camera goes to the bottom, when it enters this space into which the shaft plainly leads, it shows nothing at all, except what I may be said to have put there. I see only my great shell surrounded by light, resting on light!” “Roland,” said Margaret, “you are crazy! Perhaps it is water which fills that cave, or whatever it is.” “Not at all,” said Roland. “It presents no appearance of water, and when the camera came up it was not wet. No; it is a cave of light.” He sat for some minutes silently gazing out of the window. Margaret drew her chair closer to him. She took one of his hands in both of hers. “Look at me, Roland!” she said. “What are you thinking about?” He turned his face upon her, but said nothing. She looked straight into his eyes, and she needed no Artesian ray to enable her to see through them into his innermost brain. She saw what was filling that brain; it was one great, overpowering desire to go down to the bottom of that hole, to find out what it was that he had discovered. “Margaret, you hurt me!” he exclaimed, suddenly. In the intensity of the emotion excited by what she had discovered, her finger-nails had nearly penetrated through his skin. She had felt as if she would hold him and hold him forever, but she released his hand.