ight. He thrust
the prints aside, and in a loud, sharp voice he gave orders to bring the
great telescope and set it up above the hole. The light was still at the
bottom, and the instant the telescope was in position Clewe mounted the
stepladder and directed the instrument downward. In a few moments he
gave an exclamation, and then he came down from the ladder so rapidly
that he barely missed falling. He went into his office and sent for
Margaret. When she came he showed her the photographs.

"See!" he said. "What I have found is nothing; even a camera shows
nothing, and when I look down through the glass I see nothing. It is
just what the Artesian ray showed me; it is nothing at all!"

"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