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.