Professor Tippengray stepped back
with a scream which caused nearly everybody in the audience to start to
his feet. Clewe expected this. He raised his hand to the company, asking
them to keep still; then he handed Professor Tippengray a stick.

"Take this," he said, "and strike that disk of light; you will find it
as solid ground as that you stand on." She did so.

"It is solid!" she gasped; "but where is the end of the stick?"

He turned off the light; there was the end of the stick, and there
was the little patch of sandy gravel, which he stepped upon, stamping
heavily as he did so. He then retired outside the screen. Professor
Tippengray turned to the audience.

"It is all right, gentlemen," she said; "there is nothing to be afraid
of. I am going on with the investigation."

Down, down, down went the light, and, telescope in hand, she stood close
to the shining edge of the apparent shaft.

"Presently," Clewe said, "you will see the end of the shaft which my
Artesian ray is making; then you will perceive a vast expanse of lighted
nothingness; that is the great cleft in the diamond which I described to
you. In this, apparently suspended in light, you will notice the broken
conical end of an enormous iron shell, the shell which made the real
tunnel down which I descended in the car."

At this she turned around and looked at him. Even into her strong mind
the sharp edge of distrust began to insert itself.

"Look!" said he.

She looked through her telescope. There was the cave of light; there was
the shattered end of the shell.

The hands which held the telescope began to tremble. Quickly Clewe drew
her away.

"Now," said he, "do you believe?"

For a few moments she could not speak, and then she whispered, "I
believe that I have seen what you have told me I should see."

Now succeeded a period of intense excitement, such as was perhaps never
before known in an assembly of scientific people. One by one, each
person was led by Clewe inside the screen and shown the magical shaft of
light. Each received the revelation according to his nature. Some were
dumfounded and knew not what to think, others suspected all sorts of
tricks, especially with the telescopes, but a well-known optician, who
by Clewe's request had brought a telescope of his own, quickly disproved
all suspicions of this kind. Many could not help doubting what they had
seen, but it was impossible for them to formulate their doubts, with
that wond