owly made his way back to the other end of the
shell, and now his eyes became somewhat accustomed to the great radiance
about him. He thought he could perceive here and there faint indications
of long, nearly horizontal lines--lines of different shades of light.
Above him, as if it hung in the air, was the round, dark hole through
which he had descended.

He rose, took his hands from the shell, and made a few steps. He trod
upon a horizontal surface, but in putting one foot forward, he felt a
slight incline. It seemed to him that he was about to slip downward!
Instantly he retreated to the shell and clutched it in a sudden frenzy
of fear.

Standing thus, with his eyes still wandering, he heard the bell of the
telephone ring. Without hesitation he mounted the shell and got into the
car. Bryce was calling him.

"Come up," he said. "You have been down there long enough. No matter
what you have found, it is time for you to come up."

Roland Clewe was not accustomed to receive commands, but he instantly
closed the sliding door of the car, seated himself, and put his mouth to
the telephone.

"All right," he said. "You can haul me up, but go very slowly at first."

The car rose. When it reached the orifice in the top of the cave of
light, Clewe heard the conical steel top grate slightly as it touched
its edge, for it was still swinging a little from the motion given to it
by his entrance; but it soon hung perfectly vertical and went silently
up the shaft.

CHAPTER XXII. CLEWE'S THEORY

Seated in the car, which was steadily ascending the great shaft, Roland
Clewe took no notice of anything about him. He did not look at the
brilliantly lighted interior of the shaft, he paid no attention to his
instruments, he did not consult his watch, nor glance at the dial which
indicated the distance he had travelled. Several times the telephone
bell rang, and Bryce inquired how he was getting along; but these
questions he answered as briefly as possible, and sat looking down at
his knees and seeing nothing.

When he was half-way up, he suddenly became conscious that he was very
hungry. He hurriedly ate some sandwiches and drank some water, and then,
again, he gave himself up entirely to mental labor. When, at last, the
noise of machinery above him and the sound of voices aroused him from
his abstraction, the car emerged upon the surface of the earth, Clewe
hastily slid back the door and stepped out. At that instant he felt