y from side to side so that only at rare
intervals did the siderunners touch the ground.

"Finally, we emerged into the open, and I found myself viewing a scene
of almost normal, earthly aspect. We were near the shore of a smooth,
shining lake. At the side a broad stretch of rolling country, dotted
here and there with trees, was visible. Near at hand, on the lake shore,
I saw a collection of houses, most of them low and flat, with one much
larger on a promontory near the lake.

"Overhead arched a gray-blue, cloudless sky, faintly star-studded, and
reflected in the lake before me I saw that familiar gleaming trail of
star-dust, hanging like a huge straightened rainbow overhead, and ending
at my feet."

CHAPTER V

THE WORLD IN THE RING

The Chemist paused and relighted his cigar. "Perhaps you have some
questions," he suggested.

The Doctor shifted in his chair.

"Did you have any theory at this time"--he wanted to know--"about the
physical conformation of this world? What I mean is, when you came out
of this tunnel were you on the inside or the outside of the world?"

"Was it the same sky you saw overhead when you were in the forest?"
asked the Big Business Man.

"No, it was what he saw in the microscope, wasn't it?" said the Very
Young Man.

"One at a time, gentlemen," laughed the Chemist. "No, I had no
particular theory at this time--I had too many other things to think of.
But I do remember noticing one thing which gave me the clew to a fairly
complete understanding of this universe. From it I formed a definite
explanation, which I found was the belief held by the people
themselves."

"What was that?" asked the Very Young Man.

"I noticed, as I stood looking over this broad expanse of country before
me, one vital thing that made it different from any similar scene I had
ever beheld. If you will stop and think a moment, gentlemen, you will
realize that in our world here the horizon is caused by a curvature of
the earth below the straight line of vision. We are on a convex surface.
But as I gazed over this landscape, and even with no appreciable light
from the sky I could see a distance of several miles, I saw at once that
quite the reverse was true. I seemed to be standing in the center of a
vast shallow bowl. The ground curved upward into the distance. There was
no distant horizon line, only the gradual fading into shadow of the
visual landscape. I was standing obviously on a concave surface, on