We have proved that the earth is
hollow. We have passed entirely through its crust to the inner world."

"Perry, you are mad!"

"Not at all, David. For two hundred and fifty miles our prospector
bore us through the crust beneath our outer world. At that point it
reached the center of gravity of the five-hundred-mile-thick crust. Up
to that point we had been descending--direction is, of course, merely
relative. Then at the moment that our seats revolved--the thing that
made you believe that we had turned about and were speeding upward--we
passed the center of gravity and, though we did not alter the direction
of our progress, yet we were in reality moving upward--toward the
surface of the inner world. Does not the strange fauna and flora which
we have seen convince you that you are not in the world of your birth?
And the horizon--could it present the strange aspects which we both
noted unless we were indeed standing upon the inside surface of a
sphere?"

"But the sun, Perry!" I urged. "How in the world can the sun shine
through five hundred miles of solid crust?"

"It is not the sun of the outer world that we see here. It is another
sun--an entirely different sun--that casts its eternal noonday
effulgence upon the face of the inner world. Look at it now, David--if
you can see it from the doorway of this hut--and you will see that it
is still in the exact center of the heavens. We have been here for
many hours--yet it is still noon.

"And withal it is very simple, David. The earth was once a nebulous
mass. It cooled, and as it cooled it shrank. At length a thin crust
of solid matter formed upon its outer surface--a sort of shell; but
within it was partially molten matter and highly expanded gases. As it
continued to cool, what happened? Centrifugal force hurled the
particles of the nebulous center toward the crust as rapidly as they
approached a solid state. You have seen the same principle practically
applied in the modern cream separator. Presently there was only a
small super-heated core of gaseous matter remaining within a huge
vacant interior left by the contraction of the cooling gases. The
equal attraction of the solid crust from all directions maintained this
luminous core in the exact center of the hollow globe. What remains of
it is the sun you saw today--a relatively tiny thing at the exact
center of the earth. Equally to every part of this inner world it
diffuses its perpetual noond