* * * *

At first it seemed that their bodies weighed twice the normal amount,
but this feeling soon passed and they looked about them with
incredulous amazement. The metal disc was quite evidently the medium
through which the repelling force was set up in the shaft, and to this
disc was connected a series of heavy cables that led to a pedestal
nearby. On the pedestal was a controlling lever and this moved over a
quadrant that was graduated in degrees, one end of the quadrant being
labeled "Up" and the other "Down." The lever now stood at a point but
a very few degrees from the center or "Zero" mark and on the down
side. Frank pulled this lever over to the full "Down" position and
they found that they could walk over the disc with normal gravity.

"I suppose," said Frank, "that if the lever is at the other end of the
scale one would fall upward with full gravity acceleration--reversed.
At zero, gravity is exactly neutralized, and the intermediate
positions are useful in conveying materials or human beings up and
down the shaft as desired. Very clever; but what is the reason for it
all?"

In the precise center of the great cavern there was a dome or
hemisphere of polished metal, and it was from this dome that the eery
light emanated. At times, when the light died down, this dome gleamed
with dull flickerings that threatened to vanish entirely. Then
suddenly it would resume full brilliance, and the sight was marvelous
beyond description. A slight hissing sound came from the direction of
the dome, and this varied in intensity as did the light.

"Gosh!" said Tommy. "That looks like silver to me. And, if it is, what
a wealthy man our friend Leland has become. He has spent his fortune
well, even if he used it all to get to this."

"Yes, but where is he?" commented Frank. Then: "Leland! Leland!" he
called.

* * * * *

His voice echoed through the huge vault and re-echoed hollowly. But
there was no reply save renewed flickerings from the dome.

Leaving the vicinity of the gravity disc, the two men advanced in the
direction of the shining dome, which was about a quarter-mile from
where they stood. Both perspired freely, for the air was very close
and the temperature high. But the light of the dome was as cold as the
light of a firefly and they had no hesitancy in drawing near. It was a
beautiful sight, this dome of silver with its flickering lights and
perfect con