ddenly. "At what time do you estimate that the
flight of the Earth in its orbit will be materially affected?"

"It is being affected this moment, Dalis, shifting the Ovidum store!"
said Sarka shortly. "Within twelve hours we will be in readiness to
start our journey!"

Remaining absolutely motionless within the domed laboratory, it was now
possible to feel the ever so slight motion, not only of the laboratory,
but of the mountain crest upon which it rested. Not so much a to-and-fro
motion as a round-about motion.

Just as the slightest sound flies outward through space endlessly, and
the slightest vibration moves outward until the end of time and of
space, Sarka knew that the vibration set up by the Beryl, slight though
it was, was already being felt at the Poles of the Earth. Not enough to
be noticed there, but existant, just the same.

"In twelve hours the world will be fighting against this combined
vibration and Anti-Gravitational Force we are starting, and second by
second accelerating," Sarka explained to Dalis: "fighting to remain on
its pathway about the Sun! But we will win against it, and with each new
vibration, each succeeding one being more strongly felt, we will force
the Earth that much more against the _pull_ which holds it in its
orbit!"

The laboratory was trembling. The mountain beneath it was trembling.
Both in accordance with scientific design. There was no element of
chance in it, for the mountain moved, and the laboratory on its crest
moved, as science willed. It was now difficult for Sarka to remain still
where he sat, for the trembling was exciting his heart action, and
causing the blood to rush to his cheeks, making him feverish. He rose
to his feet and began pacing the floor.

He strode to the jade lever, moved it ahead a fraction of a fraction of
an inch, and perceptibly the murmuring of the Beryl increased, as did
the trembling of the laboratory and of the mountain.

* * * * *

Twelve hours later exactly, Sarka shouted a single word to Dalis.

"Now!"

The laboratory was swinging about in a sort of circle in a way that made
one dizzy if one remained still for the merest second. Sarka, glancing
out into the Outside, across which blew the storms of the heights, and
noting that no cracks appeared in the surface of the world's vast roof,
knew that this swaying motion had been transmitted evenly to all the
Earth, and that, so far at least, his calculation