"Dual-control spheres on top," Tom explained, "will receive by radio
signal the pulse frequency computed in Washington."

He added that inside each sphere was a "pulsemaker." This would produce
changes in the pressure of the hydraulic fluid by affecting the kinetic
energy of the fluid's atoms.

The pressure changes would then be enormously magnified in the four
hydraulic output drivers. When the unit was embedded in rock,
underground, the huge pistons would send out counter shock waves through
the earth's crust to neutralize the enemy waves.

"Wow!" Hank Sterling was breathless at the sheer scope of the young
scientist's newest invention. "I'll get hot on the job right away."

After forty-eight hours of round-the-clock work, the equipment was
ready. Tom conferred by telephone with both Dr. Miles in the Bureau of
Mines and Bernt Ahlgren in the Pentagon. He had already chosen the spots
for the detector-transmitter check points.

Tom told the men that he believed the best spot for the Quakelizor
itself was on a certain government reservation in Colorado. A deep
underground cave there would provide a perfect site.

"We'll be close enough to the San Andreas fault to prevent a really
huge-scale disaster," Tom explained. "And the Rocky Mountain structure
will give us a good bedrock medium for shooting out waves anywhere
across the continent."