nstruments. Almost as fast as they charged them, the tiny bits
of gold-leaf collapsed together. Presently the man on the end of the
line shouted.

"Maximum discharge!" he cried.

Dr. Bird looked around. Every man stood ready at his post. The next
man signalled that the borer was under him. Carnes felt himself
trembling. He did not know what the doctor was about to do, but he
felt that the fate of America hung in the balance. Whether it remained
free or became the slave of Soviet Russia would quickly be decided.

Slowly the borer made its way forward. With a pale face, Jones
signalled the news that it had reached the point the doctor had
indicated. Dr. Bird raised his hand.

"Power!" he cried.

The electrician closed a switch and power surged through the cables
around the bar. The earth rocked and quivered. A hundred yards east of
the bar a flash of intolerable red light sprang from the ground with a
roar like that of Niagara. Toward the bar it moved with gathering
momentum.

"Back, everyone!" roared Dr. Bird.

* * * * *

The men sprang back. The searing ray approached the bar. It touched
it, and bar and truck disappeared into thin air. A splutter of sparks
came from the severed ends of the wire. The ray disappeared. Carnes
rubbed his eyes. Where the truck had rested on solid ground was now a
gaping wound in the earth.

"Projector forward!" cried the doctor. "Hurry, men!"

The trucks bearing the battery of projectors moved forward until they
were at the edge of the hole. Portable cranes swung the lamps out, and
men swarmed over them. The projectors were pointed down the hole.
Carnes joined the doctor in peering down. A hundred yards below them
the terrible ray was blazing. As they watched, its end came in sight.
The ray was being projected forward from the end of a black
cigar-shaped machine which was slowly moving forward.

"That's your target, men!" cried the doctor. "Align on it and signal
when you are ready!"

One by one the projector operators raised their hands in the signal of
"ready." Still the doctor waited. Suddenly the forward movement of the
black body ceased. The ray was stationary for a moment and then moved
slowly upward. A terrific roaring came from the cavern.

"Projector switch!" roared the doctor, his heavy voice sounding over
the tumult.

"Ready, sir!" a shrill voice answered.

"Power!"

* * * * *

From each of the p