just opposite him there was an excellent
chance that the longer one of the free ends would drop directly upon
the machine.

And in his possession he had a possible means of severing that
cable--the pistol that was still crammed in his belt. There were four
shots remaining in the pistol. The cable was barely half an inch thick,
but the range was so short that he could not very well miss. If the
silver-colored metal was as soft as it looked, the heavy bullets should
be enough to tear through it.

Foster thrust the pistol as close to the cable as he could reach. Then,
with the muzzle scarcely a yard from the silver strand, he fired. The
heavy bullet caromed from the cable's surface, but not before it had
torn a gash nearly a third of the way through it.

There was a sudden cessation of activity below as the slug in the
machine looked up at the sound of the shot. Swift inspiration seized
Foster and he promptly sent his next shot down at the machine itself.
The bullet glanced harmlessly off, but his ruse worked. Apparently
believing that Foster was merely trying another futile attack upon it,
the machine turned its attention back to the men it had cornered. Foster
could be attended to later.

* * * * *

Foster slipped and nearly fell just as he fired at the power line the
next time and his shot missed. That left him only one remaining
cartridge. Aiming with infinite care he sent his last shot smashing
squarely into the part of the cable remaining intact.

It trembled and sagged as the bullet cut the remaining metal nearly
through. Only a bare thread was left, yet that thread held. Sick at
heart over the narrow margin by which his effort had failed, Foster
stared in despair at the nearly severed cable. It needed only one solid
blow to tear that last thread of metal apart, but the cable was just
far enough away to be effectively beyond his reach.

Then suddenly Foster's eyes narrowed. There was a way remaining by which
the weakened power line could be broken. A single hurtling dive out and
downward from the girder would send his own body crashing squarely into
the metal strand. Beneath the smashing impact of his one hundred and
eighty pounds the nearly severed cable was certain to break.

Foster shuddered as he realized what that dive into space would mean. He
was not thinking of the fall itself. The thirty-foot drop to the
diamond-hard floor of the cavern would in all probability mean d