his friend's advice came
home to him, Seaton sat down and pulled out his pipe. There was a tense
silence for an instant. Then he leaped to his feet and darted into his
room, returning with an object-compass whose needle pointed upward.

"DuQuesne did it," he cried exultantly. "This baby is still looking
right at him. Now let's go--make it snappy!"

"Not yet. We should find out how far away they are; that may give us an
idea."

Suiting action to word, he took up his stopwatch and set the needle
swinging. They watched it with strained faces as second after second
went by and it still continued to swing. When it had come to rest Crane
read his watch and made a rapid calculation.

"About three hundred and fifty million miles," he stated. "Clear out of
our solar system already, and from the distance covered he must have had
a constant acceleration so as to approximate the velocity of light, and
he is still going with full...."

"But nothing can possibly go that fast, Mart, it's impossible. How about
Einstein's theory?"

"That is a theory, this measurement of distance is a fact, as you know
from our tests."

"That's right. Another good theory gone to pot. But how do you account
for his distance? D'you suppose he's lost control?"

"He must have. I do not believe that he would willingly stand that
acceleration, nor that he would have gone that far of his own accord. Do
you?"

"I sure don't. We don't know how big a bar they are carrying, so we
can't estimate how long it is going to take us to catch them. But let's
not waste any more time, Mart. For Cat's sake, let's get busy!"

"We have only those four bars, Dick--two for each unit. Do you think
that will be enough? Think of how far we may have to go, what we may
possibly get into, and what it will mean to Dottie if we fail for lack
of power."

Seaton, though furiously eager to be off, paused at this new idea, and
half-regretfully he replied:

"We are so far behind them already that I guess a few hours more won't
make much difference. It sure would be disastrous to get out near one of
the fixed stars and have our power quit. I guess you're right, we'd
better get a couple more--make it four, then we'll have enough to chase
them half our lives. We'd better load up on grub and X-plosive
ammunition, too."

* * * * *

While Crane and Shiro carried additional provisions and boxes of
cartridges into the "Skylark," Seaton once more mount