system. Anyone operating around Sol would be apt to use
the decimal system. Hrohrakak’s 1000 points in no one
direction.
“Now as to Hlilav’s 1024—that number is the tenth
power of two. As far as I know, no natural species of being
uses the binary system. However, it is the rule with.
robots. The indications are that Hlilav is working for the
Interstellar Brotherhood of Free Business Machines or
some like organization, and, as we both know, the robots
are not ones to pound the war drums or touch off the war
fuses, for they are always the chief sufferers.
“That leaves Fa’s 1728. Jim, the first thing you told
me about the Arcturians was that they were hexadactylic
bipeds. Six fingers on one hand means 12 on two—and
almost a mortal certainty that the beings so equipped by
nature will be using the duodecimal system, in many
‘ ways the most convenient of all. In the duodecimal sys-
tem, *one thousand’ is not 10 times 10 times 10, but 12
times 12 times 12—which comes out as 1728 exactly in our
decimal system.
“As you said, *one thousand’ of the going unit is the
price of a being’s life. Someone paid *one thousand’ gold
martians by an Arcturian would have 1728 in his pocket
according to our count.
*The size of Pa’s purse seemed to me an odds-on indi-
cation that he was in the pay of the Arcturians war party.
Incidentally, he must have felt very smart getting that
extra 728—a more principled beast-criminal would have
scorned to profit from a mere difference in numerical
systems.”
The Young Captain took some time before he answered.
He smiled incredulously more than once, and once he
shook his head.
Finally he said, “And you asked me to go ahead, Scan,
and make my accusation, with no more indication than
that?”
“It worked for you, didn’t it?” the Old Lieutenant;
countered briskly. “And as soon as Fa started to confess,
you must have known I was right beyond any possibility
of doubt. Telepaths are always truth-tellers.”
The Young Captain shot him a very strange look.
“It couldn’t be, Sean—?” he said softly. “It couldn’t be
that you’re a telepath yourself? That that’s the alien
thought system you’ve been studying with your Martian
witch doctor?”
“If it were,” the Old Lieutenant replied, “I’d tell—”
He stopped. He twinkled. “Or would I?”