bes, some of which resembled radio tubes in their
sockets.

"Ah," he murmured. "Photo-electric tubes. It should be fairly easy
for you to keep apace with that for the reason that this
particular branch of science is still in its infancy and we are
all groping in the dark. No matter how little you know about the
matter, Judge, you cannot know a great deal less than any of us."

"That's your modesty, Professor. I had just been installing some
of the simpler devices when," his fine features clouded, "this
deplorable, this terrible affair interrupted me." There was
silence for a moment. With a visible effort of the will, he
continued:

"I am so glad you and Mr. Matthews are here. I am rather vague
about it. While I enjoy finding things out for myself, this has
been rather difficult. I am not certain I understand the photo-cell's
sensitiveness to color. You see, I was trying--"

"Why, that is comparatively simple, Judge. I see you have
everything needed right here."

"Yes, I got it all from a catalogue. But now that I have it, what
am I going to do with it?"

Professor Brierly stepped forward. He and Matthews worked quickly,
deftly, the old scientist uttering a word of explanation now and
then. The venerable jurist watched their deft handling of
intricate mechanism with keen interest and obvious enjoyment.

After half an hour that seemed to Justice Higginbotham only a few
minutes, so keen had been his absorption in the task, Professor
Brierly and Matthews stepped back. Professor Brierly had three
cards colored red, green and blue in his hand. He pointed to three
indicators that he had connected to wires running from a tube.

"You see, Judge, the three indicators are marked respectively with
the colors of these cards. As I pass these cards in front of the
tube, the corresponding indicator will record its passage. Watch!"

He passed the cards in front of the tube slowly, first in one
order then another. He changed their order; he increased their
speed. The result was the same. The respective indicators each
time, rapidly or slowly recorded the passage of the corresponding
color correctly.

Justice Higginbotham beamed with admiration.

"I told you you were modest, Professor. It would have taken me
weeks or months to do that. I've been working on rather an
ambitious project with these tubes, you may laugh when I tell you;
I was well on the way with it when," once more his features
clouded, "this hellish thing int