errupted me."

Professor Brierly, glad to take the other's mind from the dreadful
tragedy stalking him and his companions, asked:

"What is the ambitious program you had mapped out that you believe
will make me laugh?"

"It is true, is it not, Professor, that the impulse transmitted by
a photo electric cell can be translated into incalculable energy;
can be made to do things that normally require a great deal of
power?"

"You have about stated the case, Judge. We know very little about
it yet, about its possibilities, but they seem endless and
practically indefinite.

"The impulse generated can be made to pick up a thread, or pull a
trigger, operate a trip hammer, blow up a mine or move a
battleship or an ocean liner, given a strong enough lever. And
that means simply a proper transformation of power or energy.

"The theory is comparatively simple. Wherever or whenever a beam
of light can be received, interrupted, modified, amplified, or
controlled in any way, a light-sensitive cell can be employed to
generate the impulse, which, properly applied, can do almost
anything.

"Does that seem too involved?" asked Professor Brierly.

"No, I think not. It was acting on that theory that I experimented
with--well, come along and I will show you."

He led the way outside, where he pointed to the overhanging rock.

"Professor, as that rock is situated now, what would happen if it
came down? You see how delicately it seems to be balanced."

"If it came down," stated Professor Brierly, "it would crush your
main building to match-wood."

"Yes, I guess it would. Well, here is what I planned. I erected a
lever behind it operated by a trigger-like arrangement. I
installed a photo-electric cell with wires running to the trigger.
I was going to shore up this side of the decline running from the
rock, so that when the trigger released it, it would be deflected
and roll into the lake.

"But at that point, this deplorable affair with our group
happened. All I needed to do was to shore up this side of it. I
was going to make quite an occasion of it. I planned to invite a
number of friends and show them that with a simple beam of light I
could move that gigantic rock."

"Hmm," commented Professor Brierly. "In view of the fact that you
have not yet made provision to deflect the rock it seems rather
dangerous to leave things in this state. If the rock came down it
would hit the roof of the porch and kill whoever happened to b