“Too bad I didn’t have time to tackle the job before Exman was kidnaped,” Tom mused.  “Think how much more he could learn with ‘eyes’ and ’ears’!”

“Stop crabbing,” Bud joked.  “Isn’t an electronic spy with a brain like Einstein’s good enough?”

Mr. Swift arrived at the laboratory an hour or so later.  He found Tom setting up an experiment with a glass sphere to which were affixed six powerful electromagnets.  Two shiny electrodes, with cables attached to their outer ends, had also been molded into the glass.  Bud was looking on, wide-eyed.

Tom explained to his father that he had blown the sphere himself, following a formula adapted from the quartz glass used for view panels in his space and undersea craft.

“What’s it for, son?” Mr. Swift asked, after studying the setup curiously.

“Don’t laugh, Dad, but I’m trying to produce a brain of pure energy.  A substitute for Exman, so we can go ahead with our sensing experiments.”

Mr. Swift reacted with keen interest and offered to help.  “But remember, son,” he cautioned, “at best you can only hope to produce an ersatz brain energy—­which will be vastly different from the real thing.  Don’t forget, Tom, the mind of a human being or any thinking inhabitant of our universe is based on a divine soul.  No scientist must ever delude himself into thinking he can copy the work of our Creator.”

“I know that, Dad,” Tom said soberly.  “Man’s work will always be a crude groping, compared to the miracles of Nature.  All I’m hoping to come up with here is a sort of stimulus-response unit that we can use for testing any sensing apparatus we devise.”

The two scientists plunged into work.  First, a bank of delicate gauges was assembled to record precisely every electrical reaction that took place inside the sphere.  Then Tom threw a switch, shooting a powerful bolt of current across the electrodes.  The field strength of the electromagnets, controlled by rheostats, instantly shaped the charge into a glowing ball of fire!

“Wow!  A real hothead!” Bud wisecracked, trying to hide his excitement.

Tom grinned as he twirled several knobs and checked the gauges.  The slightest variation in field strength triggered an instant response from the ball of energy.  Mr. Swift tried exposing it to radio and repelatron waves.  Each time the gauges showed a sensitive reaction.

“Looks as if we’re in business, Dad!” Tom said jubilantly.

Bud left soon afterward as the two Swifts buckled down to work on the problem of perfecting an apparatus to simulate the human senses.  Each concentrated on a different line of approach.

At noon they broke off briefly for a lunch wheeled in by Chow.  Then silence settled again over the laboratory.

Tom had rigged up a jointed, clawlike mechanical arrangement with sensitive diaphragms in its “finger tips.”  The diaphragms were connected to a transistorized circuit designed to modulate the field current to the electromagnets.