Mr. Swift looked on eagerly as Tom explained and demonstrated his touch
apparatus. By moving a pantograph control, Tom was able to manipulate
the claws like a hand with fingers. Whenever they touched any material,
the brain gauges instantly registered an electrical reaction inside the
sphere.

The swing of a voltmeter needle showed how firmly the substance resisted
the claw's touch, thus indicating its hardness or softness.

"With a computer device, such as we planted in Exman," Tom went on, "the
brain would also be able to assimilate the textural pattern of any
substance."

"Wonderful, son!" Mr. Swift exclaimed. "I hope I can do as well with
this artificial sense of sight I'm working on."

Another hour went by before Mr. Swift was ready to test his own
arrangement.

"You've probably heard of the experiments conducted with blind persons,"
he told Tom. "By stimulating the right part of their brain with a lead
from a cathode-ray-tube device, an awareness of light and dark can be
restored."

Tom nodded.

"Well, I'm using the same principle," Mr. Swift went on, "but with a
sort of television camera scanning setup."

He asked Tom to draw the drapes and shut off the room lights, throwing
the laboratory into complete darkness, except for the weirdly glowing
"brain" in the glass sphere. Then Mr. Swift shone a flashlight at the
scanner. The brain responded by glowing more brightly itself!

Next, after the drapes were opened again and the overhead fluorescent
lights switched on, Mr. Swift painted a pattern of black-and-white
stripes on a large piece of cardboard. He held this up to the scanner.

Visible ripples of brightness and less-brightness passed through the
glowing ball of energy inside the sphere. It was reproducing the striped
pattern!

"Dad, that's amazing!" Tom said with real admiration.

Mr. Swift shook his head. "Pretty crude, I'm afraid. The brain energy by
itself can't take the place of a picture tube in a TV receiver. What we
need is an analog computer to sum up the scanning pattern picked up by
the camera tube and then pass this information along in code form."

Before Tom could comment, the alarm bell rang on the electronic brain.
The Swifts dropped everything and rushed to the machine.

"Wonder if it's Exman?" Tom exclaimed.

The answer was quickly revealed as the keys began punching out the
incoming message on tape. At the same time, a flow of strange
mathematical symbols flashed, one af