hrust deep in the intestines of something
radionic, his fingers working on it with the deft rhythm of a good
surgeon at his thousandth appendectomy. The bifocals had returned to
their incongruous perch on the dome of the head. Gus didn't need them;
even as he stared at his job he worked by touch alone.

"What is it?" Lee asked.

"Pulsemeter," came the quiet answer. "She's a dandy. Still got some bugs
in her, though."

A melodious chime came from a big instrument panel built into the wall
of the oval room. Dropping a number of tiny precision tools upon a piece
of velvet, Gus rushed over to the panel. A great many indicator needles
were tremulously receding around their luminous dials.

For a minute or so he went through the complex and precise ritual of a
bank cashier closing the vault.

"They'll do it every time," he said reproachfully. "Catch me by
surprise."

Lee grinned. It wasn't The Brain's fault if the midnight signal
surprised Gus. It merely announced that the current was being cut off by
the main power station. Repetition of this maneuver throughout all the
convolutions and glands of The Brain was required for the added safety
of the maintenance engineers, a double-check, a routine. Pointing to the
gadget which looked somewhat like a big radio console Lee asked:

"This pulsemeter, Gus, what does it do? I haven't seen it before."

"You haven't?" the little man frowned. "Ah, no; you haven't. It's
standard in most apperception centers, but not in yours. That's because
in yours The Brain works under a permanent problem-load."

Lee shook his head. "I don't get it, Gus; you know I'm the village idiot
of this mastermind community."

"It's like this," Gus explained. "The Brain has a given capacity. The
Brain also has an optimal operation speed, a definite rhythm in which it
works best. Now, if they feed The Brain too many problems too fast, it
results in a shock load, the operations rhythm gets disturbed,
efficiency goes down. On the other hand if The Brain works with an
under-capacity problem load, that's just as bad. In that case the
radioactive pyramidal cells will overheat and decompose. Consequently we
must aim at a balanced and an even problems load. That's why these
pulsemeters are built into all problem-intake panels for the operators
to check upon their speeds.

"Take an average problem--rocket ballistics, let's say--parts of it may
be as simple as adding two and two and others so bad Einstein woul