"Expensive," said Paul, "and about as reliable as a putty ruler. You can imagine what the scrap heap looked like, and what hell it was to be a service manager in those days. Hangovers, family squabbles, resentments against the boss, debts, the war - every kind of human trouble was likely to show up in a product one way or another." He smiled. "And happiness, too. I can remember when we had to allow for holidays, especially around Christmas. There wasn't anything to do but take it. The reject rate would start climbing around the fifth of December, and up and up it'd go until Christmas. Then the holiday, then a horrible reject rate; then New Year's, then a ghastly reject level. Then things would taper down to normal - which was plenty bad enough - by January fifteenth or so. We used to have to figure in things like that in pricing a product."

"Do you suppose there'll be a Third Industrial Revolution?"

Paul paused in his office doorway. "A third one? What would that be like?"

"I don't know exactly. The first and second ones must have been sort of inconceivable at one time."

"To the people who were going to be replaced by machines, maybe. A third one, eh? In a way, I guess the third one's been going on for some time, if you mean thinking machines. That would be the third revolution, I guess - machines that devaluate human thinking. Some of the big computers like EPICAC do that all right, in specialized fields."

"Uh-huh," said Katharine thoughtfully. She rattled a pencil between her teeth. "First the muscle work, then the routine work, then, maybe, the real brainwork."

"I hope I'm not around long enough to see that final step. Speaking of industrial revolutions, where's Bud?"

"A barge was coming in, so he had to get back to work. He left this for you." She handed him a crumpled laundry slip with Bud's name on it.

Paul turned the slip over and found, as he had expected, a circuit diagram for a mouse detector and alarm system that might very well work. "Astonishing mind, Katharine."