"That?" he asked in blank amazement. "Why—why then all those telephone poles and dynamos and lighting-equipment I noticed in this era are powered by electricity!"
"What did you think they were powered by?" Martin asked coldly.
"Slaves," the robot said, examining the lamp. He switched it on, blinked, and then unscrewed the bulb. "Voltage, you say?"
"Don't be a fool," Martin said. "You're overplaying your part. I've got to get going in a minute. Do you want a jolt or don't you?"
"Well," the robot said, "I don't want to seem unsociable. This ought to work." So saying, he stuck his finger in the lamp-socket. There was a brief, crackling flash. The robot withdrew his finger.
" F(t) —" he said, and swayed slightly. Then his fingers came up and sketched a smile that seemed, somehow, to express delighted surprise.
" Fff(t)! " he said, and went on rather thickly, " F(t) integral between plus and minus infinity… a-sub-n to e …."
Martin's eyes opened wide with shocked horror. Whether a doctor or a psychiatrist should be called in was debatable, but it was perfectly evident that this was a case for the medical profession, and the sooner the better. Perhaps the police, too. The bit-player in the robot suit was clearly as mad as a hatter. Martin poised indecisively, waiting for his lunatic guest either to drop dead or spring at his throat.
The robot appeared to be smacking his lips, with faint clicking sounds.
"Why, that's wonderful," he said. "AC, too."