"Why?"
"Well, the pattern it's set for is the shape of an automobile. See here." He picked up a card from his desk, and cut in the outlines of a streamlined car like those of that year. "Since only one eye is used," he continued, "The thing can't tell the difference between a full-sized vehicle at a distance and this small outline nearby. It has no sense of perspective."
He held the bit of cardboard before the eye of the mechanism. Instantly came its roar of "A-a-gh-rasp!" and it leaped forward a single pace, arms upraised. Van Manderpootz withdrew the card, and again the thing relapsed stolidly into its place.
"What the devil!" I exclaimed. "What's it for?"
"Does van Manderpootz ever do work without reason back of it? I use it as a demonstration in my seminar."
"To demonstrate what?"
"The power of reason," said van Manderpootz solemnly.
"How? And why ought it to work on gasoline instead of electric power?"
"One question at a time, Dixon. You have missed the grandeur of van Manderpootz's concept. See here, this creature, imperfect as it is, represents the predatory machine. It is the mechanical parallel of the tiger, lurking in its jungle to leap on living prey. This monster's jungle is the city; its prey is the unwary machine that follows the trails called streets. Understand?"
"No."