"Third thing: there's only one city on this continent, and it's protected by a screen that nobody ever heard of."
Hilton pondered, then turned to the captain. "Will you please run a search-pattern, sir? Fine-toothing only the hot spots?"
The planet was approximately the same size as Terra; its atmosphere, except for its intense radiation, was similar to Terra's. There were two continents; one immense girdling ocean. The temperature of the land surface was everywhere about 100°F, that of the water about 90°F. Each continent had one city, and both were small. One was inhabited by what looked like human beings; the other by usuform robots. The human city was the only cool spot on the entire planet; under its protective dome the temperature was 71°F.
Hilton decided to study the robots first; and asked the captain to take the ship down to observation range. Sawtelle objected; and continued to object until Hilton started to order his arrest. Then he said, "I'll do it, under protest, but I want it on record that I am doing it against my best judgment."
"It's on record," Hilton said, coldly. "Everything said and done is being, and will continue to be, recorded."
The _Perseus_ floated downward. "_There's_ what I want most to see," Hilton said, finally. "That big strip-mining operation ... that's it ... hold it!" Then, via throat-mike, "Attention, all scientists! You all know what to do. Start doing it."
Sandra's blonde head was very close to Hilton's brown one as they both stared into Hilton's plate. "Why, they look like giant armadillos!" she exclaimed.
"More like tanks," he disagreed, "except that they've got legs, wheels _and_ treads--and arms, cutters, diggers, probes and conveyors--and _look_ at the way those buckets dip solid rock!"
The fantastic machine was moving very slowly along a bench or shelf that it was making for itself as it went along. Below it, to its left, dropped other benches being made by other mining machines. The machines were not using explosives. Hard though the ore was, the tools were so much harder and were driven with such tremendous power that the stuff might just have well have been slightly-clayed sand.
Every bit of loosened ore, down to the finest dust, was forced into a conveyor and thence into the armored body of the machine. There it went into a mechanism whose basic principles Hilton could not understand. From this monstrosity emerged two streams of product.