incredible knowledge and skill to make the star-flung outposts of civilization ready to receive new, vast surges of humanity! Contents SOLAR CONSTANT Bordman waked that morning when the partly-opened port of his sleeping-cabin closed of itself and the room-warmer began to whir. He found himself burrowed deep under his covering, and when he got his head out of it the already-bright room was bitterly cold and his breath made a fog about his head. He thought uneasily it's colder than yesterday! But a Senior Colonial Survey Officer is not supposed to let himself seem disturbed, in public, and the only way to follow that rule is to follow it in private too. So Bordman composed his features, while gloom filled him. When one has just received senior service rating and is on one's very first independent survey of a new colonial installation, the unexpected can be appalling. The unexpected was definitely here, on Lani III. He'd been a Survey Candidate on Khali II and Taret and Arepo I, all of which were tropical, and a Junior Officer on Menes III and Thotmes—one a semi-arid planet and the other temperate-volcanic—and he'd done an assistant job on Saril's solitary world, which was nine-tenths water. But this first independent survey on his own was another matter. Everything was wholly unfamiliar. An ice-planet with a minus point one habitability rating was upsetting in its peculiarities. He knew what the books said about glacial-world conditions, but that was all. The denseness of the fog his breath made seemed to grow less as the room-warmer whirred and whirred. When by the thinness of the mist he guessed the temperature to be not much under freezing, he climbed out of his bunk and went to the port to look out. His cabin, of course, was in one of the drone-hulls that had brought the colony's equipment to Lani III. The other emptied hulls were precisely ranged in order outside. They were connected by tubular galleries, and painstakingly leveled. They gave an impression of impassioned tidiness among the upheaved, ice-coated mountains all about. He gazed down the long valley in which the colony lay. There were monstrous slanting peaks on either side that partly framed the morning sun. Their flanks were ice. The sky was pale, and the sun had four sun-dogs geometrically about it. Normal post-midnight temperatures in this valley ranged around ten below zero—and this was technically summer. But it was colder than ten below zero