Uller Uprising | Page 5

which results in colorless arterial blood and violet veinous, as the titanium flips back and forth between tri and tetra-valent states.
7. EFFECT ON INTRUDING ITEMS
Water decomposes into oxygen and hydrofluoric acid. All organic matter (earth type) converts into oxygen, carbon tetrafluoride, hydrofluoric acid, etc., with more or less speed. A rubber gas mask lasts about an hour. Glass first frosts and then disappears. Plastics act like rubber, only a little slower. The heavy metals, iron, nickel, copper, monel, etc., stand up well, forming an insoluble coat of fluorides at first and then doing nothing else.
8. WHY GO THERE?
Large natural crystals of fluorides, such as calcium difluoride, titanium tetrafluoride, zirconium tetrafluoride, are extremely useful in optical instruments of various forms. Uranium appears as uranium hexafluoride, all ready for the diffusion process. Compounds of such non-metals as boron are obtainable from the atmosphere in high purity with very little trouble. All metallurgy must be electrical. There are considerable deposits of beryllium, and they occur in high concentration in its ores.

PROLOGUE
On Satan's Footstool
The big armor-tender vibrated, gently and not unpleasantly, as the contragravity field alternated on and off, occasionally varying its normal rate of five hundred to the second when some thermal updraft lifted the vehicle and the automatic radar-altimeter control acted to alter the frequency and lower it again. Sometimes it rocked slightly, like a boat on the water, and, in the big screen which served in lieu of a window at the front of the control cabin, the dingy-yellow landscape would seem to tilt a little. If unshielded human eyes could have endured the rays of Nu Pupis, Niflheim's primary, the whole scene would have appeared a vivid Saint Patrick's Day green, the effect of the blue-predominant light on the yellow atmosphere. The outside 'visor-pickup, however, was fitted with filters which blocked out the gamma-rays and X-rays and most of the ultra-violet-rays, and added the longer light-waves of red and orange which were absent, so that things looked much as they would have under the light of a G0-type star like Sol. The air was faintly yellow, the sky was yellow with a greenish cast, and the clouds were green-gray.
A thousand feet below, the local equivalent of a forest grew, the trees, topped with huge ragged leaves, looking like hundred-foot stalks of celery. There would be animal life down there, too--little round things, four inches across, like eight-legged crabs, gnawing at the vegetation, and bigger things, two feet long, with articulated shell-armor and sixteen legs, which fed on the smaller herbivores. Beyond, in the middleground, was open grassland, if one could so call a mat of wormlike colorless or pastel-tinted sprouts, and a river meandered through it. On the skyline, fifty miles away, was a range of low dunes and hills, none more than a thousand feet high.
No human had ever set foot on the surface, or breathed the air, of Niflheim. To have done so would have been instant death; the air was a mixture of free fluorine and fluoride gasses, the soil was metallic fluorides, damp with acid rains, and the river was pure hydrofluoric acid. Even the ordinary spacesuit would have been no protection; the glass and rubber and plastic would have disintegrated in a matter of minutes. People came to Niflheim, and worked the mines and uranium refineries and chemical plants, but they did so inside power-driven and contragravity-lifted armor, and they lived on artificial satellites two thousand miles off-planet. This vehicle, for instance, was built and protected as no spaceship ever had to be, completely insulated and entered only through a triple airlock--an outer lock, which would be evacuated outward after it was closed, a middle lock kept evacuated at all times, and an inner lock, evacuated into the interior of the vehicle before the middle lock could be opened. Niflheim was worse than airless, much worse.
The chief engineer sat at his controls, making the minor lateral adjustments in the vehicle's position which were not possible to the automatic controls. One of the radiomen was receiving from the orbital base; the other was saying, over and over, in an exasperatedly patient voice: "Dr. Murillo. Dr. Murillo. Please come in, Dr. Murillo." At his own panel of instruments, a small man with grizzled black hair around a bald crown, and a grizzled beard, chewed nervously at the stump of a dead cigar and listened intently to what was--or for what wasn't--coming in to his headset receiver. A couple of assistants checked dials and refreshed their memories from notebooks and peered anxiously into the big screen. A large, plump-faced, young man in soiled khaki shirt and shorts, with extremely hairy legs, was doodling on his notepad and eating candy out of a bag. And a black-haired girl in a suit of coveralls three sizes too big for her,