“Our troubles seem to spring mostly from the fact that this planet isn’t anything like Sarr,” Feth pointed out dryly. Ken was forced to admit the justice of this statement, and stored away the rapidly growing stock of information about his companion. Enough of Feth’s former reserve had disappeared to make him seem a completely changed person.
The suits were brought into the shop and gone over with extreme care. The one used on Planet Four appeared to have suffered no damage, and they spent most of the time on the other. The examination this time was much more minute than the one Ken had given it on board the Karella, and one or two new discoveries resulted. Besides the bluish deposit Ken had noted on the metal, which he was now able to show contained oxides, there was a looser encrustation in several more protected spots which gave a definite potassium spectrum — one of the few that Ken could readily recognize — and also a distinct odor of carbon bisulfide when heated. That, to the chemist, was completely inexplicable. He was familiar with gaseous compounds of both elements, but was utterly unable to imagine how there could have been precipitated from them anything capable of remaining solid at “normal” temperature.
Naturally, he was unfamiliar with the makeup of earthly planets, and had not seen the fire whose remains had so puzzled Roger Wing. Even the best imaginations have their limits when data are lacking.
The joints had, as Feth expected, shrunk at the seals, and traces of oxides could be found in the insulation. Apparently some native atmosphere had gotten into the suit, either by diffusion or by outside pressure after the sulfur had frozen.
“Do you think that is likely to happen with the packing properly tightened?” Ken asked, when this point had been checked.
“Not unless the internal heaters fail from some other cause, and in that case you won’t care anyway. The over-tightening cut down the fluid circulation in the temperature equalizing shell, so that at first severe local cooling could take place without causing a sufficiently rapid reaction in the main heaters. The local coils weren’t up to the job, and once the fluid had frozen at the joints of course the rest was only a matter of seconds. I suppose we might use something with a lower freezing point than zinc as an equalizing fluid — potassium or sodium would be best from that point of view, but they’re nasty liquids to handle from chemical considerations. Tin or bismuth are all right that way, but their specific heats are much lower than that of zinc. I suspect the best compromise would be selenium.”
“I see you’ve spent a good deal of time thinking this out. What would be wrong with a low specific heat liquid?”
“It would have to be circulated much faster, and I don’t know whether the pumps would handle it — both those metals are a good deal denser than zinc, too. Selenium is still pretty bad in specific heat, but its lower density will help the pumps. The only trouble is getting it. Well, it was just a thought — the zinc should stay liquid if nothing special goes wrong. We can try it on the next test, anyway.”
“Have you thought about how you are going to justify this next trial, when Drai asks how come?”
“Not in detail. He won’t ask. He likes to boast that he doesn’t know any science — then he gloats about hiring brains when he needs them. We’ll simply say that we have found a way around the cause of the first failure — which is certainly true enough.”