“Theoretical grounds?”
“Yes. For example, while fluorine is still gaseous under those conditions, it’s much too active to be expected in the free state. The same is true of chlorine — which may be liquid — and oxygen. On the other hand, hydrogen seems very likely, along with hydrogen sulfide and other volatile compounds of both those elements. Nitrogen should be present, and the inert gases — though I don’t know how I can test for those.
“I’ve built little cells containing various materials, along with built-in heaters; and I’m going to warm them up one at a time after landing this torpedo and opening it to the atmosphere. Then I’ll bring it back and see what the air did to my samples. I have magnesium and titanium, which should detect the nitrogen, and sodium, and a couple of sulfides which should be reduced if there’s much hydrogen, and so on. The report may not be complete, but we should learn something.”
“So I should say, from what little I know about it Were you planning to send the torpedo out right away?”
“Yes; everything seems to be ready, unless there are complications from your department.”
“Nothing much. We were just going to send one out ourselves; our native signalled a short time ago.”
“Can you control two torpedoes at once?”
“Yes, easily. It occurs to me, however, that it might be best for you to keep a mile or two away from our homing station, and make your descent when that part of the planet is in darkness. The natives are diurnal, we are sure; and it would be a pity to scare them off if any of your chemical reactions are bright or noisy or smelly.”
“Or affect some sense we don’t know about. All right; you have a good point. Do you want me to wait until you have finished your trading, or go ahead of you if the chance occurs?”
“I don’t see that it matters much. I don’t remember whether it will be night or day there when the torpedoes arrive overhead; there’s a table for figuring it up in the office, and we’ll check before arrival time. I’d say if it was day, we’d go right down while you waited, and if it’s night you get first shot.”