Hal Clement - Heavy Planet

Beerchermarlf and Takoorch, like the rest of the Kwembly’ s crew, were taken by surprise when the lake froze. Neither had had any occasion for several hours to look around, since the maze of fine cords on which their attention was focused was considerably more complicated than, say, the rigging of a clipper ship. Both knew exactly what to do, and there was little need for conversation. Even had their eyes wandered from the job, there was little else to see. They were under the immense bulk of their vehicle, roofed by the pneumatic “mattress” which distributed its weight among the trucks, walled partly by the trucks themselves and partly by the blackness of Dhrawn’s night which swallowed everything beyond the range of their little portable lights. So they had not seen, any more than the sailors inside the Kurmbly, the tiny crystals which began to form at the surface of the lake and settle to the bottom, glinting and sparkling in the Kwembly ’s floods. They had completed reconnecting on the port row, Number 1, all the way from bow to stern and were working their way forward on Row 2 when they discovered that they were trapped. Takoorch’s battery light was fading a trifle, and he took it over to the nearest fusion converter, which happened to be on a Row 1 truck, for recharging. He was quite startled to find that he couldn’t get at or even see the converter; after a few seconds of fumbling and looking he called Beetchermarlf. It took nearly ten minutes for them to establish that they were completely enclosed by an opaque white wall, impenetrable even to their strength. It had welded all the outer trucks together and filled all the spaces between them from mattress above to cobbles below, nearly three feet of height, on the average. Inside the wall they were still free to move about. Their tools were edged rather than pointed, and too small to make appreciable way against the ice, though it took fully an hour of scraping to convince them both of that. Neither was greatly concerned as yet; obviously the ice was immobilizing the Kwembly , and the rest of the crew would have to dig down to them in the interest of freeing the vehicle if not for the prime purpose of rescue. Of course their supply of life hydrogen was limited, but this meant less to them than a corresponding oxygen shortage would have to a human being. They had at least ten or twelve hours yet of full activity, and when the hydrogen partial pressure dropped below a certain value they would simply lose consciousness. Their body chemistry would slow down more and more, but fifty and perhaps a hundred hours would pass before anything irreversible occurred. One of the reasons for Mesklinite durability, though human biologists had had no chance to find it out, was the remarkable simplicity of their biochemistry. The two were calm enough, in fact, to go back to their assigned work; and they were almost to the front of Row 2 before another discovery was made. This one did perturb them. The ice was creeping inward. It was not coming rapidly, but it was coming. As it happened, neither of them knew any better than Ib Hoffman what being frozen into a block of the stuff was likely to do to them. Neither had the slightest desire to learn. At least there was still light. Not all the power units were on outside trucks, and Takoorch had been able to recharge his battery. This made it possible to make another, very careful search of the boundaries of their prison. Beetchermarlf was hoping to find unfrozen space either near the bottom or, preferably, near the top of the walls around them. He did not know whether the freezing would have started from the top or the bottom of the pond. He was not familiar, as any human being would have been, with the fact that ice floats on liquid water. This was just as well, since it would have led him to an erroneous conclusion in this instance. The crystals had indeed formed at the top, but they had been denser than the surrounding liquid and had settled, only to redissolve as they reached levels richer in ammonia. This pseudo-convection effect had had the result of robbing the lake rather uniformly of ammonia until it had reached a composition able to freeze almost simultaneously throughout. As a result, the search turned up no open spaces. For some time the two lay between two of the trucks, thinking and occasionally checking to see how far the freezing had progressed. They had no time measuring equipment, and therefore no basis for estimating the speed of the process. Takoorch guessed that it was slowing down; Beetchermarlf was less sure. Occasionally an idea would strike one of them but the other usually managed to find a flaw in it. “We can move some of these stones, the smaller ones,” Takoorch remarked at one point. “Why can’t we dig our way under the ice?”

“Where to?” countered his companion. “The nearest edge of the lake is forty or fifty cables away, or was the last I knew. We couldn’t begin to dig that far in these rocks before our air gave out, even if there was any reason to suppose the freezing didn’t include the water between the rocks underneath. Coming up before the edge wouldn’t get us anywhere.” Takoorch admitted the justice of this with an acquiescent gesture and silence fell while the ice grew a fraction of an inch nearer. Beetchermarlf had the next constructive thought. “These lights must give off some heat, even if we can’t feel it through the suits,” he suddenly exclaimed. “Why shouldn’t they keep the ice from forming near them, and even let us melt our way to the outside?”

“Worth trying,” was Takoorch’s laconic answer. Together they approached the frosty barrier. Beetchermarlf built a small cairn of stones leaning against the ice, and set the light, adjusted for full brightness, at its top. Then both crowded close, their front ends part way up the heap of pebbles, and watched the space between the lamp and the ice. “Come to think of it,” Takoorch remarked as they waited, “our bodies give off some heat, don’t they? Shouldn’t our just being here help melt this stuff?”

“I suppose so.” Beetchermarlf was dubious. “We’d better watch to make sure that it doesn’t freeze at each side and around behind us while we’re waiting here.”

“What will that matter? If it does, it means that we and the light together are enough to fight the freezing and we should be able to melt our way out.”

“That’s true. Watch, though, so we’ll know if that’s happening.” Takoorch gestured agreement. They fell silent again. The older helmsman, however, was not one to endure silence indefinitely, and presently he gave utterance to another idea. “I know our knives didn’t make much impression on the ice, but shouldn’t c it help if we did some scraping right here where it’s nearest the light?” He unclipped one of the blades they carried for general use and reached toward the ice. “Wait a minute!” exclaimed Beetchermarlf. “If you start working there, how are we ever going to know whether the heat is having any effect?”

“If my knife gets us anywhere, who cares whether it’s the heat or the work?” retorted Takoorch. Beetchermarlf found no good answer ready, so he subsided, muttering something about “controlled experiments” while the other Mesklinite went to work with his tiny blade. As it happened, his interference did not spoil the experiment, though it may have delayed slightly the appearance of observable results. Body heat, lamp heat, and knife all together proved unequal to the job; the ice continued to gain. They had to remove the lamps from the cairn at last, and watch the latter slowly become enveloped in the crystalline wall. “It won’t be long now,” Takoorch remarked as he swung the lights around them. “Only two of the power units are free, now. Should we charge up the lights again before they go, or isn’t it worth the trouble?”