by Hal Clement
During the journey the crew is also forced to defy this conditioning; while trading in a strange city discovered en route, they are attacked by the natives, whose method of assault consists of rolling large rocks from the hill completely encircling the town. The only escape for the Mesklinites is by jumping or climbing to the tank’s roof; the vehicle itself is saved by destroying with high-explosive shells the only rock in a position to do it serious damage. After this, the Mesklinites become almost comically defiant of their old fears, jumping and climbing with what amounts to recklessness and causes Barlennan some concern.
The journey is continued, and is almost at its end when the tank encounters an apparently insuperable obstacle—a cliff some sixty feet in height dropping away ahead of them, and extending as far as can be seen in either direction. The tank cannot possibly negotiate such a drop; and even in the relatively feeble gravity of the equatorial zone sixty feet is too much for the Mesklinites—and for their ship.
Further aerial reconnaissance indicates that the cliff extends much too far in both directions to be rounded, but that two rivers empty over its edge within reasonable distance of the tank’s present position. The travelers proceed to one of these and, again at Barlennan’s suggestion, the Bree is disassembled and hoisted over the edge, together with her crew. The ship is quickly put together again by the river at the cliffs foot, and launched. She proceeds on her way alone, while Lackland, who has done all he could on Mesklin’s surface, calls the rocket to take him back to Toorey.
On the way downstream, Barlennan encounters savages of his own species and for the first time in his life sees a canoe. He is deeply impressed with the load-carrying powers of this strange, hollow boat—the Bree is a collection of rafts bound together to combine strength with flexibility—and acquires one, dreaming of revolutionizing the maritime commerce of his nation.
Eventually he reaches the ocean and heads south, guided and aided by weather reports and predictions from above. In sheltering from a storm in a group of islands near the seven-gravity latitude, the crew encounters another nation of their own species which has mastered flight, to the intense surprise of the watching scientists; Mesklin’s intense gravity and hydrogen atmosphere had made such a feat on the part of the semi-civilized natives seem unlikely at the very least. Barlennan learns much, although the islands guard fiercely the secrets of their gliders from the “barbarian” visitors. He learns, for example, of missile weapons, which are quite impossible at his two-hundred-gravity home latitude; the islanders drop spears from their gliders, and also use crossbows. The Bree escapes with some difficulty after an official of the islanders becomes convinced that the Bree’s crew is deliberately spying. Resuming his southward journey, Barlennan learns why canoes are not used by his people; the increasing gravity causes a corresponding increase in pressure below the ocean surface, and the canoe towing behind the ship is crushed. Barlennan is almost equally so some time later, when the Bree, after reaching the southern end of the ocean and ascending the river to the point indicated by the photographs and radio fixes as being closest to the grounded rocket, finds herself at the foot of another cliff. This one is a full three hundred feet in height; and three hundred feet in Mesklin’s polar gravity corresponds to a vertical distance, on Earth, of some thirty-five miles. The rocket is somewhere beyond the top of the cliff.
XV.
The change of mind that had so affected the Bree’s crew was not temporary; the unreasoning, conditioned fear of height that had grown with them from birth was gone. They still, however, had normal reasoning power; and in this part of their planet a fall of as much as half a body’s length was nearly certain to be fatal even to their tough organisms. Changed as they were, most of them felt uneasy as they moored the Bree to the river bank only a few rods from the towering cliff that barred them from the grounded rocket.
The Earthmen, watching in silence, tried futilely to think of a way up the barrier. No rocket that the expedition possessed could have lifted itself against even a fraction of Mesklin’s polar gravity; the only one that had ever been built able to do so was already aground on the planet. Even had the craft been capable, no human or qualified nonhuman pilot could have lived in the neighborhood; the only beings able to do that could no more be taught to fly a rocket than a Bushman snatched straight from the jungle. Two or three generations of education could no doubt produce Mesklinites fit for the task; but that would be much too long to wait.
“The journey simply isn’t as nearly over as we thought.” Rosten, called to the screen room, analyzed the situation rapidly. “There should be some way to the plateau or farther slope—whichever is present—of that cliff. I’ll admit there seems to be no way Barlennan and his people can get up; but there seems to be nothing preventing their going around.” Lackland relayed this suggestion to the captain.
“That is true,” the Mesklinite replied. “There are, however, a number of difficulties. It is already getting harder to procure food from the river; we are very far from the sea. Also, we have no longer any idea of how far we may have to travel, and that makes planning for food and all other considerations nearly impossible. Have you prepared, or can you prepare, maps with sufficient detail to let us plan our course intelligently?”
“Good point. I’ll see what can be done.” Lackland turned from the microphone to encounter several worried frowns. “What’s the matter? Can’t we make a photographic map as we did of the equatorial regions?”
“Certainly,” Rosten replied. “A map can be made, possibly with a lot of detail; but it’s going to be difficult. At the equator a rocket could hold above a given point, at circular velocity, only six hundred miles from the surface—right at the inner edge of the ring. Here circular velocity won’t be enough, even if we could use it conveniently; even a parabolic path would intersect the surface of the planet, since the world’s curvature is so small in the polar regions. We’d have to use a hyperbolic orbit of some sort to get short-range pictures without impossible fuel consumption; and that would mean speeds relative to the surface of several hundred miles a second. You can see what sort of pictures that would mean. It looks as though the shots will have to be taken with long-focus lenses, at extremely long range; and we can only hope that the detail will suffice for Barlennan’s needs.”
“I hadn’t thought of that,” admitted Lackland. “We can do it, though; and I don’t see any alternative in any case. I suppose Barlennan could explore blind, but it would be asking a lot of him.”
“Right. We’ll launch one of the rockets and get to work. We can rig some of the astronomical lenses with film holders that already have focal-plane shutters; that should give scale enough.” Lackland gave the substance of this conversation to Barlennan, who replied that he would stay where he was until the information he needed was obtained.
“I could either go on upstream, following the cliff around to the right, or leave the ship and the river and follow to the left. Since I don’t know which is best from the point of view of distance, we’ll wait. I’d rather go upstream, of course; carrying food and radios will be no joke otherwise.”
“All right. How is your food situation? You said something about its being hard to get that far from the ocean.”
“It’s scarcer, but the place is no desert. We’ll get along for a time at least. If we ever have to go overland, we may miss you and your gun, though. This crossbow has been nothing but a museum piece for nine tenths of the trip.”
“Why do you keep the bow?”
“For just that reason—it’s a good museum piece, and museums pay good prices. No one at home has ever seen, or as far as I know even dreamed of, a weapon that works by throwing things. You couldn’t spare one of your guns, could you? It needn’t work, for that purpose.” Lackland laughed.
“I’m afraid not; we have only one. We don’t expect to need it, but I don’t see how we could explain giving it away.”
Barlennan gave the equivalent of an understanding nod, and turned back to his o
wn duties. He had much to bring up to date on the bowl that was his equivalent of a globe; the Earthmen, throughout the trip, had been giving him bearing and distance to land in all directions, so he was able to get most of the shores of the two seas he had crossed onto the concave map.
It was also necessary to see to the food question; it was not, as he had told Lackland, really pressing, but more work with the nets was going to be necessary from now on. The river itself, now about two hundred yards wide, appeared to contain fish enough for their present needs, but the land was much less promising. Stony and bare, it ran a few yards from one bank of the stream to end abruptly against the foot of the cliff; from the other, a series of low hills succeeded each other for mile after mile, presumably far beyond the distant horizon. The wind came steadily around the cliff from the left.
The cliff itself seemed to have been pushed up bodily from below by the cataclysmic natural forces always at work in Mesklin’s interior, where pressures existed sufficient to keep a good part of the planet’s mass in the degenerate, enormously dense state characteristic of white dwarf stars. The rock of the escarpment’s face was polished glass-smooth, as sometimes happens even on Earth to the rocks at the sliding edges of a fault. Climbing it, even on Earth, would have required the equipment and body weight of a fly—on Mesklin, the fly would have weighed too much. Vegetation was present, but not in any great amount, and in the first fifty days of their stay no member of the Bree’s crew saw any trace of land animal life. Occasionally someone thought he saw motion, but each time it turned out to be shadows cast by the whirling sun, now hidden from them only by its periodic trips beyond the cliff. They were so near the south pole that there was no visible change in the sun’s altitude during the day.
It might easily have been possible for hunting parties to become lost, except for the presence of the towering wall of stone that held them here. As a landmark it was ideal, or almost so; it would be visible from any hilltop for many miles, until it merged with the rising horizon—certainly much farther than any hunters would go; the only trouble would be the impossibility of determining from a distance just what part of the level cliff top was above the Bree’s position. That, however, could also be solved; parties could go out bearing either definitely right or definitely left of the line straight away from the barrier. Then if they returned straight toward it, they would know whether they struck the river upstream or down from the desired point. Barlennan made sure this was understood by the entire crew before he allowed anyone to explore. Then, food more or less assured and examination of the neighborhood well under way, he settled down to wait.
For the Earthmen, the time was a little more active. Four of the expedition, including Lackland, manned the rocket and dropped planetward from the rapidly moving moon. From their take-off point the world looked rather like a pie plate with a slight bulge in the center; the ring was simply a line of light, but it stood out against the background of star-studded blackness and exaggerated the flattening of the giant world.
As power was applied both to kill the moon’s orbital velocity and bring them out of Mesklin’s equatorial plane the picture changed. The ring showed for what it was, but even the fact that it also had two divisions did not make the system resemble that of Saturn. Mesklin’s flattening was far too great for it to resemble anything but itself—a polar diameter of less than twenty thousand miles compared to an equatorial one of some forty-eight thousand has to be seen to be appreciated. All the expedition members had seen it often enough now, but they still found it fascinating.
The fall from the satellite’s orbit gave the rocket a very high velocity, but, as Rosten had said, it was not high enough. Power had to be used in addition; and although the actual pass across the pole was made some thousands of miles above the surface, it was still necessary for the photographer to work rapidly. He was using a very narrow angle lens, and took several exposures on each pass; but correlating them was still going to be a job.
Three runs were actually made, each taking between two and three minutes for the actual photography and many more for the whipping journey around the planet. They made reasonably sure that the world was presenting a different face to the sun each time, so that the height of the cliff could be checked by shadow measurements on all sides; then, with the photographs already fixed and on one of the chart tables, the rocket spent more fuel swinging its hyperbola into a wide arc that intercepted Toorey, and killing speed so that too much acceleration would not be needed when they got there. They could afford the extra time consumed by such a maneuver; the mapping could proceed during the journey.
Results, as usual with things Mesklinite, were interesting if somewhat surprising. In this case, the surprising fact was the size of the fragment of planetary crust that seemed to have been thrust upward en bloc. It was shaped rather like Greenland, some thirty-five hundred miles in length, with the point aimed almost at the sea from which the Bree had come. The river leading to it, however, looped widely around and actually contacted its edge at almost the opposite end, in the middle of the broad end of the wedge. Its height at the edges was incredibly uniform; shadow measurements suggested that it might be a trifle higher at the point end than at the Bree’s present position, but only slightly. There were no sawtooth shadows to indicate gaps in the wall.
Except at one point. One picture, and one only, showed a blurring of the shadow that might be a gentler slope. It was also in the broad end of the wedge, perhaps eight hundred miles from where the ship now was. Still better, it was upstream—and the river continued to hug the base of the cliff. It looped outward at the point where the shadow break existed as though detouring around the rubble pile of a collapsed slope, which was very promising indeed. It meant that Barlennan had sixteen or seventeen hundred miles to go instead of fifty, with half of it overland; but even the overland part should not be overwhelmingly difficult. Lackland said so, and was answered with the suggestion that he make a more careful analysis of the surface over which his small friend would have to travel. This, however, he put off until after the landing, since there were better facilities at the base.
Once there, microscopes and densitometers in the hands of professional cartographers were a little less encouraging, for the plateau itself seemed rather rough. There was no evidence of rivers or any other specific cause for the break in the wall that Lackland had detected; but the break itself was amply confirmed. It was apparently a cleft, narrower than Lackland had thought, leading from the inner plateau to the base; and at its foot there was, as expected, a pile of detritus that had diverted the river on which the Bree had traveled.
The pile itself should have been the product of a river, like the cleft from which its material had presumably come; but no evidence of such a stream could be found. Furthermore, there was no sign of liquid anywhere on the plateau, and no certain evidence of life in any form. The densitometer indicated that the center of the region was lower than the rim, so that it was actually a gigantic shallow bowl; but its depth could not be determined accurately, since there were no distinct shadows across the inner portion. The analysts were quite sure, however, that its deepest part was still well above the terrain beyond the cliffs.
Rosten looked over the final results of the work, and sniffed.
“I’m afraid that’s the best we can do for him,” he said at last. “Personally, I wouldn’t have that country on a bet even if I could live in it. Charlie, you may have to figure out some way to give moral support; I don’t see how anyone can give physical.”
“I’ve been doing my best all along. It’s a nuisance having this crop up when we were so close to home plate. I just hope he doesn’t give us up as a bad job this close to the end; he still doesn’t believe everything we say, you know. I wish someone could explain that high-horizon illusion to his—and my—satisfaction; that might shake him out of the notion that his world is a bowl, and our claim to come from another is at least fifty per cent superstition on our part.”
“You mean yo
u don’t understand why it looks higher?” one of the meteorologists exclaimed in a shocked tone.
“Not in detail, though I realize the air density has something to do with it.”
“But it’s simple enough—”
“Not for me.”
“It’s simple for anyone. You know how the layer of hot air just above a road on a sunny day bends sky light back upward at a slight angle, since the hot air is less dense and the light travels faster in it; you see the sky reflection and tend to interpret it as water. You get more extensive mirages sometimes even on Earth, but they’re all based on the same thing—a dens’ or ‘prism’ of colder or hotter air refracts the light. It’s the same here, except the gravity is responsible; even hydrogen decreases rapidly in density as you go up from Mesklin’s surface. The low temperature helps, of course.”
“All right if you say so; I’m not a—” Lackland got no chance to finish his remark; Rosten cut in abruptly and grimly.
“Just how fast does this density drop off with altitude?” The meteorologist drew a slide rule from his pocket and manipulated it silently for a moment.
“Very roughly, assuming a mean temperature of minus one sixty, it would drop to about one per cent of its surface density at around fifteen or sixteen hundred feet.” A general stunned silence followed his words.
“And . . . how far would it have dropped at . . . say . . . three hundred feet?” Rosten finally managed to get the question out. The answer came after a moment of silent lip movement.
“Again very roughly, seventy or eighty per cent—probably rather more.”