When they next met, Vickers felt happier than ever; for Main’s first words were a request for the method the Earthmen had employed to modify their climate. He asked, politely enough not to give offense, that Vickers translate Rodin’s explanation rather than attempt to give one of his own; evidently he wanted precision. Vickers assented gladly. Rodin had found some details of the operation in Vickers’ library, and was able to add much more from his own memory; so for half an hour he and Vickers alternated relation and translation, while the absorbed Heklan listened silently, his round face showing no expression that Vickers could interpret.
“An absorbing tale,” Trangero said when the Earthmen had finished. “I applaud the ingenuity of your meteorologists and astronomers. I have seen no maps of your planet, but I gathered that much of its land area is in the middle latitudes, as is the case with Hekla. An operation such as you have described would open to us millions of square miles of land areas which at present we can use only in summer and autumn, if at all. It is a pity that it would not be effective on this planet.”
For a moment Vickers sat, stunned by the Heklan’s matter-of-fact remark.
“Why would it not work here?” he finally asked. “I have gathered that carbon dioxide is no more dangerous to you than to us; and it should be as effective a blanketing agent here. I realize the enormous thickness and extent of your ice caps, but even they would eventually yield to a general increase in temperature.”
“Undoubtedly they would,” replied Marn. “Unfortunately, your plan remains unworkable. In the first place, the atmosphere of this planet already contains approximately one and a half percent of carbon dioxide. More would not harm us, but neither would it help. You have forgotten something, which Rodin should have remembered if he knows as much of astronomy as our science requires. Our sun is much redder than yours; and an increase in the atmospheric content of any infrared opaque gas such as carbon dioxide, ozone, or water vapor would cut out nearly as much additional incident radiation as it would retain the natural heat. I admit there would be some gain, but to make it enough to be a real help would demand a radical change in our atmosphere. You are working under different conditions here than you met on your own world, and your meteorology will not help us.”
Vickers thought furiously as the Heklan fell silent. Rodin, who had not understood a word of the last conversation, realized from his friend’s expression that something had gone seriously wrong. He tapped Vickers’ shoulder to gain his attention, and asked for an explanation. It was given to him.
“Is he right, Dave?” asked Vickers, at the end. “Surely there is some modification of that trick that would work for this world. I hate to give up that idea.”
“I can’t, on the spur of the moment, think of anything that would serve,” replied Rodin, “but it seems to me that there must be some fairly simple solution. If necessary, we can call in one of the physics or chemistry boys, though I don’t like to do that. I’d advise you not to appear too perturbed about the matter — after all, this was supposed to be one of Marn’s suggestions. Just let the conversation ride on for an hour or two, and we can talk it over at dinner.”
Vickers recognized the soundness of this bit of advice, and endeavored to abide by it. He was never sure that Marn had not noticed and interpreted the symptoms of annoyance the Earthman must have shown; but the creature never gave any indication of realizing what had occurred.
The rest of the morning was spent in answering his questions about beings and events beyond the R Coronae system.
In spite of his promise, Rodin said practically nothing at dinner; and immediately after the meal he repaired to the library. Vickers followed, and occupied a seat well out of the meteorologist’s way. Silence ensued, broken only by the rustling of paper and the occasional scratch of a stylus in Rodin’s hand. Vickers neither wrote nor read; he sat and thought, while his friend worked. In his own way, he also was working.
Presently Rodin looked up. “Marn is a bright specimen, no doubt,” he said, “but he went a little too far when he implied that our knowledge of meteorology would not be helpful here. There are plenty of ways to alter climate in any direction you please, and some of them must be applicable to this planet. Of course, we want methods which will require the use of plenty of heavy machinery, so that we can sell them the equipment; but that doesn’t narrow the field much, when one is working on a world-wide scale.
“The problem works down to a reasonably simple root. With a given solar constant, there are a number of things that can happen to the incoming energy. A certain percentage is reflected, and a certain percentage absorbed. Modification of that ratio offers one means of climate control; that, in effect, is what we suggested to Marn. It may yet be possible, but the nature of R Coronae’s radiation makes it difficult.
“If you take the absorbed energy as it is, the next point is distribution. Currents in the atmosphere and hydrosphere normally take care of that business; and both of those are subject to interference and consequently to control. Ocean currents, of course, are easier to direct; and it might be worth while to examine more closely the distribution of land and water areas of this planet, with that thought in mind. Distribution by air currents is modified by the height, friction values, existing temperature, and Heaven knows what other characteristics of the land over which they flow; that’s the sad fact that makes meteorology more of a nightmare than a science, at times.
“I should say that redirection of ocean currents offered your best bet; we can try it on Marn, anyway. It will depend a lot on Hekla’s geography, but he will realize that as well as I and will be able to pass judgment. That’s the best I have to offer at the moment.”
At least, Vickers realized, there was still hope even from his point of view. The construction work that would be required by such a plan meant plenty of heavy machinery. He agreed with Rodin on the subject of working the plan into the next conversation with Marn.
The Heklan readily agreed to show Rodin something of the geography of his world, when the meteorologist put the question up to him. He left the Earthmen for a moment, and returned with a heavy book, which proved to be an atlas. Inside its front cover was a folded leaf which opened into a map, several feet square, of the planet. It was on a projection similar to Goode’s homolosine and showed the entire surface of the world; but only a few scattered areas in the arctic and antarctic regions showed anything like the detail displayed on the settled, tropical islands. The Heklans had done little exploring of their own polar caps; Marn said that such regions as the maps showed in detail were in the neighborhood of meteorological stations similar to the one on Observatory Hill.
Rodin, however, was not particularly interested in the polar caps. He examined closely the sea which extended entirely around the globe in the equatorial regions, broken only by the large islands and archipelagos on which most of Main’s race dwelt. In both the northern and southern hemispheres there lay enormous continental masses divided by relatively narrow arms of sea; and the more the meteorologist looked at these, the more confidence he felt in the practicability of diverting warm currents up those arms.
“I see that you have settlements near the equatorial coasts of these land masses,” he finally said to Marn. “Why is it not possible to spread further inland?”
“The extremes of temperature in the continental interiors not only make settled life there impossible, but cause violent and uncomfortable weather at the coast settlements and on the nearer islands,” was the answer, as Rodin had expected. “The polar caps never melt entirely down to the ground over more than a tiny fraction of their area. They are too thick; and any gains made in the warm seasons are lost in the cold ones — quite evenly; the planet has reached a state of near equilibrium in that respect. It is unfortunate from the point of view of living space requirements; but I hate to picture the results of a major change which would interfere with that stability.”
“Why should that be serious?” asked Rodin. “I had been considering that angle ever since our last talk; and it seems to me that sea walls could be designed to deflect the currents which now run around the planet in the equatorial ocean, into these arms of the sea which reach up between the continents. If this were done, it should result in an earlier melting of the ice to the east of the water, permitting the bare ground to absorb more radiant heat. That should gradually operate to get you ahead of the melting-freezing cycle, and the new equilibrium point should give you a good deal of livable land space.”
Marn appeared interested.
“Could you go into a little more detail on that plan? I should like to hear how completely you have been able to handle the situation.”
Rodin bent over the map, and began to indicate what he considered the best location and design for the sea walls, working as well as he could from a memory of the current-control installations on Vega V. Marn was unable to give him much data on ocean depth, but that was not too important. The coasts of the continents involved had a more direct bearing on the situation, and Marn was well informed on their nature. Rodin once more began to feel hopeful. He finished his exposition with the words, “If you feel that the undertaking is practical, any or all of the peoples of the Federation will be glad to help you with experience and equipment.”
Marn did not answer for several moments, and the expectations of the Earthmen mounted with each second of delay. They should have known better by this time.
“It is a well thought out program; better planned, I think, than your first,” the Heklan finally said. “Of course, you are under a handicap in that you are so completely ignorant of Heklan conditions. Your ingenuity and evident experience, however, have started me hoping that perhaps some of your Federation scientists could perform this feat, which seems to me impossible. I hope you will present the problem to your colleagues of the Federation, and that some of them will see fit to give their attention to the matter.” He paused, as though to give Vickers a chance to translate this speech; but before the man could do so, he appeared to have a further idea. “I think it would do no harm to let my people know of your presence, Vickers,” he said. “I am sure they would be fascinated by the possibilities you have unfolded to me; and I don’t believe your reason for wanting secrecy is valid any longer.”
Vickers found himself in the hot part of a pincer movement, and thought furiously as he translated Trangero’s speech to Rodin. “I guess we can let him broadcast if he wants to,” he concluded, “but please do some fast talking on this weather business. He hasn’t told me why your sea walls won’t work; just takes it for granted.”
“I don’t believe he would tell me; and I believe it would work,” answered the meteorologist. “He’s keeping something up his sleeve, and we’ll never worm it out of him. I think we’d better get out of here, and take a little trip. That would give us a chance to check my idea for ourselves — he’s quite right in saying that I don’t know enough about this planet. It might also present us with a better opportunity to do our work than this weather station seems to offer. Why not let these fellows announce our presence, and use the occasion to make a tour of the planet?”
Vickers could think of nothing better, and Marn seemed agreeable. So did Serrnak Deg, when the matter was broached to him. And so it was that the little lifeboat rose from Observatory Hill on what proved to be one of the most trying journeys either man had ever made. Serrnak Deg and Marn Trangero watched the sliver of metal vanish to the south; then they looked at each other, with almost human grins wrinkling their grotesque features. They left the tiny platform from which they had been watching, and entered the elevator. Marn got off at the level on which his office was situated, but Deg went on down; and Vickers would have been interested to note that the Heklan proceeded directly to the room from which the Earthman had been so carefully kept.
But Vickers had no opportunity to note this fact. He watched the cumulus banner above the hill fade into the haze astern; and when it was out of sight, he gave his attention to the landscape unfolding below them. It seemed a sufficiently pleasant country, of forested hills and open plains; but a close inspection of the forests showed great tree-ferns and fungi rather than normal trees, and Vickers knew that in Hekla’s ten or twelve years of winter even this coastal strip was a howling, blizzard-racked desert of snow and ice; and just out of sight to the right as they followed the seacoast southward was the remnant of a giant ice cap where the heights were still snow-capped even at this season.
Rodin was only moderately interested in the view, until the coast began to curve gently westward. Then he began to make careful checks, using one of the maps he had obtained at the weather station. Several times he lowered the ship to the water, checking its depth and temperature; frequently he cruised as low as was safe among the hills and above the trees, examining Vickers knew not what characteristic of the planet’s surface. The meteorologist’s pile of notes and computations grew in thickness, while Vickers did little save look on and enjoy himself.
Southward they drove, breaking away from the coast and moving far out over a broad stretch of sea, until the geodet told them they were nearly above the equator; then westward, still dropping occasionally for Rodin’s perpetual measurements, over more water, interrupted at times by islands. Twice they saw what were evidently Heklan communities; each time they were small, but each boasted a landing strip similar to, but much longer than, the one on Observatory Hill. Several winged aircraft were parked in the open near each strip, and a single machine, similar in exterior design to the terrestrian lifeboat. Vickers was curious about its method of propulsion, since the Heklans were without atomic power, but he did not bother to descend to investigate.
For ninety hours they chased the sun, veering far enough to right and left to examine the near shores of most of the continental masses.
Each time they did so, Rodin expressed greater confidence in his plan; and as the geodet told them that they were again approaching the longitude of Observatory Hill, he swung the ship northward, prepared to argue its merits to the limit.
Vickers took over the controls for a time, to let the meteorologist straighten out the last of his paper work. It was a token job, since the automatic controls were holding the craft on course and at a constant pressure altitude. They were cruising at a very moderate speed, since Rodin wanted time for his work; they were, Vickers calculated, about an hour and a half from the observatory. The usual layer of haze was overhead — thicker than normal, Vickers decided; the red sunlight pouring through the upper ports seemed less intense than usual.
He did not see the clouds until they were less than twenty miles ahead. It was the first extensive cumulus development he had seen on Hekla, and he debated calling Rodin; but he decided such clouds could not be too unusual, and failed to do so. He simply sat and watched the wall of vapor grow more distinct as the little ship approached it. It extended as far as he could see on either side and — up. An airplane pilot of an earlier century would not have come within miles of that angry black barrier; Rodin might have decided to go over it, but Vickers let the automatic controls carry the tiny machine straight into its heart. Even then, if the altitude control had been connected to the radio altimeter, no harm might have been done; unfortunately, Vickers had tied it in to the atmospheric pressure gauge, in anticipation of reaching land.
The initial turbulence made no impression on ship or occupants; but five seconds after the sun had faded from sight the ship stuck its nose into the low pressure of an updraft, and Vickers left his seat. For several seconds he was dazed by the force with which his head struck the ceiling. In those few seconds the ship lost six thousand feet of altitude as the automatic controls sought a level of pressure equal to that at which they had been set. Before they succeeded, and before Vickers could regain his feet and the manual controls, the updraft was passed; and he was pressed helplessly against the deck as the ship plunged upward again. As it slowed, he seized the back of his chair and tried to brace himself against the sickening motion. For a moment he was partially successful, and he dared to let go with one hand in order to reach once more for the controls. As he touched them, there was a violent sideward lurch; and his hand, instead of striking the toggle controlling the altitude mechanism, opened the bar switch handling the sensation currents from the attitude gyros on the automatic pilot.
The ship could not have been out of control more than three or four minutes altogether; but those minutes were more than enough. Without the gyros, she no longer held an even keel, but pitched, yawed, rolled completely over again and again, still striving to follow the dictates of the altitude control. That barometer was sensitive enough for control in the upper stratosphere of planets like Earth and Thanno; and in the tremendous pressure changes accompanying turbulence in Hekla’s dense atmosphere the little device went mad. Vickers, dazed and bleeding, bouncing from floor to ceiling and wall to wall of the control room, finally managed to hold on to the board long enough and firmly enough to set the selector at zero pressure. Still bucking and rolling, the ship went shooting upwards, and at last broke out into the crimson sunlight---more than thirty kilometers above the ocean, if the radio altimeter could be believed. The air was calmer here, and the ship quieted down enough for Vickers to level it by manual control, reset the toppled attitude gyros, and cut them in again.
With a steady deck once more under his feet, he staggered back to the library where Rodin had been working. The meteorologist had taken a beating, but had suffered less damage than Vickers, owing chiefly to the fact that the library furniture was for the most part heavily upholstered. He made acrid inquiry into the cause of the disturbance, and was not particularly sympathetic with Vickers’ injuries. They went forward to the control room together, and Vickers gazed through the port at the innocent-looking, fluffy pink mass below them while Rodin applied antiseptic and dressings to his contusions. When he had finished this job, the meteorologist began to observe, too.
Vickers had halted the ship when he had regained control, and they were hanging motionless above the wall of vapor. They were still in sight of the edge where they had entered it; and when Rodin set the ship in motion again, they ran within a few minutes into an almost equally sharp termination on the other side. The front was only thirty or forty miles wide; and this, together with the altitude of the cumulus barrier, indicated a frontal slope that made Rodin whistle. Then he stopped to think; and the more he thought the less he was able to understand how a mass of cold air of such size and, apparently, extreme low temperature could have wandered so far from the pole in midsummer. Then he remembered the violence which had resulted from a very slight temperature change, during the warm front he had watched at Observatory Hill; and he took the ship down on the cold side of the front to the altitude at which they had been flying when they ran into trouble, and compared temperatures. The difference was not great, but it was far greater than had been the case on the other occasion; and considering the density and other peculiarities of Hekla’s atmosphere, it could account for such a violent front. It remained to account for the air mass. Rodin began to think out loud, as he considered this problem.
“This stuff appears to be of polar continental origin, judging by its temperature and dryness,” he said. “It’s not extremely cold, but in Hekla’s atmosphere it could still have formed over the polar ice cap, and probably did. On Earth, such a mass couldn’t come anything like this far south in summer. The normal surface circulation is too strong for it, and remains too strong as long as the ground is receiving much solar energy. However, it could be forced down like this if we supposed another, still colder, mass to the east of its source region, against which it was carried by the normal trade circulation and thence deflected southward. Also, a general cooling of the continental areas to the south of the source region might permit it to be carried down here around a normal cyclone.
“Either supposition demands a decrease in ground surface temperature comparable to that experienced at the onset of winter. I can’t imagine any large area waiting until this late in the summer to become covered by snow; but I can’t see any other means of dropping the temperature of a large area to any great extent, unless the axis of the planet shifts enough to decrease insolation in this hemisphere.” He grinned wryly as he made that remark; he realized perfectly well that the application of sufficient force to shift the axis of a major planet would buckle its crust at the very least, and more probably disrupt the world.
“How about night cooling?” asked Vickers. “This planet rotates more slowly than Earth.”
“Not enough; in summer the nights are short anyway; and why would it wait until now, fully two Earth years after midsummer, to take effect?”
“Then how about this mist that seems to have been cutting off some of the sunlight of the last day or two? You must have noticed it — it appears to be above any level at which we’ve flown, so it can’t be very dense; but it seems to be practically planet-wide, and cuts off enough light for me to notice without instruments.”
“I hadn’t noticed it particularly,” said Rodin thoughtfully. “A high layer of water vapor or dust would have a blanketing effect, and would actually increase surface temperature, even though it cut off some visible light. However, there’s something to the idea; the stuff might just possibly have a high reflecting power, I suppose. It won’t hurt us to go up and find this layer, anyway.”
Rodin went back to the controls, and started the ship climbing slowly. Then he started the recorder of the radiograph he had set up at one of the portholes when he had first arrived, and waited while they rose through the thinning atmosphere to a level at which the outside pressure was no longer detectable. There he stopped ship and recorder, and removed the graph from the latter. The haze layer, if it existed, should have betrayed its presence by a more or less sharp break in the curve — or rather, a change in its slope — at the proper level; but Rodin, to his disgust, was unable to find anything of the sort by visual inspection. He was beginning to check the instrument for flaws that would affect its sensitivity, when Vickers remarked that the sun seemed still to be rather weaker than usual — rather as Sol would appear from Earth during a partial eclipse, allowing for the difference in their intrinsic luminosities.
“An eclipse?” queried Rodin. “Hekla has only two satellites big enough and near enough to produce a respectable eclipse; and even the partial phase would last only a few hours. You noticed this dimness a couple of days ago.”
He went to the port and looked up at the sun. From Hekla’s surface the human eye could bear to look directly at R Coronae’s immense disk, but here above the atmosphere it was a little too bright for comfort. He rummaged in a drawer under the control panel, found a pair of shielded goggles; with these he approached the port again, and looked long and earnestly at the fuzzy crimson blot hanging in the blackness of space. At last he called Vickers, gave him the goggles, and asked him to look, describe, and if possible explain what he saw. Vickers obediently donned the eye shields and went to the port.