There was such a stream, easily navigable by a vessel like the Bree, passing within fifty miles of the desired spot; but it emptied into an ocean which had no visible connection with that which Barlennan’s people sailed. The latter was a long, narrow, highly irregular chain of seas extending from somewhat north of the equator in the general neighborhood of Lackland’s station almost to the equator on the opposite side of the planet, passing fairly close to the south pole on the way — fairly close, that is, as distances on Mesklin went. The other sea, into which the river near the rocket emptied, was broader and more regular in outline; the river mouth in question was at about its southernmost point, and it also extended to and past the equator, merging at last with the northern icecap. It lay to the east of the first ocean chain, and appeared to be separated from it by a narrow isthmus extending from pole to equator — narrow, again by Mesklinite standards. As the photographs were gradually pieced together, Lackland decided that the isthmus varied from about two to nearly seven thousand miles in width.
„What we could use, Barl, is a passage from one of these seas into the other,” remarked Lackland one day. The Mesklinite, sprawled comfortably on his ledge outside the window, gestured agreement silently. It was past midwinter now, and the greater sun was becoming perceptibly dimmer as it arched on its swift path across the sky to the north. „Are you sure that your people know of none? After all, most of these pictures were taken in the fall, and you say that the ocean level is much higher in the spring.”
„We know of none, at any season,” replied the captain. „We know something, but not much, of the ocean you speak of; there are too many different nations on the land between for very much contact to take place. A single caravan would be a couple of years on the journey, and as a rule they don’t travel that far. Goods pass through many hands on such a trip, and it’s a little hard to learn much about their origin by the time our traders see them in the western seaports of the isthmus. If any passage such as we would like exists at all, it must be here near the Rim where the lands are almost completely unexplored. Our map — the one you and I are making-does not go far enough yet. In any case, there is no such passage south of here during the autumn; I have been along the entire coast line as it was then, remember. Perhaps, however, this very coast reaches over to the other sea; we have followed it eastward for several thousand miles, and simply do not know how much farther it goes.”
„As I remember, it curves north again a couple of thousand miles past the outer cape, Barl — but of course that was in the autumn, too, when I saw it. It’s going to be quite troublesome, this business of making a usable map of your world. It changes too much. I’d be tempted to wait until next autumn so that at least we could use the map we made, but that’s four of my years away. I can’t stay here that long.”
„You could go back to your own world and rest until the time came — though I would be sorry to see you go.”
„I’m afraid that would be a rather long journey, Barlennan.”
„How far?”
„Well — your units of distance wouldn’t help much. Let’s see. A ray of light could travel around Mesklin’s ‘rim’ in — ah — four fifths of a second.” He demonstrated this time interval with his watch, while the native looked on with interest. „The same ray would take a little over eleven of my years; that’s — about two and a quarter of yours, to get from here to my home.”
„Then your world is too far to see? You never explained these things to me before.”
„I was not sure we had covered the language problem well enough. No, my world cannot be seen, but I will show you my sun when winter is over and we have moved to the right side of yours.” The last phrase passed completely over Barlennan’s head, but he let it go. The only suns he knew were the bright Belne whose coming and going made day and night, and the fainter Esstes, which was visible in the night sky at this moment. In a little less than half a year, at midsummer, the two would be close together in the sky, and the fainter one hard to see; but Barlennan had never bothered his head about the reason for these motions.
Lackland had put down the photograph he was holding, and seemed immersed in-’thought. Much of the floor of the room was already covered with loosely fitted pictures; the region best known to Barlennan was already mapped fairly well. However, there was yet a long, long way to go before the area occupied by the human outpost would be included; and the man was already being troubled by the refusal of the photographs to fit together. Had they been of a spherical or nearly spherical world like Earth or Mars, he could have applied the proper projection correction almost automatically on the smaller map which he was constructing, and which covered a table at one side of the chamber; but Mesklin was not even approximately spherical. As Lackland had long ago recognized, the proportions of the Bowl on the Bree — Barlennan’s equivalent of a terrestrial globe — were approximately right. It was six inches across and one and a quarter deep, and its curvature was smooth but far from uniform.
To add to the difficulty of matching photographs, much of the planet’s surface was relatively smooth, without really distinctive topographic feature; and even where mountains and valleys existed, the different shadowing of adjacent photographs made comparison a hard job. The habit of the brighter sun of crossing from horizon to horizon in less than nine minutes had seriously disarranged normal photographic procedure; successive pictures in the same series were often illuminated from almost opposite directions.
„We’re not getting anywhere with this, Barl,” Lackland said wearily. „It was worth a try as long as there might be short cuts, but you say there are none. You’re a sailor, not a caravan master; that four thousand miles overland right where gravity is greatest is going to stump us.”
„The knowledge that enables you to fly, then, cannot change weight?”
„It cannot.” Lackland smiled. „The instruments which are on that rocket grounded at your south pole should have readings which might teach us just that, in time. That is why the rocket was sent, Barlennan; the poles of your world have the most terrific surface gravity of any spot in the Universe so far accessible to ib. ‘There are a number of other worlds even more massive than yours, and closer to home, but they don’t spin the way Mesklin does; they’re too nearly spherical. We wanted measures in that tremendous gravity field — all sorts of measures. The value of the instruments that were designed and sent on that trip cannot be expressed in numbers we both know; when the rocket failed to respond to its takeoff signal, it rocked the governments of ten planets. We must have that data, even if we have to dig a canal to get the Bree into the other ocean.”
„But what sort of devices were on board this rocket?” Barlennan asked. He regretted the question almost in the same instant; the Flyer might wonder at such specific curiosity, and come to suspect the captain’s true intentions. However, Lackland appeared to take the query as natural.
„I’m afraid I can’t tell you, Barl. You simply have no background which would give words like ‘electron’ and ‘neutrino’ and ‘magnetism’ and ‘quantum’ any meaning at all. The drive mechanism of the rocket might mean a little more to you, but I doubt it.” In spite of Lackland’s apparent freedom from suspicion, Barlennan decided not to pursue the subject.
„Would it not be well,” he said, „to seek the pictures that show the shore and inland regions east of here?”
Lackland replied, „There is still some chance, I suppose, that they do meet; I don’t pretend to have memorized the whole area. Maybe down next to the icecap — how much cold can you people stand?”