Free Mission of Gravity by Hal Clement

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?”
    „We are uncomfortable when the sea freezes, but we can stand it — if it does not get too much colder. Why?”
    „It’s just possible you may have to crowd the northern icecap pretty closely. We’ll see, though.” The Flyer riffled through the stack of prints, still taller than Barlennan was long, and eventually extracted a thin sheaf. „One of these. ” His voice trailed off for a few moments. „Here we are. This was taken from the inner edge of the ring, Barl, over six hundred miles up, with a narrow-angle telephoto lens. You can see the main shore line, and the big bay, and here, on the south side of the big one, the little bay where the Bree
    is beached. This was taken before this station was built — though it wouldn’t show anyway.
    „Now let’s start assembling again. The sheet east of this.” He trailed off again, and the Mesklinite watched in fascination as a readable map of the lands he had not yet reached took form below him. For a time it seemed they were to be disappointed, for the shore line gradually curved northward as Lackland had thought; indeed, some twelve hundred miles to the west and four or five hundred north, the ocean seemed to come to an end — the coast curved westward again. A vast river emptied into it at this point, and with some hope at first that this might be a strait leading to the eastern sea, Lackland began fitting the pictures that covered the upper reaches of the mighty stream. He was quickly disabused of this idea, by the discovery of an extensive series of rapids some two hundred and fifty miles upstream; east of these, the great river dwindled rapidly. Numerous smaller streams emptied into it; apparently it was the main artery for the drainage system of a vast area of the planet. Interested by the speed with which it broke up into smaller rivers, Lackland continued building the map eastward, watched with interest by Barlennan.
    The main stream, as far as it could be distinguished, had shifted direction slightly, flowing from a more southerly direction. Carrying the mosaic of pictures in — this direction, they j found a range of very fair-sized mountains, and the Earthman looked up with a rueful shake of his head. Barlennan had come to understand the meaning of this gesture.
    „Do not stop yet!” the captain expostulated. „There is a similar range along the center of my country, which is a fairly narrow peninsula. At least build the picture far enough to determine how the streams flow on the other side of the mountains.” Lackland, though not optimistic — he recalled the South American continent on his own planet too clearly to assume any symmetry of the sort the Mesklinite seemed to expect — complied with the native’s suggestion. The range proved to be fairly narrow, extending roughly east-northeast by west-southwest; and rather to the man’s surprise the numerous „water” courses on the opposite side began very quickly to show a tendency to come together in one vast river. This ran roughly parallel with the range for mile after mile, broadening as it went, and hope began to grow once more. It reached a climax five hundred miles downstream, when what was now a vast estuary