This was a long speech for Hans. Charlie looked surprised, then called, “Nixie! Heel!”
The dog had been supervising the van; he turned and came at once to Charlie’s left and rear. Hans relaxed, said, “Better,” and placed himself so that the dog trotted between them.
When the jungle loomed up over them, pierced here by a road, Mr. Qu’an held up his arm and called out, “Halt! Check watches.” He held up his wrist and waited; everybody else did the same.
Jock Quentin, an Explorer Scout equipped with twoway radio, spoke into his microphone, then said, “Stand by…oh nine eleven.”
“Anybody fail to check?” continued Mr. Qu’an. “All you with polarizers, establish base line.”
Hans took out an odd-looking pair of spectacles with double lenses which rotated and a sighting device which snapped out. “Try it.”
“Okay.” Charlie accepted them gingerly. He did not yet own a light-polarizing sighter. “Why are we going to establish base line if we’re going to stay on marked roads?”
Hans did not answer and Charlie felt foolish, realizing that the time to lea~rn how not to get lost was before you got lost. He put on the polarizers and tried to establish base line.
“Base line” was the prime meridian of Venus, the direction from Borealis of the Sun at noon. To find that direction it was necessary first to find the Sun itself (in a grey, thickly overcast sky), then, using a watch, figure where the Sun would be at noon.
That direction would be south — but all directions from Borealis were south; the city lay on the north pole of the planet. The mapmakers used Borealis as a zero point and the direction of the Sun at noon as a base line With the aid of transceivers, radar beacons, and radi compass, they were gradually establishing a grid o reference points for the few hundred square mile around Borealis. A similar project was going on at Souti Pole City. But the millions of square miles between pole were unknown country, more mysterious and incredibl3 vaster than any jungle on Earth. There — was a sayin~ among the Scouts that streams at the equator were “hol enough to boil eggs,” but nobody knew. As yet, no ship had landed near the equator and managed to come back.
The difficulty of telling directions on Venus is very great. The stars are always invisible. Neither magnetic compasses nor gyro compasses were of any use at the poles. Nor is there moss on the north sides of trees, nor any shadows to read — Venus is not only the land that time forgot; it is also the place of no directions.
So the colonists were forced to establish new directions. From Borealis toward the Sun at noon was prime meridian, called “base line,” and any direction parallel to that was “base.” — Back the other way was “reverse”; the two intermediate directions were “Left demi” and “right demi.” By counting clockwise from “base,” any other direction could be named.
It was not a perfect system since it used square coordinates for a spherical surface. But it was better than nothing in a place where the old directions had turned slippery — where all directions away from the city were “south” and where east and west, instead of being straight lines, were circular.
At first, Charlie could not see why, if they were going to use four directions, they didn’t call them “north,” “south,” “east” and “west,” instead of ringing in these silly names, “base,” “reverse,” “right demi,” and “left demi.” It was not until he saw in school a map of the colony, with the old familiar directions, north, south, east, west, on it and a “base line” grid drawn on top of it that he realized that the problem was not that simple. To go east on that map you went counterclockwise on one of those little circles — but how could you tell what direction “east” was unless you knew where you were? And how could you tell how much to curve left in order to keep going east? When compasses were no good and the Sun might be in any direction, north, south, east, or west, depending on which side of the city you were on?