The Potter of Firsk and Other Stories by Jack Vance

May’s office. His eyes were blood-shot, his jowls sagged, and he walked with an air of extreme fatigue.
    “Well,” snapped Acco May, “what’s the story?”
    The large man slumped into the chair. “He got past us.”
    Acco May sprang to his feet. “How in thunder did that happen?…Four boats!”
    The space-man shook his head. “I thought you said he was heading for Sanatoris Beta.”
    “He is, you dumb sheepherder!”
    The large man glared sullenly at the passionate May.
    “We was strung out along course, straight as the Galactic Liners. He came out, we saw that, but nowhere near us. Looked like he was going off more toward Alcyone.”
    Acco May chewed his lip. “Well, it’s a cinch once he gets off course he’s out of the running entirely…Okay then, Rock. I guess you’re not to be blamed. He’s off course, you say?”
    “Way off course,” said Rock the space-man.
    Acco May smiled grimly. “Well, it’s a quick way to make twelve million munits. Almost as quick as he made it off me.”
    Several months later, the judge read sentence: “By your own admission guilty of piracy, grand larceny, assault and murder, I sentence you to comprehensive cerebral correction and five years close observation. Have you anything to say?”
    Acco May stared at the judge, eyes like tiger-slits. “No.”
    The guards stepped forward. Acco May turned his head toward where Magnus Ridolph sat in dignity. He thrust aside the guards.
    “Just a minute,” he said. “I want to talk to that old hellion sitting yonder.”
    The guards hesitated, glanced for permission to the judge. But the judge was sweeping for his chambers.
    Magnus Ridolph decided the matter by stepping forward.
    “You wish to speak to me?”
    “Yeah. I know there’s about two hours of Acco May left, and after that a man looking like me goes around wearing my clothes. First I want to know how the devil did you make Sanatoris in twelve days?”
    Magnus Ridolph raised his eyebrows. “By correct astrogation.”
    Acco May made an impatient gesture. “Yes, yes, I know. But what’s the inside?”
    Magnus Ridolph’s gaze wandered to the Martian scarab on Acco May’s finger. “The ring your—ah, frog-man found—I confess it has struck my fancy. I always envied my old friend Rimmer Vogel when he wore the ring which was so like it.”
    Acco May wrenched it off his finger with a savage smile. “No tickee no washee, hey? Okay, here’s your fee. Now what’s the pitch?”
    Magnus Ridolph gestured eloquently. “Ordinary astrogation, nothing more. With the exception, possibly, of a small refinement I have developed.”
    “What’s the refinement?”
    Magnus Ridolph turned Acco May the blandest of stares.
    “Have you ever examined a Mercator projection of, let us say, the planet Earth?”
    “Naturally.”
    “The shortest course between two points, when charted on a Mercator projection, appears as a curve, does it not?”
    “Yes.”
    “Classical space charts,” said Magnus Ridolph, “are constructed after the pattern of a Mercator projection. The coordinates meet rectilinearly, the grid components running perfectly parallel but to infinity. This is an admirable system for short voyages, just as use of the Mercator projection results in little error on a cruise across Long Island Sound.
    “However on voyages of some duration, it is necessary to remember that the earth and—on a larger scale—space is curved, and to make the necessary correction. Then we find a very significant saving of time. A journey which by classical astrogation requires thirteen days,” said Magnus Ridolph, turning upon Acco May his wide guileless gaze, “may be accomplished in twelve days by use of the proper correction—though to the ignorant eye, it would appear as if the astrogator is far off his course.”
    Acco May turned his back on Magnus Ridolph, his mouth like an inverted V. “Take me away,” he muttered. “Maybe the new me will be brighter. If he is, he’s going to go