m back to magic again. Make a doll like a man and stick
pins in it--and the man dies. Make a model of the universe within the
sky, and any changes in that should change reality. The symbol was the
thing, and a model was obviously a symbol.

He began trying to plan a model with three thousand stars in their
orbits, trying to find some simple way of moving them. The others
watched in fascination. They apparently felt that the diagrams he was
drawing were some kind of scientific spell. Ser Perth was closer than
the others, studying the marks he made. The man suddenly pointed to his
computations.

"Over and over I find the figure seven and the figure three thousand. I
assume that the seven represents the planets. But what is the other
figure?"

"The stars," Hanson told him impatiently.

Ser Perth shook his head. "That is wrong. There were only two thousand
seven hundred and eighty-one before the beginnings of our trouble."

"And I suppose you've got the exact orbits of every one?" Hanson asked.
He couldn't see that the difference was going to help much.

"Naturally. They are fixed stars, which means they move with the sky.
Otherwise, why call them fixed stars? Only the sun and the planets move
through the sky. The stars move with the sky over the world as a unity."

Dave grunted at his own stupidity. That really simplified things, since
it meant only one control for all of them and the sky itself. But
designing a machine to handle the planets and the sun, while a lot
simpler, was still a complex problem. With time, it would have been easy
enough, but there was no time for trial and error.

He ripped up his plans and began a new set. He'd need a glass sphere
with dots on it for the stars, and some kind of levers to move the
planets and sun. It would be something like the orreries he'd seen used
for demonstrations of planetary movement.

Ser Perth came over again, staring down at the sketch. He drowned in
doubt. "Why waste time drawing such engines? If you want a model to
determine how the orbits should be, we have the finest orrery ever built
here in the camp. We brought it with us when we moved, since it would be
needed to determine how the sky should be repaired and to bring the time
and the positions into congruence. Wait!"

He dashed off, calling two of the mandrakes after him. In a few minutes,
they staggered back under a bulky affair in a protective plastic case.
Ser Perth stripped off the case to reveal the