orrery to Hanson.

It was a beautiful piece of workmanship. There was an enormous sphere of
thin crystal to represent the sky. Precious gems showed the stars,
affixed to the dome. The whole was nearly eight feet in diameter. Inside
the crystal, Hanson could see a model of the world on jeweled-bearing
supports. The planets and the sun were set on tracks around the outside,
with a clockwork drive mechanism that moved them by means of stranded
spiderweb cords. Power came from weights, like those used on an
old-fashioned clock. It was obviously all hand work, which must make it
a thing of tremendous value here.

"Sather Fareth spent his life designing this," Ser Perth said proudly.
"It is so well designed that it can show the position of all things for
a thousand centuries in the past or future by turning these cranks on
the control, or it will hold the proper present positions for years from
its own engine."

"It's beautiful workmanship," Hanson told him. "As good as the best done
on my world."

Ser Perth went away, temporarily pleased with himself, and Hanson stood
staring at the model. It was as good as he'd said it was--and completely
damning to all of his theories and hopes. No model he could make would
equal it. But in spite of it and all its precise analogy to the universe
around him, the sky was still falling in shattered bits!

Sather Karf and Bork had come over to join Hanson. They waited
expectantly, but Hanson could think of nothing to do. It had already
been done--and had failed. The old man dropped a hand on his shoulder.
There was the weight of all his centuries on the Sather, yet a curious
toughness showed through his weariness. "What is wrong with the orrery?"
he asked.

"Nothing--nothing at all, damn it!" Hanson told him. "You wanted a
computer--and you've got it. You can feed in data as to the hour, day,
month and year, turn the cranks, and the planets there will turn to
their proper position exactly as the real planets should run. You don't
need to read the results off graph paper. What more could any analogue
computer do? But it doesn't influence the sky."

"It was never meant to," the old man said, surprise in his voice. "Such
power--"

Then he stopped, staring at Hanson while something almost like awe
spread over his face. "Yet ... the prophecy and the monument were right!
You have unlocked the impossible! Yet you seem to know nothing of the
laws of similarity or of magic, Dave Hanson. Is t