An equatorium is a device representing the motions of one or
more heavenly bodies about the "equator" or zodiac. Equatoria were widely
used as educational and ornamental devices in the Renaissance, and could be
very large, intricate, and beautiful. One particularly interesting use of them
was in training mathematical astronomers. The equatorium simulated here was
designed for this end, by Johann Schoner, a mathematical practitioner of
Click here to use the equatorium
or
Click here to see it animated for ten yerars of planetary motion