Home->Ptolemaic System

About the Equatorium


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 Nuremberg in the first half of the sixteenth century. It models the motion of Mars. In the original book, readers are invited to make the device for themselves, and this can indeed be done. Our digital version allows the dynamic features of the equatorium to be seen easily.




Click here to use the equatorium




Click here to see it animated for ten yerars of planetary motion