An equatorium is a medieval astronomical instrument, dating from the 11th Century. Based on the Ptolemaic theory of equants (epicycles, eccentrics, &c), it was used for predicting planetary positions. No examples are known in period armory; the illustration is taken from a 15th C. French artifact in the Oxford Museum of the History of Science. See also astrolabe, clock, sphere, sundial.
Alfred of Durham bears: Paly sans nombre azure and argent, on a bend sinister engrailed between a hemispheric astrolabe and an equatorium Or, three estoiles gules.
Alya Zengerlin bears: Per bend argent and sable, two mullets in bend purpure and an equatorium Or.