It combines the planisphere and armillae of Hipparchus and others, and the theodolite of Theon, and was usually of brass, varying in diameter from a couple of inches to a foot or more.
- An Egypto-Greek planisphere, first described by Bianchini, 17 resembles in its general plan the circular zodiac of Dendera.
Probably the most ancient zodiacal representation in existence is a fragment of a Chaldaean planisphere in the British Museum, once inscribed with the names of the twelve months and their governing signs.
Him, together with his invention of the planisphere, enabled him to solve a number of elementary problems; and he was thus led to bestow especial attention upon the position of the equinox, as being the common point of origin for measures both in right ascension and longitude.
(Primitive Constellations, 1899) has compiled a Euphratean planisphere, which he regards as the mother of all others.