Armillary Sphere from Epytoma Ioa[n]nis de Mo[n]te Regio in Almagestu[m] Ptolomei

Epytoma Ioa[n]nis de Mo[n]te Regio in Almagestu[m] Ptolomei

Armillary Sphere

In this picture, we can see two scholars seated beneath a grand structure called an armillary sphere. An armillary sphere is an ancient tool that represented the heavens. It used geometrical angles to create a model of what scientists believed the galaxy looked and moved. It has other names: the spherical astrolabe, the armilla, and the armil. It’s also related to the astrolabe which was used by sailors to determine the position of the Sun and stars; this was needed in order to navigate. The armillary sphere, invented hundreds of years ago, is one of the oldest astronomical tools in the world. It was used as a teaching tool, and it was used in Ancient Greece, Asia, and the Islamic Empire.