Petrus Apianus - Astronomicum Caesareum - Ingolstadt, 1540
volvelle - medieval instrument consisting of a series of concentric rotating disks, used to compute the phases of the moon and its position in relation to that of the sun
(via sirobtep)
Petrus Apianus - Astronomicum Caesareum - Ingolstadt, 1540 volvelle - medieval instrument consisting of a series of...
Petrus Apianus - Astronomicum Caesareum - Ingolstadt, 1540