Astrolabe

Astrolabe, with three plates for latitudes 19° 26° 21° 23° 28° 35° with numbered almucantars every 6° and lines for unequal and Babylonian hours. There was probably originally a fourth plate; on the back are a sexagesimal sine and cosine graph of the arcs of the signs with an unequal hour diagram, and a shadow-square;

Kind

artefact

Date

1700–1799 CE