Portal:Science/Featured picture/6
From Wikipedia, the free encyclopedia
An 18th Century Persian astrolabe used for determining the time at both day and night. The points of the curved spikes on the front rete plate, mark the positions of the brightest stars. The name of each star being labeled at the base of each spike. The back plate, or mater is engraved with projected coordinate lines. From the Whipple Museum of the History of Science in Cambridge.
