HEMISFERIUM Astrolabe - Hemispherium Replica Antique Scientific Instrument The astrolabe, translated as 'star searcher' has become a representation of the celestial sphere, using its planispheric form to answer problems involving the rising or setting of bodies and other issues related to the horizon in a specific place. This is a high quality brass replica of the original model, first designed by astronomer Hipparchus (150 BC). Constructed to the highest quality, a working piece of scientific history. Made from intricate scientifically accurate parts to help you with your astrological calculations. Like a calculator for the stars and sun.