Hindu astrolabe commisioned at Jaipur, India, 1836.
© Science Museum / Science & Society Picture Library
This Hindu astrolabe made of bras inlaid with silver was commisioned by Manna Lala from an instrument maker in Jaipur, India. The astrolabe is a two-dimensional depiction of a celestial sphere whose layout is achieved using the mathematical technique of stereographic projection. This front view shows the moveable fretwork plate called the rete which denotes star positions by curved pointers. From its origins in the Ancient World, Islamic astronomers developed the astrolabe and its use spread. Popular in Medieval and Renaisance Europe, its many uses included timekeeping, astrology and surveying.