One of two photographs of a universal circle. The 'Great Circle' (side view) designed by London instrument maker Jesse Ramsden (1735-1800) and completed by Matthew Berge, successor and son-in-law to Ramsden, was built for the Royal Observatory of Palermo in Sicily, Italy. Ramsden worked for various well-known instrument makers such as Sisson, Adams and Dollond, before starting on his own business in 1762. He went on to become the foremost instrument maker of his day.
© Science Museum / Science & Society Picture Library