Early English telescope, 1673.

This is the oldest complete telescope in the Science Museum's collection. It was made by Christopher Cock, one of the first optical instrument makers in London, and is signed 'Christopher Cock, Londini 1673'. It is decorated with gold designs, including a Royal coat of arms. The instrument consists of five draw tubes, measures 4 feet 6 1/2 inches (1376mm) when fully extended, and gives a magnification of about 14.