Engraving by John Jones after R Home of Jese Ramsden (1735-1800), 'Optician to his Majesty'. Ramsden was also a mathematical-instrument maker. Ramsden concentrated on optical instruments and was responsible for erecting a 5 foot vertical circle that surrounded the observatory at Palermo. This circle greatly influenced circles replacing quadrants in observatory design at the end of the 18th century. Ramsden was elected to the Royal Society in 1786.
© Science Museum / Science & Society Picture Library