Warren De La Rue, British astronomer and physicist, c 1860s.
© Science Museum / Science & Society Picture Library
Warren de La Rue (1815-1889) was a pioneer of astronomical photography, a chemist and microscopist. He invented the silver chloride battery and researched the discharge of electricity in gases. A pioneer of celestial photography, he invented the photoheliograph, a device which allowed the Sun to be mapped using photography and carried out research on photo-active chemicals and the wave theory of light. He was also a brilliant astronomer and discovered 525 nebulae.