John Frederick William Herschel (1792-1871), British astronomer and chemist. The son of William Herschel, he studied nebulae (galaxies) and double stars. He set up an observatory in South Africa, mapping the southern skies. In England, he worked on the chemistry of photography, coining the term 'photographic negative' and being the first to use sodium thiosulphate (hypo) as a fixing agent. He was also the first person to produce a photograph on a glass plate and to apply photography to astronomy. He was made a baronet in 1838. This artwork (of a photograph) is from volume II (1873) of 'Portrait Gallery of Eminent Men and Women in Europe and America'.