Portrait of Sir John Frederick William Herschel (1792-1871) made by the photographer Julia Margaret Cameron in 1867. An English polymath, Sir John Herschel, like his father, was a scientist, astronomer and a mathematician. He was also a physicist and a pioneer in the chemistry of photography. A fellow of the Royal Society, in his paper entitled ¨~??Note on the Art of Photography¨~?? he was credited with creating the use of the terms, 'photographic', 'photography', 'negative', 'positive' and 'snapshot'. He became a founding member of the Royal Astronomical Society. In 1836 Mrs. Cameron met him in Cape Town, South Africa, when his astronomical investigations were charting the stars of the southern hemisphere. In 1839 he introduced her to the new invention of photography. They developed a friendship that lasted 31 years until he died in 1871.