This first full-length biography of Sir John Herschel tells of a remarkable man who contributed to nearly every branch of astronomy and to half a dozen other sciences as well. The only son of the astronomer Sir William Herschel (founder of stellar astronomy and discoverer of the planet Uranus), he comes vividly to life in descriptions of his personality and his varied achievements. Making admirable use of John Herschel's unpublished correspondence, diaries, and notebooks, the author covers his extensive astronomical observations at Cape Town in South Africa, his pioneering work in photography and in physical optics in Britain, and his unhappy experiences as Master of the Mint - and much more. John Herschel was so attractive and enterprising an individual that his biography will appeal to general readers as well as to professionals - historians of science, astronomers, and scientists in related fields.