John Herschel

Sir John Frederick William Herschel, 1st Baronet (7 March 1792 to 11 May 1871) was an English polymath who worked as a mathematician, astronomer, chemist, inventor and experimental photographer, and who invented the blueprint and did botanical work. In astronomy he originated the use of the Julian day system, and he named seven moons of Saturn and four moons of Uranus, the seventh planet, which had been discovered by his father, Sir William Herschel. He also made many contributions to the science of photography and investigated colour blindness and the chemical power of ultraviolet rays. His Preliminary Discourse of 1831 advocated an inductive approach to scientific experiment and theory-building and was an important contribution to the philosophy of science.