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