Sir John Frederick William Herschel, 1st Baronet KH (March 7, 1792-May 11, 1871) was an English mathematician, astronomer, chemist, and experimental photographer/inventor. He was the son of astronomer Sir William Herschel and the father of 12 children. Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus. He made many contributions to the science of photography, … microscopy.fsu.edu
The cyanotype process is based on the photosensitivity of iron (ferric) salts and Herschel was the first to discover this photosensitivity. www.photograms.org/chapter02.html
The definitive Wikipedia entry for John Herschel. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/John_Herschel
