Henri-Alexandre Deslandres

Henri-Alexandre Deslandres (born July 24, 1853, Paris, France—died Jan. 15, 1948, Paris) was a French physicist and astrophysicist who in 1894 invented a spectroheliograph, an instrument that photographs the Sun in monochromatic light. (About a year earlier George E. Hale had independently invented a spectroheliograph in the United States.) After graduating from the École Polytechnique (“Polytechnic School”) in 1874 and spending seven years in the army, Deslandres worked in the laboratories of the École Polytechnique...