A photographic process invented and marketed in 1839 by Louis Daguerre (1787- 1851). The first practical photographic system, a daguerreotype was a positive print made on a light-sensitized copper plate.  By 1860 new, less expensive processes had almost completely replaced it. Pronunciation here. Web resource here. Video here.

Louis_Daguerre_2Daguerreotype of Louis Daguerre by Jean-Baptiste Sabatier-Blot. 1844.