1901 - Peter Cooper Hewitt 1904 - heatlamp (incandescent) 1905 - Hoskins and Marsh 1905 - heatlamp (incandescent) 1906 - Hanau 1908 - heatlamp (incandescent) 1911 - Georges Claude 1915 - sunlamp (mercury) 1918 - heatlamp (incandescent) 1919 - Kurt Huldschinsky 1923 - heatlamp (metal wire) 1925 - heatlamp (incandescent) 1928 - sunlamp (mercury) 1929 - sunlamp (mercury)