mercury vapour lamp
circa 1975
mercury vapour lamp
MA/V mercury vapour lamp
circa 1946
High pressure mercury vapour lamp
circa 1951
Osram high pressure mercury vapour lamp
circa 1945
mercury/tungsten light bulb
circa 1970
Osram mercury vapour lamp
circa 1940
Mercury vapour electric lamp made by Whouse Cooper Hewitt
1915
Mercury vapour electric lamp
1900