Mercury vapour electric lamp
- Made:
- 1900
Cooper-Hewitt mercury vapour lamp tube, no. 66770.
Invented in 1900 these lamps were hung from the ceiling so that by pulling a string the tube could be tilted, allowing the mercury to flow between the contacts. Current flowing through the mercury vapourized it creating a gaseous atmosphere which then took over the flow of current as the stream of liquid mercury was broken.
