Collection Storage Facility
Ontario Hydro acquired this artifact for its Museum of Electrical Progress in the late 1960s, transferring it to the national collection in 1992.
This sodium-vapour spotlight lamp used heated sodium gas to produce light. It was designed to illuminate public buildings, airport landing strips, and heavy-volume highways.
Sodium lamps were introduced for street lighting in 1933. However, even though they were twice as efficient as incandescent or mercury bulbs, low-pressure sodium bulbs, like the one used in this lamp, allowed only a monochrome view of objects. High-pressure sodium (HPS) bulbs, which enabled people to see an object’s original colours, even at night, were only developed in 1966. The arrival of HPS bulbs on the Canadian market coincided with Expo 67 in Montreal, although they had been installed a year earlier in Calgary, on an experimental basis.