November 7, 1940, Winnipeg Tribune (source)
Here's a test to see how old you are: do you remember car window frost shields ?!
For those that don't, they were squares of plastic - slightly raised - with an adhesive strip around the edge. You stuck them to the inside of your car windows and the vacuum created in the space between the plastic and the glass kept the inside of the window from fogging or frosting up in the cold. (The Ashdown's ad above markets a more expensive version consisting of a sheet of glass with a rubber gasket.) If you want to get technical about it, here's a 1941 patent for a frost shield that explains how the work in excruciating detail !
November 25, 1926, Manitoba Free Press
October 24, 1952, Winnipeg Free Press
Frost shields burst onto the automotive scene in the winter of 1926-27, long before front and rear window defrosters were a gleam in a the eye of an automotive engineer. They were soon a standard part of your basic winter tune-up, along with radiator grill covers and winter anti-freeze.
November 30, 1955, Manitoba Free Press
In 1937 it became law that your windshield, rear window and front-row side windows had to be fitted with frost shields from December 1st to March 31st. When spring came, the car owner then had the unenviable task of trying to remove what was left of the shield and its adhesive residue.
As windshield defrosters became more commonplace in the 1950s and rear window defrosters in the 1970s, the demand for frost shields diminished. You might be surprised to know, though, that their use is still noted in Manitoba's Highway Traffic Act:
Frost Shields Required
57(2) The windshield, rear windows, and windows at both sides of the driver's seat, of every motor vehicle at all times between the first day of November in each year and the thirty-first day of March next following, both dates inclusive, shall be equipped with adequate frost shields of a size and type that will prevent or minimize the condensation thereon of moisture in the atmosphere and allow the driver to have a view sufficiently clear and unobstructed to permit him to operate the vehicle with safety to other persons and vehicles on the highway, unless the vehicle is otherwise so equipped or constructed as to secure a like result.
November 24, 1959, Ottawa Citizen (source)
Winnipeg was a hub for the manufacture of frost shields. In the mid-1940s there were at least four companies that made them. James B. Carter Ltd. (above) was likely the largest and sold them across the country. Through various mergers the company became Temro Phillips which still manufactured car interior heaters in Winnipeg until the plant was closed in 2012.
In case you think that frost shields have disappeared into history, they haven't. They are still used in construction equipment, helicopters and out-buildings. The only company I could find that still manufactures them is, of course, right here in Manitoba. Check out Custom Tarps and Filters in Brandon !