Toronto. Projectors predate both photography and electricity. Called magic lanterns, they were often used by both magicians and charlatans. There are even people today who collect magic lanterns and slides (the Magic Lantern Society was formed about the same time as the PHSC). Magic lanterns and drawn coloured slides were made as toys as well. They were used to entertain and enlighten both adults and children before movies, television, and computers became so common.
After photography arrived in 1839, the devices became popular in churches to project biblical scenes illustrating guest talks and the words of hymns allowing the congregation (those who were literate) to follow along.
In the late 1930s, the magic lanterns (now called slide projectors) proved to be a means to view both black and white and colour pictures. By the 1950s, the slide dimensions were standardized and the devices took off with brightness, sharpness, and ease of use paramount. Straight line slide trays became common until they too were made obsolete when Kodak offered their round version holding 80 slides. Colour slides had far better resolution than the colour prints of the day.
One of a great many makers was the Viewlex (I always thought the name was Viewlux) company of Long Island, New York. These projectors began disappearing as the Kodak Carousel trays took off. Carousels also disappeared in time as digital projectors fell in price. Digital projectors, like we use today in our monthly talks, offer both stills and videos. Every auction and fair seems to attract projectors and trays for those of us who have a bad case of nostalgia (I have a 50 year old Kodak Carousel sitting a few feet from my desk).
This image of the Viewlex was taken from an ad in the November 28, 1955 issue of LIFE magazine. If you buy online, be careful – scammers are using the Viewlex and other logos to flog cheap Chinese digital projectors with low resolution and lumens at outrageous prices.