The magic lantern was an early type of image projector, developed in the 17th century.
It used a concave mirror behind a light source to direct as much of the light as possible through a small rectangular sheet of glass – the magic lantern slide – on which was the painted or photographic image to be projected – and onward into a lens at the front. The lens was adjusted to focus at the distance of the projection screen or wall.
Initially, candles or oil lamps were used, producing very dim projections. Improvements in lighting took the form of the Argand lamp from the 1790s, limelight in the 1820s, electric arc light in the 1860s and finally the incandescent electric lamp.
The magic lantern could project moving images by the use of various types of mechanical slide, which could be over a foot long at times and could contain gears cranks and pulleys. Even in still slides there was little standardisation. Peck and Snyder, a company with great influence in the magic lantern industry, sold slides measuring 4.5 by 7 inches. ‘English pattern’ slides were 3.5 by 3.5 inches, ‘French pattern slides’ were 3.25 by 4 inches, and the ‘standard European size’ was 3.25 by 3.25 inches.
The art of projection reached a high-point in the 1870-1880 period, and the magic lantern played a very important part in Victorian society. Temperance and religious lectures were given but the lantern was also used in education, for the demonstration of scientific principles, to relay the latest news of world events, and to create ‘phantasmagoria’ shows. By this time, images were being transferred to slides by photographic means, and then coloured by hand. Lanterns of this time could have up to four projection tubes.
With the advent of cinema the days of the big lantern shows were numbered, but magic lanterns were still used in schools and institutes, and photographic and printed slides were still being manufactured in the 1940s.