In the silent era, local movie theaters used glass slides to promote coming attractions. The images on the slides were projected onto the screen to let movie-goers know what to expect in the coming weeks. This was especially useful as some small towns only had weekly newspapers, but movie turnover in theaters could be as often as every three days.
Enjoy the slide show below of images from glass slides theaters used to promote Charlie Chaplin Mutual films during their original release. Courtesy of Matt Vogel.
Click the icon on the bottom-right to view in full screen.