lantern slides

Lantern slides are transparent images—often made of glass or thin plastic—used in early multimedia presentations. They are placed inside a magic lantern or similar device that projects the image onto a wall or screen by shining a light through the slide and using a lens. People historically used lantern slides for education, entertainment, and communication before modern projection technology. Typically, they feature photographs, illustrations, or text, and were often stored in slide carousels or cases for easy transport and projection at events or lessons.