English mahogany and brass bi-unial magic lantern

The magic lantern is an important ancestor of cinema. Developed in the 1600s, magic lanterns use a light source, lenses and transparent slides to project religious, educational or entertaining scenes and stories.

Originally, lanternists used candles or gaslight to illuminate their slides, which usually limited their projections to one lens. When limelight was invented in the 1800s, it not only produced brighter, clearer projections but also allowed lanternists to control the light source, leading to more creative approaches and inventions. One was the bi-unial lantern, like this one, which uses two lenses to superimpose different slides onto the same screen to create the illusion of time or movement.