How did Magic Lanterns work?

Magic Lantern

Magic Lantern, 90.5.129a-c, unidentified maker, United States, Gift of the Estate of Gerard Dallas Jencks. Photographs by David Bohl.

The lantern employed an artificial light source, which evolved from candles and kerosene lamps to limelight and electricity, and a combination of lenses to enlarge small transparent images or miniature models and project them onto a wall or screen. Lanterns could vary from a simple wooden box with brass parts to ornately designed boxes with multiple lenses.

In America, magic lanterns were often referred to as “stereopticons” so as not to be confused with entertainment provided by more basic toy lanterns. “Stereopticons” were usually biunial or double lens lanterns. The terms “Sciopticon” and “Optical Lantern” were sometimes used in a similar manner. Many times Masonic and fraternal regalia manufacturers referred to special lodge lanterns as “Secret Society lanterns.” These lanterns were lightweight and made for travel.

Magic Lantern History
How did Magic Lanterns work?