Imagine yourself seated in a mid-nineteenth century parlor. The time is early afternoon but the room is dark as night, with heavy quilts secured over all the windows, and only a couple of dim lamps to provide light. You're surrounded by whispering friends and acquaintances, people from around town who have heard a rumors about Magic Lantern shows and want to see one for themselves. In the back of the room is the lantern itself, smaller than you had imagined and difficult to make out in the darkness. A few bright lines of light trace its contours, and the brass casing radiates heat, both indicating the fire that must be burning inside of it.
Suddenly, a painting of a pretty seated woman appears on the wall in front of you, eight or ten feet wide and just as tall. There's no frame, and the picture is so bright in contrast with the rest of the room that it seems to radiate light. On closer inspection it is doing just that, since you can see the face of the man to your right in the pale yellow ambiance. Very nice, but not worth the ten cents, you think to yourself, then quickly silence the thought as trivial.
Loud and deep, the presenter's voice booms out from beside the machine, telling the illuminated lady's story. As he speaks, there appear distortions around her knees, phantasmagorical. It happens so slowly that at first you are not even sure that you're seeing anything, but soon they are unmistakably real, the forms of young children. As the speaker says aloud their names, their appearance is made complete on the image, quite a remarkable effect. You settle into your chair for what will prove a lengthy and compelling show.
Before photography was commonplace, and long before the rise of motion pictures, the magic lantern held sway in multimedia entertainment. It was a comparatively simple device: a box with a source of light, often gas or limelight, and mirrored walls; a smoke-stack (!) to let out the exhaust of combustion; a clip which held a single slide with one or more images; and one or two lenses to focus the image. In essence, a slide projector. When paired with a good speaker and interesting slides, the presentation must have been marvelously entertaining and novel to their audience.
The earliest magic lantern-like devices were made in the early 1400's, and projected with candle light alone and no lenses for focusing. It was described in a book by Giovanni de Fontana, and is told (after translation) to provide an image of the devil as "a nocturnal appearance for terrifying viewers." Two hundred years later, in 1646, a Jesuit named Athanasius Kircher published a design which projected with sunlight or candle light, and used a convex lens to focus the image. Soon after that working with the lanterns caught on, and Christiaan Huygens is known to have made a few. Thomas Walgensten coined the term Lanterna Magica for the device, and toured Europe doing shows and selling lanterns. In 1666 Samuel Pepys bought one from John Reeves, a London optician who had gone into the Magic Lantern manufacturing business.
Many variations on the common design were made in the years following. Lanterns were designed to use every form of light conceivable at the time, from focused sunlight to electric arcs. Lanterns with two or more bodies and lenses were constructed, so images could be smoothly faded from one slide to the next. By 1886 a Magic Lanterns were available for any amount between $5 for a children's' model to $75 for an extreme luxury design. Later competition in the market would bring children's lanterns down to 75 cents. They were sold to families wanting a visual aspect added to their Victrola, entrepreneurs who would travel the countryside doing shows, and kids who could do shows for their friends with the included tickets and handbills.
Slides were where all the real intrigue of magic lanterns came from, and many of them survive today. Still images were printed on glass plates that were usually at least three and a half inches on the side. Printing was done by photochemical or traditional means. They were often painted by hand with translucent ink, giving them that charming Victorian colored photograph look. Subjects could be fine art, moral stories, fairytales, news pictures, bawdy humor, nature scenes, and so forth. Slides for children's' lanterns were smaller and more cheaply manufactured, and often sold in bulk without descriptions. Ultra-fragile mica, safer and cheaper than glass, was used for these slides, and few have survived.
Moving images were also possible on the magic lantern, accomplished by slides made of two or more panes of glass that could move independently. Slides were manufactured that could have rotating sections, areas that slid back and forth, swung, etc. Some were even made with integrated shutters, so that a crudely animated picture could be displayed. These special slides cost between $1.75 to $5.00 and up, and were an investment suitable only for traveling shows and the very well off.
There were also a surprising amount of abstract moving slides made, which projected images that might today be considered psychedelic. Chromatropes, for instance, featured two painted glass circles which rotated in opposite directions, which the catalog states are "almost equal to a grand display of fire-works." Along the same lines was the Eidotrope, which had counter-rotating perforated disks that projected sort of a star-vortex that could be colored with special inserts. Coolest of all was the Cycloidotrope, which could be described as a kind of projected spirograph. It had an arm suspended on a few clockwork gears, which traced intricate looping and spiraling patterns onto a disk coated with soot. The effect was of a complex pattern being traced out on the screen by an invisible hand.
Thanks Bruce Sterling's Dead Media Project for most of this knowledge.
Also, respect to anybody who adds the FBI's Magic Lantern software to this node, as well as the Czech playhouse of the same name.