Ghosts and Magic…and Glass?: Pepper’s Ghost and glass optics

Doing research one day for a patron inquiring about possible sizes of plate glass in the early 20^th century, I came across a reference to an intriguing invention of the 19^th century involving plate glass which was used by theatrical companies. Called Pepper’s Ghost, it first appeared on stage in a production of Charles Dickens’ The Haunted Man in 1862.

The plate glass (which was so clear as to be invisible to the audience) was placed at an angle on stage, reflecting the image of an actor in a pit below the stage. When the ghost was ready to make its appearance, the room beneath the stage would be brightened, allowing the” ghost” (or reflection of the actor) to appear suddenly to the audience.

This curiosity of the Victorian age not only answered my patron’s question (yes, plate glass was being produced in large sizes, even before the plate glass process was automated!), but it provided a glimpse into scientific investigations of light and optics that had begun much earlier in history. You can trace these investigations in the Rakow Library’s collection of materials on early optics.

Pepper’s Ghost got its name from a scientist at the Royal Polytechnic Institute, John Henry Pepper. Pepper had recently seen an invention by engineer Henry Dircks who had the idea to use plate glass to create the illusion of ghosts.

Theatrical performances involving supernatural elements, called Phantasmagoria, were popular at the time, but Dircks’ invention proved too expensive to be of interest to theatres. Pepper, however, was able to modify the invention so that it was affordable for theaters to install. He and Dircks filed a patent and Pepper’s Ghost became the rage of London, and– rather quickly– other cities world-wide. P.T. Barnum, in his account of Humbugs of the World (1866), refers to “Professor Pepper, at the Royal Polytechnic Institute, in London, [who] invented a most ingenious device for producing ghosts which should walk about upon the stage in such a perfectly astounding manner as to throw poor Hamlet’s father… quite into the ‘shade.’ ‘Pepper’s Ghost’ soon crossed the Atlantic, and all our theatres were speedily alive with nocturnal apparitions” (quoted from the Gutenberg Project’s edition of Humbugs of the World).

Dircks himself wrote in his publication, The Ghost (1863) that the illusion was so popular that the Thames Plate Glass Company had completely sold out of the large plates of glass necessary for performing the stage trick.

Barnum wrote about Pepper’s Ghost as if it were merely an entertainment, but Professor Pepper and Dircks saw the Ghost as a means to educate audiences about scientific principles of physics, light and optics. Other scientists, like Augustin Privat-Deschanel, in his Elementary Treatise on Natural Philosophy, made reference to Pepper’s Ghost as well, describing it as one of several “ingenious illusions that have been contrived” which rely on “the laws of reflection from plane surfaces” (From the Internet Archive). Pepper’s Ghost is still studied by illusionists and magicians today. Disney even adopted it for use in the Haunted Mansion in the 1960s to create the illusion of ghosts in its grand ballroom!*

Pepper’s ghost, however, was just the latest variation upon an even older technology called the Magic Lantern which had fascinated 17^th century scientists. Its exact origins are unknown, but the earliest image of the lantern appears in Athanasius Kircher’s Ars Magna Lucis et Umbrae, published in 1646. Dutch scientist Christiaen Huygens is typically given the credit for inventing the lantern, however, and some historians even believe a form of the magic lantern existed prior to the 17^th century.

The lantern contained a mirror and a candle and had a tube attached to it, with convex lenses on either side. Inside the tube was a glass plate with a painted image–for a Phantasmagoria, the image would be of a ghost, skeleton, demon or other creepy character. The image would be projected onto a wall or screen of some kind.

Later innovators, like Etienne Gaspard Robertson, a successful Belgian producer of Phantasmagoria and professor of physics, would put the lantern on wheels so that the images would seem to swoop in towards audiences, often causing viewers to scream with terror. His patented “Fantoscope” was a huge hit with his audiences, making him a kind of 19^th century Alfred Hitchcock.

Interestingly, another glass invention, Benjamin Franklin’s glass armonica, was frequently used as a musical accompaniment to Robertson’s spectral shows, presumably because of its eerie quality.

Robertson claimed, in his Mémoires: Récréatifs Scientifiques et Anecdotiques (1831) that his shows were a success only “if my spectators, shivering and shuddering, raise their hands or cover their eyes out of fear of ghosts and devils dashing towards them.” Robertson’s Memoirs describe his invention and his shows thoroughly and his work continues to intrigue illusionists and magicians. Harry Houdini even had a copy of Robertson’s Memoirs in his personal library!

Magic Lanterns became so popular that versions for the home were marketed for a time. Marcel Proust writes, in volume one of Remembrance of Things Past, about receiving a gift of one of these lanterns which he kept in his room.  Advertisements from the late 19^th century show families gathered around the lantern in their living room, watching spectral images projected on the wall. You could even order one through the mail, as seen in pages from a T.H. McAllister catalog, along with slides to use in the lantern.

These inventions may seem purely frivolous, but they represented innovations in thinking about light, glass, and optics that were significant at the time.

They are clearly the ancestors of the Cinématographe developed by the Lumière brothers and Thomas Edison’s Kinetoscope, both late 19^th century innovations in “moving pictures.” More than that, though, the Magic Lantern and Pepper’s Ghost are, in fact, two in a long list of inventions, from the mundane to the supernatural, which rely upon that versatile and unique substance we call glass.  Find out more about these wondrous and clever inventions by calling, emailing or visiting the Rakow Library to explore our collection on early optics.

*Jim Steinmeyer’s Two Lectures on Theatrical Illusion, published in 2001, provides a comprehensive history of various versions of the Ghost trick.  Steinmeyer’s book is available in the Rakow Library collection.