firstname.lastname@example.org (Bruce Sterling)
Magic Lanternware: Slide mechanismsSource(s): THE HISTORY OF MOVIE PHOTOGRAPHY by Brian Coe, Eastview Editions, Westfield NJ, 1981, ISBN 0-89860-067-0 Peck and Snyder's Catalog (aka "Price List of Out & Indoor Sports and Pastimes") 1886, reprinted 1971 by Pyne Press (LC# 75-24886, ISBN 0-87861-094-4)
ARCHAEOLOGY OF THE CINEMA by C. W. Ceram, Harcourt Brace and World (1955?), LC # 65-19106
To the modern eye a magic lantern most resembles a kerosene-fired slide projector. This preconception overlooks the slides themselves, however. Lantern slides were large, bulky, complex objects of glass, paint, wood and metal. Many had built-in mechanical features. So the lantern's projected images were not necessarily static, but could be graced with limited animation. Some slides could even create complex, constantly moving screen displays.
Lantern slides came in several physical formats. Peck and Snyder's proprietary slides were 4 1/2 by 7 inches. The "usual English pattern" was 3 1/2 x 3 1/2 and the "French pattern" was 3 1/4 by 4 inches. (Brian Coe describes the standard European size as 3 1/4 by 3 1/4 inches.) But specialized slides could be over a foot long, containing gears, cranks, cogs, or even belts and pulleys.
Slides were attached in front of the condensing lenses, outside the body of the lantern itself. They slid into place horizontally through metal runners at top and bottom.
The following describes some of the mechanical variants of the lantern slide.
Lever Action Slides. A lever protruded from one corner of the slide, attached to a second, overlapping pane of painted glass. When the lever was depressed or lifted the second glass rotated through a brief arc, resulting in a single animated movement on the lantern's screen.
The Peck and Snyder catalog enthuses: "The moving effects produced on the screen are very life-like. (...) The horse is put in motion by the lever, and appears to be cantering. (...) The children go up and down as natural as can be, and the audience can hardly believe that they are not alive. The No. 2 Electro Radiant Magic Lantern reproduces these pictures 8 to 12 feet in diameter. We conside the Lever one of the very best mechanical effects." Peck and Snyder sold lever-action slides for between $1.75 and $2.25.
Brian Coe's History of Movie Photography describes double and even triple lever-action slides, but the truly elaborate ones were apparently rare. Peck and Snyder does not offer any doubles or triples.
Slip slides. Slip slides had two panes of glass, with a thumb-and-finger notch cut into one corner of the wooden frame. The moving pane of glass was gripped and pulled by hand, a very simple operation. Slip slides often used black patches to obscure and reveal details of the background slide. Coe describes sub-varieties of "slipping slides" that were pulled with tabs.
Peck and Snyder: "Part of the picture is painted on one glass and the other on part on another glass. The two are arranged in a frame so that one glass slips over the other, and very comical effects are produced. It is a great mystery to the uninitiated, and they cannot understand how the transformations are made." Peck and Snyder retailed these for a thrifty seventy-five cents each.
Mechanical Slides: Rackwork and Pulley Slides. Early rotary slides sometimes used a belt-and-pulley drive, with two brass disks turned in contrary directions by belt drives and a little hand-crank. This technique was rivalled and eventually replaced by the neater and more accurate rack-and-pinion system. A single round disk of glass with a toothed brass rim could be cranked and rotated indefinitely. This caused repeated rotary animation on the screen. Rackwork slides cost $4.25 to $5.00 in Peck and Snyder's catalog. The catalog offers no pulley slides circa 1886.
Chromatropes. Says Peck and Snyder: "These are handsomely painted geometrical or other figures on two glasses, which, by an ingenious arrangement of crank pinion and gear wheels, are made to revolve in opposite directions, producing an endless variety of changes, almost equal to a grand display of fire-works."
Chromatrope cranks could produce single rackwork rotation against a fixed background, or double counter-rotation of both disks of glass. Peck and Snyder's chromatropes could project various brightly colored psychedelic moire' patterns up to twelve feet across. Professional chromatrope displays in large urban theaters must have been quite mind- boggling.
The Eidotrope was a chromotrope variant using counter-rotating disks of perforated metal, showing a swirling pattern of brilliant white dots on the screen. "Tinters" or colored translucent sheets could be added to tint the display. Coe describes Eidotropes, but Peck and Snyder does not offer any Eidotropes for sale circa 1886. C. W. Ceram's ARCHAEOLOGY OF THE CINEMA states that Eidotropes were powered by pulleys and "superseded" by Chromatropes.
The Cycloidotrope (see Coe p 19) was a truly remarkable variant, a kind of lantern spirograph. A black disk of smoked glass rotated within the slide frame, and a stylus on a pivoted arm traced a pattern in the soot against the moving glass. This appeared on the screen as a brilliant white line tracing a regular geometric design, an increasingly complex animated display. The stylus could be re-set as the cycloidotrope rotated, producing interlocking rosettes and similar mechanical geometries. Peck and Snyder do not sell or mention this impressive but labor-intensive graphic device. Images very similar to those generated by the Eidotrope and Cycloidotrope are now quite popular in computer screen-savers.
Dioramic Slides. These very elongated slides were twice as wide as normal slides, 4 1/2 by 12 or 14 inches. Peck and Snyder: "These slides are exceedingly beautiful. The painting is artistic and elaborate, and the wonder is they can be sold so cheaply. A scene is painted on fixed glass, and over this is made to pass a long procession of figures -- soldiers, vessels, trains of cars, caravans, as the case may be -- with the most pleasing and wonderful effects." The colored background image was small and square, but the pane with little figures was over a foot long. The figures slid along in front of the painted background. Peck and Snyder sold dioramic slides for $3 each.
Panorama slides. These landscape-style slides were over a foot long and could be gently drawn past the condensing lenses, "panning" across the picture. Like diorama slides, they often had a procession of moving figures as well. They cost $3.35 to $4.50 from Peck and Snyder.
Coe states that a London optician named J. Darker succeeded in attaching a kaleidoscope to the lens of a magic lantern in the 1860s. Says Coe: "His projection Kaleidoscope produced a remarkable effect when used to fill a large screen with a colorful, constantly changing pattern." (The Kaleidoscope itself, an optical toy which is very much alive, was invented by Sir David Brewster and patented in 1817.)