Zoetrope Patented: The Birth of Animated Pictures

A spinning drum with slits in its sides made still images appear to move, and the modern entertainment industry has been chasing that illusion ever since. William Lincoln received a US patent for the zoetrope on April 23, 1867, improving upon a device first described by British mathematician William George Horner in 1834. The principle was simple: a sequence of slightly different drawings placed inside a revolving cylinder could, when viewed through narrow slits, create the convincing illusion of continuous motion. The eye retained each image just long enough for the next to replace it seamlessly. Horner had called his version the daedaleum, but the device attracted little commercial interest until Lincoln redesigned it for mass production. Milton Bradley, the game manufacturer, began selling Lincoln's zoetrope in the United States in 1867, marketing it as a parlor toy. At prices accessible to middle-class families, the zoetrope became one of the most popular optical toys of the Victorian era, joining a growing family of devices, including the thaumatrope, phenakistoscope, and praxinoscope, that exploited persistence of vision for entertainment. The science behind the zoetrope is the same phenomenon that makes cinema and television possible. The human visual system processes a rapid succession of still images as continuous motion when those images change faster than approximately 10-12 frames per second. Film projectors typically run at 24 frames per second, and modern displays at 60 or more. Every screen you have ever watched, from a nickelodeon to an IMAX theater to the phone in your pocket, relies on the same perceptual quirk that made Horner's drum spin to life. The zoetrope also represented a democratization of animation. Unlike earlier devices that could only be viewed by one person at a time, the zoetrope allowed a group to watch simultaneously. Lincoln's patent laid no claim to the optical principle itself, only to the specific mechanical design, which meant that the technology spread rapidly and inspired further innovation. Within three decades, Thomas Edison and the Lumiere brothers would replace spinning drums with flexible film stock, but the fundamental trick remained identical.