An invention in 1832 by Belgian physicist Joseph Plateau, the phenakistoscope was one of the first devices to create moving pictures. It consisted of two cardboard discs mounted on the same axis, one with a sequence of images around its circumference and the other with a number of equidistant slits in it. When the user spun the discs – and, on holding the phenakistoscope up to a mirror, looked through the slits – the images appeared to move.
Plateau was initially successful in marketing the phenakistoscope as a children’s toy. Unfortunately for him, it was soon outshone by the better-known zoetrope (invented in 1834), which required no mirror and could be viewed by more than one person at a time.