The phenakistoscope uses the principle of persistence of motion to create an illusion of movement. It consists of two disks mounted on the same axis. The first disc has slots around the edge, and the second contains drawings of successive action, drawn around the disc in concentric circles. a Phenakistoscope's discs spin together in the same direction. When viewed in a mirror through the first disc's slots, the pictures on the second disc will appear to move.
