Optical Devices - Phenakistoscope

      This contraption is called the "Phenakistoscope". It was made by physicist "Joseph Plateau". Joseph and his sons showed this invention in 1832. This creates an illusion of motion by using a "persistence of motion principle". This principle was already known by a Greek mathematician named Euclid and Isaac Newton. This principle was only truly known when Joseph Plateau introduced this invention.
        The phenakistoscope works by having two discs placed on one axis. One disc has slots around the edge, and the other has a series of drawings placed in a circular formation. These two discs both spin in the same direction.