3/ The theory of the animated cartoon was introduced before the invention of the cinema by half a century. When working to create conversation pieces for Victorian shops, people discovered the principle of persistence of vision. If drawings of the stages of an action were shown in fast succession, the human eye would perceive them as a continuous movement. One of the first commercially successful devices, invented by the Belgian Joseph Plateau in 1832, was the phenakistoscope, a spinning cardboard disk that created the illusion of movement when viewed in a mirror, in 1834, William Horner invented the zoetrope, a rotating drum lined by a band of pictures. The Frenchman Émile Reynaud in 1876 adapted the principle into a form that could be projected before a theatrical audience. Reynaud became not only animation's first entrepreneur but also the first artist to give personality and warmth to his animated characters. 1. What is the passage mainly about? 3