regard to moving objects’. Many inventors put his theory to the test with pictures posted on coins that were flipped by the thumb, and with rotating disks of drawings. A particular favorite was the zoetrope, slotted revolving drum through which could be seen clowns and animals that seemed to leap. They were hand drawn on strips of paper fitted inside the drum. Other similar devices were the hemitrope, the phasmatrope, the phenakistoscope, and the praxinoscope. It is not possible to give any one person credit for having invented the motion picture. In the 1880s the Frenchman Etienne Jules Marey