A zoetrope is one of several pre-film animation devices that produce the illusion of motion by displaying a sequence of drawings or photographs showing progressive phases of that motion. It was basically a cylindrical variation of the phénakisticope, suggested almost immediately after the stroboscopic discs were introduced in 1833. The definitive version, with easily replaceable picture strips, was introduced as a toy by Milton Bradley in 1866 and became very successful. Etymology The name zoetrope was composed from the Greek root words ζωή zoe, "life" and τρόπος tropos, "turning" as a translation of "wheel of life". The term was coined by inventor William E. Lincoln. Technology The zoetrope consists of a cylinder with cuts vertically in the sides. On the inner surface of the cylinder is a band with images from a set of sequenced pictures. As the cylinder spins, the user looks through the cuts at the pictures across. The scanning of the slits keeps the pictures from simply blurring together, and the user sees a rapid succession of images, producing the illusion of motion. From the late 19th century, devices working on similar principles have been developed, named analogously as linear zoetropes and 3D zoetropes, with traditional zoetropes referred to as "cylindrical zoetropes" if distinction is needed. The phenàkistope is also a success and The zoetrope works on the same principle as its predecessor, the phenakistoscope, but is more convenient and allows the animation to be viewed by several people at the same time. Instead of being radially arrayed on a disc, the sequence of pictures depicting phases of motion is on a paper strip. For viewing, this is placed against the inner surface of the lower part of an open-topped metal drum, the upper part of which is provided with a vertical viewing slit across from each picture. The drum, on a spindle base, is spun. The faster the drum is spun, the smoother the animation appears. Earlier rotating devices with images An earthenware bowl from Iran, over 5000 years old, could be considered a predecessor of the zoetrope. This bowl is decorated in a series of images portraying a goat jumping toward a tree and eating its leaves. Though the images are sequential and seem evenly distributed around the bowl, to have the images appear as an animation the bowl would have to rotate quite fast and steadily while a stroboscopic effect would somehow have to