thaumatrope
A thaumatrope is a simple optical toy dating from the early 19th century. It consists of a disc with different images on its two faces and strings attached to the opposite edges. When the strings are pulled taut and the disc is spun rapidly, the two pictures fuse into a single image in the viewer’s perception due to persistence of vision, creating a illusion of motion or combination.
Its invention is commonly attributed to English physician John Ayrton Paris, who popularized the device in
A typical example shows a bird on one side and a cage on the other; when spun,
Legacy and significance: the thaumatrope is regarded as an early step in the history of animation and