Chromatrope

A chromatrope is a type of magic lantern slide that produces dazzling, colorful geometrical patterns set in motion by rotating two painted glass discs in opposite directions, originally with a double pulley mechanism but later usually with a rackwork mechanism.
The chromatrope was possibly invented around 1841 by English glass painter and showman Henry Langdon Childe, by which year it was listed in the Royal Polytechnic Institution catalogue. . It was added as a novelty to the program of the Royal Polytechnic Institution, which had previously included many other types of magic lantern shows with moving images, such as phantasmagoria and dissolving views.