The Collaborative International Dictionary
Anorthoscope
Anorthoscope \A*nor"tho*scope\, n. [Gr. 'an priv. + ? straight + -scope.] (Physics) An optical toy for producing amusing figures or pictures by means of two revolving disks, on one of which distorted figures are painted.
Wiktionary
anorthoscope
n. An optical device (often a toy) used to produce a form of anamorphosis or to view distorted figures