Word of the Day - Thaumatrope

Thaumatrope: An optical toy consisting of a paper disk with a picture printed on each side, with two pieces of string attached on either side of the disk. When the strings are twirled quickly between the fingers, the disk spins and the two pictures appear to blend into one, due to a phenomenon known as persistence of vision. The thaumatrope was a popular toy in the 19th century.