Cut out a disc of cardboard or pasteboard, and drill three holes near
the edge on two opposite sides, in each of which tie a length of string.
In the centre on one side paint a jockey seated, and on the other
centre, upside down as compared with the man, a running horse.
_Performances._—If you take the strings, one set in each hand, and whirl
the disc round as on a horizontal axle, the strings will twist and keep
up the movement, during which the two pictures will unite as one. Other
objects may be a bird and cage, a juggler doing the knife or ball
tossing trick, a rat and trap, &c.