An advertising card, featuring "The Tumbling Cubes" illusion. The front of the card has a pattern of red, black, and blue square and diamond shapes, while the back of the card has the instructions for the illusion.
THE TUMBLING CUBES.
PRESENTED BY PEARS' SOAP.
GAZE steadily at the centre when you will
see alternately
ONE CUBE on the top of TWO CUBES,
each having "PEARS" on the top side;
or,
TWO CUBES on the tope of ONE CUBE,
each having "PEARS" on the bottom side.
The Cubes, in fact, appear to be continuously turning topsy-turvy, thus: -
