[Illustration: Fig. 95.]
The puzzle is as follows:—After placing three red wafers in the squares
Nos. 1, 2 and 3, and three blue wafers in Nos. 5, 6 and 7, you are to
move the three blues into the squares occupied by the reds and the three
reds into the squares occupied by the blues (keeping within the
squares), the reds moving towards the right, and the blues to the left,
not being allowed to move back after once moving forward. You are to
jump only one at a time, and have the privilege of moving either card
into a vacant square adjoining. The first move, of course, is either
from 3 or 5 into 4.
_Explanation._ Move blue wafer from 5 to 4; red wafer from 3 to 5,
jumping 4; red from 2 to 3; blue 4 to 2, jumping 3; red from 6 to 4,
jumping 5; blue from 7 to 6; red from 5 to 7, jumping 6; red from 3 to
5, jumping 4; red from 1 to 3, jumping 2; blue from 2 to 1; blue from 4
to 2, jumping 3; blue from 6 to 4, jumping 5; red from 5 to 6; red from
3 to 5, jumping 4; and blue from 4 to 3, which performs the puzzle,
having changed the three blue wafers from their former places into those
of the red, and the red into those of the blue. This may be shown to a
person a number of times, and if done quickly not one in ten will be
able to perform it.