Hanky Panky has to make two oval boards: but it so happens that the area, exclusive of hand-holes in the centre, and the circular piece, are the same. To cut his stuff, on finding the centre of the circle, he strikes a second circle, half the diameter of the first, with the same centre. Then he cuts the whole into quarters, by means of two lines drawn at right angles to each other, then cuts along the inner circle (Fig. 92) and puts the pieces together, as in Figs. 93, 94.
CHECKER PUZZLE.
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.
THE UNDETACHABLE CYLINDER.
Cut a slit close to one edge lengthwise of half a playing card, and of the other piece make a cutting in the following shape:—
