For a pivot take a needle stuck in a cork, and, as magnetic needles, two old corset steels will do very well. If these cannot be had a clock spring may do instead.

Magnetize these two steel rods by rubbing them with a magnet. In the middle of one of the rods punch a small hollow so that it may freely move on the needle in the cork without fear of falling off. You have thus manufactured a rough compass.

Then cut out four dolls in paper, two gentlemen and two ladies, and stick them in the extremities of the two magnetized needles. Remember to put at each end a figure of the opposite sex.

Now, each time you present a man to the other man, which is placed on the magnetized needle, they will repel each other; if to a lady, the dolls are attracted.

The explanation is easy. You will have taken care to put the puppets on contrary poles: a man on the positive pole, a lady on the negative pole. In this way the principle enunciated above is thoroughly proved and easily grasped.

One may easily vary this experiment by replacing the gentlemen and ladies by personages of actual notoriety, or of the company, in placing them in groups which have a mutual dislike to each other, such as the schoolmaster and pupil, etc.