CHAPTER II.
ABOUT MAGNETS AND MAGNETISM.
Fig. 20
24. Natural Magnets. Hundreds of years ago it was discovered that a certain ore of iron, called lodestone, had the power of picking up small pieces of iron. It was used to indicate the north and south line, and it was discovered later that small pieces of steel could be permanently magnetized by rubbing them upon the lodestone.
25. Artificial Magnets. Pieces of steel, when magnetized, are called artificial magnets. They are made in many forms. The electromagnet is also an artificial magnet; this will be treated separately.
26. The Horseshoe Magnet, Fig. 20, is, however, the one with which we are the most familiar. They are always painted red, but the red paint has nothing to do with the magnetism.
Fig. 21.