CHAPTER II.
MAGNETS.

11. Kinds of Magnets. Among the varieties of magnets which we shall discuss, are the natural, artificial, temporary, permanent, bar, horseshoe, compound, and electro-magnet.

Fig. 2.

The Horseshoe Magnet, H M ([Fig. 2]), is the most popular form of small magnets. The red paint has nothing to do with the magnetism. The piece, A, is called its armature, and is made of soft iron, while the magnet itself should be made of the best steel, properly hardened. The armature should always be in place when the magnet is not in use, and care should be taken to thoroughly clean the ends of the magnet before replacing the armature. The horseshoe magnet is artificial, and it is called a permanent magnet, because it retains its strength for a long time, if properly cared for.

EXPERIMENT 5. To study the horseshoe magnet.

Apparatus. [Fig. 2]. The horseshoe magnet, H M (No. 16).

12. Directions. (A) Remove the armature, A, from the magnet, then move A about upon H M to see (1) if the curved part of H M has any attraction for A, and (2) to see if there is any attraction for A at points between the curve and the extreme ends of H M.

13. Poles; Equator. The ends of a magnet are called its poles. The end marked with a line, or an N, should be the north pole. The unmarked end is the south pole. N and S are abbreviations for north and south. The central part, at which there seems to be no magnetism, is called the neutral point or equator.