The filings will arrange themselves in curved lines, diverging from one pole of the magnet and meeting again at the opposite pole. The lines of force are considered as extending outward from the north pole of the magnet, curving around through the air to the south pole and completing the circuit back through the magnet.
Fig. 14.—Magnetic Phantom showing the Lines of Force about a Horseshoe Magnet.
Figure 14 shows the lines of force about a horseshoe magnet. It will be noticed that the lines cross directly between the north and south poles.
The difference between the magnetic fields produced by like and unlike poles is shown in Figure 15.
Fig. 15.—Lines of Force between Like and Unlike Poles.
A study of this illustration will greatly assist the mind in conceiving how attraction and repulsion of magnetic poles take place.
It will be noticed the lines of force between two north poles resist each other and meet abruptly at the center. The lines between a north and a south pole pass in regular curves.
The Earth is a Great Magnet. The direction assumed by a compass needle is called the magnetic meridian.