Fig. 7.—Several Different Methods of Making a Simple Compass.
Compass. Figure 7 shows several other different ways of making compasses. The first method is to suspend a magnetized needle from a fine silk fiber or thread.
The second method illustrates a very sensitive compass made from paper. Two magnetized needles are stuck through the sides with their north poles both at the same end. The paper support is mounted upon a third needle stuck through a cork.
A compass which more nearly approaches the familiar type known as a pocket compass may be made from a small piece of watch-spring or clock-spring.
The center of the needle is annealed or softened by holding it in the flame of an alcohol lamp and then allowing it to cool.
Lay the needle on a piece of soft metal such as copper or brass, and dent it in the center with a punch.
Balance the needle on the end of a pin stuck through the bottom of a pill-box.
Magnetic Substances are those which are attracted by a magnet. Experiment with a number of different materials, such as paper, wood, brass, iron, copper, zinc, rubber, steel, chalk, etc. It will be found that only iron and steel are capable of being attracted by your magnet. Ordinary magnets attract but very few substances. Iron, steel, cobalt, and nickel are about the only ones worthy of mention.
Attraction through Bodies. A magnet will attract a nail or a tack through a piece of paper, just as if nothing intervened.