What Is a Lodestone?
A lodestone is a variety of the mineral named magnetite which is a natural magnet. The name magnet comes from the name of the mineral magnetite and this in turn derived its name from the fact that it was first discovered in Magnesia. The word magnet really means the “Stone of Magnesia.”
A lodestone is one of the mysteries of nature. Its properties can more nearly be understood if we examine an artificial magnet, which is generally made in the form of either a straight bar or a shoe. An artificial magnet is made of iron. If you drop a bar magnet into a box of iron filings, the filings attach themselves to the bar. If you examine it closely you observe that most of the filings attach themselves to the ends of the bar. Therefore we call the ends of the bar the poles of the magnet.
If you suspend a magnetic needle at its center of gravity so that it is absolutely free to turn, you will soon find one end of the needle pointing north and the other south of course. The end which is pointed toward the north is called the north pole and the other the south pole. If you have a horse-shoe magnet, you can demonstrate this for yourself. Rub the end of your magnet over a sewing needle and oil the needle so that when you lay it on the surface of a glass of water it will float. Then look at it closely. You will see the needle slowly turn until finally it becomes quite still. If you have a compass at hand so that you know surely which is north and which is south, you will find one end of the needle pointing north and the other south. You can then place the end of your magnet against the outside of the glass and draw the needle toward your magnet. Your horse-shoe magnet has its north and south poles close together.
If you have a bar magnet and the end of the needle with the eye in it is pointing north, you can drive the needle on the surface of the water away from you by touching the outside of the glass opposite that end of the needle with the north pole of your magnet. On the other hand, if you reverse the experiment and place the south pole of your magnet to the side of the glass, the needle will come toward the magnet. In other words then the like poles of a magnet repel each other and the unlike poles attract each other.
Another interesting way to show this is to take two lodestones or two magnets and let a lot of iron filings attach themselves to the ends of them. Then when you have done this, point the two north poles of the magnets or lodestones at each other close together. You will be intensely interested in seeing how quickly the mysterious something that is in the magnets makes the filings on the two ends of the magnet try to get away from each other. On the other hand when you put a north and south pole together, they form a union of the iron filings.
Another strange thing about a magnet is that if you break it in two, each half will be a complete magnet in itself with a north and south pole also, and this is true no matter how many times you break it into pieces. From this we learn that each tiny particle or molecule throughout the bar is a magnet by itself.
WHAT A LODESTONE IS
This is a picture of a complete electro magnet. The magnet is attached to the arm of a crane by the loop in the center and when the magnet then comes in contact with any kind of iron or steel it lifts it as soon as the current is turned on. By making the electric current stronger, greater weight can be lifted. Many tons of material can be lifted at one time. An electro magnet will do the work of many men at much less cost.
In this picture we see the magnet lifting a great weight of miscellaneous pieces of scrap iron. As many as twenty tons can be lifted and transferred from one place to another at one time.
Some things can be magnetized while others cannot. Many substances have not the property of magnetizing other substances when they have once been attracted by a magnet. These are called magnetic substances. They remain magnetized only as long as they are in touch with the magnet; other substances when once magnetized become permanent magnets. Steel and lodestone have this faculty. A compass needle is an artificial magnet which becomes a permanent magnet when rubbed with a magnet.