[L. magnes, from Magnesia."] An ore of iron, "the loadstone," first found at Magnesia, a city in Lydia ; now found in different parts of the world, especially in Sweden and in the

States of New York and New Jersey. A load stone or natural magnet has the peculiar properties of attracting iron and some of its ores, and of pointing to the poles. If a loadstone be held near to iron filings, they will cling to it in a cluster. Tacks and small nails may be raised by it, and if the loadstone be a large one it will hold up quite a heavy weight. This power which the loadstone has of attracting iron is called magnetism. Bars of iron or steel may have the properties of the loadstone or natural magnet imparted to them, and hence we have what are called artificial magnets. Common iron will not keep its magnetic properties long, but steel will. Artificial magnets are made of various . forms, the most common being the bar shape. Powerful permanent magnets are made by placing several thin magnetized bars side by side, fastened firmly together. Such a collection of magnets is called a magnetic battery, and is more powerful than a solid bar of the same weight. A bar of soft iron may have the properties of a magnet imparted to it by sending a current of electricity through a coil of wire surrounding it. It is then called an electro-magnet (See Dynamo.)