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How A Magnetic Compass Was An Essential Part Of Early Voyages
No one exactly knows where the magnetic compass originated or how people learned to make use of them. What is known is that the ancient Greeks were aware of the valuable uses of magnetism even in those early times. At the same time, the Chinese became aware of the ability of an iron bar stroked with a lodestone to point a directional north-south two thousand years ago. It is believed that the idea to create the first magnetic compass is brought to Europe probably from China by Arab traders. Believe it or not the simplest kinds of magnetic compass were used in the Mediterranean as early as the 12th century. These instruments were not very precise but they were enough guides in the vast seas. Magnetic compasses work because the Earth is surrounded by a huge magnetic field. Our planet has two magnetic poles that lie near the South and North poles. This huge magnetic field that surrounds the Earth causes a magnetized 'needle' of steel or iron to swing into a north-south direction when hung from a thread or stuck through a piece of wood or straw floating in a basin of water. The needles were magnetized by stroking them with a lodestone. Lodestones are a lump of magnetic rock called magnetite and these need to be carried on the ship always because the needle cannot keep its magnetic property. During the 15th century, mariners came to notice that the magnetic compass does not precisely point to the Earth's true north; instead the needle makes an angle with true north which varies from place to place. After a while, an improvement was made on the from place to place magnetic compass. The magnetic needle was mounted under a card on a sharp pin then placed in a little turned ivory or wooden box. These compass cards were marked out originally in points instead of in degrees. These points represent 32 wind directions that sailors were familiar of when voyaging at sea. There are 4 main points called cardinal points which are North, South, East and West. Today, magnetic compasses are not only used at sea, it can be used in flights, travelling on foot, etc. Compasses are even incorporated in common accessories now like watches and necklaces. Article Directory: http://www.articledashboard.com For centuries, navigators were able to travel around the world and record geographical data with the use of compasses. Find out more about magnetic compass. |
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