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North corresponds to 0°, so east is 90°, south is 180° and west is 270°. The history of the compass started more than 2000 years ago during the Han dynasty (202 BC – 220 AD). The first compasses were made of lodestone, a naturally magnetized stone of iron, in Han dynasty China. [ 1 ][ 2 ] It was called the "South Pointing Fish" and was ...
Lodestone. Lodestones are naturally magnetized pieces of the mineral magnetite. [1][2] They are naturally occurring magnets, which can attract iron. The property of magnetism was first discovered in antiquity through lodestones. [3] Pieces of lodestone, suspended so they could turn, were the first magnetic compasses, [3][4][5][6] and their ...
The first compasses in ancient Han dynasty China were made of lodestone, a naturally magnetized ore of iron. [2] [10] The wet compass reached Southern India in the 4th century AD.
A Han dynasty (202 BC–220 AD) ladle-and-basin lodestone south-pointing compass, used by ancient Chinese geomancers, but not for navigation. However, it was not until the time of Shen Kuo that the earliest magnetic compasses would be used for navigation.
Compass: Although an ancient hematite artifact from the Olmec era in Mexico dating from about 1000 BC indicates the possible use of the lodestone compass long before it was described in China, the Olmecs did not have iron, which the Chinese found could be magnetised by contact with lodestone. [31]
History of geomagnetism. A reconstruction of an early Chinese compass. A spoon made of lodestone, its handle pointing south, was mounted on a brass plate with astrological symbols. [1] The history of geomagnetism is concerned with the history of the study of Earth's magnetic field. It encompasses the history of navigation using compasses ...
Based on his find of an Olmec hematite artifact in Central America, the American astronomer John Carlson has suggested that "the Olmec may have discovered and used the geomagnetic lodestone compass earlier than 1000 BC". If true, this "predates the Chinese discovery of the geomagnetic lodestone compass by more than a millennium".
A lodestone cut out of rock and floated in water returns to the same direction. Iron heated to white heat and cooled lying along a meridian also acquires magnetism. But stroking with other materials fails—he proved this with an experiment with 75 diamonds in front of witnesses. The best way to magnetize a compass (magnetized versorium).