China's early compass was also called?

China's early compass was also called Sina. During the Warring States period, people used the magnetism of magnets and the polarity of fingers to make an instrument to indicate the south. Sina is shaped like a spoon with a round and smooth bottom. You can rotate freely on the "site". At rest, the spoon handle will stop in the direction pointing south.

However, due to the weak magnetism of natural magnets, it is easy to lose magnetism when grinding, and it is difficult to overcome the friction with the site and indicate the direction correctly, so it has not been widely used.

Extended data:

After that, the guide fish appeared, which was cut into fish shape with thin iron leaves and magnetized by geomagnetic field. When it is used, it floats on the water, and the iron leaf fish can guide it. Until the Song Dynasty, it was more convenient to use a natural magnet to rub a steel needle to magnetize it, make a compass, and install it on a compass with 24 directions.

Compass is the result of China ancient working people's understanding of magnet magnetism in long-term practice. As one of four great inventions of ancient china, its invention has played an inestimable role in the development of human science, technology and civilization. In ancient China, the compass was first used for rituals, etiquette, military affairs and divination, and to determine the orientation when looking at geomantic omen.

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