How to use the compass?

Compass is an important instrument, which is widely used in astronomy, geography, military affairs, navigation and divination, as well as the location of houses and graves. It is the continuation and development of the compass, one of the four great inventions in ancient China. It is a traditional practical folk handicraft developed on the basis of the compass.

At first, people used a compass to refer to a compass, but it quickly developed into a compass with a magnetic needle and a compass, or a compass. The azimuth disk is still the twenty-four azimuth of the Han Dynasty, but the disk has evolved from a square to a ring. The appearance of compass is undoubtedly a great progress in the history of compass development. Just look at the position of the magnetic needle on the azimuth board and you can determine the azimuth. At that time, the compass was still a water compass, and the magnetic needles were all floating on the water through the wick. Although the dry compass is superior to the water compass because the magnetic needle has a fixed fulcrum, it is still inconvenient to use at sea.

When the pallet swings greatly with the seagoing ship, the pointer tends to be too inclined to rotate against the pallet. From14th century to16th century, a universal bracket called "universal bracket" appeared on the European navigation compass. It consists of two copper rings with slightly different diameters, so that the small circle is just inscribed on the big circle. They are connected by a pivot and then mounted on a fixed bracket by the pivot. The drought compass is hung on the inner ring, so that no matter how the hull swings, the drought compass can always remain horizontal. Before the compass was used for navigation, navigation at sea could only be based on the sun, moon and stars. In case of bad weather, there is nothing to do. After the compass is used for navigation, the course can be identified regardless of cloudy weather. Geological compass mainly plays the following roles in field work: measuring azimuth and measuring rock occurrence factors.