Sina was invented in the Spring and Autumn Period and the Warring States Period (now the Sina model in the Warring States Period is based on the drawings and records of the Han Dynasty).
In the Song Dynasty, there was a kind of guide fish (how to do it and what it looks like).
Later, the compass was developed according to the guide fish, which is the closest to the present compass.
During the Warring States period, our people have discovered the characteristics of magnets pointing north and south, and created "Sina". Determine the specific time with Sina. These explanations showed that Sina had been applied in many aspects at that time. In the early Northern Song Dynasty, people discovered the artificial magnetization method, and made a compass by rubbing a steel needle with a natural magnet. Later, people learned to fix the compass in the azimuth plate and made a compass needle. At that time, the compass was still a water compass, that is, the magnetic needle floated across the wick on the water. The water compass was used throughout the Southern Song Dynasty. As for the drought compass, China did not appear until the Jiajing period of the Ming Dynasty (1522- 1566).
The invention of the compass
The invention of compass has no exact time and inventor. Ceng Gongliang's General Theory of Martial Arts in the Northern Song Dynasty mentioned that "compass fish" was used to help identify the direction when marching. As for the "compass fish", it is a fish-like steel plate, five minutes wide and two inches long, with a sunken abdomen and a shape like a boat. After magnetization, it floats on the water to distinguish the north from the south.
Shen Kuo in the Northern Song Dynasty recorded three related records: how to make a compass, the earliest discovery of magnetic declination in the world, and how to make a compass by artificial magnetization. Shen Kuo not only recorded the development at that time, but also compared the manufacturing methods, which became the best reference for understanding the invention of the compass at that time.