What do the compasses s and n stand for?

N stands for North, and S stands for South.

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.

Sina is the earliest magnetic conductor. The name "Sina" began in the Warring States Period (475 BC-22 BC1year) and ended in the Tang Dynasty (665438 AD+08 AD-907 AD). Because Sina's ancient meaning has been constantly evolving, it has forged an indissoluble bond with a series of ancient inventions.

The earliest document that recorded Sina was Guiguzi, which wrote: "Zheng people take jade and will take Sina's car because they are not confused." As can be seen from the records in Guiguzi, in order to avoid getting lost, Zheng people must take Sina with them to "get jade".