Northern Song Compass Navigation

Timeline

1. 1071–1074Bianjing Bureau of Armaments · Kaifeng CityThe Wujing Zongyao records a thin iron piece shaped like a fish, magnetized by the Earth's magnetic field and placed in a bowl of water to indicate direction, a navigational device for the Northern Song military navy. More portable than the sinan, it became one of the precursor forms of the compass.
2. 1075–1078Quanzhou Port · Quanzhou CityMerchant ships on the southeast coast used the compass for direction when sailing from ports such as Quanzhou and Guangzhou, combining it with course records and island landmarks to navigate day and night. The Song Maritime Trade Offices' management of sea trade promoted the practical use of navigation technology.
3. 1078–1080Runzhou (Zhenjiang) · Zhenjiang CityShen Kuo observed in Runzhou and elsewhere that the magnetic needle pointed slightly east of true north—the phenomenon of magnetic declination—and described various compass-making methods, including rubbing a steel needle with a magnet and floating a needle on water. This understanding provided a theoretical basis for later compass correction in navigation.