Geomancer's compas, Chinese.

Geomancy is the art of succesfully orienting buildings. The Chinese geomantic system is known as feng shui. In Chinese thought, feng shui is a system of good and evil influence in the natural surroundings, which needs to be taken into consideration when designing and siting buildings. Wooden compases such as this one were used to determine the most healthy position to build a house. The locations for buildings were carefully chosen so that the forces of Yin and Yang were balanced correctly, thus reducing the chance of illnes.