The luopan is the compass of the feng shui practitioner, the specialised instrument by which a site is oriented and read according to the principles of Chinese geomancy.
Rings around a needle
At the centre of the luopan sits a magnetic needle, and around it are arranged concentric rings inscribed with the directions, the trigrams, the celestial stems and earthly branches, the constellations and the other categories of Chinese cosmology, so that once the needle is aligned the practitioner can read from the rings the qualities assigned to each direction at that spot. The instrument thus condenses a whole cosmological system into a device that can be turned upon a particular place, and reading it is a specialised skill requiring long training.
Siting the living and the dead
Feng shui, the art of siting buildings, rooms and graves so as to accord with the currents of the landscape, uses the luopan to determine the auspicious orientation of a house, a door or a tomb, and the placing of a grave in particular is held to affect the fortunes of the descendants, which made the geomancer a figure of real consequence. The instrument is the practitioner essential tool, the means by which the invisible qualities of a site are made legible. It belongs to the broad world of Chinese religion and cosmology, drawing on the same categories used in divination and the calendar, and it remains in use wherever feng shui is practised, from the siting of graves to the arrangement of modern buildings.