Accession No
1208
Brief Description
geomantic compass, by Wu Iu-heng, Chinese
Origin
China
Maker
Wu Iu-heng
Class
magnetism
Earliest Date
Latest Date
Inscription Date
Material
wood (boxwood); glass; metal (steel)
Dimensions
diameter 153mm; thickness 20mm
Special Collection
Provenance
Inscription
Description Notes
Boxwood circular disc; inscription on base with maker’s name, country (Xing An) and village (Xiu Yi); rounded edges. 15 rings of characters, mostly in black but a few in red. Inset compass with NS line and steel needle (half red).
Condition: good; complete.
References
Events
Description
Magnetic compass
The magnetic compass consists of a magnetic needle attached to a compass card, graduated into angular points, and is used for navigation. The first known dry pivoted compass is dated as early as 1269.
The compass indicates the direction of the magnetic pole but there are problems caused by the difference between magnetic and true north (true north being the useful reading). The variation between the two must be calculated in order to obtain an accurate reading. True north was sometimes simply offset from the direction of magnetic north, but this did not allow for geographical variation. For this, charts were needed. The iron used in building ships during 19th century also led to problems because the magnetism of iron affected the compasses on board.
18/10/2002
Created by: Saffron Clackson on 18/10/2002
FM:43576
Images (Click to view full size):
