Accession No

1738

Brief Description

geomantic compass, by Xi Yang-San, Chinese

Origin

China

Maker

Xi Yang-San

Class

magnetism

Earliest Date

Latest Date

Inscription Date

Material

wood (boxwood); glass; metal (steel)

Dimensions

diameter 117mm; thickness 16mm

Special Collection

Holden-White collection

Provenance

On loan from The Fitzwilliam Museum, University of Cambridge. Donated by Charles Holden-White to the Fitzwilliam Museum. C. Holden-White collection.

Inscription

Description Notes

Boxwood disc with rounded sides and 9 concentric circles of characters, mostly in black paint, but a few in red; inset compass with steel needle and NS line; inscription and signature on reverse: ‘Xi Yang-San Xing An Wang Yang’.

Condition: fair; 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:43572