Accession No

1673

Brief Description

geomantic compass, by Zheng Guo-Shu, Chinese, 19th Century

Origin

China

Maker

Zheng Guo-Shu

Class

magnetism

Earliest Date

1800

Latest Date

1900

Inscription Date

Material

wood; glass; metal (steel)

Dimensions

diameter 148mm; thickness 15mm

Special Collection

Provenance

On loan from The Fitzwilliam Museum, University of Cambridge, from 08/1973. Donated by C.W. Phillips of Selwyn College to The Fitzwilliam Museum in 11/1940.

Inscription

Description Notes

Circular; turned wood, painted black on base with rounded edge; red rim; gold upper surface with 14 (15?; 11-2-2000) concentric rings of characters. Central inset compass with NS line; blued steel needle and glazed cover; inscription on reverse in red paint (‘Zheng Guo-Shu’), almost obscured by heavy varnish.
‘Fitzwilliam Museum’ paper label on base.

Condition: fair (varnish chipped); 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:43578