Accession No
2710
Brief Description
compass, marine, in binnacle, 1850 (c)
Origin
Maker
Class
navigation; magnetism
Earliest Date
1850
Latest Date
1850
Inscription Date
Material
paper (card); wood (mahogany, other); metal (brass); glass
Dimensions
height 292mm; breadth 185mm; depth 163mm
Special Collection
Provenance
Purchased from Christie’s, South Kensington, London, England; lot 214, 8/1/1981.
Inscription
Description Notes
Mariner’s dry card compass in wooden binnacle with brass fittings. Black and white printed 32-point compass rose with fleur-de-lys N and the other cardinal points marked. Outside 0-90-0-90-0 by 1o. Brass mounted pivot. Brass bowl slung in brass gimbal ring, mounted in mahogany box (piece of rim moulding missing). Box sits in wooden binnacle with 3 brass handles, glazed hinged door in front and wooden hinged door behind. Circular glazed aperture in side with brass fitting for oil lamp.
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:44462
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