Compass card

Dry compass

Card: Consists of a paper band attached to the metal circumference and metal centre by fine silk threads. The paper is white with black markings graduated to quarter points and with two sets of quadrantal maarkings in degrees, one set being mirrored for use with a prism.

Needle: The six needles, in three sets of two, ar thin. They are suspended beneath the card on a different silk thread system to that of the card. Lengths 3.25" (8.3 cm), 2.75" (7.0 cm) and 2.0" (5.1 cm)

Pivot: Consists only of a thin aluminium "washer" which holds the radial silk threads

Object Details

ID: ACO1023
Type: Compass card
Display location: Not on display
Creator: Kelvin & James White Ltd; Thomson, William
Date made: 1897
Credit: National Maritime Museum, Greenwich, London, Admiralty Compass Observatory
Measurements: Overall: 10 mm; Diameter: 203 mm