Compass card

Card for a dry card compass

Card: Mica covered with paper. Brown with black markings graduated to quarter points and 0 - 180 East and West of North Point. Hollow centre with angled brass bridge holding screw in pivot spike. Has two slits for needles to move in.

Needle: Two edge bar needles mounted on brass framework. Both swing from individual centres thus allowing amount of dip to be seen. 7" long by 0.4" deep.

Pivot: Brass and steel spike mounted on brass bridge on centre of card.

Object Details

ID: ACO1005
Type: Compass card
Display location: Not on display
Creator: Keen, R. J.
Date made: Mar 1854
Credit: National Maritime Museum, Greenwich, London, Admiralty Compass Observatory
Measurements: Overall: 35 mm; Diameter: 215 mm