Compass card
Dry compass
Card: Mica covered with paper, white with black markings, graduated to 1/2 points and quadrantally in degrees. N point indicated by a five-pointed star. Centre of card has a 1.2" (3.0 cm) diameter hole to accommodate curved brass pivot bridge.
Needle: 9.8" (25.0 cm) long flat bar type with pointed ends and an expanded centre. Two brass balancing weights are mounted at E & W points.
Pivot: Inverted type, having a steel pivot point screwed into the top of a brass bridge mounted above card and secured to expanded centre of needle.
Card: Mica covered with paper, white with black markings, graduated to 1/2 points and quadrantally in degrees. N point indicated by a five-pointed star. Centre of card has a 1.2" (3.0 cm) diameter hole to accommodate curved brass pivot bridge.
Needle: 9.8" (25.0 cm) long flat bar type with pointed ends and an expanded centre. Two brass balancing weights are mounted at E & W points.
Pivot: Inverted type, having a steel pivot point screwed into the top of a brass bridge mounted above card and secured to expanded centre of needle.
For more information about using images from our Collection, please contact RMG Images.
Object Details
ID: | ACO0867 |
---|---|
Type: | Compass card |
Display location: | Not on display |
Creator: | Unknown |
Date made: | circa 1825 |
Credit: | National Maritime Museum, Greenwich, London, Admiralty Compass Observatory |
Measurements: | Overall: 25 mm; Diameter: 250 mm |