Dry compass
Dry compass
Card: Mica covered with paper, white with black markings, graduated to quarter points and quadrantally in degrees. At centre part of card is a circle graduated in Roman numerals to 24 hours and an inner graduation quadrantal 1 - 8
Needle: Two slightly curved edge bar needles, 7.5" (19.0 cm) in length, attached to card by brass struts. A small brass balancing disc is mounted to South side of centre of card.
Pivot: Bell shaped brass pivot cup and balancing weight, fitted with jewell cal at apex of bell, attached to centre of card by a brass disc set in card. Upper part of jewel cap has a stile pin set in it, for taking bearings of the sun by its shadow cast on card.
Card: Mica covered with paper, white with black markings, graduated to quarter points and quadrantally in degrees. At centre part of card is a circle graduated in Roman numerals to 24 hours and an inner graduation quadrantal 1 - 8
Needle: Two slightly curved edge bar needles, 7.5" (19.0 cm) in length, attached to card by brass struts. A small brass balancing disc is mounted to South side of centre of card.
Pivot: Bell shaped brass pivot cup and balancing weight, fitted with jewell cal at apex of bell, attached to centre of card by a brass disc set in card. Upper part of jewel cap has a stile pin set in it, for taking bearings of the sun by its shadow cast on card.
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Object Details
ID: | ACO1007 |
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Type: | Dry compass |
Display location: | Not on display |
Creator: | Cameron |
Date made: | 1853 |
Credit: | National Maritime Museum, Greenwich, London, Admiralty Compass Observatory |
Measurements: | Overall: 80 mm; Diameter: 200 mm |