Dry compass

Card- Mica covered with paper. White with black and white markings, graduated to 1/4 points and quadrantally in degrees.
Needle- One solid edge bar type, 7.7" long, having a heavy centre boss which carries the pivot cap. Fitted with two sliding weights, two brass strips carrying sliding weights are fitted in E-W direction. The needle is mounted on a light metal ring which is screwed to card.
Pivot- Small cone-shaped brass pivot cap with jewel at top, attached to centre boss of needle.

Object Details

ID: ACO0945
Type: Dry compass
Display location: Not on display
Creator: Henry Barrow & Co
Date made: 1837-1840; 1837-40
Credit: National Maritime Museum, Greenwich, London, Admiralty Compass Observatory
Measurements: Overall: 20 mm; Diameter: 190 mm