Dry compass

Card-Mica covered with paper, blue with blue and black markings, graduated to 1/4 points and quadrantally in degrees. At centre of card is 3" dia. hole.
Needle- Four light edge bar needles composed of one thin strip of steel, 2 x 7.25" and 2 x 5.25" long, all 0.6" deep. The upper edges of the needles are slightly rounded in concave fashion which reduces their depth to 0.25" at centre. All attached to a light metal ring which is screwed to card.
Pivot Cone-shaped brass pivot cap with jewel at top screwed through centre of light framework consisting of two short arms secured to the two inner needles and two long arms secured to the metal ring of card.

Object Details

ID: ACO0993
Type: Dry compass
Display location: Not on display
Creator: Creak, E. W.
Date made: 1885
Credit: National Maritime Museum, Greenwich, London, Admiralty Compass Observatory
Measurements: Overall: 25 mm; Diameter: 192 mm