Liquid compass - aircraft

Liquid compass
Bowl: White metal painted black. Fill hole on side. Azimuth circle. Expansion chamber beneath bowl. Bowl rests on spring plate. Has four steadying arms at side. White inside with black lubber spike. Glazed.
Card: Thin strip of paper with hollow centre. Domed float at centre with radiating arms. Eight damper arms are attached to strip. Strip in white with black markings graduated to 4 cardinal points and 0-360 degrees.
Needle: Four needles in tubes slung beneath card on a framework.
Pivot: Unsighted
Azimuth Circle: Has knob for moving circle. Has adjustable prismatic sights with V and Nipple line up, also a hinged jet reflector. Two hinged filters. Across circle is hollow arch and wire sight with bubble level and nipple. This can be sen in prism and used as sighting line.
O.A. height 7" (17.8cm)

Object Details

ID: ACO0343
Type: Liquid compass - aircraft
Display location: Not on display
Creator: Air Ministry
Date made: 1923
Credit: National Maritime Museum, Greenwich, London, Admiralty Compass Observatory
Measurements: Overall: 150 mm; Diameter: 135 mm
Parts: Liquid compass - aircraft