Bowl-Black painted brass, with a patent bubble trap and filler plug at base. A lead weight is also fitted to base. Inside of bowl painted white with four black painted lubber lines 90 degs apart, painted on side. Mounted in gimbal ring 6.5" (16.5cm) dia. which acts in one direction only and which is attached to outer casing by eliptical springs. Outer casing, brass 7" (17.8cm) dia.
Card-Dia. 4" (10.2cm) White painted mica (?) of floatless type, with black markings, graduated to 360 degs. Attached by four wire struts to pivot at centre. Above pivot are four curved metal struts which curve upwards towards verge glass, to prevent card lifting off pivots.
Needle-Two needles of circular section 2" (5.1cm) long, mounted below card.
Pivot-Jewelled pivot cap carried at centre of card engages on pivot stem secured at base of bowl.