Bowl: Black painted brass, expansion chamber at base, two filler plugs at side. Inside of bowl painted white, with black lubber pointer extending from side of bowl to edge of card. Black painted brass verge ring has two fixing holes for mounting prism on the side nearest to the observer. Bowl is housed in black painted brass gimbal mounting 9.0" (22.9cm) dia with roller bearing gimbals. Three hooked brackets are fitted to gimbal ring for securing the brass domed cover. Large prism in anodised metal case, hinged at base, with brass operating lever at side.
Card: 5" (12.7cm) dia mica, painted white with black markings, graduated to 16 points and quadrantally in degrees. Degree figures are reversed for reading through prism. Card is attached at centre to special "cistern" type float.
Needle: Unsighted.
Pivot: Unsighted.
In fitted oak box 11" x 11" x 11 " (28.0 x 28.0 x 28.0 cm) containing expansion nut and fitted with leather securing strap.