Bowl-Grey painted brass, filler plug at side, expansion chamber at base. Base carries a metal cover in which an electric lamp is fitted. Inside of bowl painted white with two black wire lubber lines mounted 180 degs apart attached to side of bowl. Mounted in black painted brass gimbal ring 7" (17.8cm) diameter.
Card-Diameter 4.5" (11.5cm) metal painted white with perforated graduations. Graduated to 360 degs. Attached by four metal struts to white painted float at centre.
Pivot- Mainly unsighted but a bridge can be seen mounted across base of bowl, to carry pivot stem.