Bowl- Copper with lead balancing ring secured inside. It is fitted with a glass bottom and a glass aperture 2.5" x 1.5" (6.4 x 3.8cm) is fitted on one side for illuminating card by a lamp.Inside of bowl painted white. The verge ring is pierced with four holes for attaching azimuth sight (missing). The lubber line consists of a silk thread stretching across the under surface of verge glass. Mounted on wooden stand by two metal brackets. Dims. 11" x7.5" x 0.75" (27.9 x 19.0 x 1.9cm)
Card- Diameter 6.8" (17.5cm) Mica covered with paper, white with black markings graduated to half points and quadrantally in degrees. At centre of card is a hole 1" (2.6cm) diameter to accommodate pivot arrangement.
Needle- Edge bar-type 6.8" (17.5cm) long with a semi-circular "rise" at centre carrying steel inverted pivot point.
Pivot- Pivot stem consists of a hollow pillar rising from a cross-bar at bottom of bowl. The part carrying the jewel fits into pillar.