Bowl-Black painted brass, filler plug at side, two side expansion chambers and hemispherical glass bottom. Inside of bowl painted white, wire lubber line attached to side of bowl. Verge ring graduated to 360 degrees.
Card-Dia. 6.3" (16cm). Mica covered with white paper marked in black with Greek lettering, graduated quadrantally in degrees and to 360 degs. Attached to large unpainted float at centre.