Bowl- White metal painted black. Glazed. White on inside. Expansion chamber at bottom. Verge graduated in white to four points and 360 degrees in 10 deg sections. Has parallel wires across glass, also white and black arrow across glass. Bowl can be turned in azimuth by screw.
Card- Spider with four arms, cross at N point. N-S arms painted black, E & w painted white. Bent at ends to increase damper effect. Dome at centre.
Needles- Two needles slung beneath card.
Dimensions: 21" x 16" x 12" (53.2cm x 40.2cm x 30.5cm)

Pivot- Unsighted