Card -Mica covered with paper, white with black markings, graduated to 1/4 points. Has decorated E point. At centre of card is a hole 1" dia. to accommodate pivot gimbal.
Needle-Heavy bar edge needle, 6.3" long 0.3" deep. Has expanded centre providing a hole 1" dia. Fitted with two brass sliding weights. Two brass crossbars are fitted, 2.4" long in an E-W direction are on each side of needle, the E crossbar carries a sliding weight. Needle and crossbars are screwed to card.
Pivot- Cone-shaped brass pivot cap mounted in double gimbals, gimbals attached by brass knee pieces to needle.