Card-Mica covered with paper, white with black markings, graduated to 1/4 points and quadrantally in degrees.
Needle- One heavy flat bar needle 6.5" long, with expanded centre to accommodate pivot, fitted with two brass sliding weights. A brass bar 6.5" long is fitted E-W, also with expanded centre and brass sliding weights. All attached to a metal ring 6" dia. which is screwed to card.
Pivot- Cone-shaped pivot cap, with jewel at top screwed through centre of needle. A heavy brass bell-shaped weight 1.6" deep is attached to needle below pivot, on a collar secured to needle by brass knee pieces. The weight is screwed onto the collar.