Bowl- Black painted brass with heavy weight around base. A card lifter mechanism is fitted to side of bowl, operating a brass collar on pivot stem. Inside of bowl painted white. At centre of verge glass a socket is fitted to accommodate the deflecting apparatus. This consists of a circular brass base with two silvered brass vertical arms 13" (33cm) long, both graduated. A sliding brass frame carrying four 2.6" (6.5cm) magnets of square section is fitted on the arms. It can be raised or lowered by a rack operated wheel and pinion. Mounted in a black painted brass gimbal ring 10.25" (26cm) diameter.
Card- Diameter 5.25" (13.3cm) mica, painted white with black markings, graduated to 360 degs. Centre of card has a hole 2.25" (5.8cm) diameter, in which the pivot cup is mounted on an aluminium framework. Two ivory strips are mounted on an aluminium framework over the hole, either side of pivot, the carrying black lines to be used for measuring dip.
Needle- Two 2.75" (7cm) needles of circular section mounted in an aluminium framework, mounted above card.
Pivot- Brass stem secured to base of bowl, carries a steel pivot point which engages in jewelled cup at centre of card.