Bowl- Brass, has a lead balancing weight secured to underside. Inside of bowl painted white, has two lubber lines painted white on metal strips, one of these being operated by a screw, to act as a card stop. An elaborate azimuth device is fitted to verge ring. Consists of two vanes carrying a telescope in U sockets; a prism and a sighting wire on the opposite vane. The prism is adjustable, vertically, for focussing and the sockets carrying the telescope are also adjustable; one vertically and the other horizontally by means of tangent screws. The telescope has a central wire for aligning an object. Mounted in a gimbal ring which is fitted with roller bearings. Attached to a bracket which revolves on a centre pin at the bottom. The whole mounted in wooden box 13.75" x 13.75" x 6.25" (34.9 x 34.8 x 15.9cm) whcih has three wooden brackets hinged on screws fitted in the bottom of box for locking the bowl.
Card- Diameter 8.15" (20.6cm) Mica covered with paper, white with black markings graduated quadrantally in degrees. At centre of card is a hole 1.75" (4.5cm) to accommodate pivot. Underside of card ahs lead balancing weights at N & W points secured by gummed paper.
Needle- Four needles of circular section attached to card by two wooden bridges and gummed
paper.
Pivot- Inverted type. A brass bridge attached to centre carries a steel pivot pin. A lyre-shaped bracket secured to bottom of bowl carries the jewel cap which is mounted in double gimbals and which has a heavy pendulous weight.
O.A. height 13" 33cm