Bowl-Copper with a brass verge ring. the bottom of the bowl is concave on its under surface; a brass ball is attached at the centre. Inside of bowl painted white with a black lubber line painted on side.
Tripod-Brass circular plate 10" (25.4cm) dia.from which a hollow cone projects 4" (10.2cm) and at the top is an aperture 1.5" (3.8cm) dia. The brass ball at base of bowl rests in the aperture in the cone, which is shaped to ensure free action. A brass rod 15" (38.1cm) long is screwed into the brass ball; this passes through the cone and carries a heavy pendulum weight. Mounted on brass tripod legs 36" (91.5cm) long. Movement of the bowl in azimuth is prevented by a projecting fin in the hole of the cone, working in a slot cut in the base.
Card-Dia. 7.5" (19cm) Mica covered with paper, blue with white markings, graduated to 1/4 points and quadrantally in degrees.
O.A.Height 41.5" (105.4cm)