The London Polaris

Consists of a silvered brass bearing plate 8" (20.3cm) dia., graduated quadrantally in degrees, by semi-circles 0-180-0-180, and to 1/4 points. At the centre of the bearing plate there is a vertical shaft carrying a dial, graduated by semi-circles 0-180, 0-180 and in hours, which can be tilted to latitude against a scale on the semi-circle underneath. Hinged sights are fitted to an alidade pivoted at the centre of the dial. One of the vanes carries crosswires, and the other a curved plate with crossed slits. Mounted in a brass gimbal ring 8.5" (21.6cm) dia. which carries a scribed lubber mark. Mounted in wooden box with lid fitted with a clinometer on one side and a leather carrying strap. The lid has the remains of a label with the heading 'The London Polaris' and the name of the nautical instrument makers Heath and Company Limited.