Our Neptune range instruments have chunky cast brass casings, 5" in diameter and either lacquered or chrome plated, with bevelled glass fronts. They can either be screwed to a wall or bulkhead or mounted on a choice of mahogany or black-stained hardwood plinths for desktop use. Clocks are quartz movement, requiring 1xAA battery. Barometers have aneroid movements and show pressure in inches and millibars. Single display plinths are 6" wide, double display plinths are 12" wide, and overall height is 7".
Quartz Movement
Quartz (silicon dioxide) crystals possess the remarkable property of oscillating at a very regular and predictable frequency when subjected to an electrical current. The first commercially available clocks to exploit this appeared in the late 1920s, and went on to supersede mechanical movements thanks to their accuracy and reduced need for maintenance.
