Shortt-Synchronome free pendulum clock
Reloj de péndulo libre Shortt-Synchronome
- Date
- 1921 · confidence high
- Place
- Edinburgh, Scotland, United Kingdom
- Credited to
- William Hamilton Shortt and Frank Hope-Jones
- Field
- Knowledge & symbols
What it is
A clock with two pendulums, a 'free' one that swings almost undisturbed and a 'slave' one that synchronises it and drives the hands, with an error of one second a year. It was the most accurate mechanical clock ever made and the observatory standard from 1920 to 1940.
The first was installed at the Royal Observatory, Edinburgh, in 1921; about 100 units were sold before quartz displaced it. It was mounted in a constant-pressure chamber.
What it led to
- observatory time standards until quartz clocks
- detection of irregularities in Earth's rotation
- broadcasting of time signals from Greenwich