Temperature-compensated pendulum
Péndulo compensado por temperatura
- Date
- 1721-1726 · confidence medium
- Place
- London, England, United Kingdom
- Credited to
- George Graham and John Harrison
- Field
- Knowledge & symbols
What it is
Pendulums whose effective length does not change with temperature: Graham uses mercury in the bob and Harrison a gridiron of rods of two metals. It reduces the daily error of clocks from a few seconds to tenths of a second.
Graham presented the mercury pendulum to the Royal Society in 1726 after trying it from 1721; Harrison devised the gridiron around 1726 and also used it in his clocks.
What it led to
- observatory clocks with an error under a second a day
- the precise time system of observatories