Inventors · 1673 – 1751
George Graham
George Graham (1673–1751) was Thomas Tompion's apprentice and successor. He invented the deadbeat escapement and the mercury pendulum, which made precision clocks far more accurate, and he gave a young John Harrison the backing to start work on his sea clocks.
Key facts
| Lived | 1673 – 1751 |
|---|---|
| Where | London, England |
| Invented | Deadbeat escapement (c. 1715), mercury pendulum (1720s) |
| Buried | Westminster Abbey, with Tompion |
| Helped | John Harrison |
Making the pendulum precise
Graham trained under Tompion and took over the business. His deadbeat escapement stopped the small backward jerk of the hands in earlier clocks and gave the pendulum a much cleaner push, and his mercury pendulum automatically corrected for heat and cold, which otherwise make a pendulum longer or shorter. For more than a century, astronomers' regulator clocks were built on his ideas.
He was also a scientific instrument maker and a Fellow of the Royal Society, building quadrants and telescopes for observatories.
The loan that changed navigation
In 1730 an unknown carpenter from Lincolnshire, John Harrison, came to London with plans for a clock that could keep time at sea. The scientific establishment was skeptical. Graham listened for hours, was impressed, and lent Harrison money with no interest so he could build his first marine timekeeper. Without Graham, the solution to the longitude problem might have come much later.
Read more: The longitude problem (history chapter) · the full story of the watchmakers
Questions people ask
What is a deadbeat escapement?
A mechanism, invented by George Graham around 1715, that releases a clock's gears with almost no backward recoil, making pendulum clocks much more accurate.
How did George Graham help John Harrison?
He met Harrison in 1730, backed his idea for a sea clock, and lent him money to build his first one.
Sources
Last updated October 18, 2026. Found an error? Tell us.