Inventors · 1629 – 1695
Christiaan Huygens
Christiaan Huygens (1629–1695), a Dutch mathematician and astronomer, built the first pendulum clock in 1656. It cut the error of the best clocks from about 15 minutes a day to around 15 seconds.
Key facts
| Lived | 1629 – 1695 |
|---|---|
| Where | The Hague, Netherlands |
| Invented | Pendulum clock (1656, patented 1657) |
| Also | Balance spring for watches (1675) |
| Clockmaker | Salomon Coster built his first clocks |
The swing that changed everything
Galileo had noticed decades earlier that a pendulum takes the same time for each swing, but he never finished a working clock. Huygens did. In 1656 he designed a clock regulated by a pendulum, and the Hague clockmaker Salomon Coster built it. It was so much more accurate than anything before that within a few years pendulum clocks spread across Europe, and many older clocks were converted.
Accuracy changed what clocks were for. For the first time it made sense to add a minute hand, and later a seconds hand, to everyday clocks.
Watches get a heartbeat
In 1675 Huygens designed a balance spring, a fine spiral spring that makes a watch's balance wheel swing at a steady rate. The English scientist Robert Hooke claimed he had the idea first, and the dispute was bitter, but the result was the same: pocket watches went from decorative to genuinely useful. Huygens also tried, and failed, to build a pendulum clock accurate enough at sea to find longitude, a problem John Harrison would solve a century later.
Read more: The mechanical clock (history chapter) · the full story of the watchmakers
Questions people ask
Who invented the pendulum clock?
Christiaan Huygens, in 1656. Salomon Coster built the first ones, and Huygens patented the design in 1657.
How accurate was the first pendulum clock?
About 15 seconds a day, compared with around 15 minutes for earlier clocks.
Sources
Last updated October 18, 2026. Found an error? Tell us.