2025 marks the 350th anniversary of the publication of Christiaan Huygens' design for the regulating balance spring. In 1675, this Dutch scientist changed the course of watchmaking history by revealing to the world a spiral spring capable of reconciling the precision and transportability of timepieces.

The exhibition presented by the Musée international d'horlogerie and Stichting Haegsche Tijd explores the origins, developments and various applications of this invention. It highlights how the balance-spring laid the foundations of modern watchmaking, and how it became a strategic component of the watch industry.

The exhibition highlights a remarkable horological heritage by bringing together rare objects, industrial tools, and unpublished archives that illustrate the evolution of this key invention. Major historical pieces are often shown for the first time in Switzerland, such as one of the oldest known table clocks by The Hague clockmaker Salomon Coster (1657) or Isaac Thuret’s spiral clock (shortly after 1675) from The Planetarium Zuylenburgh Collection. From the 1675 Journal des Sçavans featuring the first published spiral drawing, to 21st-century silicon experiments and Charles-Édouard Guillaume’s Nobel-winning alloys, the exhibition showcases the innovations that refined the balance-spring.

Yet the balance-spring is not without its limits. Craftsmen and engineers have been striving to improve its properties for centuries through incremental innovation. Today, other options are being explored. Will they put an end to the hairspring's centuries-old hegemony?

Exhibition extended until 2 november