How the Atmos clock functions

Jaeger-LeCoultre's Atmos clock is a mechanical timepiece invented in 1928 that powers itself using minimal temperature fluctuations through a hermetically sealed capsule containing ethyl chloride gas. As the temperature changes, the gas expands or contracts, driving a mechanism that winds the clock—requiring no manual winding and allowing it to run for approximately two days on just a one-degree temperature change. The clock represents a remarkable engineering achievement that combines traditional craftsmanship with innovative technology and has remained virtually unchanged in construction since the early 1930s.