Jaeger-LeCoultre Atmos watch

Atmos JAEGER-LECOULTRE watch.
Bronze and glass.
In working order.
With its case.
Measurements: 22,5 x 18 x 13,5 cm.

The Atmos table clock of the Swiss firm Jaeger-LeCoultre is a luxury piece of extraordinary precision and quality. Its open structure invites you to study its mechanism to understand its secret. Made in bronze, it has a round white dial with bronze profile, Breguet hands and Roman numerals. The particularity of this watch lies in the fact that it works by taking energy from changes in ambient temperature and atmospheric pressure, so that it can run for years without human intervention. Its energy source is a hermetically sealed capsule containing a mixture of chloroethane gas and liquid, which expands in an expansion chamber when the temperature rises, compressing a coiled spring. When the temperature drops, the gas condenses and the spring decompresses. This constant motion coils the mainspring. A single degree of temperature variation (in the range of 15 to 30°C) or a pressure variation of 3 mmHg is enough to keep the watch operational for two days. The little added energy needed for its operation requires the mechanism to work with the least possible amount of friction, hence a torsion pendulum is used as a regulating mechanism, which consumes less energy than the ordinary pendulum, since it oscillates only twice a minute (1/60th of the number of oscillations of a conventional pendulum clock).