Atmos table clock; JAEGER LE COULTURE, Switzerland, c. 1990.

Atmos table clock; JAEGER LE COULTURE, Switzerland, c. 1990.
Brass.
Shows slight signs of wear.
Measurements: 22 x 18 x 13.5 cm.
The Atmos model by Jaeger-LeCoultre is much more than just a table clock; it has become an icon of 20th-century Swiss watchmaking. Its distinctive open case, crafted from bronze, allows the mechanism to be viewed. Its white circular dial, framed in bronze, combines Roman numerals and Breguet-style hands, lending the piece a classic and elegant aesthetic. However, its true appeal lies within: the Atmos is capable of operating virtually autonomously, without the need for manual winding or a battery, by harnessing small variations in atmospheric temperature and pressure.
This ingenious system relies on a hermetically sealed capsule containing chloroethane, whose expansion and contraction in response to temperature changes drives a mechanism that keeps the mainspring wound. A variation of just one degree Celsius, between 15 and 30 °C, can provide approximately two days of operation. Even small variations in atmospheric pressure help power the mechanism. The Atmos’s extreme energy efficiency requires minimizing any energy loss. For this reason, it incorporates a torsion pendulum, which oscillates only twice per minute, compared to the numerous oscillations of a conventional pendulum watch. The result is an extraordinarily delicate and silent mechanism, capable of transforming nearly imperceptible changes in the environment into energy for timekeeping.
Originally conceived by engineer Jean-Léon Reutter and later developed by Jaeger-LeCoultre, the Atmos has become a true icon of Swiss watchmaking. Founded in 1833 in Le Sentier, Switzerland, Jaeger-LeCoultre is one of the great manufacturers of Swiss fine watchmaking.