The Jaeger-LeCoultre Atmos clock
Engineering that has inspired generation after generation
The optimal operating temperature of the Jaeger-LeCoultre Atmos is between 15 and 30 degrees Celsius. If the temperature increases or decreases by just 1 Kelvin, the gas expands or contracts correspondingly. The energy gained is stored away efficiently in a mechanical spring, thus creating a power reserve of up to 48 hours. As the mechanism is so sensitive, it's important to keep the Jaeger-LeCoultre Atmos in a room with a stable temperature.
Since the gas mixture only generates a relatively low amount of drive energy, the Jaeger-LeCoultre Atmos is designed to operate with only a limited number of parts. The movement has to be kept under glass in order to protect the sensitive movement from dust. This is because even tiny particles can cause friction which could affect its accuracy. In this way the the Jaeger-LeCoultre Atmos clock maintains a precision of 30 seconds to 1 minute per month.
Due to their low drive energy, Atmos table clocks can only achieve a slow rotation. For this reason, they don't have a second hand or chimes. However, a moon phase display is an option, as in the Jaeger-LeCoultre Atmos Classique Phases de lune.