Atmos table clock by Jaeger Le Coultre, Rose Gold plated Classic model. 

Ø cm 16 Ø cm 23,5 h cm 20

The Atmos is a perpetual motion clock, the functioning of which was conceived by Jean-Lèon Reutter in 1928, with the Atmos 0 model. The first version involved the use of a mixture of mercury and ammonia which, expanding when subjected to changes in temperature, activated the movement cylinder of the mechanism in the watch.

In 1935 Jaeger Le Coultre acquired the rights to Atmos and patented a new version, the Classic Model (Atmos 2), inventing a new method of recharging which involves the use of a bellows containing chloroethane, a gas very sensitive to temperature variations . 

The temperature variations cause the gas to expand and contract, with a consequent "accordion" motion of a membrane, which in turn is connected to the mainspring, generating perpetual motion. 

Atmos is a legendary clock, and is currently one of the main gifts of the Swiss confederation.