Jaeger-LeCoultre Atmos

At first glance, Jaeger-LeCoultre's Atmos looks like any other table clock. However, the Atmos is incredibly unique: It's not powered by a battery, weights, or key winding, but rather by temperature changes in its immediate environment. Seeing as the clock is sensitive to dust, its ingenious technology is safely contained in a glass case. Jaeger-LeCoultre decided against adding a seconds hand in order to save energy.

In terms of price, most Atmos clocks cost under 10,000 euros. However, some cost more, such as the Atmos Réédition. This clock, first produced in the 1930s, has a historic design with a large, round glass bell jar supported by a steel platform; it is available for 20,000 euros. Even more expensive are the blue crystal Atmos models designed by the Australian designer Marc Newson. Only 28 clocks (reference number Q5165103) were produced, and their price reflects their rarity: They cost around 100,000 euros.

Most Atmos models have conservative designs with metal pieces made of gold-plated brass. You can purchase one of these clocks in good or very good condition for 2,000 euros. The Classique version (reference number 5101202) has a dial featuring Roman numerals and is available for around 5,000 euros. The Jaeger-LeCoultre Atmos Classique is 22.5 cm tall, 20 cm wide, and has a depth of 15.5 cm. In addition to the gold versions, there are also silver-gray versions made of rhodinized brass.

The Marina version (costing around 4,000 euros) is in a solid case and features maritime imagery such as ships, fish, and water plants. You can find a special model of this version, the China Aquarium, under reference number 5806.

Seeing as most complications require massive amounts of energy, Jaeger-LeCoultre forwent extras on the Atmos in favor of a smoothly running clock. One exception is the version with a moon phase display at the six o'clock position; it costs around 6,500 euros.

The Swiss engineer Jean-Léon Reutter (1899-1971) invented the Atmos in 1928. Jaeger-LeCoultre bought the patent shortly thereafter. The company has more or less kept the design of the atmospheric clock consistent since 1945. From a physics point of view, the Atmos is a heat engine; for Swiss state guests, on the other hand, it's a gift. The Swiss government gives its official visitors an Atmos clock as a lasting memory and symbol of the Swiss people's special watchmaking skills.

The Atmos runs even more precisely than the chronometer norm established for wristwatches . Usually, the clock deviates from the reference time by about one minute each month. When regulated even more precisely, it's possible that the clock will deviate by only 30 seconds per month. This is an astounding value considering the pendulum only undergoes 120 alternations per hour. In comparison, the balance wheel of a modern wristwatch vibrates at 28,800 alternations per hour. The Atmos's pendulum is supported by a suspension wire made of Elinvar, a material that is resistant to temperature changes – an important characteristic for this clock.