Leonardo da Vinci may have been able to demonstrate the physical impossibility of constructing a perpetual motion machine, but that hasn’t stopped people from continually trying to do so. In 1928, for example, a Neuchatel engineer called Jean-Leon Reutter built a clock driven quite literally by air. It took the Jaeger-LeCoultre workshop a few more years to convert this idea into a technical form that could be patented, and to perfect it to such a degree that the Atmos practically achieved perpetual motion. The technical principle is a beguiling one: a hermetically sealed capsule is filled with a gas which expands as the temperature rises and contracts as it falls, making the capsule move like a concertina. This motion constantly winds up the mainspring, a variation in temperature of only one degree in the range between 15 and 30 degrees centigrade being sufficient for two days’ operation. To convert this small amount of energy into motion, everything inside the Atmos naturally has to work as smoothly and quietly as possible.
The balance, for example, executes only two torsional semi-oscillations per minute, which is 60 times slower than the pendulum in a conventional clock. So it is not surprising that 60 million Atmos clocks together consume no more energy than one 15-watt light bulb. All its other parts, too, are not only of the highest precision. Admirers of advanced technology, however, are not the only ones who get their money’s worth.
Connoisseurs of elegant forms, precious materials and traditional craftsmanship do so as well, because every Atmos is still made entirely by hand. With some models a single clock takes a whole month to produce, not counting the five weeks of trial and adjustment that every Atmos has to undergo. Only then are Jaeger-LeCoultre master-watchmakers satisfied enough to authenticate an Atmos clock with a signature and allow another one to leave the workshop.
Subsequently, many end up in the very best of homes, because for decades the world’s most celebrated watchmaking country has been presenting its distinguished guest with this masterpiece of Swiss artistry. The Atmos has had the honour of associating with great statesmen, royalty, and other renowned people including President John F. Kennedy, Sir Winston Churchill, General de Gaulle and Charlie Chaplin.