The clock which runs off air

July 20, 2014
‘Complication’ has been the buzzword in the horology world for the last year or so. Seemingly the greater the technology in a timepiece, the better it must be. But as is so often the case with timeless style, less can be more. Nowhere else does that statement ring more true than in Jaeger-LeCoultre’s Atmos clock. Incredibly, this unique piece of craftsmanship does not require a battery nor manual winding, and it uses just a 240th part of the energy required by an ordinary wristwatch. It’s secret is a hermetically sealed capsule containing a mixture of gaseous and liquid ethyl chloride, which feeds off variations in temperature to power the iconic timepiece. It quite literally runs off air. [gallery link="none" ids="5926,5925"] When the temperature rises a spiral spring is compressed, which then relaxes when the temperature drops; this motion constantly winds the mainspring. A temperature change of just one degree is enough to power the clock for 48 hours. It also relies on the movements functioning without lubricant, to ensure no energy is wasted. And it most certainly achieves that objective: it would take 60 million Atmos clocks to equal the energy consumption of a single 15-watt electric light bulb. Invented in 1928, the Atmos clock is a real work of horological genius. It works in near-perpetual movement, telling the time unaided for centuries. The latest model and third variation is the Classique Phases de Lune, which comes in a pink gilt cabinet, yellow gilt or rhodium. Details: visit