The Value Proposition: The Amazing, Incredible, And Semi-Affordable Atmos Clock From Jaeger-LeCoultre

June 11, 2015

As the current new guy at HODINKEE, it gives me no small pleasure to introduce C I should say, re-introduce C an old reader favorite: The Value Proposition. Its been on hiatus for some time but youve asked us repeatedly to bring it back, and we listened.In Value Proposition we bring you a look at some of horologys biggest and best bang-for-the-buck C timepieces that, in a world where price increases have for over a decade shut more and more out of enjoying mechanical horology, really over deliver in the value department. In general this means things in the under $10,000 category but at the same time, you might see us occasionally cover something like, say, a $15,000 minute repeater that sounds as nice as a $300,000 chiming complication, which seems unlikely, but hey, if it exists, youll read about it here first.Today, lets talk about the Atmos clock, from Jaeger-LeCoultre. The Atmos is nothing more nor less than one of the absolute coolest horological contrivances you can place on your desk at any price, and its always been a mystery to me why more serious mechanical horology fans dont have one. The Atmos is a clock that has no external power source, and never needs to be wound by hand, nor is it powered (as most pendulum clocks are) by a suspended weight. Instead, the Atmos clock gets its power from minute changes in atmospheric temperature (hence the name). The Atmos Marquetrie Le Baiser Clock Heres how it works: inside every Atmos clock is a capsule filled with ethylene chloride gas. As temperature rises and falls, the gas expands or contracts, making the capsule expand or contract in turn. The wall of the capsule is connected to a short chain, which moves back and forth as the capsule grows or shrinks, and this reciprocating motion is used to wind the mainspring. The Atmos 566 Blue Clock, designed by Marc Newson The reason for using ethylene chloride is that it starts to evaporate at about 54 degrees Fahrenheit, which means the sweet spot for maximum volume change in response to temperature is right smack in the middle of the most likely indoor ambient temperatures. ?(As it happens it is also an intoxicant C a mild central nervous system depressant, in fact C but if you are cracking open your Atmos clock in search of a, shall we say, relaxing interlude you probably dont deserve one.) In that temp range, the Atmos converts thermal variations into mechanical energy efficiently enough that left to its own devices, the clock will run essentially indefinitely. The first Atmos clock was designed by one Jean-Lon Reutter, who started making them in 1928 (there were earlier clocks made that used temp changes for power but they used bimetallic strips C of brass/steel C that flex back and forth as temp changes; this is the same principle behind compensating balances and for that matter, mechanical thermostats). The Atmos RED Clock designed by Sir Jonathan Ive and Marc Newson; we went hands on with it in 2013. In order to conserve energy, the absolutely huge balance only swings twice per minute; its suspended from an Elinvar wire (Elinvar is a nickel-steel alloy that exhibits minimal changes in elasticity when temperature changes, and its essential here because if you used a steel wire, youd see pretty wide swings in accuracy as temperature changed). A slowly twisting wire used to produce isochronal oscillations in a clock is known as a torsion pendulum. The Atmos converts thermal variations into mechanical energy efficiently enough that left to its own devices, the clock will run essentially indefinitely (the mechanism's so efficient that a one degree change in temp provides enough juice for 48 hours' run time). The Atmos Hybris Artistica Marquetrie As you can see this is pretty incredibly ingenious and if you have the ability to be thrilled to the core by clever mechanical engineering (and we presume you do or you wouldnt be here) you probably want one already.?Thats the proposition, ready for the value? The Atmos Classique Clock The good news is that relative to the amount of interest and beauty you get, an Atmos clock is almost unbelievably affordable. Now, dont get me wrong C Jaeger-LeCoultre does make some incredibly expensive Atmos clocks that are also superb, unique works of art. For instance, you can, if youre inclined, get yourself a stunning marquetry-cased Atmos clock, with a motif after the famous painting The Kiss, by Gustav Klimt, for $242,000 (this is actually still available and if you want one, call up Jaeger-LeCoultre and tell 'em Hodinkee sent you). You can get one designed by the internationally renowned Marc Newson, for a bit less C about $129,000.But you can also C hold onto your socks C get a stunning moonphase Atmos clock in your choice of one of three finishes for $8,800, fresh from the boutique: the Atmos Classique Moonphase. If a moonphase is a little too darned lyrical for you (you stubborn pragmatist, you) you can get the Classique for even less: $7650. We wouldn't lie to you. (Pre-owned, theyre even less but buyer beware: these clocks need to be moved and handled carefully and theres an excellent chance of getting a lemon if you dont know what you are about.) Atmos Classique Phases de Lune, stainless steel Yes, boys and girls, for less than you could easily spend on any number of thoughtlessly designed, carelessly executed, and listlessly marketed watches whose most efficient aspect is how quickly they separate a fool from his money, you could instead get one of the most intriguing, clever, and flat out beautiful pieces of horological artistry ever to come down the pike. You cant wear it on your wrist? ?Please C theres more to life than showing off. Just get an embroidered bracelet that says My other timepiece is an Atmos.We said up top that an Atmos can run "essentially indefinitely" but that's a bit of poetic license; in fact, Jaeger LeCoultre tells us they recommend a 10-15 year service interval depending on climate (generally a hotter and more humid climate will necessitate a shorter interval between services) which can be done either by a qualified local clockmaker, or the manufacture in Le Sentier. --Ed. (updated June 14, 2015.) Shop this story Visit Hodinkee affiliate Crown & Caliber to shop pre-owned Jaeger-LeCoultre models