Since its introduction in the early twenties, the Atmos Clock became pretty soon world famous and the clock was even able to capture a place on the desks of renowned people like Sir Winston Churchill, John F. Kennedy and General Charles DeGaulle, to name a few. But the mysterious Atmos clock also won the hearts of many watch collectors around the globe. And…..honestly I really do not know one single person, that’s seriously interested in watches, that does’nt own- or would’nt love to own, a new or vintage Atmos clock. The fondness for this clock, among watch collectors, probably arose because of its long and exiting history, its magic way of working and of course also because it is produced by the highly regarded brand, that also gave us the famous Reverso- and Memovox (alarm) watch; Jaeger-LeCoultre.

The history of the Atmos clock is huge, very detailed and complex, actually impossible to describe well, in two or three posts and it won’t do justice to what this clock is all about either, but I will try to give an idea, in three short articles, of what the clock is and what the charm is, to make clear why this clock is so popular among watch collectors.

The concept of the clock dates back to 1927/1928, when the in France living Jean-Léon Reutter, designed the first prototype. Reutter was engaged as a radiological engineer by the Company Generale de Radiologie and he presented his invention to the directors, who were very exited about his concept.
The Company Generale de Radiologie, started in 1929 a workshop to manufacture the Atmos Clock and Jean-Léon Reutter, the ‘father and creator’ of the clock, was appointed as manager of this first little ‘Atmos Manufacture’. But three years later LeCoultre (now Jaeger-LeCoultre) and The Company Generale de Radio (CGR) signed contracts, that LeCoultre would produce the movements for CGR. LeCoultre however was also very interested to turn this special timepiece, into their own clock and to add it to their own collection of watches and clocks. And so it happened that in 1935 both companies came to an official agreement, to transfer all rights, production and remaining stock, to the Manufacture of LeCoulte. It took LeCoultre however another few years, to finalise the concept, solve some technical problems and to get it into a visual shape, that could finally be patented. Later on it it proved to be a very good and lucrative move, since 50.000th Atmos clock had left the factory in 1952, half a century after the first patent was filled.

The pre Atmos clocks produced by Reutter, had just the name Atmos on the dial. As soon as the clocks were produced by LeCoultre, they were labeled under their own name, including the word Atmos. Engraved in the movement and later on also silk screened on the glass.


The working principle of the clock is actually not thát complicated and the many Atmos clocks that are still around, all over the world have proven that they are pretty accurate and are able to run without problems, for many years.


Basically the Atmos is a clock that works fully ‘automatic’, or should I say that the clock works independently?
Since we know from an ‘automatic’ watch that it needs to be winded, to be able to start. Not so for the Atmos, since it actually runs on air and to be more precisely, on the temperature differences in your room or office. A hermetically closed capsule contains a gaseous mixture that expands when the temperature rises and shrinks when the temperature drops one or two degrees. When the capsule swells it winds the clock movement. A temperature fluctuation of just one or two degrees is more than enough to let the clock run for about two to four days.
All the components of the Atmos clock are incredibly precise and dependable, to let the caliber operate almost without any wear.

When I, last month, visited one of the largest Atmos clocks collections I have ever seen,
the ‘Van Brug Collections‘ in the Netherlands, I did not only see many of the different clocks produced by LeCoultre, in the forties and fifties,

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I also discovered, in the line up of about 50 different Atmos clocks, the impressive Jean Léon Reutter clocks, from around 1933/1934, that I had never seen in the flesh before, like the Model PO1, the amazing clocks under that bell jar, made ​​of glass. Jaeger-LeCoultre did recently two absolute cool re-issues of the 1930 and the 1934 model, that are in their current collection.
I’ll come to the current collection later, in Part Three.

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While these about 80 years old clocks, under their mysterious glass dome, look impeccable, impressive and if just landed from Mars, my heart skipped a beat when I discovered a table clock in a closed steel housing, from the same period, that I had never seen in the flesh before, nor in books or publications.

I was so impressed by the appearance of this clock, that I’ll keep it for part two, that you can find HERE
Besides that, it would make this post a bit too long.
So stay tuned!

With the kind and generous help by John Hubby, Director at the National Association of Watch and Clock Collectors from 2001 to 2011, serving as Chair of the Board of Directors for the last two years of his term and currently the Principal Administrator of the NAWCC Message Board, one of the largest and most active horological sites on the Internet that is dedicated purely to education of NAWCC members and the general public.