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Jean-Léon Reutter did not discover perpetual motion when he created the Atmos.

The Atmos, the other Jaeger-LeCoultre icon


Atmos L.A.C. Around 1934

Perpetual motion is - to quote the definition coined by Webster, a physician who lived at the beginning of the 20th century - the "movement of a mechanism which could continue to function indefinitely without drawing energy from an external source". The quest for perpetual motion constitutes one of mankind's grandest aspirations, the genuine Holy Grail of inventors and scientists alike from all ages. Truth to tell, as Leonardo da Vinci demonstrated in the 16th century, perpetual motion is basically a fantasy because it defies the laws of classical physics. In particular, the fundamental law of thermodynamics that was formulated by Lavoisier in the 18th century, according to which "nothing is created, nothing is lost, everything is transformed".

In spite of that, its apparent impossibility has never quite succeeded in discouraging the most determined idealists. Numerous watchmakers fall into this category. For good reason, too, since this mechanism clearly applied to watch-making. Jean-Léon Reutter (1899-1971) was undoubtedly both idealistic, and determined. This Swiss engineer was born in Neuchâtel and dedicated his life to researching perpetual motion. At the age of 14, he was already designing his first perpetual clock in his exercise books. Leaving nothing to chance, he studied at the École polytechnique fédérale in Zurich and then at the École supérieure d'électricité in Paris. In 1928, he presented his first prototype for a revolutionary clock with a complex system capable of drawing energy from atmospheric pressure changes, hence its name, Atmos. In inventing Atmos, Jean-Léon Reutter did not discover perpetual motion - and he never claimed to have done so, either - but his mechanism came very close as it was able to function, theoretically speaking, for an unlimited length of time with the help of an almost non-existent quantity of energy and without any human intervention whatsoever.


Atmos Type moderne, 1935

When this invention was made public, shock waves ran through the scientific world and the press reacted with enthusiasm. More than a hundred articles were published over four months in European, American and even South African newspapers. However, as the historian François Jéquier reminds us, "Inventing is one thing. Manufacturing, mass producing and marketing do not flow from the same source." Indeed, manufacturing the Atmos, albeit in limited amounts, proved extremely difficult. Reutter simplified the winding system; he enclosed a mixture of mercury and ammonia in a U-shaped glass tube. One end of the tube was thermally insulated and the other was not. Consequently, a change in the ambient temperature would make the gas expand, and, together with the weight of the mercury, cause the tube to rotate, which in turn wound the clock.

In 1930, the Atmos was introduced onto the market, supported by its first publicity campaign. However, Reutter had set about this task too quickly. His clocks did not live up to expectations, until the day when Jacques-David LeCoultre happened to spot one of his clocks in the window of a Paris watchmaker. He had heard about the Atmos but had always had reservations, being aware of how difficult it was to manufacture. Out of curiosity, he bought the model in the window, examined it, and identified its positive and negative points. Growing more interested, he contacted the inventor and suggested some solutions. With the result that, in 1932, the watchmakers of the 'Grande Maison' began working alongside Reutter on an in-depth study of the Atmos.


Atmos Marqueterie du millénaire

Atmos 1988

The most ingenious aspect of the system is due to its extreme simplicity. At a temperature of between 15°C and 30°C, the variation of a single degree is enough to ensure that it functions autonomously for two days. To enable such a feat to be performed, the clock must work with an almost total absence of friction and in a totally stabile environment. Its balance turns extremely slowly. It oscillates only once a minute, i.e. 60 times less than a classic clock, or 14,400 times less than a wristwatch! It is suspended on a very long thread which is very flat and highly delicate, and fixed to the top of the clock. The torsion of this thread is enough to hold and then pull the balance successively in one direction and then the other. Without this thread, nothing would be possible. Made from an alloy that does not react to temperature change, and was invented by Charles-Édouard Guillaume, the Swiss physicist who was awarded the Nobel Prize for Physics, the thread is produced artificially at the Manufacture, using a secret process. In terms of supplies, it takes about 6 years to secure enough metal of a suitable quality for producing it. That is why it is stored in a safe, inside a bank.



The result is extraordinary. 60 million Atmos do not consume as much energy as a single 15 Watt light bulb! The mechanism is so perfect that the wheel-work does not have to be oiled. Furthermore, the oil would age too quickly as the Atmos is designed to run for more than a thousand years.

The specialists in the Manufacture have never stopped developing ways of improving the Atmos. In 1990, when it still seemed impossible to introduce a further complication, given it has so very little energy, they met this new challenge by creating the Atmos Vendôme which displays moon phases. Since then, further innovative improvements have followed. This means that the Atmos range today has never been so complete. Atmos classiques, Atmos régulateurs, Atmos du millénaire, Atmos marqueterie, and the ultimate model, the Atmos mystérieuse. The family of classic Atmos perpetuates the timeless aesthetics of the models that were designed in the 1940s which have virtually remained unchanged since then. Their charm has endured throughout the decades as they are designed in accordance with the principles of balance, symmetry and purity. Their glass walls are framed by rhodium or golden posts, in perfect harmony with the base.



Atmos régulateur phases de lune

The simple version, Jaeger-LeCoultre 562 calibre, which displays the hours and the minutes is joined by the complicated version Jaeger-LeCoultre 560 calibre, which also accommodates a disc for the months and the phases of the moon. While the Moon is revolving around the Earth, it has to make an extra revolution during its orbit to maintain its position in relation to the Sun. That is why each lunar month is slightly longer than the sidereal month. Yet, the lunar phase of the Atmos is so accurate that a difference of only one day in the course of 3,821 years will appear! The Atmos family was extended in 2005 with a new generation: the Atmos classiques transparentes which include a cabinet made entirely of crystal. Designed especially for them, the Jaeger-LeCoultre 563 and 564 calibres are attached to the back glass wall. Thus, the mechanism seems to float in the air. The bridges, wheel-work and other elements of the movement have been re-designed and decorated so that they are graced by transparency. For the first time in an unlimited Atmos series, the bellows-shaped capsule can be seen.

The second Atmos family was created in 2002. The Atmos régulateurs are a tribute to the regulators of times past. Their two solid silver dials, one for the hours and the other for the minutes, are designed to prevent friction between the superimposed hands and therefore to optimize accuracy. They evoke an age when regulators were the most accurate time-keepers in the world and the basis of all time-keeping. A circle displaying the 24 hours floats solemnly in the centre of the clock.


Atmos classique phases de lune

Atmos classique transparente

Atmos classique phases de lune

Two limited series comprising fifty models were created in 2004 and 2005: the Atmos régulateur phases de lune, and the Atmos régulateur transparente, equipped with Jaeger-LeCoultre 581 and 582 calibres. They both focus on the beauty of the skeletal regulator movement, total crystal transparency and, lastly, the mechanical virtuosity of the moon phases... Unfortunately, we will not be here to see if the third family of Atmos, the Atmos du millénaire, can keep their promise to make it to the fourth millennium. These unique clocks were created, in fact, to mark the years on a dial that shows the numbers 2000 to 3000, by means of a hand which will circle the dial three times in the course of a millennium. As an accessory, the Atmos du millénaire displays the hours, minutes, months and moon phases.



Atmos Vendôme, 1996

Atmos classique

Based on the Atmos Atlantique, the Atmos du millénaire models were designed by the Kohler and Rekow workshop in 1987; they breathe gently within a mineral crystal case set on a trapezoidal base with a futuristic design, mounted on three rhodium-plated brass cones. It constituted an exceptional challenge for the Manufacture, which has aimed blindly at the future without ever knowing whether it has met the challenge. While the Atmos does like to reveal the beauty of its mechanism, it is also capable of concealing it. The Atmos marqueterie are made from specialist woods, assembled by an exceptional inlayer, who has the distinction of being the finest craftsman in France. Exclusively manufactured in limited series, they have provided new interpretations of the works of the Czech artist Alfons Mucha, especially his paintings 'Dawn' and 'Dusk' which illustrate, through their subtle use of nudity, the evanescence of time, contrasted with the solidity and vitality of the wood.


Atmos I, around 1933

Atmos classique, 1934

When they were fitted with the Atmos millénaires features, the Atmos marqueterie were provided with a secret compartment containing tubes that held ten parchments, a pen-holder and a solidified ink-stick from China to tell the story of the clock up to the end of every century. This clock could also be delivered in a traveling trunk, to protect it during the journeys that it would inevitably undergo in the course of 1000 years. Created in 2003 to celebrate the 75 years since the birth of this famous clock, the Atmos mystérieuse, Jaeger-LeCoultre 583 calibre, is worthy of all superlatives. It is the most complicated Atmos, fitted with the most valuable casing. As if by magic, its operating principle is hidden from our gaze. The clock eclipses the forces that drive its hands, which allows the light to thoroughly penetrate the mechanism and dial. Every five minutes, the wheel-work of the winding-mechanism supplies an extremely regular flow of energy.

pub 1930

Publicity for the Atmos clock, 1930

The twenty-five examples in the limited series are decorated with 18-carat gold, silver, Baccarat crystal, Galuchat ivory, and white mother-of-pearl plates, and set with 360 diamonds. This piece constitutes the ultimate achievement, one that crowns the anniversary of the Atmos clock. It contains 1,982 diamonds. Its base and tip are raised on onyx pyramids and fashioned from eleven kilos of gold. The columns are made of Rock-crystal, the dial of solid silver and the bell of Baccarat crystal.


Atmos prototype, 1928

The instruments of our daily lives are increasingly directed towards saving energy and using alternative and renewable energies. The Atmos was therefore ahead of its time and is today, more than ever, established as an extraordinarily up-to-date object. A master piece of clock and watch art, an innovatory object in both technical and aesthetic terms, the Atmos has mastered the art of linking the past, present and future. How else to define a clock that is 'powered by the breath of time' ?

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Date : April 25th 2013

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