"Pendulum (perpetual) Atmos De Jaeger Le Coultre, From The 50s"Atmos pendulum called (perpetual) Jaeger le Coultre, made in the 50s. White annular dial with Arabic numerals and numerals. Perpetual motion. The Atmos clock was invented in the late 1920s by the engineer Reuter, and worked at the time with a barometric capsule that back the movement, thanks to tiny differences in atmospheric pressure. (Hence the name) ... The brand Jaeger Le Coultre bought the patent at the time, and continues manufacturing for more than 90 years. The power source of the Atmos pendulum consists of a hermetically sealed Vidie capsule containing a gas, ethyl chloride. This gas expands in a membrane when the temperature increases which has the effect of compressing the coil spring. When the temperature falls, the gas condenses and the spring is released. It is this mechanism that perpetually feeds the pendulum. Thus, an Atmos can work for years without any human intervention. A simple variation of one degree (for a temperature between 15 ° C and 30 ° C) or a variation of pressure of 3 mm Hg is enough to feed the pendulum for two days. To operate the pendulum with this modest source of energy, the mechanism is designed with the minimum of friction possible, that is why it does not have oil in its wheels. The measurement of time is done using a pendulum that consumes less energy than an ordinary clock. Indeed, it performs a single oscillation per minute which is sixty times less than a classic clock or 14 400 times less than a wristwatch. Sixty million combined Atmos consume less energy than a fifteen watt light bulb! The pendulum is suspended on a wire of élinvar of an extreme finesse. Twisting this wire allows to retain and then drive the balance successively in one direction and then in the other. Invented by Charles-Edouard Guillaume, Nobel Prize in physics, this wire, composed of an alloy that is very insensitive to temperature changes, is artificially aged using a secret process. It is perfect, it has been completely revised by a specialist, and is guaranteed as a new I am at your disposal for any additional information or photos.