ATMOS CLOCK Atmos Pendule Perpetuelle No. 1083 Circa 1930 France
Signed: Atmos Pendule Perpetuelle No. 1083
The spring-driven movement is constructed between circular plates and has a rotating balance suspended with a thin metal torsion spring beneath the movement. The main spring is wound by a system activated by temperature differences. The temperature changes make a large drum move, winding the mainspring in very small steps. If the temperature does not change, the clock can run for another 90 days. The movement is numbered at the back on a wide strip behind the drum 1083.
The circular white enamel dial has a Roman chapter ring with five-minute and minute divisions. The time is indicated by a pair of blued-steel Breguet hands. The centre is marked Atmos Pendule Perpetuelle. The maker has signed the clock under the VI Brevete J.L. Reutter.
The chromium plated brass case has windows on four sides with bevelled glass sheets. There are doors to the front and the back. Below the front door is a slide with which the rotating balance can be secured to stop the clock so that it can be moved.
Duration Infinite; however when there are no temperature fluctuations the clock will run for another 90 days.
Height 24 cm.
Width 17.5 cm.
Depth 15.5 cm.
*Price € 16500
– J. Zeeman, Het klokkenlexicon, Zwolle, 2003, p. 17.
– Jean Lebet, Von der Luft leben, die Geschichte der Pendeluhr Atmos.
Jean-Léon Reutter (1899-1971) was the inventor and maker of the Atmos clock. In 1913 this Parisian engineer began to experiment with mechanism, which eventually would lead to the production of Atmos clocks. His ideas were based on those of James Cox which dated back to 1765. The first commercially produced clock appeared on the market in 1926 and the first patent was applied for in 1929. Reutter used a U-shaped tube positioned in such a way that it could slightly swing. The horizontal part and part of the vertical tubes were filled with mercury, the space above the mercury being filled with a fast evaporating liquid and the corresponding saturated vapour. One vertical tube was insulated, the other was not. When the temperature rose, the pressure in non-insulated part more than in the other and a small quantity of mercury moved from one side to the other, which made the U-tube tip over to one side a little. This motion was used to wind the mainspring. When the temperature dropped the opposite happened. Later versions of the atmos clock used a metal drum filled with ethyl chloride.