The Atmos clock was invented by Jean-Léon Reutter in 1928 and is manufactured by Jaeger-LeCoultre. It is powered by small changes in temperature and atmospheric pressure, requiring no winding. The serial number can be used to determine the approximate year of manufacture.
Serial Number Chart
| Serial Numbers | Year |
|---|---|
| 1 – 500 | 1930–35 |
| 501 – 3,000 | 1936–40 |
| 3,001 – 10,000 | 1941–48 |
| 10,001 – 30,000 | 1949–52 |
| 30,001 – 60,000 | 1953–56 |
| 60,001 – 100,000 | 1957–60 |
| 100,001 – 150,000 | 1961–64 |
| 150,001 – 200,000 | 1965–68 |
| 200,001 – 260,000 | 1969–72 |
| 260,001 – 320,000 | 1973–76 |
| 320,001 – 380,000 | 1977–80 |
| 380,001 – 450,000 | 1981–85 |
| 450,001 – 520,000 | 1986–90 |
| 520,001 – 600,000 | 1991–97 |
The serial number is usually found on the back of the movement or on the bottom of the clock base.