"Atmos Clock" Atmospheric mechanical torsion pendulum clock by the venerable Swiss ﬁrm Jaegar Le Coultre. A marvel of engineering originally invented by Cornelious Derbble in the 17th century. Without getting two technical, there is a chamber ﬁlled with ethyl chloride that expands and contracts due to changes and temperature. The resulting energy from this motion powers the mechanism in perpetuity. Jaegar has been producing this model continuously since 1936 with very little variation from their original model.