A JAEGER LECOULTRE ATMOS CLOCK CIRCA 1960s Silver dial with gilt dagger batons, 4 sided brass case with 5 glass panels, dimensions are approx 22cm/18cm/13.5cm. The clock gets energy from minute temperature and pressure variations in the atmosphere and a change of just 1 degree Celsius between the range of 15 to 30 degrees is enough to power the clock for 2 days. Designed for minimal power consumption, wear and resistance its heart beats just twice per minute, 60 times less than a conventional clock and 240 times less than a wristwatch movement.