Atmos II self-winding clock by Jaeger-LeCoultre, 1930s

Image number: 1939-259

Atmos II self-winding clock by Jaeger-LeCoultre, 1930s

This clock has a bellows filled with ethyl chloride gas which expands and contracts with changes of temperature and atmospheric pressure. These movements wind a large spring by a ratchet mechanism, so the clock never needs to be wound.

Source: De Trevars Ltd

Image number:
1939-259
Credit:
Science Museum/Science & Society Picture Library
Image rights: