Le Coultre continued to sell the Atmos I while it was developing the Atmos II, which the primary improvement was the change from an ammonia and mercury "bellows" to a canister filled with ethyl chloride.
Jean-Leon Reutter, in France, designed the Atmos Clock in 1927 and this is referred too as the Atmos 0.
These serial numbers start with 600,000 and is still being made today under various caliber numbers and model names.
Worldwide manufacturer for Atmos clock and Jaeger-Le Coultre watches: Jaeger-Le Coultre SA 980 Brooke Road P. Box 1608 Winchester, VA USA 22601-1608 540-665-0300 or Fax 540-665-4130 Web site address: they may not ship reliably and we cannot assume that level of risk, even using third-party insured shippers like UPS; there just isn't enough margin in them to make the risk worthwhile for our business model.
An Atmos can therefore expect to enjoy a service life of a good 600 years, although with today's air pollution a through cleaning is recommended about every twenty years.
Admirers of advanced technology, however, aren't the only ones who get their money's worth.