Jaeger-LeCoultre's Geophysic Chronometer was launched during a period of extensive scientific exploration in the mid 20th century. The scientific community announced 1958 as the International Geophysic Year, a global collaboration of 67 countries spanning the planet studying all aspects from the atmosphere to the oceans. In this new age of research there was a growing need for tool watches, from dive watches to anti-magnetic timekeepers. Researchers and explorers who were in the field needed precision watches that could also endure extreme environments.

Jaeger LeCoultre’s Geophysic Chronometre featured the high grade caliber P478/BWSbr, based on the famed caliber 488 used in the Mark XI made for the British Royal Air Force. With a self-compensating balance spring, central hacking mechanism, and Glucydur balance wheel, the movement was shielded from magnetism with an inner iron case. Designed for maximum robustness, a screw-down caseback was used for improved water resistance, permitting work on research vessels in the middle of the ocean, or in the freezing cold at the Antarctic research station.

The Geophysic Chronometre was produced mostly in stainless steel for one year only in around 1,000 examples. Examples in 18 karat yellow gold are extremely rare, with only a handful known to have appeared publicly to date. The present model is offered in excellent original condition, and is an elusive, hardly-ever-seen chronometer for the collector.