Right from its founding in 1833, the Jaeger-LeCoultre watchmaking Manufacture has asserted itself through technical advances that soon earned its luxury watches benchmark status in terms of sturdiness and precision. Within this context, it is thus hardly surprising that - at a time in the mid-20th century when the scientific community composed of researchers from many different countries was preparing to undertake a program of major scientific explorations as part of the International Geophysical Year - the Grande Maison in the Vallée de Joux decided to take part in this unique initiative by creating an exceptional precision instrument: the Geophysic® watch.