Height 9.25 in., Width 7.5 in., Depth 5.5 in. This Atmos perpetual clock by Le Coultre -- the iconic Swiss maison known today as Jaeger-LeCoultre -- is housed in the classic rectangular gold plated brass and glass case with four corner column supports, the white chapter ring dial signed Le Coultre with Arabic quarter numerals at 3, 6, 9 and 12, gold baton hour markers, gold dagger hands and an open central aperture revealing the gilded movement and gear train beneath. The Atmos, first invented by Jean-Leon Reutter in 1928 and produced by Jaeger-LeCoultre from 1935, is among the most ingenious timepieces ever created -- powered entirely by minute changes in atmospheric temperature and pressure acting on a sealed ethylene chloride capsule, requiring no winding, no battery and theoretically capable of running indefinitely without human intervention. The Le Coultre signature on the dial rather than the full Jaeger-LeCoultre name suggests this is an earlier production example, likely from the 1950s to mid 1960s, a period during which both names appeared on Atmos dials. The movement should be examined for the serial number which will allow precise dating -- the clock appears to be running and in very good overall condition with the gold plating bright and the glass panels clean and undamaged. The Swiss government presents the Atmos as its official diplomatic gift to foreign heads of state, a distinction that underscores the enduring prestige of this remarkable timepiece.