The Atmos Clock; It was in 1928 that the Neuchâtel engineer Jean-Léon Reutter patented his design for a mechanism that ran on variations in pressure. The Atmos’s high-precision movement lives on air alone: that is, its sole source of energy is variations in the ambient air temperature. Each time the latter rises or falls by a single degree centigrade, the mechanism is able to store up enough energy to guarantee 48 hours of function. Its secret? A hermetically sealed gas-filled capsule which expands when the temperature rises and contracts when it drops: each time it does so it winds the clock’s mainspring. Drawing its inspiration from a brilliant invention, the Atmos has practically achieved perpetual motion...