Two mountaineers are squarely in the middle of the almost vertical, mostly ice-covered north face of Pointe Whymper in the Grandes Jorasses. These two daredevils were Geneva mountain guide Michel Vaucher and the Italian mountaineer Walter Bonatti and their watch: Favre Leuba’s Bivouac, the world’s first mechanical wristwatch with an aneroid barometer for altimetry and air pressure measurement.