Power reserve: a technical innovation by A.L. Breguet to save his good name
Abraham Louis Breguet was an extraordinary inventor and an outstanding watchmaker, but also a very smart seller. He immediately undertood the psychological trick beyond his most practical work, the automatic watch. This (pocket) watch could self-wind itself thanks to a rotor activated by the walking of its owner.
It was quite risky, for Breguet, to explain to the French Minister Talleyrand why his “perpetuelle” (the French name of Breguet’s automatic watch) stopped often, while General Bonaparte’s one did not. Affirming that the reason could be the too sedentary life of the Prince could be outrageous, and the guillotine was always ready!
Breguet -brilliant!- solution was adding to the watch an indication of the power reserve, in order to instil doubt about the reason of a possible low charge: “Is it the watch that does not work properly… or is it me not moving enough to make it wind”?