Celebrated clockmaker from Neuchâtel (Switzerland). Three inventions designed by Breguet in the late eighteenth century make him the leading figure of modern clockmaking - even more so than the countless variants on, and refinements, to sundry devices introduced by him and by his students over the years. The three inventions are: a spiral balance spring with an overcoil, an empirical anticipation of the spring end-curves computed some sixty years later by Phillips; the tourbillon, which compensates for position errors by the escapement; and the pendule sympathique, a fixed clock that rewinds a pocket watch and sets it to the right time. At the very least, the third device may be seen as the expression of a boundless, pioneering imagination. Appointed by Louis XVIII (1755-1824) clockmaker to the Navy and knight of the Légion d'Honneur. Breguet also invented a thermometer that bears his name.