Pierre Jaquet-Droz was a famous watchmaker and like his son Henri-Louis (1752-1791), a brilliant designer of clocks and automata (the so-called androids). He was born July 28, 1721 in Villeret and died on November 28, 1790 in Biel.
The androids built by him were mechanically driven characters which, for example, wrote a word on a piece of paper, a drew a portrait or played music on a keyboard See “The Scribe”, “The Musician” and “The draftsman” in the Museum of Art-History Neuchâtel. These legendary machines became world famous - and almost brought their inventors to be burnt on pyre for alleged witchcraft.
Jaquet-Droz, moreover, about 1755 invented a unique form of automatic winding for watches. As an energy source he used the different expansion behavior of two metals at temperature fluctuations, which he converted into kinetic energy.