Watch in brass by Pierre Duhamel; Paris, France (and Geneva), early 17th century; dia 1⅝” (4.13 cm.).
This watch has no balance spring, regulation being effected by increasing or decreasing the tension of the mainspring using the worm at the top of the movement. The case is enamelled, but the movement plainer than those later in the century and the cock for holding the balance has pierced feet longer than on later movements.
