Power Reserve Indicator
Some high grade watches have an extra dial on the face indicating how much power is left in the mainspring, often graduated in hours the watch has left to run. Since both the arbor and the barrel turn, this mechanism requires a differential gear that measures how far the arbor has been turned, compared to the barrel.
Read more about this topic: Mainspring
Famous quotes containing the words power and/or reserve:
“But the life of Spirit is not the life that shrinks from death and keeps itself untouched by devastation, but rather the life that endures it and maintains itself in it. It wins its truth only when, in utter dismemberment, it finds itself.... Spirit is this power only by looking the negative in the face, and tarrying with it. This tarrying with the negative is the magical power that converts it into being. This power is identical with what we earlier called the Subject.”
—Georg Wilhelm Friedrich Hegel (1770–1831)
“Her face had the seamed reserve of the old in this country [Japan]. It was a neighborhood poignantly rich in old ladies.”
—Angela Carter (1940–1992)