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:
“and men strive with each other not for power or the accumulation of paper
but in joy create for others the house, the poem, the game of
athletic beauty.
Then washed in the brightness of the vision,
I saw how in its radiance would grow and be nourished and suddenly
burst into terrible and splendid bloom
the blood-red flower of revolution.”
—Dudley Randall (b. 1914)
“One should never make one’s debut with a scandal. One should reserve that to give an interest to one’s old age.”
—Oscar Wilde (1854–1900)