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:
“I am willing, for a money consideration, to test this physical strength, this nervous force, and muscular power with which I’ve been gifted, to show that they will bear a certain strain. If I break down, if my brain gives way under want of sleep, my heart ceases to respond to the calls made on my circulatory system, or the surcharged veins of my extremities burst—if, in short, I fall helpless, or it may be, dead on the track, then I lose my money.”
—Ada Anderson (1860–?)
“I understood that all the material of a literary work was in my past life, I understood that I had acquired it in the midst of frivolous amusements, in idleness, in tenderness and in pain, stored up by me without my divining its destination or even its survival, as the seed has in reserve all the ingredients which will nourish the plant.”
—Marcel Proust (1871–1922)