The following animations repeat indefinitely, but they cannot be reset. I suggest you use Firefox and install the following extension (or similar if others exist):
Firefox addon to toggle animated gifs
The animations below show the mainspring being unwound from the perspective of the arbor wheel and wound from the perspective of the barrel. The most useful perspective is that of God and the Barrel.
Unwinding Relative to the Arbor Wheel Winding Relative to the Barrel