This center wheel revolves once an hour and turns the minute hand.
This uniformity of freedom will be found absent in cheaper watches; for instance, a center wheel may have 0.02 mm.
Center StaffThe arbor attached to the center wheel which carries the minute hand.
Third WheelThe wheel in the train between the center wheel and the fourth wheel.
The center wheel must revolve once in each hour, which is 61⁄2 times faster than the barrel.
The chief business of the third wheel is to make the fourth turn in the same direction as the center wheel.