Many people are led to believe that the functioning of automatic watches is a kind of perpetual motion and that, consequently, it is enough to fasten the timepiece to the wrist to see it start up again without any problems. But the reality is different. Every watch runs smoothly as long as the barrel retains energy equal to about one third of its total autonomy. In practice, a mechanical model with a total autonomy of 40 hours will run regularly for about 26 hours, after which there will be irregularities - even considerable ones - in the running constancy.
The winding system is able to function properly if the timepiece is worn on the wrist of an average person. It often happens that people who are no longer very young or who are used to spending a lot of time behind a desk do not make sufficient movements to store energy in the barrel in excess of that which is indispensable for proper functioning. This leads to abnormal behaviour of the watch, such as periodic delays alternating with inexplicable advances. It would then be a good idea to try winding the timepiece manually, or wearing it on the right wrist (on the left, for left-handers), which is generally moved more often and more energetically. If the defect disappears, we must take note that the problem does not depend on the watch. In this case, the best solution is to buy a special rotor box to be used during the night hours to keep the watch wound at all times.
