35. _Principle of Pinning Point Alterations._
When an alteration of any pinning point is necessary, the extent and direction of the alteration are determined by the rate of the watch. For instance, if a spring is pinned at the fast point and if a slightly slower pendant up rate is desired, the spring can be broken off at the collet and pinned one-eighth above the horizontal line.
If the rate is to be made slightly faster, the spring can be let out a trifle at the collet, the over coil reformed or the stud moved forward on the over coil so that the collet point of attachment will come slightly below the horizontal line when the spring is placed in beat. The former alteration causes an approach toward the slow point and in making the latter alteration we assume that the fast point is a trifle below the horizontal line on that particular watch. When altering springs from the extreme fast point to the extreme slow point, it is advisable to remove a trifle less of the inner coil than the extreme calculation. This will cause the point of attachment to be slightly above the horizontal line on the slow side and will most always produce the result desired and if it does not, there is still a possibility of further alteration. The same principle applies in making an alteration from the extreme slow to the extreme fast point and in this case the point of attachment to collet may be just a trifle below the horizontal line.
The theory of this is that all shortening of the coil from the fast to the slow point produces a slower rate pendant up, until the extreme slow point is reached. After passing this extreme slow point the pendant up rate begins to grow faster until the extreme fast point is reached. [A]The designations "right" and "left" in regard to pinning points are used with the explicit understanding that the individual is facing the train side of the movement. The same designations used as referring to position rates, or results to be expected in positions should be interpreted to mean with the individual facing the dial side of the watch.
36. _Same Principles Apply in Case of American Hunting Models._
The points shown in Figures 14 and 15 refer generally to American hunting models. In all other high grade watches the location of the balance and spring will be found either to the right or left of the center of the watch.