Presume the existence of a vertical line through the center of hairspring and collet as shown at "A B" Fig. 9.
hairspring concave or convex in form instead of perfectly level.8.
Thus the balance receives the power to keep it in motion, swinging it as far as the hairspring allows.
New balance staff, two balance screws changed, hairspring trued and cleaned.
The hairspring should be removed and the pivots known to be straight and polished before testing.
The gradual weakening or loss of elastic force of the hairspring is also a factor to be considered.
As we set the bankings the pallets are all right; but to test matters, let us remove the hairspring and put the balance in place.
Original truing of the hairspring is made necessary by the fact of attaching the collet to its center.
The hairspring however, was found to be pinned at the slow pendant up point as per illustration in Fig. 22.
When rust begins its attack upon any point of a hairspring there will be a constant loss in time until its advance is stopped.