The so-called gold spring shown at H, Figs. 141 and 142, should also be as light as is consistent with due strength and can be made of the composite metal used for gold filled goods, as the only real benefit to be derived from employing gold is to avoid the necessity of applying oil to any part of the escapement.  If such gold metal is employed, after hammering to obtain the greatest possible elasticity to the spring, the gold is filed away, except where the spring is acted upon by the discharging jewel h.  We have previously mentioned the importance of avoiding wide, flat contacts between all acting surfaces, like where the gold spring rests on the horn of the detent at p; also where the detent banks on the banking screw, shown at G, Fig. 142.  Under this principle the impact of the face of the discharging jewel with the end of the gold spring should be confined to as small a surface as is consistent with what will not produce abrasive action.  The gold spring is shaped as shown at Fig. 142 and loses, in a measure, under the pipe of the locking jewel, a little more than one-half of the pipe below the blade of the detent being cut away, as shown in Fig. 143, where the lines r r show the extent of the part of the pipe which banks against the banking screw G.  In this place even, only the curved surface of the outside of the pipe touches the screw G, again avoiding contact of broad surfaces.

We show the gold spring separate at Fig. 144.  A slight torsion or twist is given to the gold spring to cause it to bend with a true curvature in the act of allowing the discharging pallet to pass back after unlocking.  If the gold spring is filed and stoned to the right flexure, that is, the thinnest point properly placed or, say, located, the gold spring will not continue in contact with the discharging pallet any longer time or through a greater arc than during the process of unlocking.  To make this statement better understood, let us suppose the weakest part of the gold spring H is opposite the arrow y, Fig. 141, it will readily be understood the contact of the discharging stone h would continue longer than if the point of greatest (or easiest) flexure was nearer to the pipe C.  If the end D^2 of the horn of the detent is as near as it should be to the discharging stone there need be no fear but the escapement will be unlocked.  The horn D^2 of the detent should be bent until five degrees of angular motion of the balance will unlock the escape, and the contact of discharging jewel h should be made without engaging friction.  This condition can be determined by observing if the jewel seems to slide up (toward the pipe C) on the gold spring after contact.  Some adjusters set the jewel J, Figs. 143 and 141, in such a way that the tooth rests close to the base; such adjusters claiming this course has a tendency to avoid cockling or buckling of the detent spring E.  Such adjusters also set the impulse jewel slightly oblique, so as to lean on the opposite angle of the tooth.  Our advice is to set both stones in places corresponding to the axis of the balance staff, and the escape-wheel mobiles.