test 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