Q M
, we draw the angle of width of teeth of 4½°, by planting the protractor on the escape center
B
. We measure the angle
E B K
, from the locking face of the pallet; the line
E B
does not touch the locking face of the pallet at the present time of contact with the tooth, therefore a line must be drawn from the point of contact to the center
B
. We did so in our drawing but do not illustrate it, as in a reduced engraving of this kind it would be too close to