Fig. 148 illustrates the common compasses used by woodworkers. Fig. 99 shows a method of setting them, and Fig. 100 shows how to hold them in striking a circle. The ordinary difficulty in using compasses is to over-strain the adjusting screws or to grasp the compasses in such a manner that the distance between the points is changed by the pressure of the fingers. Hold them nearly vertical and revolve them in either direction according to the grain of the wood or the position of the circle.

For most work it is better to sharpen the end of one leg of the compasses to a rather blunt round point and the end of the other leg to a flat knife-like point.

Do not use compasses to pry with, to make holes for screws, or for similar uses. Do not strike them on the top end with the hammer or use the hammer claws to turn the screws.

Fig. 148. Compasses.