Fig. 1449.
Thus, [Fig. 1449] represents a pair of spring dividers, the bow spring at the head acting to keep the points apart, and the screw and nut being employed to close and to adjust them.
Fig. 1450.
Another form is shown in [Fig. 1450], the legs being operated by a right and left-hand screw, which may be locked in position by the set-screw shown.
Fig. 1451.
For very small circles the fork scriber shown in [Fig. 1451] is an excellent tool, since it may be used with great pressure so as to cut a deep line in the surface of the work. This tool is much used by boiler makers, but is a very useful one for the machinist for a variety of marking purposes, which will be described with reference to [vice work].