Paragraph 7. It is sometimes more desirable to gauge a line with a lead pencil and ruler than with the marking gauge. With the left hand hold the ruler at the desired distance from the end, that is, if you wish to gauge a line l 1/2" from the working edge, with the thumb and finger hold the ruler at that distance. Then as the finger drags against the working edge it will serve as the head of the marking gauge (shown in Figure 24), and keep the pencil at exactly the same distance from the edge. The pencil should be held firmly against the end of the ruler, then by sliding the ruler the length of the material, with the finger held firmly against the working edge, the line will be drawn parallel with the working edge. The motion may be either toward or from you, as you choose.

Figure 24.