Rulers (Instruments) (Topical Term)

Jensen, C. Fundamentals of engineering drawing, 2nd ed., 1985: p. 10-11 (Scales are used only for measuring and are not to be used as a straightedge when drawing lines ... Scales are made with a variety of combined scales marked on their surfaces. This combination of scales spares the drafter the necessity of calculating the sizes to be drawn when working to a scale other than full size.)