Industrial drawing and geometry; an introduction to various branches of technical drawing (1911)
Spooner, Henry John, 1856- · London, New York [etc.] Longmans, Green, and co. · leaf 27
nd blackness of a line very much depend upon the pressure exerted on the pencil.21a. Defects in Lines.—The main defects in lines which should be avoided are : Varying thickness, caused by varying the amountof pressure exertedupon the pencil. Want of sharpness, the sides of the lines having a…
Mechanical drawing · Geometrical drawing
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