Wallis, Rolland S. [from old catalog], Iowa state college of agriculture and mechanic arts, Ames. Dept. of engineering extension. [from old catalog] · Ames, Iowa, Engineering extension department, Iowa state college · leaf 22
Fig. 23.—Full-circle protractor. type (Fig. 22) for the mechanical draftsman. In the plotting of sur-veyors notes the topographical draftsman usually finds the full-circletype (Fig. 23) convenient. 19 Beam Compasses.-This instrument (Fig. 24) is used when it is neces-sary to draw circular ares of… … Fig. 24.—Beam compasse essentially of a bar or beam on which may be clamped suitable attach-ments for holding the needle point and the pen or pencil points lnepen point (c) replaces the pencil point (d) in mkmg; and all thesepoints, including the divider points (b), are interchangeable. A…
Mechanical drawing
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