Practical draughtsmen's work, with numerous engravings and diagrams (1903)
Hasluck, Paul N. (Paul Nooncree), 1854-1931, ed · Philadelphia, D. McKay · leaf 91
Fig. 145.—Hyperbola. Fig. 146.—Helix. outer edges are not in one plane; being bent round to acylindrical form, the sides are foreshortened. This will be better understood after the curve is drawn as shownby Fig. 147. Commence with the centre line ab. From point cin it describe a semicircle D A E of…
Mechanical drawing
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