Elements of plane and solid free-hand geometrical drawing, with lettering; and some elements of geometrical ornamental design, including the principals of harmonic angular ratios, etc. In three parts ... for draughtsmen and artisans; and teachers and students of industrial and mechanical drawing (1878)
Warren, S. Edward (Samuel Edward), 1831-1909 · New York, J. Wiley & sons · leaf 159
, in Fig. 15, but larger,its longer side being equal to aside of the circumscribing squarein Fig. 15, while its half 2, 6, 10, is a triangle of 30°, 60°, 90°. CI K\ ILINEAR GEOMETRIC BEAUTY. 105 By the definition of the ellipse (Art. CI), describe arcs with4 and 12um the rectangle) as centres, and… … So much being done, divide the sides of the rectangle, eachinto four equal parts, and join the points of division as in thesquare, which, as before, will divide the rectangle into sixteenequal parts, and the circumference of the ellipse into twelveparts, which, however, are not equal. 64. We shall…
Geometrical drawing · Mechanical drawing
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