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 61
traight in the mid-dle, and sharply curved at the ends, while its left-hand halfis convex upwards, and its right-hand half equally so down-wards ; and each with a vertical tangent at its extremities. Of the two spirals, it will be seen that one increases its radiusuniformly, giving equal radial… … Ex. 113. An exercise of peculiar utility, is found in sketchingeasy curves through several given scattered points. This opera-tion frequently occurs in geometrical drawing, when other than
Geometrical drawing · Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
