Worthen, William Ezra, 1819-1897, [from old catalog] ed · New York, Appleton · leaf 686
Fig. 1629. i ARCHITECTURAL CONSTRUCTION. 669 … Fig. 1630. The later architects, by converting this section into a circle, the four-sided pyramid became a conoid, and all the ribs forming the conoidal surface became alike in curvature, so that they all might be made simple circular arcs; these ribs are continued with unaltered curvature till…
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer04inte-221-76.webp)
