A text book of geometrical drawing : abridged from the octavo edition : for the use of schools in which the definitions and rules of geometry are familiarly explained, the practical problems are arranged from the most simple to the more complex, and in their description technicalities are avoided as much as possible : with an introduction to isometrical drawing : and an essay on linear perspective and shadows ... (1849)
preceding problem. Note.—In all these diagrams, the result is nearly the same.Figs. 1 and 2 are similar figures, although each is produced by adifferent process. The proportions of an oval, drawn as figure1, must always be the same as in the diagram; but, in figs. 2and 3, the proportions may be… … y/^Mimfie. lUjii^cUvkSons. PLATE XIII. 49 vature is too abrupt. These figures are often improperly calledellipses, and sometimes false ellipses. Ovals are frequently usedfor bridges. When the arch is flat, the curve is described frommore than two centres, but it is never so graceful as the…
