§ XIX. Our first constituents of ornament will therefore be abstract lines, that is to say, the most frequent contours of natural objects, transferred to architectural forms when it is not right or possible to render such forms distinctly imitative. For instance, the line or curve of the edge of a leaf may be accurately given to the edge of a stone, without rendering the stone in the least _like_ a leaf, or suggestive of a leaf; and this the more fully, because the lines of nature are alike in all her works; simpler or richer in combination, but the same in character; and when they are taken out of their combinations it is impossible to say from which of her works they have been borrowed, their universal property being that of ever-varying curvature in the most subtle and subdued transitions, with peculiar expressions of motion, elasticity, or dependence, which I have already insisted upon at some length in the chapters on typical beauty in "Modern Painters." But, that the reader may here be able to compare them for himself as deduced from different sources, I have drawn, as accurately as I can, on the opposite plate, some ten or eleven lines from natural forms of very different substances and scale: the first, _a b_, is in the original, I think, the most beautiful simple curve I have ever seen in my life; it is a curve about three quarters of a mile long, formed by the surface of a small glacier of the second order, on a spur of the Aiguille de Blaitière (Chamouni). I have merely outlined the crags on the right of it, to show their sympathy and united action with the curve of the glacier, which is of course entirely dependent on their opposition to its descent; softened, however, into unity by the snow, which rarely melts on this high glacier surface. The line _d c_ is some mile and a half or two miles long; it is part of the flank of the chain of the Dent d'Oche above the lake of Geneva, one or two of the lines of the higher and more distant ranges being given in combination with it. [Illustration: Plate VII. ABSTRACT LINES.]