Page:The Poetry of Architecture.djvu/142

130 which we know to depend upon fixed mathematical principles, though those principles are not always developed, it is to be observed, that country is always most beautiful when it is made up of curves, and that one of the chief characters of Ausonian landscape is, the perfection of its curvatures, induced by the gradual undulation of promontories into the plains. In suiting architecture to such a country, that building which least interrupts the curve on which it is placed will be felt to be most delightful to the eye. Let us take then the simple form a b c d, interrupting the curve c e. Now, the eye will always continue the principal lines of such an object for itself, until they cut the main curve; that is, it will carry on a b to e, and the total effect of the interruption will be that of the form c d e. Had the line b d been nearer a c, the effect would have been just the same. Now, every curve may be considered as composed of an infinite number of lines at right angles to each other, as m n is made up of o p, p q, &c. (Fig. 34), whose ratio to each other varies with the direction of the curve. Then, if the right lines which form the curve at c (Fig. 35) be increased, we have the figure c d e, that is, the apparent interruption of the curve is an increased part of the curve itself.