§ V. These (_b_ and _c_) are the profiles of two vast families of cornices, springing from the same root, which, with a third arising from their combination (owing its origin to æsthetic considerations, and inclining sometimes to the one, sometimes to the other), have been employed, each on its third part of the architecture of the whole world throughout all ages, and must continue to be so employed through such time as is yet to come. We do not at present speak of the third or combined group; but the relation of the two main branches to each other, and to the line of origin, is given at _e_, Fig. V.; where the dotted lines are the representatives of the two families, and the straight line of the root. The slope of this right line, as well as the nature of the curves, here drawn as segments of circles, we leave undetermined: the slope, as well as the proportion of the depths of X and Y to each other, vary according to the weight to be carried, the strength of the stone, the size of the cornice, and a thousand other accidents; and the nature of the curves according to æsthetic laws. It is in these infinite fields that the invention of the architect is permitted to expatiate, but not in the alteration of primitive forms. § VI. But to proceed. It will doubtless appear to the reader, that, even allowing for some of these permissible variations in the curve or slope of X, neither the form at _b_, nor any approximation to that form, would be sufficiently undercut to keep the rain from running back upon it. This is true; but we have to consider that the cornice, as the close of the wall's life, is of all its features that which is best fitted for honor and ornament. It has been esteemed so by almost all builders, and has been lavishly decorated in modes hereafter to be considered. But it is evident that, as it is high above the eye, the fittest place to receive the decoration is the slope of X, which is inclined towards the spectator; and if we cut away or hollow out this slope more than we have done at _b_, all decoration will be hid in the shadow. If, therefore, the climate be fine, and rain of long continuance not to be dreaded, we shall not hollow the stone X further, adopting the curve at _b_ merely as the most protective in our power. But if the climate be one in which rain is frequent and dangerous, as in alternations with frost, we may be compelled to consider the cornice in a character distinctly protective, and to hollow out X farther, so as to enable it thoroughly to accomplish its purpose. A cornice thus treated loses its character as the crown or honor of the wall, takes the office of its protector, and is called a DRIPSTONE. The dripstone is naturally the attribute of Northern buildings, and therefore especially of Gothic architecture; the true cornice is the attribute of Southern buildings, and therefore of Greek and Italian architecture; and it is one of their peculiar beauties, and eminent features of superiority.