§ XII. If we were to add a fourth curve to the component series, we should have forty-eight more cornices: but there is no use in pursuing the system further, as such arrangements are very rare and easily resolved into the simpler types with certain arbitrary additions fitted to their special place; and, in most cases, distinctly separate from the main curve, as in the inner line of No. 14, which is a form of the type _e_, the longest curve, _i.e._, the lowest, having deepest curvature, and each limb opposed by a short contrary curve at its extremities, the convex limb by a concave, the concave by a convex. § XIII. Such, then, are the great families of profile lines into which all cornices and capitals may be divided; but their best examples unite two such profiles in a mode which we cannot understand till we consider the further ornament with which the profiles are charged. And in doing this we must, for the sake of clearness, consider, first the nature of the designs themselves, and next the mode of cutting them. [Illustration: Plate XVI. CORNICE DECORATION.] § XIV. In Plate XVI., opposite, I have thrown together a few of the most characteristic mediæval examples of the treatment of the simplest cornice profiles: the uppermost, _a_, is the pure root of cornices from St. Mark's. The second, _d_, is the Christian Doric cornice, here lettered _d_ in order to avoid confusion, its profile being _d_ of Plate XV. in bold development, and here seen on the left-hand side, truly drawn, though filled up with the ornament to show the mode in which the angle is turned. This is also from St. Mark's. The third, _b_, is _b_ of Plate XV., the pattern being inlaid in black because its office was in the interior of St. Mark's, where it was too dark to see sculptured ornament at the required distance. (The other two simple profiles, _a_ and _c_ of Plate XV., would be decorated in the same manner, but require no example here, for the profile _a_ is of so frequent occurrence that it will have a page to itself alone in the next volume; and c may be seen over nearly every shop in London, being that of the common Greek egg cornice.) The fourth, _e_ in Plate XVI., is a transitional cornice, passing from Byzantine into Venetian Gothic: _f_ is a fully developed Venetian Gothic cornice founded on Byzantine traditions; and _g_ the perfect Lombardic-Gothic cornice, founded on the Pisan Romanesque traditions, and strongly marked with the noblest Northern element, the Lombardic vitality restrained by classical models. I consider it a perfect cornice, and of the highest order.