the roof, but eaves to throw the rain off the wall. The same is true with regard to pediiuents or caps over windows: they suggest a means of protecting an opening from the wet; and porches over doorways are equally obvious contrivances. Everything, in short, which is actually constructive, or which suggests what was or may be a constructive expedient, is a legitimate object of decoration, and affords the architect unlimited scope for the display of taste and skill, without going out of his way to seek it.
The difficulty in applying ornaments borrowed from other styles is, that although they all suggest construction, it is not the construction of the buildings to which they are applied. To use Pugin's clever antithesis, "they are constructed ornament, not ornamented construction," and as such can never satisfy the mind. However beautiful in themselves, they are out of place, there is no real or apparent use for their being there; and, in an art so essentially founded on utilitarian principles and common sense as architecture is, any offence against constructive propriety is utterly intolerable.
The other class, or decorative ornaments, are forms invented for the purpose, either mere lithic forms, or copied from the vegetable kingdom, and applied so as to give elegance or brilliancy to the constructive decoration just described.
The first and most obvious of these are mere mouldings, known to architects as Scotias, Cavettos, Ogees, Toruses, Rolls, etc.—curves which, used in various proportions, either horizontally or vertically, produce, when artistically combined, the most pleasing effect.
In conjunction with these, it is usual to employ a purely conventional class of ornament, such as frets, scrolls, or those known as the bead and reel, or egg and dart mouldings; or in Gothic architecture the billet or dog-tooth or all the thousand and one forms that were invented during the Middle Ages.
In certain styles of art, vegetable forms are employed even more frequently than those last described. Among these, perhaps the most beautiful and perfect ever invented was that known as the honey-suckle ornament, which the Greeks borrowed from the Assyrians, but made so peculiarly their own. It has all the conventional character of a purely lithic, with all the grace of a vegetable form; and, as used with the Ionic order, is more nearly perfect than any other known.
The Romans made a step further towards a more direct imitation of nature in their employment of the acanthus leaf. As applied to a capital, or where the constructive form of the bell beneath it is still distinctly seen, it is not only unobjectionable, but productive of the most pleasing effect. Indeed it is doubtful if anything of its class has yet been invented so entirely satisfactory as the Roman Corinthian order, as found, for instance, in the so-called Temple of Jupiter
