Page:Vitruvius the Ten Books on Architecture.djvu/141

109 in the original must be placed above the principal rafters, is put in the copy below them, the result will be a work constructed on false principles. Neither did the ancients approve of or employ mutules or dentils in pediments, but only plain coronae, for the reason that neither principal nor common rafters tail into the fronts of pediments, nor can they overhang them, but they are laid with a slope towards the eaves. Hence the ancients held that what could not happen in the original would have no valid reason for existence in the copy.

6. For in all their works they proceeded on definite principles of fitness and in ways derived from the truth of Nature. Thus they reached perfection, approving only those things which, if challenged, can be explained on grounds of the truth. Hence, from the sources which have been described they established and left us the rules of symmetry and proportion for each order. Fol­lowing in their steps, I have spoken above on the Ionic and Cor­inthian styles, and I shall now briefly explain the theory of the Doric and its general appearance.

1. of the ancient architects said that the Doric order ought not to be used for temples, because faults and incongruities were caused by the laws of its symmetry. Arcesius and Pytheos said so, as well as Hermogenes. He, for instance, after getting together a supply of marble for the construction of a Doric tem­ple, changed his mind and built an Ionic temple to Father Bac­chus with the same materials. This is not because it is unlovely in appearance or origin or dignity of form, but because the ar­rangement of the triglyphs and metopes (lacunaria) is an em­barrassment and inconvenience to the work.

2. For the triglyphs ought to be placed so as to correspond to the centres of the columns, and the metopes between the triglyphs