On Architecture

8. Thus, over each portion of the architrave two metopes and two triglyphs [*](That is: two metopes with a triglyph between them, and half of the triglyph on either side.) will be placed; and, in addition, at the corners half a triglyph and besides a space large enough for a half triglyph. At the centre, vertically under the gable, there should be room for three triglyphs and three metopes, in order that the centre intercolumniation, by its greater width, may give ample room for people to enter the temple, and may lend an imposing effect to the view of the statues of the gods.

9. The columns should be fluted with twenty flutes. If these are to be left plane, only the twenty angles need be marked off. But if they are to be channelled out, the contour of the channelling may be determined thus: draw a square with sides equal in length to the breadth of the fluting, and centre a pair of compasses in the middle of this square. Then describe a circle with a circumference touching the angles of the square, and let the channellings have the contour of the segment formed by the circumference and the side of the square. The fluting of the Doric column will thus be finished in the style appropriate to it.

10. With regard to the enlargement to be made in the column at its middle, let the description given for Ionic columns in the third book be applied here also in the case of Doric. Since the external appearance of the Corinthian, Doric, and Ionic proportions has now been described, it is necessary next to explain the arrangements of the cella and the pronaos.

1. THE length of a temple is adjusted so that its width may be half its length, and the actual cella one fourth greater in length than in width, including the wall in which the folding doors are placed. Let the remaining three parts, constituting the pronaos, extend to the antae terminating the walls, which antae ought to be of the same thickness as the columns. If the temple is to be more than twenty feet in width, let two columns be placed between the two antae, to separate the pteroma from the pronaos. The three intercolumniations between the antae and the columns should be closed by low walls made of marble or of joiner's work, with doors in them to afford passages into the pronaos.

2. If the width is to be more than forty feet, let columns be placed inside and opposite to the columns between the antae. They should have the same height as the columns in front of them, but their thickness should be proportionately reduced: thus, if the columns in front are in thickness one eighth of their height, these should be one tenth; if the former are one ninth or one tenth, these should be reduced in the same proportion. For their reduction will not be discernible, as the air has not free play about them. Still, in case they look too slender, when the outer columns have twenty or twenty-four flutes, these may have twenty-eight or thirty-two. Thus the additional number of flutes will make up proportionately for the loss in the body of the shaft, preventing it from being seen, and so in a different way the columns will be made to look equally thick.

3. The reason for this result is that the eye, touching thus upon a greater number of points, set closer together, has a larger compass to cover with its range of vision. For if two columns, equally thick but one unfluted and the other fluted, are measured by drawing lines round them, one line touching the body of the columns in the hollows of the channels and on the edges of the flutes,