4The length of a temple must be twice its width. The cell itself is to be in length one fourth part more than the breadth, including the wall in which the doors are placed. The remaining three parts run forward to the antæ of the walls of the pronaos, which antæ are to be of the same thickness as the columns. If the temple be broader than twenty feet, two columns are interposed between the two antæ, to separate the pteroma from the pronaos. The three intercolumniations between the antæ and the columns may be enclosed with fence work, either of marble or of wood, so, however, that they have doors in them for access to the pronaos.
2If the width be greater than forty feet, columns opposite to those which are between the antæ, are placed towards the inner part, of the same height as those in front, but their thickness is to be diminished as follows. If those in front are an eighth part of their height in thickness, these are to be one ninth; and if the former are a ninth, or a tenth, the latter are to be proportionally diminished. For where the air does not play round them, the diminution thus made will not be perceived; lest, however, they should appear slenderer, when the flutes of the external columns be twenty-four in number, these may have twenty-eight, or even thirty-two. Thus, what is taken from the absolute mass of the shaft, will be imperceptibly aided by the number of the flutes, and though of different thicknesses, they will have the appearance of being equal.
3This arises from the eye embracing a greater number of surfaces, and thence producing on the mind the effect of a larger body. For if two columns, equally thick, one of them without flutes, and the other fluted, are measured round with lines, and the line is passed over the flutes and their fillets, though the columns are of equal thickness, the lines which girt them will not be equal, for that which passes over the fillets and flutes will of course be the longest. This being the case, it is not improper in confined and enclosed situations to make the columns of slenderer proportions, when we have the regulation of the flutes to assist us.
4The thickness of the walls of the cell must depend on the magnitude of the work, taking care, however, that the antæ are the same thickness as the columns. If built in the ordinary way, they are to be of small stones, very carefully laid, but if of square stone or marble, the pieces should be chiefly small and of equal size, because then, the upper stones coming over the middle of the joint below them, bind the work together and give it strength; fillets of lime used in pointing the joints and beds give the work an agreeable appearance.