‹‹‹ Vitr. 3.5.7 | Table of Contents | Vitr. 3.5.9 ›››
8The method of describing volutes, in order that they may be properly turned and proportioned, will be given at the end of the book. The capitals being completed, and set on the tops of the shafts, not level throughout the range of columns, but so arranged with a gauge as to follow the inclination which the small steps on the stylobata produce, which must be added to them on the central part of the top of the abacus, that the regularity of the epistylia may be preserved: we may now consider the proportion of these epistylia, or architraves. When the columns are at least twelve and not more than fifteen feet high, the architrave must be half a diameter in height. When they are from fifteen to twenty feet in height, the height of the column is to be divided into thirteen parts, and one of them taken for the height of the architrave. So from twenty to twenty-five feet, let the height be divided into twelve parts and a half, and one part be taken for the height of the architrave. Thus, in proportion to the height of the column, is the architrave to be proportioned;
8With regard to the method of describing volutes, at the end of the book a figure will be subjoined and a calculation showing how they may be described so that their spirals may be true to the compass.
The capitals having been finished and set up in due proportion to the columns (not exactly level on the columns, however, but with the same measured adjustment, so that in the upper members there may be an increase corresponding to that which was made in the stylobates), the rule for the architraves is to be as follows. If the columns are at least twelve feet and not more than fifteen feet high, let the height of the architrave be equal to half the thickness of a column at the bottom. If they are from fifteen feet to twenty, let the height of a column be measured off into thirteen parts, and let one of these be the height of the architrave. If they are from twenty to twenty-five feet, let this height be divided into twelve and one half parts, and let one of them form the height of the architrave. If they are from twenty-five feet to thirty, let it be divided into twelve parts, and let one of them form the height. If they are higher, the heights of the architraves are to be worked out proportionately in the same manner from the height of the columns.