Page:Vitruvius the Ten Books on Architecture.djvu/124

94 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.

9. For the higher that the eye has to climb, the less easily can it make its way through the thicker and thicker mass of air. So it fails when the height is great, its strength is sucked out of it, and it conveys to the mind only a confused estimate of the dimen­sions. Hence there must always be a corresponding increase in the symmetrical proportions of the members, so that whether the buildings are on unusually lofty sites or are themselves somewhat colossal, the size of the parts may seem in due proportion. The depth of the architrave on its under side just above the capital, is to be equivalent to the thickness of the top of the column just under the capital, and on its uppermost side equivalent to the foot of the shaft.

10. The cymatium of the architrave should be one seventh of the height of the whole architrave, and its projection the same. Omitting the cymatium, the rest of the architrave is to be divided into twelve parts, and three of these will form the lowest fascia, four, the next, and five, the highest fascia. The frieze, above the architrave, is one fourth less high than the architrave, but if there are to be reliefs upon it, it is one fourth higher than the architrave, so that the sculptures may be more imposing. Its cy­matium is one seventh of the whole height of the frieze, and the projection of the cymatium is the same as its height.

11. Over the frieze comes the line of dentils, made of the same height as the middle fascia of the architrave and with a projec­tion equal to their height. The intersection (or in Greek ) is apportioned so that the face of each dentil is half as wide as its height and the cavity of each intersection two thirds of this face in width. The cymatium here is one sixth of the whole height of this part. The corona with its cymatium, but not including the sima, has the height of the middle fascia of the architrave, and the total projection of the corona and dentils should be equal to the height from the frieze to the cymatium at the top of the corona.