‹‹‹ Vitr. 4.1.10 | Table of Contents | Vitr. 4.1.12 ›››
11The method of setting out the capital is as follows. Its height, including the abacus, is to be equal to the diameter of the lower part of the column. The width of the abacus is obtained by making its diagonal from opposite angles, equal to twice its height. It will thus have a proper front on each face. The faces of the four sides of the abacus are to be curved inwards from its extreme angles, equal to one ninth of its extent. The thickness of the lower part of the capital must be equal to the diameter of the top of the shaft, exclusive of the apotheosis and astragal. The height of the abacus is a seventh of the height of the whole capital;
11The proportions of this capital should be fixed as follows. Let the height of the capital, including its abacus, be equivalent to the thickness of the base of a column. Let the breadth of the abacus be proportioned so that diagonals drawn from one corner of it to the other shall be twice the height of the capitals, which will give the proper breadth to each face of the abacus. The faces should curve inwards, by one ninth of the breadth of the face, from the outside edge of the corners of the abacus. At the bottom the capital should be of the thickness of the top of the column omitting the congé and astragal. The height of the abacus is one seventh of the height of the capital.