The ends of the bolster between the volutes consist of concave or ogee curves, which are symmetrically arranged from a centre line; moulded ridges or conventional leaf detail decorate the centre.
The form of the Ionic capital, while suitable for a façade, requires some modification if it is to be carried round the side of a building, owing to the great dissimilarity in the front and side views. In this case the end volute of the capital at the angle of the building is projected forward at an angle of 45 degrees, and the side is then treated in the same way as the front.
In late Renaissance buildings this difficulty was overcome by making all the volutes project at angles of 45 degrees, so that the four faces of the capital were uniform. This entails the bolster being dispensed with, and the volutes, no longer connected laterally, spring directly from the top of the ovolo moulding, and the space between the springing lines is occupied by a husk.
No. 162. Ionic Capital. Detail of Angular Volute.
As the volutes make equal angles they conform more or less to a square plan. The plan of the abacus is composed of four concave curves with small straight intervals at the meeting angles. The general proportions for this form of capital are the same as for the bolster type.
Corinthian Capital
The Corinthian capital differs widely from those of the preceding orders in proportion and detail.
Its general form may be described as a bell, which is circular on plan. It springs from the upper extremity of the shaft, from which it is separated by a necking moulding.