Corinthian Pedestal
The same general divisions as the Ionic will give the proportions of the Corinthian pedestal, the difference being that of the scale and the detail of the mouldings.
The capping may be divided into two. The top half consists of a fillet, reversa and facia, and the lower half a supporting cyma recta, a bead and a cavetto curve. The plinth mouldings are the same as those of the Ionic pedestal with the addition of a torus beneath the ogee. The height of this torus is one-fourth the total height and is about equal to that of the cavetto and bead together.
When the pedestal is employed the arch becomes proportionately larger. In the Doric order the columns are then spaced seven and a half diameters apart; in the Ionic seven and three quarters, and in the Corinthian eight diameters centre to centre.
The archivolt, the radius of which is determined by the above spacing, is supported as before by an impost and pilaster. The base of the pilaster consists of a slightly projecting block equal in height to the plinth block of the pedestal.
The height of the arch varies slightly, inasmuch as the inner curve may be about a diameter from the architrave, but in the Corinthian order should not fall below the level of the necking moulding of the capital.