two equal parts, in conformity with the rule of Vitruvius.
The projection of the step before the line of the shaft varies
inconsiderably.
We have no data for ascertaining the original height of
the columns of this Ionian temple. Ttherefore suppose the
species of the temple to have been either eustyle or systyle,
and consequently the height of the column, including the
capital and base, to have been 9½ diameters or 40.2.6. As
the columns exceed 25 feet in height, the extent of the
abacus of the capital is to be made equal to the lower
diameter of the shaft and one ninth part, or 4.8.44; which
exceeds the abacus of the other by 4.84 inches. But it is to
be observed that, when the height of the column exceeded
40 feet, the upper diaméter was to the lower in the ratio of
7 to 8: hence the upper diameter of the shaft ought to be
3.8.45; which is greater than the diameter of the other
column, and consequently requires a greater extent of
abacus.
The depth of the volute, according to Vitruvius, should
be eight parts of the nineteen, into which the extent of the
abacus is divided: this depth, therefore, in the Vitruvian
column will be 1.11.76, which differs from that of the other
by of an inch only.
PLATE VIII.
Fig. 1. The volute at large described from the different
centres.