The next thing is to study the
principal elements of a Greek temple as seen in elevation.
This brings us to the subject of the Greek "orders." There
are two principal orders in Greek architecture, the Doric
and the Ionic. The term "order," it should be said, is
commonly restricted in architectural parlance to the column
and entablature. Our illustrations, however, show all the
features of a Doric and an Ionic facade. There are several
points of agreement between the two: in each the columns
rest on a stepped base, called the crepidoma, the uppermost
step of which is the stylobate; in each the shaft of the
column tapers from the lower to the upper end, is channeled
or fluted vertically, and is surmounted by a projecting
member called a capital; in each the entablature consists of
three members – architrave, frieze, and cornice. There the
important points of agreement end. The differences will best
be fixed in mind by a detailed examination of each order
Our typical example of the Doric order
is taken from the Temple of Aphaia on the island of Aegina –
a temple probably erected about 480 B.C. The column consists
of two parts, shaft and capital. It is of sturdy
proportions, its height being about five and one half times
the lower diameter of the shaft. If the shaft tapered upward
at a uniform rate, it would have the form of a truncated
cone. Instead of that, the shaft has an entasis or swelling.
Imagine a vertical section to be made through the middle of
the column. If, then, the diminution of the shaft were
uniform, the sides of this section would be straight lines.
In reality, however, they are slightly curved lines, convex
outward. This addition to the form of a truncated cone is
the entasis. It is greatest at about one third or one half
the height of the shaft, and there amounts, in cases that
have been measured, to from 1/80 to 1/140 of the lower
diameter of the shaft.
Observe that the entasis is so slight that the
lowest diameter of the shaft is always the greatest
diameter. The illustration is unfortunately not quite
correct, since it gives the shaft a uniform diameter for
about one third of its height.