Architecture: Classic and Early Christian

by T. Roger Smith; John Slater

The cornices employed in classic architecture may be almost invariably subdivided into three parts: the supporting part, which is the lowest,—the projecting part, which is the middle,—and the crowning part, which is the highest division of the cornice. The supporting part in a Greek Doric cornice is extremely small. There are no mouldings, such as we shall find in almost every other cornice, calculated to convey the idea of contributing to sustain the projection of the cornice, but there are slabs of marble, called mutules (Fig. [64]), dropping towards the outer end, of which one is placed over each triglyph and one between every two. These seem to recall, by their shape, their position, and their slope alike, the ends of the rafters of a timber roof; and their surface is covered with small projections which resemble the heads of wooden pins, similar to those already alluded to. The projecting part, in this as in almost all cornices, is a plain upright face of some height, called “the corona,” and recalling probably a “facia” or flat narrow board such as a carpenter of the present day would use in a similar position, secured in the original structure to the ends of the rafters and supporting the eaves. Lastly, the crowning part is, in the Greek Doric, a single convex moulding, not very dissimilar in profile to the ovolo of the capital, and forming what we commonly call an eaves-gutter.

At the ends of the building the two upper divisions of the cornice—namely, the projecting corona and the crowning ovolo—are made to follow the sloping line of the gable, a second corona being also carried across horizontally in a manner which can be best understood by inspecting a diagram of the corner of a Greek Doric building (Fig. [57]); and the triangular space thus formed was termed a pediment, and was the position in which the finest of the sculpture with which the building was enriched was placed.

In the Parthenon a continuous band of sculpture ran round the exterior of the cell, near the top of the wall.

One other feature was employed in Greek temple-architecture. The anta was a square pillar or pier of masonry attached to the wall, and corresponded very closely to our pilaster; but its capital always differed from that of the columns in the neighbourhood of which it was employed. The antæ of the Greek Doric order, as employed in the Parthenon, have a moulded base, which it will be remembered is not the case with the column, and their capital has for its principal feature an under-cut moulding, known as the bird’s beak, quite dissimilar from the ovolo of the capital of the column (Fig. [65]). Sometimes the portico of a temple consisted of the side walls prolonged, and ending in two antæ, with two or more columns standing between them. Such a portico is said to be in antis.

Fig. 65.—Elevation and Section of the Capital of a Greek Anta, with coloured decoration.

The Parthenon presents examples of the most extraordinary refinements in order to correct optical illusions. The delicacy and subtlety of these are extreme, but there can be no manner of doubt that they existed. The best known correction is the diminution in diameter or taper, and the entasis or convex curve of the tapered outline of the shaft of the column. Without the taper, which is perceptible enough in the order of this building, and much more marked in the order of earlier buildings, the columns would look top-heavy; but the entasis is an additional optical correction to prevent their outline from appearing hollowed, which it would have done had there been no curve. The columns of the Parthenon have shafts that are over 34 ft. high, and diminish from a diameter of 6·15 ft. at the bottom to 4·81 ft. at the top. The outline between these points is convex, but so slightly so that the curve departs at the point of greatest curvature not more than ¾ in. from the straight line joining the top and bottom. This is, however, just sufficient to correct the tendency to look hollow in the middle.

A second correction is intended to overcome the apparent tendency of a building to spread outwards towards the top. This is met by inclining the columns slightly inwards. So slight, however, is the inclination, that were the axes of two columns on opposite sides of the Parthenon continued upwards till they met, the meeting-point would be 1952 yards, or, in other words, more than one mile from the ground.

Another optical correction is applied to the horizontal lines. In order to overcome a tendency which exists in all long lines to seem as though they droop in the middle, the lines of the architrave, of the top step, and of other horizontal features of the building, are all slightly curved. The difference between the outline of the top step of the Parthenon and a straight line joining its two ends is at the greatest only just over 2 inches.