The Greeks made use of the vertical and horizontal line in their architecture; the curved line was not used, except, of course, in decoration. The half-diameter of the column was the module or unit by which the whole building was measured, and the column was limited in height according to the diameter of its base. This did not preclude freedom in design; on the contrary, freedom was allowed and practised to such an extent that hardly two Grecian buildings of any one order were alike in proportion or design. Even the mouldings were varied in curve and proportion; these members that were with the Romans merely segments of circles, were in section with the Greeks either parts of the curve of the ellipse or parabola, and in many cases were designed by freehand. Some very subtle devices to overcome natural optical effects when viewing the buildings have been discovered by Mr. Pennethorne and Mr. Penrose, more especially in the Parthenon.
It is well known that the entasis, or slight swelling made in Greek columns, which makes a convex line of their profiles, is done to prevent the column from looking hollowed in the centre, which it would do if it were perfectly straight; but in addition to this the architects above named have discovered in the Parthenon a correction in the vertical lines, to prevent the apparent tendency which all high vertical lines have to spread out at the top, in the making of the columns to incline slightly inwards; and the steps of the basement and horizontal lines of the architraves are found to be slightly curved upwards in the middle to prevent the tendency that all long horizontal lines have to droop in the middle.
Thus we learn how admirably painstaking, and how well the Greeks applied their profound knowledge to their architecture, as they did in everything else.
The joints of their marble masonry were as a rule so fine and accurate in the fitting together, that it has been said a razor edge could not be inserted between them.
Fig. 300.—The Parthenon. Greek Doric, enlarged Section of Annulets at A.
The Greek Doric order (Fig. 300) is without a base; the shaft of the column has twenty flutings; sunk lines or rings encircle the shaft a little below the moulding of the capital. This moulding—the echinus—is of the best possible profile that a supporting member could have; it is divided from the shaft by three or five annulets. Above the echinus rests the square tile-like cap—the abacus—which carries the architrave. The latter is a marble beam with square ends, and above the architrave is the frieze separated by a band (taenia). The frieze has triglyphs alternating with metopes. The former consists of channelled pier-like forms one over and one between each column, and the metopes are square panels between two triglyphs on which are usually found sculptured subjects. At the bottom of each triglyph, separated by a fillet, is a row of pegs, cylindrical or conical in shape, called “guttæ” or drops.
Above the frieze the cornice projects, which in profile consists of a flat band—the corona—and the crowning member, an ovolo moulding. Under the projecting eave of the cornice are slanting slabs of marble—parallel to the roof tiles—placed one over each triglyph, and one over each metope. These are called mutules, and they have rows of guttæ on their under surface.
The crowning members of the cornice are carried around the sloping lines of the triangular pediments at each end of the building. On the pediments were sculptured the figure subjects that had usually some relation to the divinity to whom the temple was dedicated; as, for example, on the Parthenon pediment the story of the birth of Athene was the subject executed and designed by Phidias, who also was the sculptor of the celebrated Panathenic frieze that adorned the outer part of the cella of the Parthenon. Ictinus was the architect of the Parthenon and also of the temples of Apollo Epicurius at Bassæ and at Phigallia, both in Arcadia. The Parthenon was finished about B.C. 438.
