The entablature which formed the superstructure consisted first of a square marble beam--the architrave, which, it may be assumed, represents a square timber beam that occupied the same position in the primitive structures. On this rests a second member called the frieze, the prominent feature of which is a series of slightly projecting features, known as triglyphs (three channels) (Fig. 63), from the channels running down their face. These closely resemble, and no doubt actually represent, the ends of massive timber beams, which must have connected the colonnade to the wall of the cell in earlier buildings. At the bottom of each is a row of small pendants, known as guttæ, which closely resemble wooden pins, such as would be used to keep a timber beam in place. The panels between the triglyphs are usually as wide as they are high. They are termed metopes and sculpture commonly occupies them. The third division of the entablature, the cornice represents the overhanging eaves of the roof. [Illustration: FIG. 63.--DETAILS OF THE TRIGLYPH.] [Illustration: FIG. 64.--DETAILS OF THE MUTULES.] 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.