78 THE PARTHENON AND ITS SCULPTURES. lowest course from which the marble tiling starts has its upper surface slanting in the same plane, the lower surface being level- bedded on the cornice beneath. On the upper slanting face are worked stops for the cover-pieces of the tiling, keeping them from slipping. Along its edge antifixffi are attached, one over each metope and triglyph. The marble tiles space up three to every two antifixse, which are thus purely " ornamental." The tiles against the edge of the gables curve upwards forming a cyma- tium to the pediment. At the bottom of the gable the cymatium returns a little way on the flanks, forming blocks from which project fine lions' heads, like spouts, but these also are orna- mental. (Fig. 66.) At the bottom of the row of marble tiles which turns up to form the cymatium is affixed on the slant a stone which for about 8 feet up the roof rises flush with the top of the cymatium, and on it, towards the bottom, is worked a level seating for the base of an acro- terion. This stone is partly caught at J the bottom by the block on which is Fig. 63.— Lacunaria. carved the lion's head. All this is best understood from Penrose's minute analysis, but I give a plan from the Stuart papers at the British Museum. (See Fig. 67 ; A, B, C, D, is the slab bedded on the tiles.) Refinements and Irregularities. The lines and planes of the Parthenon are adjusted and modified in many ways from what we are apt to think should be the normal procedure in building. The stylobate on which the columns rest rises in a curve about four inches at the centre of the flanks while at the fronts it rises about three inches. The architrave follows a similar curve. All the columns have a delicate entasis, that is, in diminishing from the base to the capital they follow a curved profile instead of a straight one. The outer columns of the peristyle lean inwards about three inches, being an angle of about i in 50. " Vertical " parts of the entablature lean still more ; the abaci of the capitals and the faces of the cornice, and other small parts, incline outwards. Perpendicular faces are the exception and not the rule. The
