of the depression in front, it raises the height of the actual seat to 15 inches. A seat of this kind would be rather low for a man of average size. But it was the practice of the Greek spectator to provide himself with a cushion, which would raise the surface to a more comfortable level. The structure of the tiers in the manner described appears to have been due to a desire for economy in the use of space. In a Greek theatre, where an immense number of people had to be accommodated with seats in tolerable proximity to the orchestra and stage, it was necessary to place them as close together as possible. If the surface of each tier had been perfectly flat from front to back, the distance between the successive tiers must have been considerably increased, in order to obtain a height of 15 inches. The depression in the tiers provided the requisite height, while allowing a much smaller interval. Along the front of the rows of seats were two sets of vertical lines engraved in the stone. The lines in the first set were 13 inches apart; the lines in the second, which are rather fainter, were at intervals of 16 inches. Probably the second series of lines was intended to mark off the separate seats. In the first series the intervals are too narrow for this purpose, and can only have served as general measures of distance. For the purpose of giving access to the different parts of the auditorium a series of passages ran in divergent lines, like the spokes of a wheel, from the orchestra up to the outside boundary. The passages were fourteen in number, and the two upon the extreme south at each side adjoined immediately upon the boundary walls. In theatres of large size, such as those of Epidaurus and Aspendos, it was usual to insert extra passages in the upper part of the auditorium. The manner in which they were arranged will be seen by looking at the plan of the Epidaurus theatre (Fig. 6). At Athens the upper portion of the building has so entirely disappeared that it is impossible to say whether it ever contained additional passages of this kind. But the great size of the theatre makes it probable that such was the case. These vertical passages were always very narrow, in order to save room. At Athens they were only about 27 inches in width, the result being that not more than one person could ascend at a time. The arrangement of the steps along the passages in the Athenian theatre was altogether exceptional, and is only paralleled at the Peiraeeus. In all other Greek theatres each tier of seats had two steps corresponding to it in the vertical passages. But at Athens, and also at the Peiraeeus, there was only one step for each tier of seats. As the seats were 13 inches high, while the steps were only 8½, it was necessary to make up the difference by building the steps with a sloping surface. The surface was furrowed over, to make the ascent more easy. The fourteen passages divided the auditorium into thirteen blocks. Such blocks were called