Since the performance was a state-function, the whole nation was theoretically expected to be present, and in point of fact enormous audiences attended: the great theatre accommodated perhaps 30,000[149] spectators. This fact governs the nature of the whole presentation. The theatre could not be roofed, and the acting therefore differed greatly from that customary in modern buildings. A Greek theatre consisted of three parts—the auditorium, the orchestra, and the “stage-buildings”. The heart of the whole is the orchestra or “dancing-ground” (ὀρχήστρα) upon which the chorus, throughout the action, were stationed—a circular area of beaten earth, later paved with marble. Beside the altar in this orchestra stood, in the earliest days of the theatre, the sacrificial table upon which the single actor mounted. This table in the fixed theatre is the descendant of the waggon from which the peripatetic actor of Thespis delivered his lines. In addition to the celebrants the passive worshippers were needed—the audience. Therefore the orchestra was placed at the bottom of a slope; and the spectators stood or sat on the higher ground. On the farther side rose the “stage-buildings,” whatever from time to time they were. The general plan, then, of any Greek theatre was this:— [Illustration] A is the circular orchestra, B the altar (θυμέλη) of Dionysus which invariably stood in the middle of it. C represents the “stage-buildings”; D, E, F, are the doors which led from the building to the open air. The building usually projected into side-wings (G, G), called παρασκήνια. H, H, are the passage-ways (πάροδοι), by which the chorus generally entered the orchestra, and by which the audience always made its way to the seats. J, J, J, is the auditorium, a vast horseshoe-shaped space rising up a hillside from the orchestra, and filled with benches. This space was intersected by gangways,[150] K, K, L, L, etc., called, perhaps, κλίμακες; the areas M, M, N, N, etc., so formed, had the name “pegs” (κερκίδες). In most theatres a longitudinal gallery O, O, O, was made for further convenience in getting to the seats. In the strictly Greek type the front line of “stage-buildings” never encroached on the circle of the orchestra. But these theatres were used in Roman times also, and altered to suit certain needs. The front of C was thrown forward so that it cut into the orchestra and obliterated the passages H, H. To replace these, entrances were tunnelled through the auditorium. Thus at Athens the orchestra is now only little more than a semicircle, though amid the ruins of the “stage-buildings” can still be seen a few feet of the kerbstone which surrounded the original dancing floor—the only surviving remnants of the Æschylean theatre; this masonry shows that the diameter of the whole was about 90 feet.