It is well known that in the earliest extant Greek plays, viz., the _Suppliants_, _Persians_, and _Prometheus Bound_ of Aeschylus, the scene is laid in the open countryside with not a house in sight and with no scenic accessories except an altar, tomb, or rock, respectively. But that this circumstance was explicable by the character of the Athenian theater did not become evident until Dr. Dörpfeld’s excavations on that site in 1886, 1889, and 1895 (see pp. 65 ff., above, and Figs. 32 and 32_a_). From 499 B.C. until about 465 B.C. the theater at Athens consisted of an orchestral circle nearly eighty feet in diameter and somewhat south of the present orchestra, and an auditorium arranged partly about it on the Acropolis slope. Immediately behind the orchestra there was no scene-building or back scene, but a six-foot declivity. Only within the orchestra itself, at the center or to one side, might there be erected for temporary use some such theatrical “property” as an altar or tomb. Consequently it was inevitable that playwrights of the early fifth century in choosing an imaginary scene for their plays should react to these physical conditions and localize the dramatic action in more or less deserted spots. Even as late as Aeschylus’ _Seven against Thebes_ (467 B.C.), although the scene no longer is laid in the countryside but on the Theban Acropolis, yet this is still a place without inhabitants or houses. It should be noted that at this period the exclusive mode of ingress and egress was by the side entrances, the parodi; under normal conditions, any movement into the orchestra or out of it, at the rear, was entirely precluded by the declivity. That such a primitive theater would suffice for the needs of that or even a later period is proved by the remains of the structure at Thoricus (Figs. 70 f.),[310] which was never brought to a higher state of development (see p. 103, above), and by the fact that even at a later period dramatists sometimes voluntarily reverted to this unpretentious stage setting. For example, in Sophocles’ _Oedipus at Colonus_ the background represented the untrodden grove of the Eumenides, so that practically all the entrances and exits were restricted to the parodi. An exceptional rear exit is afforded by Aeschylus’ _Prometheus Bound_, and an exceptional rear entrance by the next play in the trilogy, the _Prometheus Unbound_. We have already seen (see pp. 166 f. and 174, above) how in the former play the hero, being represented by a dummy, cannot speak until Hephaestus leaves the scene by a side entrance and makes his way behind the rock upon which Prometheus is bound. In the absence of a scene-building, the six-foot declivity must have been utilized to conceal the second half of this movement. Now the _Prometheus Bound_ ends as the Titan and his crag sink into the depths; at the beginning of the _Prometheus Unbound_ this crag has emerged from the abyss. What was the reason for this maneuver? Obviously