The use of painted scenery, natural as it appears to us, was only invented very gradually by the Athenians. For a long time the erection at the back of the stage continued to retain its original character. It was regarded, not as a back-scene, but merely as a retiring-place for the actors. The notion of covering it over with painted scenery, in such a way as to make it represent the supposed scene of action in the play, was a development of comparatively late times. The old drama had no scenic background. The action was supposed to take place in some open region; the decorations were confined to such properties as could be put up on the stage; the wooden hoarding in the rear was nothing more than the front of the actors’ room. Things were still in this primitive condition when Aeschylus wrote his four earlier plays. The progress of the art of scenic decoration can be traced very distinctly by comparing these plays with his later tragedies. In the first four there is no mention of any scenery, no clear definition of the exact spot where the action is taking place. The scenic appliances are limited to properties erected in front of the hoarding. In the Supplices the scene is laid in an open district at some distance from the city. In the centre is an altar of the gods, at which the suppliants take refuge.[566] Otherwise there is a total absence of local colouring. In the Persae, the next in order of his plays, the action is also laid at a distance from the palace. The only object mentioned as actually in sight is the tomb of Darius.[567] In the Septem the performers are gathered together within the walls of Thebes beside an altar on some rising ground, from which the towers of the city are visible.[568] But there is no clear definition of the scene, and no mention of any palace or other building from which the actors make their entrance. In the Prometheus the action takes place in a rocky region of Scythia. But in all probability the cliff to which Prometheus is chained was merely built up upon the stage. There is nothing in the play to suggest an elaborate representation of the view. In these four plays the background was still a bare wall with doors for the actors. It had no scenic significance. But when we come to the Oresteia, the last dramatic production of Aeschylus, a great change is noticeable. The scene is now laid in front of a building which is clearly defined and frequently referred to. In the first two tragedies it is the palace of Agamemnon at Argos; in the third it is the temple of Apollo at Delphi, and later on the temple of Athene at Athens.[569] The contrast between these plays and the earlier ones, as regards local colour and allusions to the scene of action, is very marked and conspicuous, and denotes a considerable advance in the art of mounting a play. The old actors’ booth had now become a regular scenic background.[570] The bare hoarding was covered with painting, to represent a palace, or a temple, or whatever else might