and chorus from passing from stage to orchestra and from orchestra to stage whenever they desired. Hence the stage of the fifth century cannot have been raised many feet above the level of the orchestra. The object of the stage was to place the actors in a prominent position, and to ensure that they should not be hidden from view by the chorus in front of them. This purpose would easily be effected by a stage of only a few feet in height. Some easy means of communication between stage and orchestra must have been provided, to enable actors and chorus to pass to and fro. A long flight of steps, or a sloping ascent, may have been used for the purpose. Such then, as far as we can tell, was the character of the stage and stage-buildings during the early period of the Greek drama. The stage-buildings consisted of a long and narrow rectangular structure, made entirely of wood, not less than two stories high, and with side-wings at each end. Between the wings was a platform about fifteen feet deep, and a few feet in height, connected with the orchestra by a flight of steps or in some similar way. This type of building lasted till the end of the fifth or middle of the fourth century. A new departure was then made. Stage-buildings began to be constructed of stone, at any rate in the lower stories. The earliest known examples are those at Athens and Eretria. But the stage itself still remained a wooden one.[399] Its depth was still about fifteen feet. As to its height we have no information.[400] The fourth century was a period of transition and development in the history of the Greek theatre; and it was probably during this century that various new experiments were made in the structure and arrangement of the stage and stage-buildings. But the first steps in the process cannot be traced in detail, owing to the lack of evidence. The final results of the various experiments, as exemplified in the theatres of a later period, will be discussed in the next section. § 8. _The later Stage-buildings of the pre-Roman period._