In size these proscenia usually conformed to the rules of Vitruvius, and were about ten feet deep, and from ten to twelve feet high. But sometimes they were much lower than he directs. The proscenium at Oropus was only 8 ft. 2 in. in height, that at Priene only 8 ft. 8 in.[419] The proscenium at Delos is given variously as 8 ft. 3 in. and 9 ft. 2 in.[420] On the other hand, the stages at Athens and at the Peiraeeus were thirteen feet above the level of the orchestra.[421] The wings by which the stage was enclosed on each side sometimes projected a few feet beyond the front line of the proscenium, as at Athens. Sometimes, as at Eretria, there was no projection, and the front of the wings was continuous with that of the stage. In many theatres, again, such as those of Megalopolis and Sicyon, there were no permanent side-wings, and the stage was terminated at each end by a mere wall.[422] In such cases it is probable that during the dramatic performances temporary side-wings of wood were erected. The theatres of Epidaurus, Oropus, Sicyon, and the later buildings at Eretria exhibit a peculiar feature in the shape of certain ramps or sloping passages visible to the audience and leading up from the parodos and the outside of the stage-buildings to the door in the walls terminating the ends of the stage. The position of those ramps is clearly shown in the plan of the Epidaurian theatre (Fig. 6). It is possible that they were used by the chorus for the purpose of descending from the first floor of the stage-buildings to the entrance of the parodos. But probably they served mainly for the entrance of actors who represented persons supposed to be coming from a distance. The objection of Robert and Dörpfeld[423] that the actor would have to come up the ramps and wait at the door of the side-wings in view of the audience for his cue, before he could enter—which they justly say would be a ridiculous sight—assumes what it is quite unnecessary to assume, namely, that plays were performed without practice or proper stage-management. Very little rehearsal would be required in order that the actor’s arrival might be duly timed. A different device for the entrance of such actors is found at Priene and Assos. There are no side-wings, but the stage is rather longer than the back-scene or the buildings of which the back-scene formed the face, and is continued for some distance down each side of the buildings. The ends of the stage are terminated by a wall containing no door. The idea seems to have been that the persons supposed to come from a distance should make their way down one of the passages on each side of the skene, and so come round the corner of the stage. The theatres at Delos, Termessos, and Ephesus seem to have employed variations of this device.[424]