The machinery of the ancient stage seems to have been very complicated. Of most of the theatrical machines we know only the names, and can form but a very insufficient conception of them. A contrivance in very frequent use was the “rolling-out machine” (ἐκκύκλημα), which, according to the statements of ancient writers, was used to show the spectators proceedings in the interior of a house--as we should say, “behind the scenes;” for in the Greek drama the scene was never laid inside a room, but everything went on in the open air. Our authorities do not, however, enable us to form any clear conception of this contrivance; probably the background opened out in some way, and the person or group which was to be seen on the machine was rolled out on a wooden scaffolding moving on rollers or wheels, which must, of course, have been decorated in some way; in some cases it may have been unnecessary to open out the background, and sufficient for the machine to be pushed in through one of the three doors. There was a similar contrivance for rolling out persons who were to be shown in the upper storey of a house at a corresponding height above the stage, as we see from the “Acharnians” of Aristophanes, where Euripides appears in this manner on a sort of balcony in the upper storey. Another contrivance bore the special name of “machine” (μηχανή), and was the origin of the expression _Deus ex machina_, used when a god, descending from Olympus, violently cut the knot of the action; this was used for suspending in the air gods, heroes, or mortals, but especially those persons who had to appear above as though flying. We cannot tell where this machine was attached, and how it was worked; there seems to have been a contrivance of this kind on either side of the stage, above the side entrances, near the side pieces, and the one on the left was used by gods, while that on the right was used for other purposes. The machine itself must usually have been kept in some upper storey of the stage structure. It must have been a somewhat dangerous means of transit; the actors who had to perform this aerial journey were usually bound fast with ropes or girths, and in the “Peace” of Aristophanes Trygaeus, when mounting on his aerial horse, the dungbeetle, which must have been a similar flying machine, implores the manager of the machinery, who has to superintend all these arrangements, to be very careful that he does not come to grief. The “gods’ speaking-place” (θεολογεῖον) appears to have been a scaffolding above the chief entrance in the background, on which the gods appeared, probably surrounded by clouds; it differed from the “machine” in showing the gods peacefully throned above, instead of bringing the Olympian deities down to earth. Connected with the “machine” was the “crane” (γέρανος), a crane-like machine let down from above, which was used when human beings were to be lifted up from the stage; as, for instance, when