It has, however, become modern practice to lower the curtain and change (shift) settings out of sight of the audience, although this is occasionally also done with all lights out and curtain up on a dark stage. This mechanistic age has added very little that is mod ern to the devices of Renaissance and antiquity, except—and this only occasionally—to work them by electric or hydraulic power. The modern mechanisms which were generally part of the techni cal equipment only of German municipal and State theatres built between 1875 and 19oo are three : The Sliding Stage, in its essentials, the eccyclema of the Greeks, is built to run on tracks and is generally driven by electric power. Groups of two or three sliding stages are usually employed. Each sliding stage is as wide as the stage opening (called the proscenium opening or proscenium arch). While scene z is play ing scene 2 is being "set" (set up) or is already in place. The curtain is lowered for an instant and scene 2 is pushed into space. The wagon stage, holding scene 1, is then "off stage" (out of sight) and can be rebuilt with scene 3 and the process reversed.
Or if the scenes are not long enough to allow this, three sliding stages can be used and scene 3 be ready off stage with scene drawn to the back (up stage). By the time scene 3 is over, there is invariably time for scene i to be "struck" (taken down) and replaced by scene 4, and the process continues indefinitely. The advantage of this system is that the time between shifts and scenes is reduced to a minimum; the disadvantage is that it requires a stage of such tremendous size that the ground rent of most cities precludes its use, unless the theatre is owned or sub sidized by the municipality. For this reason this system of scene shifting, notwithstanding its numerous advantages, has not be come widespread.
The Revolving Stage, which was traditional on the Japanese popular stage, was seen there by the German technician, Lauten schlager, copied literally and imported into Germany. It is a turntable set level with the stage floor, and propelled by a windlass from below. The settings are arranged on it in rotation like the segments of a pie, all set before the play begins, and can be shifted in the twinkling of an eye. The advantages are obvious: speed of shifts and the fact that heavy and high constructions, such as rocks, walls, etc., can be used, which would be only slowly and laboriously moved in any other way. The disadvantages, less obvious, are : (I) In order to get a maximum number of scenes on to the circle of the turntable, they have to be triangular in shape—often a decided pictorial limitation. (2) Each sector must be so completely bounded as to hide the others, an open stage under a full sky, often artistically desirable, being impractical.
(3) A deep stage for mob scenes, etc., often cannot be arranged for the same reason. (4) For any great number of scenes, as in a Shakespearian performance, even the largest revolving stage is inadequate. This can be obviated by ingenious dove-tailing for which Max Reinhardt and his designer Stern were particularly noted, and also by the practice, common in Germany, of beginning theatrical performances at 7.00 or 7.3o and having a half-hour intermission for refreshment in the course of the evening, during which an entirely new sequence of scenes can be set up for the rest of the evening. For this reason the revolving stage is not com mon outside of Germany. Moreover, for certain kinds of scene shifts, as in Ibsen's Little Eyolf, where a three-sided interior must alternate with an exterior, an unobstructed view over the fjords, it is of no use whatsoever. The revolving stage cannot therefore be exclusively relied upon. And for that reason alone the expense of installing it usually bars it from being built as part of a theatre's equipment.
The Sinking Stage, of which the most notable types are those in Germany, built by Hasait and Linnebach for the Dresden opera house and State theatre respectively. The stage floor from front to back is divided into three large platforms which are supported by elevator plungers. Each section can be raised independently to turn the stage into a series of grandiose terraces or lowered separately to the cellar and a new scene set and brought into place. In conjunction with sliding stages, as Linnebach uses it, there is no problem of scene-shifting that cannot be easily and successfully solved. The sinking stage allows for more freedom of design than the segmental system of the revolving stage, and the interior and exterior scenes can succeed each other with ease. It was devised to offset the limitations of the revolving stage which had become apparent by 189o. Unfortunately, it is extremely costly to in stal. The machinery required to move these platforms, heavily weighted with settings at sufficient speed to make scene-shifts quickly, is an elaborate piece of mechanical engineering, and the necessity for excavating a deep cellar underneath the stage adds greatly to the initial cost of constructing a theatre. For these reasons, except in playhouses whose repertory involves a daily change of classics or opera on a lavish scale, the capital investment is usually prohibitive. In consequence, elevator stages are not common even in Germany.