The essential point in all this compacting is: when cumbered with more scenes than you wish to use, determine first which scenes contain indispensable action, and must be kept as settings; then consider which of the other scenes may by ingenuity be combined with them.
Evidently a dramatist must develop great ingenuity and skill in so re-working scenes originally conceived as occurring in widely separated places and times that they may be acted in a single set. As has been said, the audience of the public theatres in Shakespeare's day imaginatively shifted the scene at any hint from text, stage properties, or even signs. With the Restoration came elaborate scenery, a gift from earlier performances at the English court and from the continental theatres which the English nobility had attended in their exile. By means of the "drawn scene" dramatists now changed rapidly from place to place. In _The Spanish Friar_, Scene 1 of Act II is "The Queen's ante-chamber." For Scene 2, "The scene draws, and shows the Queen sitting in state; Bertram standing next her; then Teresa, etc." These drawn scenes held the stage until very recently. Painted on flats which could be pulled off stage from left and right, these scenes could not be "drawn" without hurting theatrical illusion. If moved in any light, all illusion departed; if changed in darkness, but not instantaneously, they interfered with illusion. To overcome these objections there have been many inventions in recent years--Revolving, Wagon, Sinking Stages.[16] Undoubtedly, these make changes of scene within the act well-nigh unobjectionable. The difficulty with them is that most are elaborate and expensive, and therefore exist in only a few theatres. It is, consequently, useless to stage a play with them in mind, for on the road it will not find the conditions of production essential to its success. Occasionally, as in _On Trial_, some simple, easily portable device makes these very quick changes possible even on the road. At present, though invention tries steadily to make change of scene so swift as to be unobjectionable, it is wiser to keep to one setting to an act, unless the play will greatly suffer by so doing, or the change is one which may be made almost instantaneously when the lights are lowered or the curtain dropped.