It remains to consider some of the expedients which the poets found useful in solving the difficulties (both of time and place) caused by local conditions. In the first place the practice of writing a series of three plays on the same general subject (see p. 198, above) often enabled the playwright to distribute his incidents in different places and time-spheres without loss of verisimilitude, for a whole trilogy was no longer than the average modern play, and each tragedy would thus correspond to a single act and, since the chorus was withdrawn at the close of each play in the trilogy and its place taken by another entirely different, changes of time and place between plays were absolutely without restriction. Thus Scythia of Aeschylus’ _Prometheus Bound_ becomes Caucasus in the second piece in the trilogy, the _Prometheus Unbound_; in the former was shown the binding of the Titan and in the latter his release, and he is said to have been bound for 30,000 years. All but two days of this time elapses between plays! In Aeschylus’ Orestean trilogy the scene of the _Agamemnon_ and _Libation-Bearers_ is laid in Argos; that of the _Eumenides_ in Delphi and Athens. Several years are supposed to pass by in the two interims. But even Aeschylus did not always employ the trilogic form, and Sophocles and Euripides rarely did. When, therefore, the three or four plays in each series were severally devoted to utterly unrelated material, it sometimes became necessary to bring almost as many events within the scope of one play as would otherwise be dealt with in a whole trilogy. Inasmuch as a large fraction of these events could not possibly be conceived of as taking place in the same locality or within the same day, it was imperative either to exclude them or to include them in some indirect fashion. Now two striking peculiarities of Euripidean technique were admirably adapted to help solve these difficulties. His prologues regularly take the form of a monologue, which, with scant regard for dramatic illusion, rehearses the story of the myth up to the point where the play begins. Again, Euripides’ dramas frequently terminate with the epiphany of a deity. This device was the accustomed recourse of unskilful playwrights, when their plots had become complicated beyond the possibility of disentanglement by natural means, in order that a god’s fiat might resolve all difficulties. It has often been charged that this was also Euripides’ motive, but most unjustly (see pp. 293 ff., below). He rather “wished, by the help of a divine foreknowledge, to put before the spectators such future events or unknown circumstances as should settle their minds, satisfy all curiosity, and connect the subject of the piece with subsequent events or even with the times of living men.”[329] Thus in Euripides’ _Andromache_ the complications of the plot are entirely solved before Thetis’ appearance at vs. 1231, and she merely gives directions for Neoptolemus’ burial and prophesies