Theatris quæ jam delineavimus affinia sunt theatra scenica: in his tamen non adeò facilè reperitur punctum oculi seu perspectivæ. Præterea, quia ex obliquitate canalium intra quos moventur scenæ, oritur ut lineæ rectæ quæ videri debent parallelæ ad lineam plani, non debeant esse parallelæ sed obliquæ, harum delineatio difficultate non caret. Incommodum istud vitari posset adhibendo canales parallelos ad poscenium, ut alicubi fieri solet, præsertim in Germaniâ. Nihilominus usus Italicus affert hoc adjumentum, ut illi quibus incumbit suggerere actoribus, vel scenas movere, aliisque similibus præesse, facilius lateant & liberius fungantur munere suo.
Ut brevem summam habeas eorum quæ deinde latius declaraturi sumus, hanc figuram contemplare. 1, 2, 3, 4, est vestigium aulæ quæ habet in longitudine centumviginti palmos Romanos, in latitudine sexaginta palmos; ut ostendit scala S triginta palmorum. Medietatem loci occupat theatrum, medietatem obtinent podia & loca spectatorum. O punctum in quo uniuntur lineæ visuales, D locus pro apparentiis rerum magis ac magis distantium. BC locus poscenii. HH sunt canales obliqui, quorum latitudo est dupla latitudinis scenarum. FG frons & facies theatri. AO ejus profunditas aut longitudo. E locus pro psaltibus, tibicinibus, & fistulatoribus. K spatium pro spectatoribus. I vestigium podiorum. L scalæ podiorum. N ipsorum elevatio. M declivitas tabulati, cum sectione & elevatione theatri, & scenis ex latere inspectis, quæ cum suis canalibus congruunt, ut demonstrant lineæ occultæ. OO linea normalis ad lineam horizontalem. P & Q elevatio scenarum coram inspectarum, quæ introrsum flectuntur; & in latitudine congruunt cum canalibus vestigii B, in altitudine cum sectionibus elevationis M; ut constat ex lineis occultis. In eâdem elevatione M pars altitudinis tribuenda est scenis, pars laquearibus R, per quæ jungitur unumquodque par telariorum. VV lineæ ad explorandum an detur vacuum inter scenas & laquearia, vel inter scenas, vel inter laquearia. In quibusdam autem scenis, loco laquearium pinguntur nubes & aer.
The Seventy-second FIGURE.
Of Scenes for the Stage.
Scenes for the Stage have very much Affinity with those lately describ’d, but the Point of Sight is not so easily found in these; and from the Obliquity of the Grooves in which the Scenes run, it comes to pass, that the right Lines which ought to appear parallel to the Line of the Plan, must not be drawn parallel thereto, but oblique; which is a Work of some Difficulty. This indeed may be avoided, by fixing the Grooves parallel to the Poscene; as is usual in some Places, especially in Germany. Nevertheless, the Italian Manner has this Advantage; That those who are employ’d to prompt the Actors, and shift the Scenes, &c. are less expos’d to Sight, in the Performance of their Business.
In this Figure I have given you an Abridgment of those things, which shall hereafter be more enlarg’d on. The Numbers 1, 2, 3, 4, denote the Area of a Hall an hundred and twenty Roman Palms in Length, and sixty in Breadth; as is manifest from the Scale of thirty Palms mark’d S. Half this Space is taken up by the Stage, the other half by the Spectators. O is the Point in which the visual Lines concenter. D is the Place of those things that are to appear most remote. BC is the Place of the Poscene. HH are the oblique Grooves, whose Lengths are double the Breadth of the Scenes. FG is the Front of the Stage. AO is its Depth or Length. E is the Place for the Musick. K is the Room for Spectators. I is the Plan of the Galleries. L the Stairs to the same. N is the Elevation of the Galleries. M shews the Declivity of the Floor, with the Section and Elevation of the Stage and Scenes view’d on the Side; answering their respective Grooves, as the occult Lines demonstrate. OO is a Line perpendicular to that of the Horizon. P and Q are the Elevation of the Scenes view’d in Front, turning inwards, in Breadth agreeing with the Length of the Grooves of the Plan B; and in Height answering that of the Sections of the Elevation M; as is evident from the occult Lines. In this Profile M, part of the Height belongs to the Scenes, and part to their Soffites, or Ceilings, R; where each Pair of these Frames are join’d. VV are the Lines by which is espy’d what Vacancy there is either between the Scenes and their Ceilings, between the Scenes themselves, or between their respective Ceilings; though in some Scenes the Place of these last is supply’d by painting therein the Air with Clouds, &c.
