Part 7

The Appearance of round things, if well design’d, masterly painted, and the Frame cut away to the Out-line of the Work, do wonderfully deceive the Eye. This Figure is drawn from the Plan, as usual; and was put in execution by me, in the Church of S. _Ignatius_ of the _Roman_ College, for the _Thursday_ and _Friday_ of the Holy Week. Within the Arch, on the Altar, was plac’d a sepulchral Urn containing the Holy Sacrament. Beneath the Altar was laid a Figure of our Saviour Christ taken down from the Cross. In the midst of the Tambour, was a Picture of the Blessed Virgin in extreme Sorrow; and on the Ballustrade, Angels mourning, bearing the Instruments of the Passion.

FIGURA Sexagesimaseptima.

Vestigium geometricum, ac prima præparatio ad figuram septuagesimamprimam.

_Egregiam adeò speciem præsetulit, atque oculis adeò imposuit machina quam construxi anno 1685, pro supplicatione quadraginta horarum, in Templo Urbis Farnesiano, ut decreverim satisfacere Studiosis, publici juris faciendo non modò imaginem totius ædificii, sed etiam illius vestigia & elevationes: quæ omnia eâ diligentiâ delineavimus, veluti Opus ipsum non pennicillo colorandum, sed lapidibus extruendum fuisset. Spatia nigrantia soliditatem designant parietum & columnarum. Cæteræ lineæ sunt crepidines stylobatarum & coronicum. Initium delineationis fiet ab iis membris, ex quibus oriuntur lineæ occultæ positæ in ~A~, (quæ autem dicuntur de hac medietate, intelligi debent de aliâ) ne multitudo linearum confusionem pariat. In ~B~ lineæ curvæ occultæ sunt vestigium tholi qui complet summitatem ædificii. Vestigium ~C~ exhibet ambulacrum interius. Omisimus autem vestigium theatri, quia paginæ angustia illud non capit._

The Sixty-seventh FIGURE.

_The Geometrical Plan, and first Preparation to the Seventy-first Figure._

The Machine which I erected in the Year 1685, in the Church _Farneze_, or _Jesuits_ Church at _Rome_, for the Devotions of the _Forty Hours_; had so admirable an Effect, and so pleasantly deceiv’d the Eye, that I resolv’d to gratify the Studious, not only with a general View, but with the Plan and Elevation thereof; all which was perform’d with such Exactness, that the Work itself seem’d rather to consist of solid Stones, than to be wrought by the Painter’s Hand. The hatch’d Part denotes the Solidity of the Walls and Columns. The other shews the Breaks and Projectures of the Pedestals and Cornices. Lest many Lines should cause Confusion, begin with those Members, which produce the occult Lines on the Side A; understanding the same also of the other half. In B the occult curv’d Lines are the Plan of the _Cupola_ which crowns this Structure. The Plan C is that of the inner Vestibule, but that of the Theater is here omitted, through Want of Room in the Page.

FIGURA Sexagesimaoctava.

Elevatio geometrica vestigii præcedentis, & secunda præparatio ad figuram septuagesimamprimam.

_In hoc schemate habes elevationem ædificii sectam in longum, quam figurâ septuagesimâ opticè projiciemus: eisdemque membris constare videbis elevationem deformatam, quibus constat elevatio geometrica. Hinc disces ad excogitandas hujusmodi machinas, eandem Architecturæ scientiam in Pictore necessariam esse, quæ ad construenda solida ædificia exigitur in Architecto._

The Sixty-eighth FIGURE.

_The Geometrical Elevation of the foregoing Plan, and second Preparation to the Seventy-first Figure._

In this Figure you have the Elevation of the aforesaid Structure dissected lengthwise; the Perspective thereof is describ’d in the Seventieth Figure; and you may observe that both of them consist of the same Members: whence you may perceive, that for designing things of this kind, the Painter ought to have no less Skill in Architecture, than is requir’d for the Execution of solid Works.

FIGURA Sexagesimanona.

Deformatio vestigii figuræ sexagesimæseptimæ, & præparatio tertia ad figuram septuagesimamprimam.

_Artificium projectionis vestigii hujus, explicatum à nobis est figurâ quadragesimasecundâ. Nimirum, ut parallelæ sint invicem distantiores, lineam plani deorsum protraximus, ut ex intuitu figuræ statim cognosces._

The Sixty-ninth FIGURE.

_The Plan of the Sixty-seventh Figure in Perspective, and third Preparation to the Seventy-first Figure._

The Artifice us’d in projecting the Perspective of this Plan, has been already shewn in the Forty-second Figure; namely, that for giving the greater Distance between the Parallels, the Ground-line is drawn much lower than its true Place; as is manifest on Inspection of the Figure.

FIGURA SEPTUAGESIMA.

Deformatio elevationis figuræ sexagesimæoctavæ, & præparatio quarta ad figuram septuagesimamprimam.

_Quæ dicta sunt de projectione vestigii nostri ædificii, habent locum in elevatione. Nimirum, ut parallelæ invicem notabiliter distarent, usi sumus industriâ quam declaravimus figurâ quadragesimasecundâ._

The Seventieth FIGURE.

_The Perspective of the Elevation of the Sixty-eighth Figure, and the fourth Preparation to the Seventy-first Figure._

What has been said of the Perspective-Plan of this Structure, is also here practis’d in the Elevation; namely, that the Parallels might be sufficiently distinct, the Perpendiculars are drawn more remote from the Point of Sight, as was shewn in the Forty-second Figure.

FIGURA Septuagesimaprima.

Theatrum repræsentans Nuptias Canæ Galilææ, constructum Romæ, anno 1685. in expositione Ven. Sacramenti in Templo Farnesiano Societatis JESU.

_Ex antecedentibus præparationibus eruimus projectionem nobilis hujus Architecturæ, quæ oculos implebat tum ad lucem solis diurnam, tum præcipuè ad lumen candelarum; ex quibus multæ palam erant expositæ, aliæ omnino latebant, ut illuminarent sex diversos ordines telariorum quibus tota machina constabat, non computando in hoc numero telaria, quæ in medio arcûs maximi exprimebant nubes refertas Angelis adorantibus Venerabile Sacramentum. Nubes istas omisimus, ne absconderentur partes interiorum ædificiorum. In disponendis autem ordinibus telariorum, servatus est modus quem declaravi figurâ sexagesimaprima & sexagesimasecunda; ac præterea in eligenda eorum distantia curatum fuit, ut candelæ in parte postica telariorum collocatæ, illuminarent faciem telariorum interiorum. Porrò quot membra præcipua in duabus faciebus majoribus, totidem distincta telaria numerabantur, quorum proinde connexiones discerni vix poterant; eorumque aliquot paria ferreis hamulis copulata erant, ut explicari ac replicari possent, ad faciliorem tractationem diuturnioremque conservationem._

_Qui hucusque sequuti me fuerint, nihil dubito quin suum iter felicissimè sint prosequuturi; atque Opera his nostris majora melioraque inventuri._

The Seventy-first FIGURE.

_A Theater representing the Marriage of ~Cana~ in ~Galilee~, erected in the ~Jesuits~ Church at ~Rome~, in the Year ~1685~; for the Solemnity of exposing the Holy Sacrament._

From the foregoing Preparations, is drawn the Perspective of this noble Piece of Architecture; which struck the Eye when seen by Day-light, but was more especially surprizing by Candle-light; many of the Candles being expos’d to Sight, and others altogether hidden, to illuminate the six different Ranges of Scenes, of which the whole Work consisted, without reckoning that in the midst of the great Arch, representing Clouds fill’d with Angels adoring the blessed Sacrament. Those Clouds are here omitted, that the inner Parts of the Work might be the better seen. In disposing the several Ranges of Scenes, the same Method was observ’d, which was deliver’d in the Sixty-first and Sixty-second Figures; and great Care was also taken in their Distances, that the Candles plac’d on the Back of one of them might illuminate the Face of the other behind it. Moreover, each Scene consisted of as many parts, as there were principal Members in the two greater Façades; so that the Joints were scarcely discernible: and some Pairs of them being coupl’d with Hinges, folded and unfolded, for the more easy managing and preserving them.

I doubt not but those who have follow’d me thus far, will be encourag’d so to prosecute their Studies, as to be able to design even greater and more noble Works, than these of mine.

FIGURA Septuagesimasecunda.

De theatris scenicis.

_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._

FIGURA Septuagesimatertia.

Aliud vestigium theatri, ubi de modo inveniendi ejus punctum.

_Si pingendæ sint scenæ theatri alicujus antea constructi, delineare oportebit vestigium geometricum ex ipso erutum, (ad formam vestigii quod cernis in hac paginâ) ut inveniatur longitudo theatri, seu distantia quam ejus punctum habet à puncto ~A~: id autem nullo negotio fiet, accipiendo distantias ~BC~ inter primos canales, & ~DE~ inter ultimos, ac ducendo visuales ~MO, NO~: nam theatrum habebit longitudinem ~AO~, ac punctum perspectivæ in vestigio theatri erit ~O~. Præterea scire oportebit longitudinem & latitudinem canalium, eorumque numerum, distantias, & flexus; ac præcipuè curandum est, ut licet sint obliqui ad lineam ~MN~, sint invicem paralleli in unoquoque latere, ac singuli tangant lineas ~MO, NO~. Jam si rectæ ~AO~ fiat æqualis recta ~FA~, in ~F~ erit punctum distantiæ: adeoque si theatrum juxta methodum à nobis tradendam depictum fuerit, spectatori qui consistat in ~F~ apparebit veluti tabula picta juxta leges perspectivæ, posita in ~A~._

The Seventy-third FIGURE.

_Another Plan of a Theater, with the Method of finding the Point of Sight therein._

If it be requir’d to paint the Scenes of some Theater already built, the Geometrical Plan thereof must first be carefully drawn, (as you see, for Example, in this Plate) that the Length of the Theater may be found; or the Distance of its Point from that of A; which is easily done, by taking the Interval BC of the first Grooves, and DE of the latter; and drawing the Visuals MO, NO: for AO is the Length of the Theater, and the Point of Sight, or Perspective, therein, is O. Moreover the Length and Breadth of the Grooves must be known, as also their Numbers, Distance, and Obliquity; and especial Care must be taken, that though they be oblique to the Line MN, that on each Side they be Parallels between themselves, and that they all touch the Lines MO, NO. If you then make AO equal to FA, the Point of Distance will be F; and if the Theater be painted according to the Rules hereafter given, it will appear to him that views it from F, as a regular Piece of Perspective plac’d in A.

Figura Septuages. quarta.

Sectio Scenarum Theatri.

_Præter vestigium Theatri delineanda est sectio scenarum. Itaque si acceptis mensuris altitudinis, quam punctum ~A~ unde incipit tabulatum, ac punctum ~D~ poscenii, habent supra planum horizontale ~FV~, fiant ex perpendiculo ~NV~ tum recta ~ADO~ ex qua innotescit declivitas tabulati, tum recta ~NO~, quæ sit parallela ad ~FV~ & æqualis rectæ ~AO~ figuræ septuagesimætertiæ; punctum theatri in elevatione est ~O~; in poscenio verò punctum theatri est ~Q~. Si maxima scenarum altitudo sit ~EB~, recta ~OE~ dat altitudinem omnium reliquarum. Vera tamen altitudo cujuslibet scenæ est illa quam habet linea major, ex minori autem dignoscitur quantum obliquitas cujusque scenæ apparenter minuat altitudinem extremæ illius lineæ. Porro excessus quo linea major superat minorem tum in summo tum in imo, diligenter notandus est, hinc enim pendet intelligentia figuræ septuagesimæquintæ. Punctum ~M~ quod est remotum ab ~N~ quantum in figura septuagesimatertia punctum ~F~ est remotum ab ~A~, designat locum unde Theatrum spectari oporteat, ut ibidem notavimus._

_In construendo tabulato solet servari hæc regula, ut altitudo puncti ~O~ sit æqualis altitudini oculi, & elevatio ex ~A~ usque ad ~D~ sit nona circiter vel decima pars ipsius longitudinis ~AD~. Expediret autem ad scenas facilius movendas, pavimentum ~F~ esse profundius pavimento ~G~, ut erecto corpore sub tabulato ambulari possit._

Seventy-fourth Figure.

_The Section or Profile of Scenes for Theaters._

Besides the Plan of the Theater, the Section of the Scenes is also to be delineated, for finding the Point of the Theater in the Elevation. Wherefore, setting the Measures of the Heights which the Point A, where the Floor of the Stage begins, and the Point D of the Poscene, have above the Level of the Horizontal FV; from the Perpendicular NV draw the right Line ADO, which gives the Declivity of the Stage; then make NO parallel to FV, and equal to AO of the Seventy-third Figure: The Point of the Theater in Elevation is O; the Point of the same on the Poscene is Q. If EB be the greatest Height of the first Scene, the Line OE determines the Height of all the others. The longest of the two Lines gives the true Height of each Scene; and the shorter discovers how much of that Height the Sight loses on the Out-line, by the oblique Position of the Scenes. Moreover, the Excess of the longer Line above the shorter, as well at top as at bottom, is to be well observ’d; for on this depends the right Understanding of the Seventy-fifth Figure. The Point M, which is as far distant from N, as that of F is from A in the Seventy-third Figure, denotes the Place from whence the Stage ought to be view’d; as is there mention’d.

In laying the Floor of the Stage, this Rule is commonly observ’d, That the Height of the Point O be made equal to the Height of the Eye, and that the Rise of the Floor from A to D, be about a Ninth or Tenth Part of the Length AD. ’Tis also requisite, for the better shifting the Scenes, that the Pavement F be sunk lower than that of G, that a Man may walk upright under the Floor thereof.

FIGURA Septuagesimaquinta.

Elevatio scenarum coram inspectarum: ubi docetur artificium ut scenæ obliquæ appareant rectæ.

_Scenæ quas vides in ~S~, habent suam latitudinem à vestigio figuræ septuagesimætertiæ, altitudinem ab elevatione figuræ septuagesimæquartæ, ac censentur erectæ & canalibus insertæ, quæ omnia repræsentantur etiam figurâ septuagesimasecunda in ~P~ & ~Q~. Velim observes quantum elevetur tabulatum in principio ~A~, in poscenio ~D~, & in puncto theatri ~O~. Similiter notare oportet elevationem singularum scenarum, quæ propter obliquitatem canalium flectuntur introrsum: iccirco lineæ ~BL~, ~KI~, partis ~C~, non videntur parallelæ ad lineam plani, ut reipsa sunt; ac visualis ~LF~ non tendit ad punctum oculi ~O~, sed ad punctum ~F~. Si autem excessus apparens, quem recta ~BK~ habet in summo & imo supra rectam ~LI~ transferatur in partem ~E~ scenarum, (iidem excessus desumi etiam possunt ex figura septuagesimaquarta) ac ducantur rectæ ~LG~, ~IH~, habebuntur lineæ apparenter parallelæ ad lineam plani. Si fiat recta ~LO~, quæ cum ~LG~ faciat angulum ~GLO~ æqualem angulo ~BLF~, eadem ~LO~ tendet exactissimè ad punctum ~O~ oculi, eâque utendum erit ut visuali._

_In ~P~ supponimus scenas ~M~ & ~N~ jacere super pavimento unas super aliis, ac duas lineas ~RT~ habere distantiam eandem cum duabus ~LI~, & ita in reliquis scenis. Ubi notandum est, lineas ~RS~, ~TV~, easdem esse cum lineis ~LG~, ~IH~, scenarum ~E~: nihilominus lineas ~RS~, ~TV~, non esse parallelas, quum tamen ~LG~, ~IH~, videantur parallelæ. Proinde, si fiat recta ~RL~, & anguli ~SRL~, ~GLO~, sint æquales, rectâ ~RL~ utendum erit tanquam visuali, in ~L~ erit punctum accidentale oculi pro pingendis scenis ~N~, ac lineæ ~RS~, ~TV~, habebuntur ut parallelæ: id autem quod superest in telario ultra tales lineas, pro nihilo computabitur, ibique pingetur aer aut aliquid aliud. Punctum accidentale oculi pro pingendis scenis ~M~ erit in ~I~._

The Seventy-fifth FIGURE.

_The Elevation of Scenes in Front, and how the oblique Scenes are made to appear direct._

The Scenes in S have their Breadth from the Plan of the Seventy-third Figure, and their Height from the Elevation of the Seventy-fourth Figure; and are suppos’d to stand perpendicularly in their Grooves; all which is also represented in P and Q of the Seventy-second Figure. I would have you observe, how much the Floor rises, from its Edge A, to the Poscene D, and to the Point of the Theater O. You should also note the Elevation of each Scene, which, by reason of the Obliquity of the Grooves, turn inward: Wherefore the Lines BL, KI, of the Part C, do not seem Parallels to the Ground-line, as they really are; and the Visual LF tends not to the Point of Sight O, but to the Point F. But if the seeming Excess, which the Line BK has at top and at bottom, above the Line LI, be transferr’d on the Side of the Scenes E, (which Excess may also be taken from the Seventy-fourth Figure) and you draw the Lines LG, IH; these Lines will appear Parallels to the Line of the Plan. Then drawing the Line LO, so as to make the Angle GLO equal to the Angle BLF, the said LO shall tend directly to the Point of Sight O; and serve for a visual Line.

In P, I suppose the Scenes M and N to lie one upon another on the Floor, and the two Lines RT to have the same Distance as the Lines LI; and so of the others. Where you are to take Notice, that the Lines RS, TV, are the same with the Lines LG, IH, of the Scenes E: and that the Lines RS, TV, are not Parallels; altho’ LG, IH, seem to be so. Therefore, if you draw the Line RL, so that the Angles SRL, and GLO, be equal; the Line RL shall serve as a Visual, and L shall be the accidental Point of Sight, for painting the Scenes of the Side N; and the Lines RS, TV, shall be us’d as Parallels. What remains on the Frame, beyond those Lines, is to be reckon’d as nothing; but you may paint there Air, or what you please. The accidental Point of Sight for painting the Scenes of the Side M, is I.

FIGURA Septuagesimasexta.

Modus delineandi exemplar scenarum.

_Iterum delineavimus scenas erectas super tabulato; in ~B~ nudas, in ~A~ depictas, additis projecturis coronicum & aliorum ornamentorum. Deformatio scenarum ~A~ eruitur methodo consuetâ ex vestigio ~C~, in quo videbis lineam plani deorsum protractam. Vestigium autem geometricum est in ~D~._

The Seventy-sixth FIGURE.

_The Manner of delineating the Designs of Scenes._

In this Plate you have another Design of Scenes erected on the Floor; the naked Scenes are B; the painted ones A; with the additional Projectures of Cornices and other Ornaments. The Draught of the Scenes A is produc’d from the Plan C, after the usual Manner; in which you may observe the Ground-line to be lower than its true place, for the greater Distinction of the Parallels. The Geometrical Plan is D.

FIGURA Septuagesimaseptima.

Modus reticulandi & pingendi scenas theatri.