Fig. lvii.
Fig. lvii.
Adumbratio figuræ sequentis.
Figuramhanc seorsim delineavi, ut videas quomodo facienda sit operis totius adumbratio, accipiendo altitudines membrorum singulorum ex elevatione; latitudines & longitudines ex vestigiis. Quæ omnia ex diagrammatis inspectione clarissimè apparent.
The rough Draught of the following Figure.
I havedrawn this Figure apart, that you may see the Manner of describing the Out-line of the whole Work, by taking the Heights of the several Members from the Elevation, and their Breadths and Lengths from the Plans; all which is very plain, upon Inspection of the Figure.
Fig. lviii.
Fig. lviii.
Ædificium Ordinis Corinthii octangulare.
Hucusquedescripsimus pilas anticas sinistras ædificii Corinthii. En hoc loco medietatem dexteram totius Operis. Integrum verò ædificium habebis figurâ sexagesimâ.
Part of an Octangular Work of theCorinthianOrder.
Hithertothe nearest left-hand Quarter of thisCorinthianDesign has been describ’d. In this Plate you have the right-hand Half of the whole Work; and in the Sixtieth Figure, the entire Perspective compleat.
Fig. lix.
Fig. lix.
Vestigia tabernaculi octangularis.
Projectionesrerum octangularium sunt quadratis difficiliores: ideò in eis explicandis diligentiæ non peperci. Moles cujus vestigia vides inA&B, convenit in multis cum eâ quam ereximus figurâ quinquagesimaoctavâ. VisualisCDrecipit sectiones perpendicularium, quæ deserviunt pro elevatione figuræ sequentis, ut sæpius dictum est. Si facies interior delineanda sit seorsim à facie anteriori, illam perficies ope linearumCE, istam ope linearumFD.
The Plans of an Octangular Tabernacle.
OctangularFigures being more difficult to be put in Perspective, than the Square; I shall use my best Endeavours to render the Method as plain as possible. The Composition whose Plans you see in A and B, has much Affinity with that describ’d in the Fifty-eighth Figure. The Visual CD receives the Sections, from which Perpendiculars are rais’d for the Elevation and Profile of the following Figure, as has been often said. If you would delineate the Back-part separate from the Fore-part, you may do the former by means of the Line CE, and the latter by that of FD.
Fig. lx.
Fig. lx.
Tabernaculum octangulare.
Hoctabernaculo aliquoties usus fui pro expositione quadraginta horarum. Si colores scitè inducti fuerint in duos ordines telariorum, resectis omnibus quæ ad molem ipsam non pertinent, spectatoribus imponet, & solida videbitur. Oportebit autem exemplar externæ faciei eruere ex parteDFvestigii & elevationis; exemplar interioris faciei eruere ex parteEC, servando in omnibus regulas quas hucusque tradidimus.
An Octangular Tabernacle in Perspective.
I havesometimes made use of this Tabernacle for the Exposition of theForty Hours. If the Colours are laid by a skilful Hand, on two Ranges of Cloth, and the Frame cut away according to the Out-line of the Work, they will wonderfully deceive the Eye, and appear as solid; but then the outer Range must be drawn after the Plan and Elevation of the Part DF in the foregoing Figure; and the inner Range after that of EC; in all things observing the Rules hitherto deliver’d.
Fig. lxi.
Fig. lxi.
Modus erigendi machinas, quæ constant pluribus ordinibus telariorum.
Exfiguræ inspectione addisces modum erigendi machinas quæ constant pluribus ordinibus telariorum. Tabernaculum hoc nostrum indiget duobus tantum ordinibus; nam telaria propinquiora oculo exprimunt faciem externam, remotiora exhibent faciem internam. Ne autem lateant stipites quibus telaria sustinentur, medietatem telariorum adumbrare omisimus. RectaLSest linea plani, rectaDGest linea horizontalis; ac punctum distantiæ quod cadit extra paginam in rectaCGprolongatâ, debet esse remotum à punctoC, quantum in superiori parte figuræ quinquagesimænonæ, punctum distantiæ est remotum à puncto oculi. Eadem horizontalisDGsecatur normaliter inCà rectaEF, quæ est sectio externæ faciei tabernaculi, & exCincipiunt divisiones in partes æquales pro reticulatione anterioris faciei telariorum, ut dicemus figurâ sexagesimasecunda. RectaILquæ est sectio internæ faciei tabernaculi, distat ad libitum à rectaEFcui est parallela. Porrò, per divisiones rectæEF(ut vides inM,N,O) ex puncto distantiæ ducendæ sunt visuales ad rectamILpro reticulatione aliorum telariorum: distantia enimDCfacit ut augere oporteat ea quæ in telariis pinguntur, alioquin justo minora viderentur. Atque hinc dignosces, cur arcus qui in telariis anterioribus pertingeret solum adB, in posterioribus elevetur usque adH.
Figura sequenti proponemus modum delineandi faciem internam telariorum, adhibita reticulatione externæ faciei: ad intelligentiam verò illius methodi, fiat in hac figurâ rectaHPparallela adDC, ac rectaBCdividatur in totidem partes æquales, in quot partes divisa fuerit rectaPC.
The Manner of erecting Machines, that consist of several Ranges of Frames.
Bycasting your Eye on the Figure, you’ll readily apprehend the Manner of erecting the several Ranges of Frames. This Tabernacle last describ’d needs only two of them; the Frame next the Eye represents the outer Face, and the hinder Frame the inner Face thereof. I have here describ’d but the Half-Breadth of the said Frames, that you might have a Sight of the Poles and Braces which support them. The Line LS is the Line of the Plan, or Ground-line; the Line DG is that of the Horizon; and the Point of Distance, which falls without the Page CG prolong’d, is as far from the Point C, as the Point of Distance is from the Point of Sight in the upper Part of the Fifty-ninth Figure. The Horizontal DG is cut perpendicularly in C by the Line EF, which is the Section of the outer Face of the Tabernacle; and from the Point C begin the equal Divisions for the Net-work of the foremost Frame, as is shewn in the Sixty-second Figure. The Line IL, which is the Section of the inner Face of the Tabernacle, may at pleasure be set nearer or farther from the Line EF, to which it is parallel. By the Divisions of the Line EF (as M, N, O) Lines are drawn from the Point of Distance to the Perpendicular IL, for the Net-work of that Frame; for the Distance DC obliges the Parts of D to be painted larger, otherwise they will appear less than they really ought. And from hence you may discern, why the Arch, which in the foremost Frame would reach only to B, does in the hindmost rise up to H.
In the following Figure is shewn the Manner of delineating the inner Frame, from the Net-work of the outer Face; for the better understanding of which, make the Line HP in this Figure parallel to DC, and let the Line BC be divided into as many equal Parts, as the Line PC was.
Fig. lxii.
Fig. lxii.
De reticulandis telariis, quæ repræsentent ædificia solida.
Duoexemplaria tabernaculi quæ seorsim delineanda sunt, conjunctim habes inA. Utrisque deservit eadem reticulatio, quam suis numeris insignivimus. Postquam ergo designaveris amplitudinem totius ædificii, cum proportione ad ipsam reticulabis pavimentumBaulæ cujuspiam quod capiat rem totam, ascriptis eisdem numeris quos habet exemplar: ejusque retis ope, ducentur in pavimento lineæ terminativæ totidem membrorum, quot futura sunt telaria exprimentia faciem externam tabernaculi. Ubi hæc parata fuerint, singula disponentur exactè suis locis in ipsomet pavimento; ac funiculis colore nigro imbutis, repetetur in telariis eadem reticulatio, additis ad libitum pluribus visualibus; quarum adjumento dum seorsim pinguntur telaria, duci queant rectæ tendentes ad punctum oculi seu perspectivæ. Alia quoque reticulatio super pavimento necessaria est pro internâ facie tabernaculi: ac duæ reticulationes pavimenti eam inter se proportionem habebunt, quam habent divisiones rectarumIL,EF, figuræ sexagesimæprimæ. Hujus retis ductu fient lineæ terminativæ telariorum cum reliquis, ut jam indicavimus.
Juxta hanc methodum nequeunt duci lineæ terminativæ interioris faciei, nisi fiat in pavimento aliud rete deleto priori, quod esset valdè laboriosum. Postquam ergo ex vestigio figuræ quinquagesimænonæ eruta sint duo exemplaria, in exemplar faciei externæ transferatur rectaPCfiguræ sexagesimæprimæ, in exemplar faciei internæ transferatur rectaBC. Si autem rectaPCdivisa fuerit in quindecim partes æquales, divideturBCin quindecim partes æquales, atque ope harum divisionum reticulare oportebit utrumque exemplar. Porrò licet quadrata in reti exemplaris faciei externæ sint majora quadratis exemplaris internæ faciei, nihilominus idem rete pavimenti deserviet pro ducendis lineis terminativis utriusque faciei. Quæ dicta sunt de duobus exemplaribus, valent de aliis quotcunque. Exempli gratiâ; si construere placeat quinque ordines telariorum, fient quinque exemplaria in papyro. Si in omnibus exemplaribus usurpetur eadem reticulatio, in pavimento facere oportet quinque diversas reticulationes. Si autem in exemplaribus fiant quinque diversæ reticulationes, in pavimento sufficit una reticulatio.
Curandum est ut singula retis quadrata in telariis sint exacta, omnesque illorum anguli sint recti. Modus expeditissimus faciendi angulos rectos est hujusmodi. Posito uno crure circini in punctoFlineæ rectæEF, alioque crure posito ubilibet inO, fiet circulusGFI, & ex punctoGdiameterGI. Si rectaHFtranseat per punctaI&F, est normalis adEF.
Of making the Net-work on Frames, for representing the Architecture as solid.
Youhave jointly in A, the two Designs of a Tabernacle, which are to be drawn separately; the same Net-work serving for both, which is also mark’d with Numbers. When you have therefore resolv’d on the Size of your Work, on the Pavement of some Room capacious enough make a Net-work answerable, and affix thereto the Numbers, as in your Copy: By the Help of which, you may on the Pavement describe the Out-line of all those Members that are requisite to the outer Frame of the Tabernacle. This being done, let the Frame be laid exactly in its place on the said Pavement, and with a black Line strike thereon the same Net-work; adding as many visual Lines as you please, which will be of Use for drawing Lines to the Point of Sight, when you come to paint the Frames asunder. Another Net-work on the Pavement is also necessary for the inner Face of the Tabernacle, which should bear such Proportion to this, as the Divisions of the Line IL do to those of EF in the Sixty-first Figure; and by this means the Out-lines of the inner Frame,&c.may be drawn, as has been shewn already.
Thus the Out-line of the inner Face can’t be describ’d, without rubbing out the first Net-work, and making a second on the Pavement; which would be very troublesom. Wherefore, from the Plan of the Fifty-ninth Figure, take the two Designs, and transfer the Line PC of the Sixty-first Figure on the outer Face, and the Line BC on the inner Face. Then if PC were divided into fifteen equal Parts, BC shall be divided in the same manner, and by these Divisions make the Net-work on each Design. And although the Squares of the outer Face be larger than those of the inner one, the same Net-work may nevertheless serve for giving the Out-line of both. What has been said of these two Designs, may be understood of many. For Instance; if five Ranges of Frames were requir’d, five Designs must be made in Paper. If in all the Designs the same Net-work be us’d, then five several Net-works must be made on the Pavement; but if the Designs have five different, then one Net-work on the Pavement will suffice.
You must be very careful that all the Squares of the Net-work be exactly divided, and at right Angles. The ready way of making a right Angle is thus: Placing one Foot of the Compasses in the Point F of the Line EF, and the other at pleasure in O, describe the Circle GFI; and from the Point G draw the Diameter GI. The Line FH drawn by the Points FI, shall be perpendicular to FE.
Fig. lxiii.
Fig. lxiii.
Vestigia ædificii quadrati.
VestigiumgeometricumAhujus ædificii habet inBsuam deformationem. Discrimen inter pilasC&Doritur ex eo, quòd inCposita sint vestigia stylobatarum, inDautem posita sint vestigia coronicum.
The Plan of a square Design.
TheGeometrical Plan of this Design A, is brought into Perspective in B. The Difference between the Parts C and D arises from hence, that the Plan of the Pedestals is plac’d in C, and that of the Cornice in D.
Fig. lxiv.
Fig. lxiv.
Ædificium quadratum.
Exdeformatione vestigii & elevationis, methodo consuetâ eruitur imago totius ædificii, quæ potest esse exemplar aræ maximæ alicujus Ecclesiæ. Hanc machinam, non sine communi approbatione, aliquoties adhibui, in apparatu quadraginta horarum; locum in medio vacuum occupantibus Angelis cum nubibus, additâ figurarum aliquot copiâ in parte inferiori. Modus faciendi in telariis remotioribus ab oculo partem tholi rotundi quam hic vides, deducitur ex iis quæ tradidimus in projectione circulorum.
A square Design in Perspective.
Fromthe Plan and Upright in Perspective, this finish’d Piece of the whole Work is delineated after the usual Manner, and may serve for the Design of a great Altar in a Church. I have sometimes, for the Solemnity of theForty Hours, expos’d this painted on a Machine, with an universal Satisfaction; Angels with Clouds possessing the higher part of the Hemisphere within, and Groups of Figures the lower part. The Manner of designing on the inner Frame, that part of the saidCupolawhich you here see, is deduc’d from what has been before said of putting Circles into Perspective.
Fig. lxv.
Fig. lxv.
Vestigium ædificii rotundi opticè imminutum.
Quisedulam operam in circulis deformandis non posuerint, eosque minimo negotio ex usu describere nequiverint, frustra conabuntur projicere vestigia ædificiorum rotundorum. Ad vitandam confusionem, proderit in vestigio notare primùm lineas occultas membrorum præcipuorum; iisque translatis in elevationem, addere sensim reliquas. Hac industriâ ego ipse in hoc schemate usus sum. Quum autem experimento didicerim summam arduitatem harum descriptionum, aliam regulam adhibere jamdiu cœpi, quam, ut suprà diximus, in aliud Opus reservamus.
The Plan of a Circular Work in Perspective.
Theythat have not diligently apply’d themselves to the putting Circles into Perspective, and, by a constant Practice, render’d the Work familiar to them, will in vain attempt that of the Plans of round Buildings. To prevent Confusion, you’ll do well, first to mark the occult Lines of the principal Members; and after those are transferr’d into the Upright, then proceed to the rest, as I myself did in this Figure. But having found by Experience, the great Difficulty of describing these round things, I have long since made use of another Method, which, as I said before, is reserv’d for another Volume.
FIG. LXVI.
FIG. LXVI.
Projectio ædificii rotundi.
Mirificeoculis imponunt imagines rerum rotundarum, si omnibus resectis quæ ad eas non pertinent, exactè delineatæ ac depictæ fuerint. Hanc figuram ex vestigio eruere oportebit methodo consuetâ, eamque in Templo S. Ignatii Collegii Romani construxi pro feriâ V & VI Hebdomadæ sanctioris. Intra arcum, super altari, locus erat urnæ sepulcrali, cum Venerabili Sacramento. Sub altari visebatur simulacrum Christi Domini è Cruce depositi: in medio columnarum, imago Beatæ Virginis dolentis; super balaustiis Angeli lugentes, cum instrumentis cruciatuum Salvatoris.
A Circular Design in Perspective.
TheAppearance 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.Ignatiusof theRomanCollege, for theThursdayandFridayof 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.
Fig. lxvii.
Fig. lxvii.
Vestigium geometricum, ac prima præparatio ad figuram septuagesimamprimam.
Egregiamadeò 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 inA, (quæ autem dicuntur de hac medietate, intelligi debent de aliâ) ne multitudo linearum confusionem pariat. InBlineæ curvæ occultæ sunt vestigium tholi qui complet summitatem ædificii. VestigiumCexhibet ambulacrum interius. Omisimus autem vestigium theatri, quia paginæ angustia illud non capit.
The Geometrical Plan, and first Preparation to the Seventy-first Figure.
TheMachine which I erected in the Year 1685, in the ChurchFarneze, orJesuitsChurch atRome, for the Devotions of theForty 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 theCupolawhich 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.
FIG. LXVIII.
FIG. LXVIII.
Elevatio geometrica vestigii præcedentis, & secunda præparatio ad figuram septuagesimamprimam.
Inhoc 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 Geometrical Elevation of the foregoing Plan, and second Preparation to the Seventy-first Figure.
Inthis 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.
Fig. lxix.
Fig. lxix.
Deformatio vestigii figuræ sexagesimæseptimæ, & præparatio tertia ad figuram septuagesimamprimam.
Artificiumprojectionis 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 Plan of the Sixty-seventh Figure in Perspective, and third Preparation to the Seventy-first Figure.
TheArtifice 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.
Fig. lxx.
Fig. lxx.
Deformatio elevationis figuræ sexagesimæoctavæ, & præparatio quarta ad figuram septuagesimamprimam.
Quædicta sunt de projectione vestigii nostri ædificii, habent locum in elevatione. Nimirum, ut parallelæ invicem notabiliter distarent, usi sumus industriâ quam declaravimus figurâ quadragesimasecundâ.
The Perspective of the Elevation of the Sixty-eighth Figure, and the fourth Preparation to the Seventy-first Figure.
Whathas 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.
Fig. lxxi.
Fig. lxxi.
Theatrum repræsentans Nuptias Canæ Galilææ, constructum Romæ, anno 1685. in expositione Ven. Sacramenti in Templo Farnesiano Societatis JESU.
Exantecedentibus 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.
A Theater representing the Marriage ofCanainGalilee, erected in theJesuitsChurch atRome, in the Year1685; for the Solemnity of exposing the Holy Sacrament.
Fromthe 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.
Fig. lxxii.
Fig. lxxii.
De theatris scenicis.
Theatrisquæ 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 scalaStriginta palmorum. Medietatem loci occupat theatrum, medietatem obtinent podia & loca spectatorum.Opunctum in quo uniuntur lineæ visuales,Dlocus pro apparentiis rerum magis ac magis distantium.BClocus poscenii.HHsunt canales obliqui, quorum latitudo est dupla latitudinis scenarum.FGfrons & facies theatri.AOejus profunditas aut longitudo.Elocus pro psaltibus, tibicinibus, & fistulatoribus.Kspatium pro spectatoribus.Ivestigium podiorum.Lscalæ podiorum.Nipsorum elevatio.Mdeclivitas tabulati, cum sectione & elevatione theatri, & scenis ex latere inspectis, quæ cum suis canalibus congruunt, ut demonstrant lineæ occultæ.OOlinea normalis ad lineam horizontalem.P&Qelevatio scenarum coram inspectarum, quæ introrsum flectuntur; & in latitudine congruunt cum canalibus vestigiiB, in altitudine cum sectionibus elevationisM; ut constat ex lineis occultis. In eâdem elevationeMpars altitudinis tribuenda est scenis, pars laquearibusR, per quæ jungitur unumquodque par telariorum.VVlineæ ad explorandum an detur vacuum inter scenas & laquearia, vel inter scenas, vel inter laquearia. In quibusdam autem scenis, loco laquearium pinguntur nubes & aer.
Of Scenes for the Stage.
Scenesfor 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 inGermany. Nevertheless, theItalianManner 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 twentyRomanPalms 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.
Fig. lxxiii.
Fig. lxxiii.
Aliud vestigium theatri, ubi de modo inveniendi ejus punctum.
Sipingendæ 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 punctoA: id autem nullo negotio fiet, accipiendo distantiasBCinter primos canales, &DEinter ultimos, ac ducendo visualesMO, NO: nam theatrum habebit longitudinemAO, ac punctum perspectivæ in vestigio theatri eritO. Præterea scire oportebit longitudinem & latitudinem canalium, eorumque numerum, distantias, & flexus; ac præcipuè curandum est, ut licet sint obliqui ad lineamMN, sint invicem paralleli in unoquoque latere, ac singuli tangant lineasMO, NO. Jam si rectæAOfiat æqualis rectaFA, inFerit punctum distantiæ: adeoque si theatrum juxta methodum à nobis tradendam depictum fuerit, spectatori qui consistat inFapparebit veluti tabula picta juxta leges perspectivæ, posita inA.
Another Plan of a Theater, with the Method of finding the Point of Sight therein.
Ifit 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.
Fig. lxxiv.
Fig. lxxiv.
Sectio Scenarum Theatri.