Horizontalis projectio mutuli inumbrati.
_In hac figurâ suas umbras mutulo addidimus: eumque si in altum supra
oculum elevaveris, & ex distantiâ quam ipsi dedimus suspexeris; miraberis
profectò, in alium longè concinniorem subitò mutatum fuisse._
The EIGHTIETH FIGURE.
_The Horizontal Projection of a shaded Corbel._
In this Figure you have the Corbel finish’d with its proper Shades;
which, if plac’d above the Eye, and beheld from the Distance here
assign’d it; you’ll be strangely surpriz’d at the sudden and most
agreeable Alteration you’ll find therein.
[Illustration: FIG. LXXXI.]
Figura Octogesimaprima.
Stylobatæ Corinthii horizontaliter contracti.
_In deformandis hisce stylobatis, usi sumus projectione vestigii &
elevationis, quam exhibet figura duodecima; ut figuram illam cum istâ
conferenti manifestissimè constabit. Porrò stylobatas pingi solere
incumbentes mutulis, diximus figurâ septuagesimaoctavâ._
The Eighty-first Figure.
_~Corinthian~ Pedestals in an Horizontal Perspective._
In delineating these Pedestals, I have made use of the Plan and Upright
put into Perspective in the Twelfth Figure; as will evidently appear,
by comparing that Figure with this. I have already mention’d, in the
Seventy-eighth Figure, that in painting these Pedestals, they are
generally suppos’d to be upheld by Corbels.
[Illustration: FIG. LXXXII.]
Figura Octoges. secunda.
Columna Corinthia horizontaliter deformata.
_Vestigium & elevatio stylobatæ, quem delineavimus figurâ duodecimâ,
suppeditat mensuras pilarum hoc loco deformandarum, ut ex iis eruatur
contractio columnæ. Huic autem soli suas umbras addidimus, ut clariùs
appareat modus & artificium totius operationis. Ex his vides, quadrata &
circulos in perspectivâ horizontali omninò retinere suam figuram, eamque
dumtaxat restringi paulatim & coarctari: quicquid in contrarium & verbis
& pennicillo docuerint Pictores nonnulli._
Eighty-second FIGURE.
_A ~Corinthian~ Column in Horizontal Perspective._
The Plan and Elevation of the Pedestal delineated in the Twelfth Figure,
gives also the Measures for reducing these Pilasters into Perspective;
from which the Contraction of the Column is taken. I have shadow’d
only this last, that the Manner of the whole Work might be the more
conspicuous. By this you see the Squares and Circles in Horizontal
Perspective always retain their Figures, without any Alteration, save
that of being gradually diminish’d and made less; notwithstanding what
some Painters have taught and practis’d to the contrary.
[Illustration: FIG. LXXXIII.]
Figura Octogesimatertia.
Capitella Corinthia horizontaliter contracta.
_Habes in hac paginâ deformationes vestigii & elevationis capitelli
Corinthii, quas desumpsimus ex delineationibus geometricis, transferendo
mensuras earum in lineas plani ~AB~, & elevationis ~AC~, ita ut facillimè
dignosci possit unde nascantur singulæ partes capitellorum nitidorum.
Nihil dubito quin deformationes horizontales sis experturus faciliores
verticalibus quas dedimus figurâ vigesimaquartâ. Nam in horizontalibus
gyrus foliorum circulis clauditur, quorum centra mutuantur latitudines
à suis vestigiis in punctis ~1~, ~2~, ~3~, ~4~; altitudines verò à
capitellis elevationis in punctis ~5~, ~6~, ~7~, ~8~._
Eighty-third FIGURE.
_A ~Corinthian~ Capital horizontally contracted in Perspective._
You have in this Plate the Perspective both of the Plan and Elevation of
the _Corinthian_ Capital, drawn from the Geometrical Descriptions, by
transferring their Measures into the Ground-line AB, and into that of the
Elevation AC; so that you may readily discover from whence every part of
the finish’d Capital is produc’d. I don’t doubt but you’ll experience
these horizontal Perspectives to be much less difficult than the vertical
propos’d in the Twenty-fourth Figure. For in these the Circuit of the
Leaves is determin’d by perfect Circles, whose Centers take their
Breadths from the Plan at the Points 1, 2, 3, 4; and their Heights from
the Capitals of the Elevation, at the Points 5, 6, 7, 8.
[Illustration: FIG. LXXXIV.]
Figura Octogesimaquarta.
Coronix Corinthia.
_Si faciendæ sint coronices quæ habeant angulos, elevatio geometrica
~A~ repræsentabit unum latus, alterum sectio ~B~. Curandum est autem,
ut crepidines partium, quas fingere volumus incumbere columnis, non
obsint concinnæ distributioni mutulorum. Ad contractionem elevationis
~A~ & sectionis ~B~, in lineam plani ~EF~ & elevationis ~EG~ transferre
oportet puncta diversarum latitudinum, quas habent in elevatione A ungues
epistylii, zophori, & coronæ, ducendo ex iis lineas ad punctum oculi;
in partem verò ~FH~ lineæ ~FE~ transferre oportet puncta longitudinis,
ducendo lineas ad punctum distantiæ. Hac industriâ perficies utramque
deformationem, quarum una geret munus vestigii, altera elevationis.
Utrobique autem designabis lineas terminativas partium coronicis, ac
sectionum ~C~ & ~D~._
Eighty-fourth FIGURE.
_A ~Corinthian~ Cornice._
If you are to describe Cornices having Angles, admit the Elevation A to
represent one Side, and the Section B the other. But Care is to be taken,
that the Breaks of those Parts which are suppos’d to be set directly over
the Columns, do not obstruct the regular Distribution of the Modillions.
For contracting into Perspective the Elevation A, and the Section B, you
must transfer into the Ground-line EF, and into that of the Elevation
EG, the Points of the several Breadths made by the Projectures of the
Architrave, Freeze, and Cornice of the Elevation A; and from them draw
Lines to the Point of Sight: Then on the Part FH of the Line FE, you
must note the Points of Length, and draw Lines from them to the Point of
Distance. By this Practice you complete these two Contractions, one of
which does the Office of a Plan, the other that of an Elevation. It’s
also requisite, that you draw the Out-line of the Members of the Cornice
on each side the Angle, & the Sections C and D.
[Illustration: FIG. LXXXV.]
Figura Octogesimaquinta.
Coronix Corinthia horizontaliter contracta.
_Soliditas coronicis cum omnibus projecturis eruta est ex vestigio &
elevatione figuræ octogesimæquartæ. Hic autem finem imponimus partibus
rerum, ad integra ædificia gradum facturi._
The Eighty-fifth Figure.
_A ~Corinthian~ Cornice in Horizontal Perspective._
The Solidity of this Cornice, with all its Projectures, is deduc’d from
the Plan and Elevation of the foregoing Figure. With this therefore I
shall conclude the Description of Parts of things, and proceed to that of
entire Structures.
[Illustration: FIG. LXXXVI.]
Figura Octogesimasexta.
Horizontalis projectio columnæ.
_Postquam sigillatim descripsimus mutulum, stylobatam, columnam &
coronicem, omnia ista conjungere placuit: ita clariùs apparebit quomodo
disponere oporteat delineationes geometricas, ut ex iis eruantur
projectiones horizontales._
_Linea plani est ~CD~, perpendicularis ~CI~. In ~A~ est elevatio
geometrica longitudinis columnæ, (supponimus columnam delineari veluti
jacentem humi.) In ~B~ ejus vestigium geometricum, cum divisionibus
latitudinis in lineâ ~ER~. Puncta longitudinis transferentur in lineam
plani ~CG~, puncta altitudinis ~EC~ transferentur in ~CF~, ducendo rectas
ex divisionibus ~CG~ ad punctum distantiæ, ex divisionibus ~CF~ ad
punctum oculi. Per sectiones verò visualis ~CO~ erigentur perpendicula, &
complebitur elevatio ~H~, ex quâ eruetur columna nitida ~L~._
_Si super vestigio ~M~ formare placeat aliam columnam, ejus latitudines
accipiendæ sunt ex columna ~B~; ac sectio projicienda est in ~N~, ut
ex hac tamquam ex elevatione eruatur columna ~P~. Si aliam columnam in
angulo addere libitum fuerit, ope sectionum ~HN~ facilè illam complebis._
The Eighty-sixth Figure.
_A Column in horizontal Perspective._
After the separate Description of a Corbel, Pedestal, Column, and
Cornice; I have here conjoin’d them all, that you might the better
perceive how to dispose Geometrical Elevations for the Business of
horizontal Perspective.
The Line of the Plan is CD, the Perpendicular CI; the Geometrical
Elevation of the Length of the Column, suppos’d to be lying on the
Ground, is A. The Geometrical Plan thereof is B, with the Divisions
of its Breadth on the Line ER. The Points of Length being transferr’d
on the Line of the Plan CG, and the Points of Height EC into CF; from
the Divisions of CG Lines are drawn to the Point of Distance; and from
those of CF to the Point of Sight. From the Sections of the Visual CO,
Perpendiculars are erected, and the Elevation H completed, from whence is
taken the finish’d Column L.
If upon the Plan M you would delineate another Column, the Breadths
thereof must be taken from the Column B, and another Profile design’d
in N, which serves as an Elevation for making the Column P. If another
Column were requir’d in the Angle, the Profiles HN assist you in the
ready Performance thereof.
[Illustration: Fig. lxxxvii.]
FIGURA Octogesimaseptima.
Præparatio necessaria ad sequentem figuram, & ad projectiones
horizontales in laquearibus vel testudinibus.
_Exhibet hæc figura in ~AA~ unum ex quatuor parietibus aulæ, cujus
altitudinem veram ~IH~ velis attollere apparenter usque in ~L~, pingendo
in laqueari, vel in testudine, seriem balaustiorum. In ~B~ est vestigium
geometricum quartæ partis laquearis. In ~C~ habetur elevatio medietatis
latitudinis. In ~D~ est sectio coronicis & mutulorum. In ~E~ posita
est elevatio medietatis longitudinis. In ~F~ est punctum oculi, in ~G~
punctum distantiæ: adeóque tota distantia est ~GF~._
The Eighty-seventh FIGURE.
_The Preparation necessary to the following Figure, and to all other
horizontal Perspectives, whether on flat or vaulted Ceilings._
The Figure AA represents one of the four Walls of a Hall, whose true
Height IH you would have appear rais’d to L, by painting a Ballustrade in
the Ceiling thereof. B is the Geometrical Plan of the fourth part of the
said Ceiling; C is the Elevation of half the Breadth; D is the Section
of the Cornice and Corbels; E is the Elevation of half the Length. In F
is the Point of Sight, in G the Point of Distance; so that the Distance
itself is FG.
[Illustration: FIG. LXXXVIII.]
Figura Octogesimaoctava.
Horizontalis projectio balaustiorum figuræ octogesimæseptimæ, cum brevi
distantia.
_Claritatis gratiâ totum laquear divisum est in quatuor partes. Prima
continet contractionem vestigii & elevationis, quæ perficiuntur methodo
consueta. Nam linea ~AOV~ est horizontalis, ~BC~ est linea plani. Punctum
oculi est ~O~, distantiæ ~E~. Secunda pars continet sectionem ~L~, quæ
dat projecturas mutulorum aliarumque partium, desumendas ex sectione ~D~
figuræ octogesimæseptimæ, deformando eam in angulis ~B~ & ~C~. Tertia
pars complectitur delineationem integram sine umbris: ultima pars eandem
complectitur cum umbris._
_Ob punctum distantiæ parum remotum à puncto oculi, nimiam amplitudinem
ac deformem apparentiam habere videtur hæc delineatio. Nihilominus, si ex
distantia ~EO~ figuram suspexeris, omnis deformitas evanescet._
_Ut fucus imperitis fiat, industrii Pictoris interest parare sibi
geminum exemplar suorum Operum, in quibus distantia sit nimis brevis;
unum videlicet palam ostendendum, in quo punctum distantiæ sit remotum à
puncto oculi, quantum necesse est ad vitandam omnem deformitatem. Alterum
verò, in ipsomet Opere clam usurpandum._
_Si pingendæ sint testudines, oportet prius facere in eis reticulationem
peculiarem; quæ quia difficilis est, & paucis explicari nequit, in aliud
Opus reservatur._
Eighty-eighth Figure.
_The horizontal Projection of the Ballustrade of the Eighty-seventh
Figure, view’d at a small Distance._
For the better Illustration of this Figure, I have divided the whole
Ceiling into Four Parts. The first contains the Plan and Elevation in
Perspective, after the usual manner; AOV being the horizontal Line, BC
that of the Plan; the Point of Sight O, and that of Distance E. The
second Part contains the Section L, which gives the Projectures of the
Corbels and other Parts taken from the Section D of the Eighty-seventh
Figure, by drawing it in the Angles B and C. The third Part comprehends
the Delineation of the Perspective without Shadows. The fourth Part
contains the same wholly shadow’d and finish’d.
Through the near Approach of the Point of Distance to the Point of Sight,
you may perhaps imagine this Draught will appear too wide, and so have an
ill Effect: But when once you view it from its due Distance EO, you will
find all such Doubts vanish and come to nothing.
When you have to deal with Persons unskill’d in these things, and are to
paint for so small a Distance; your best way is to make two Draughts; one
for publick Shew, in which you may place the Point of Distance so far
from the Point of Sight, as is necessary for preventing Deformity; and
the other you may privately make use of in performing your Work.
If you are to paint arch’d or vaulted Ceilings, a particular kind of
Net or Lattice-work must first be made therein; the Performance whereof
being difficult, and not capable of being explain’d in few words, I have
reserv’d it for another Volume.
[Illustration: FIG. LXXXIX.]
Figura Octogesimanona.
Horizontalis projectio architecturæ in laqueari quadrato.
_Si laquear sit quadratum, & valde distans ab oculo, architecturam huic
similem in eo depingere licebit. ~A~ est elevatio geometrica; eadem verò
deformata in ~B~ & ~C~, gerit munus vestigii & elevationis. Medietas
unius ex quatuor partibus, usui esse potest in toto opere, aut premendo
chartam, aut eâ perforatâ, immittendo per foramina carbonem minutissimè
contusum._
Eighty-ninth FIGURE.
_An horizontal Projection of Architecture in a square Ceiling._
If the Ceiling be square, and very remote from the Eye, you may paint
in it some such Piece of Architecture as this. A is the geometrical
Elevation; the same reduc’d into Perspective in B and C does the Office
of a Plan and Elevation. The Half of one of the four Parts may suffice
for the Draught of the whole Work, either by tracing over the Lines of
the Paper, or by pricking small Holes therein, and pouncing them through
with Charcole finely powder’d.
[Illustration: FIG. XC.]
FIGURA Nonagesima.
Horizontalis projectio tholi.
_Initium hujus rei fiet à vestigio geometrico, in quo duæ series
circulorum designant columnas; aliæ lineæ designant stylobatas,
ac projecturas & ungues basium & coronicum. Linea plani est ~AB~,
horizontalis ~CD~, perpendicularis ~AD~. Punctum oculi est ~O~, distantiæ
~D~; adeóque figura hæc debet habere supra oculum altitudinem ~DO~.
Punctum oculi positum fuit extra ipsum tholum, ut qui eum aspiciunt,
minus defatigentur, ac plus appareat de architectura & de artificio;
secus verò contingeret si punctum oculi esset in medio. Itaque puncta
lineæ ~EF~ transferentur in partem ~AG~ lineæ ~AD~. Centrum ~I~ vestigii
transferetur in ~H~ & ex omnibus his punctis fient visuales ad ~O~.
Deinde altitudine tholi, ac divisionibus partium singularum tum ipsius,
tum laternæ, translatis in lineam ~AB~, ex punctis divisionum fient rectæ
ad punctum distantiæ ~D~. Ubi autem hæ secant visualem ~AO~, erigentur
perpendicula, quorum sectiones cum visuali ~HO~ dabunt centra pro
singulis circulis. Inter visuales ~AG~ ducere oportet lineas terminativas
columnarum & coronicum; quemadmodum fieret, si ex vestigio eruta fuisset
elevatio geometrica. His positis, aggredieris delineationem opticam
ipsius tholi, translatis in perpendicularem ~EO~ centris ope parallelarum
~HI~, ~LN~; ac semidiametro ~LM~ fiet circulus ~NP~ pro simâ coronicis:
semidiametro ~ST~ fiet circulus ~QR~, & sic de reliquis. Quomodo autem
per rectas ex angulis vestigii ad punctum oculi, habeantur ungues
coronicis, ostendunt numeri ~1~, ~2~, ~3~, ~4~; lineæ verò laterales
unguium tendunt ad centra suorum circulorum, ut videre est in ~N 3, 4~.
In vestigio, ne nimium occupetur, mutulos omisimus._
_Ex his patet necessitas faciendi vestigium geometricum totius tholi, ac
non sufficere vestigium unius columnæ; quum singulæ peculiares exigant
deformationes. Quum autem Opus ipsum delineandum ac pingendum fuerit,
ipsum desumere non poteris ex parvo exemplari, ope reticulationis;
Quinimo suis locis ducere oportebit lineas visuales, & invenire centra
omnium circulorum. Figendo autem funiculum in singulis centris, ipsius
adjumento facillimè absolves omnes circumferentias._
The Ninetieth Figure.
_A Cupola in horizontal Perspective._
In the Execution of this Work, you are to begin with the Geometrical
Plan; in which the two Ranges of Circles denote the Columns, the other
Lines shew the Pedestals, with the Projectures and Breaks of the Bases
and Cornices. The Line of the Plan is AB, that of the Horizon CD, the
perpendicular Line is AD. The Point of Sight is O, that of Distance D;
wherefore this Figure ought to be plac’d as much above the Eye, as the
Height DO. I have set the Point of Sight something without the Cupola,
that the Eye might be less weary’d in viewing the Work, and embrace more
of the Architecture, than it could have done, had the Point of Sight been
in the midst. The Points of the Line EF are transferr’d into AG, part of
the Line AD. The Center of the Plan I is continu’d to H, and from all
these Points visual Lines are drawn to O. Then placing the Heights of
every part both of the Cupola and Lantern on the Line AB, from the Points
of those Divisions draw Lines to the Point of Distance D; and where they
cut the Visual AO, erect Perpendiculars intersecting the Line HO; which
Points are the Centers of the several Circles. On the Visuals, between
AG, must be describ’d the Out-lines of the Columns and Cornices, in like
manner as when a Geometrical Upright is rais’d from a Plan. This done,
you proceed to the Delineation of the Cupola itself in Perspective,
by transferring into the Perpendicular EO the several Centers of HO,
by Parallels to HI, as LN, _&c._ On the Center, with the Interval LM,
describe the Circle NP, for the Nose of the Cornice; and with the
Semidiameter ST describe the Circle QR, and so of the rest. The Numbers
1, 2, 3, 4, shew how the Breaks of the Cornice are determin’d by Lines
from the Angles of the Geometrical Plan tending to the Point of Sight,
till they intersect the Circle: The Returns of which Breaks are made by
Lines tending to the Centers of their respective Circles; as is plain
from N 3, and N 4. In this Plan I have omitted the Corbels, lest I should
too much encumber the Work.
Hence appears the Necessity of making the Geometrical Plan of the whole
Cupola, the Plan of a single Column not being sufficient; by reason each
requires its particular Delineation. And when the Work itself is to be
drawn for painting, you can’t well take it from a small Draught by way of
Net-work or Squares, but the visual Lines should be drawn in their proper
places, and the several Centers found; in which, by fixing Strings, you
may readily describe the Circumferences of all the Circles.
[Illustration: FIG. XCI.]
Figura Nonagesimaprima.
Tholus figuræ nonagesimæ, cum luminibus & umbris.
_Tholus quem vides in hac paginâ, pollicetur sibi vitam diuturniorem
illo, quem super telario plano insignis amplitudinis, depinxi anno 1685.
in Templo S. Ignatii Collegii Romani. Proinde si casus aliquis illum
absumat, non deerunt qui ex isto eundem in melius reficiant. Mirati
fuerunt Architecti nonnulli, quòd columnas anteriores mutulis imposuerim,
id enim in solidis ædificiis ipsi non facerent. Verùm eos metu omni
liberavit amicissimus mihi Pictor, ac pro me spopondit, damnum omne se
statim reparaturum, si fatiscentibus mutulis, columnas in præceps ruere
contingat._
The Ninety-first Figure.
_The Cupola of the Ninetieth Figure, with its Lights and Shades._
The Cupola in this Plate will in all Likelihood be of longer Duration,
than that which I painted on a very large Table, for the flat Ceiling
of the Church of S. _Ignatius_ of the _Roman_ College, _anno_ 1685. For
if that suffer by any Accident, with the help of this its place may be
supply’d by a better. Some Architects dislik’d my setting the advanc’d
Columns upon Corbels, as being a thing not practis’d in solid Structures;
but a certain Painter, a Friend of mine, remov’d all their Scruples,
by answering for me, That if at any time the Corbels should be so much
surcharg’d with the Weight of the Columns, as to endanger their Fall, he
was ready to repair the Damage at his own Cost.
[Illustration: FIG. XCII.]
Figura Nonages. secunda.
Tholus octangularis.
_Ex circulo fiet octagonum, accipiendo medietatem quadrantis circuli,
ut habeantur singula latera octagoni. In eisdem lateribus distribuetur
vestigium geometricum totius architecturæ, cum projecturis omnium
membrorum, juxta modum quem servavimus in limbo circulari figuræ
nonagesimæ. Utiliter etiam fieret elevatio geometrica totius Operis;
quamvis ob spatii angustias ego eam omiserim. Deinde positâ una cuspide
circini in centro circuli, extendetur alia cuspis ad altitudinem
singularum projecturarum inter spatium ~A~ & ~B~, ut hic vides: atque
ope parallelarum, omnia transferentur in lineam ~CD~, ut fiat optica
deformatio, quam poscit sectio elevationis, cum aliis præparationibus,
ut in figura præcedenti. Nam hic quoque ope circulorum invenire oportet
puncta extrema in prominentiis membrorum singulorum architecturæ: ut
conjungendo puncta per lineas rectas, quæ forment facies octagoni,
compleatur totum Opus._
Ninety-second Figure.
_An Octangular Cupola._
From the Circle describe the Octagon, by taking half the Quadrant of the
former for each Side of the latter. On these Sides the Geometrical Plan
of the whole Architecture is to be dispos’d, with the Projectures of
all the Members thereof, in the same manner as was done in the circular
Border of the Ninetieth Figure. It will also be expedient, to make the
Geometrical Elevation of the whole Work, tho’ thro’ Want of Room I have
here omitted it. Then placing one Point of the Compasses in the Center
of the Circle, extend the other to the Height of the several Projectures
between A and B, as you see in the Figure; and by help of the Parallels
transfer them all into the Line CD, for putting the Profile of the
Upright into Perspective, and drawing the other Requisites, as in the
foregoing Figure. For here also, by means of the Circles, are found
the extreme Points of the Projectures of the several Members of the
Architecture; and by conjoining these Points with strait Lines agreeable
to the Shape of the Octagon, the whole Work is completed.
[Illustration: FIG. XCIII.]
FIGURA Nonagesimatertia.
Vestigium templi Ludovisiani S. Ignatii almæ urbis.
_Constitueram huic Libro finem imponere figurâ nonagesimasecunda;
nihilominus ut satisfaciam precibus amicorum, cupientium addiscere modum
reticulationis opticæ, quæ adhibetur in superficiebus irregularibus,
ejusque memini figurâ octogesima octava, publici juris facere decrevi
ejus construendæ methodum. Ipsiusmet retis ope delineavi non solùm
ædificium mox repræsentandum, sed etiam figuras omnes testudinis templi
Ludovisiani, in qua pingenda nunc occupor. Eademque reticulatione, quæ
erit ultima figura hujus Libri, dabimus Operi nostro suum complementum;
quum nulla sit superficies, in qua suas delineationes juxta Perspectivæ
regulas, earum rerum Studiosi absolvere nequeant._
_Exhibet hæc figura vestigium totius templi. Quamvis enim non indigeam
nisi testudine inter januam maximam & tholum; proderit nihilominus
Architecturæ Studiosis, universi Operis elegantiam ac symmetriam per
otium contemplari._
The Ninety-third FIGURE.
_The Geometrical Plan of the Church of S. ~Ignatius~ at ~Rome~._
I had once determin’d to end this Book with the Ninety-second Figure; but
at the Request of some Friends, who were desirous to learn the Making
of Perspective Net-work for irregular Surfaces, as was hinted in the
Eighty-eighth Figure; I resolv’d to publish the Manner of performing
the same. By the Help of this Net-work, I delineated not only the
Architecture now to be treated of; but also each Figure in the Vault of
the Church of S. _Ignatius_, which I am at present employ’d in painting.
The Method is laid down in the last Figure of this Book, and entirely
completes the same; there being no Superficies, how irregular soever, but
the Studious may thereon describe, by these Rules, whatever Perspective
he has occasion for.
This Figure contains the Plan of the whole Church; for though my present
Design requir’d no more than the Vault of the Nave, between the great
Door and the Cupola; I thought it might be nevertheless acceptable to
the Curious in Architecture, to have a View of the whole Design, so
celebrated for the Elegancy and Proportion of its Parts.
[Illustration: FIG. XCIV.]
Figura Nonages. quarta.
Orthographia templi Ludovisiani.
_Vt magis tibi gratificer, orthographiam seu elevationem templi
Ludovisiani in longum dissecti delineavi, cum omnibus mensuris quæ
vestigio sunt communes; addito tholo juxta ideam Autoris. Ejus autem
nondum constructi loco, positum est in ~A~ & ~B~ telarium cum tholo
depicto, de quo supra in figuris nonagesimâ & nonagesimaprimâ._
Ninety-fourth FIGURE.
_The Orthography, or Geometrical Elevation of the Inside of S.
~Ignatius~’s Church._
For your greater Satisfaction, I have here given the Geometrical Upright
of the Church dissected lengthwise, with all its Measures agreeable to
those of the Plan; as also the Cupola design’d by the Author: Which not
being yet built, instead thereof is plac’d between A and B, the painted
Cupola before describ’d in the Ninetieth and Ninety-first Figures.
[Illustration: FIG. XCV.]
Figura Nonages. quinta.
Aliæ præparationes ad figuras nonagesimamoctavam & nonagesimamnonam.
_Ex hac figura in quatuor partes divisa, disces ex uno intuitu methodum
qua sum auspicatus opticam delineationem templi Ludovisiani. Prima pars
exhibet latus dextrum testudinis inter januam templi ac tholum. Secunda
pars continet vestigium ejusdem testudinis, arcubus ac lunulis distinctæ.
Tertia pars continet latus dextrum testudinis usque ad summitatem
fenestrarum, unde incipit Architectura quam pingimus in fornice. Quarta
pars est vestigium geometricum fornicis, cum prominentia quam habent
arcus in summitate jam dicta fenestrarum. Fingimus autem eandem esse
soliditatem, tum ædificii depicti, tum navis templi; solæ enim columnæ,
quæ respondent pilis templi, prominent extra ædificium._
The Ninety-fifth Figure.
_Other Preparations to the Ninety-eighth and Ninety-ninth Figures._
By this Figure divided into four Parts, you will at first Sight perceive
the Method I observ’d in beginning the Perspective Design of this Church
of S. _Ignatius_. The first Part shews the right-hand Side of the Vault
between the Door and the Cupola. The second contains the Plan of the same
Vault, with its Arches and Lunettes. The third Part represents the same
right-hand Side, to the top of the Windows; where begins the Architecture
painted in the Vault. The fourth Part contains the Geometrical Plan of
that part of the Vault which is painted; with the Lunettes made by the
Arches above the Heads of the aforesaid Windows. The Disposition of the
painted Architecture above, is the same with that of the Nave of the
Church; save that, answerable to the Pilasters below, I have suppos’d
Columns projecting over the Work.
[Illustration: FIG. XCVI.]
Figura Nonagesimasexta.
Aliæ præparationes ad figuras nonagesimamoctavam & nonagesimamnonam.
_Prima pars figuræ hujus trifariam divisæ, repræsentat elevationem
geometricam lateris templi supra coronicem, & ædificii in testudine
pingendi. Secunda pars complectitur arcum testudinis maximum, &
elevationem geometricam faciei ejusdem ædificii. Tertia pars exhibet
vestigium totius ædificii pingendi in testudine, cujus amplitudo
eadem est cum amplitudine navis, ut antea dicebamus. Porrò vestigium
geometricum non minus necessarium est ad pingendum ædificium, quàm ad
ipsum ex materiâ solidâ extruendum, ut alibi monuimus._
The Ninety-sixth Figure.
_Other Preparations to the Ninety-eighth and Ninety-ninth Figures._
In this Figure, which consists of three parts, the first represents the
Geometrical Elevation of the Right-side of the Nave above the Cornice,
and of the Design painted in the Vault. The second contains the great
Arch of the Vault, and the Geometrical Elevation of the Front of the
said Design. The third part shews the Plan of the whole Work painted on
the Vault, the Extent and Disposition of which is the same with that of
the Nave, as beforemention’d. The Geometrical Plan, as I have formerly
hinted, is no less necessary for the painting a Design in Perspective,
than it is for raising a Structure with solid Materials.
[Illustration: FIG. XCVII.]
Figura Nonages. septima.
Alia præparatio ad figuras nonagesimamoctavam & nonagesimamnonam.
_Ut optica projectio vestigii & elevationis quartæ partis totius Operis
distinctior evaderet, mensuras partium singularum quadruplicavi,
eandemque methodum in hac delineatione tenui, quæ figuris
octogesimasextâ, octogesimaseptimâ, octogesimaoctavâ, & octogesimanonâ,
explicata fuit. Punctum oculi positum est in medio navis Ecclesiæ;
punctum distantiæ est in lineâ ex quâ incipit arcus testudinis._
Ninety-seventh Figure.
_Another Preparation to the Ninety-eighth and Ninety-ninth Figures._
That the Perspective of the fourth part of the Plan and Elevation of
this Work might be more distinct, I have in this Figure made the Measures
of each part four times as big as in the former; and have kept the
same Method in this Delineation, as was deliver’d in the Eighty-sixth,
Eighty-seventh, Eighty-eighth, and Eighty-ninth Figures foregoing. I have
set the Point of Sight in the midst of the Nave of the Church; and the
Point of Distance is in the Line from which the Arch of the Vault springs.
[Illustration: FIG. XCVIII.]
Figura Nonages. octava.
Quadrans Architecturæ horizontalis in fornice, cum luminibus & umbris.
_Habes in hac paginâ quadrantem totius Operis, modo consueto erutum ex
præcedenti: nimirùm, cuspide circini ex angulis vestigii accipiuntur
lineæ perpendiculares; ex angulis verò elevationis desumuntur lineæ
parallelæ, ac lineæ visuales ad punctum oculi._
Ninety-eighth Figure.
_A fourth Part of the Architectonical Design, painted on the Vault of S.
~Ignatius~’s Church; with its Lights and Shadows._
In this Figure you have a Quarter of the whole Work, drawn from the
foregoing Figure, after the usual Manner; namely, by taking with the
Compasses the perpendicular Lines from the Angles of the Plan; and the
parallel Lines from those of the Elevation, as also the visual Lines to
the Point of Sight.
[Illustration: FIG. XCIX.]
Figura Nonagesimanona.
Alter quadrans totius Operis.
_Ob diversitatem duorum quadrantum, tum in longitudine, tum in luminibus
& umbris, seorsim apponendum utrumque censui; ut in eis delineandis omnem
difficultatem tibi adimerem._
The Ninety-ninth Figure.
_Another Quarter of the whole Design._
By reason of the Difference of the two Quarters, as well in Length, as in
their Lights and Shadows, I resolv’d to describe them separately, that
you might find no Difficulty in designing the whole Work.
[Illustration: FIG. C.]
FIGURA Centesima.
Modus reticulationis faciendæ in testudinibus.
_Opera quæ fiunt in planis, contenta sunt duplici reticulatione, ut notum
est. Nam una earum fit in exemplari, altera fit in superficie in quâ
ipsum Opus pingendum est. At verò testudines exigunt tres reticulationes.
Prima fit in exemplari, quod supponimus delineatum esse juxta regulas
Perspectivæ horizontalis. Secunda reticulatio constat ex funiculis, &
est pensilis; cujus formam geometricam habes in ~M~. Locum ubi figendi
sunt clavi qui sustineant funiculos, exhibent rectæ ~AB~, ~EF~: optica
verò deformatio retis est in ~N~. Punctum oculi est ~O~, distantiæ est
~LO~. Itaque si imagineris, tempore nocturno, lumen candelæ aut lucernæ
existere in ~O~, atque à reti ex funiculis projici lineas umbrosas in
testudinem, eædemque lineæ pennicillo colorentur, habebitur tertia
reticulatio ad pingendam testudinem necessaria._
_Dixi ~si imagineris~, quia in testudinem obductam tabulato, ac remotam
à reti, & multò magis à lumine, vel projici nequeunt umbræ, vel
nequeunt esse vividæ ac distinctæ, ut oportet. Itaque ubi nimia fuerit
distantia, figes in ~O~ extremitatem fili; eóque usque ad testudinem
extenso, utéris veluti radio ac lumine candelæ, ad notandum umbræ
locum. Proderit etiam, ut super tabulato motum fili obsecundes lumine
alicujus candelæ, quod ipsi filo proximè admoveas. Atque his aliisque
adminiculis, tuâque industriâ, colores induces super lineis umbrosis, ac
tertiam reticulationem absolves. Posset etiam rete ex filis figi in parvâ
distantiâ à coronice, puta in ~GH~, unde incipit basis ædificii: tunc
autem umbræ in fornice sunt magis distinctæ ac visibiles._
_Diligentissimè curabis, ne mensuræ exemplaris discrepent ullatenus à
mensuris testudinis: ut rete incidens in angulos, arcus, aut lunulas
testudinis, exactè respondeat reti exemplaris. Demum si in vitia quæ
emendari nequeant, incidere nolis; scito, regulas omnes Perspectivæ
horizontalis, æquè in hominibus aut animalibus, ac in columnis aut
coronicibus pingendis, omnino servari oportere._
The Hundredth Figure.
_The Method of drawing the Net or Lattice-Work on Vaults._
For Works on a flat Superficies, two Net-works are sufficient; as has
been already intimated: One drawn on the Copy; the other on the Table to
be painted. But for arch’d Surfaces, or Vaults, three are requir’d: One
made on the Copy, which I suppose drawn according to Rules of horizontal
Perspective. The second consists of a Frame of small Cords or Threads,
to be hung up; the Geometrical Form of which is M. The Lines AB, EF,
shew the Place where this Frame is to be fix’d, in the same manner as
the Perspective N. The Point of Sight is O; of Distance, LO. Therefore,
if you imagine a Lamp or Candle fix’d in the Night-time at the Point O;
the Shadows of the Thread, thrown thereby on the Vault, being trac’d by a
Pencil, make the third Net-work requir’d for painting the same.
I say, _if you imagine_ a Lamp thus fix’d; because either the Scaffold
to the Vault, or the great Distance of the Vault from the Net-work, or
the greater of both from the Light, may prevent the Shadows from being
thrown at all, or at least, may render them so faint, as not to be
distinct enough for the purpose. Therefore, where this happens, instead
of the Light fix one End of a Thread in the Point O; and extending the
other to the Vault, make use of it as a Ray from the Lamp or Candle, for
describing the Place of the Shadows. It will be also of great use, to
second the Motion of the Thread with the Light of a Candle you may have
by you on the Scaffold, holding the same near the Thread itself. By this,
and other such Helps, which your own Industry will suggest, you may lay
these Shadows in Colours, and complete the third Net-work requir’d. The
Frame of Threads may also be fix’d nearer the Vault at some Distance
above the Cornice, as at GH, where the painted Architecture begins; for
the Shadows thrown on the Arch will by that means become more visible and
distinct.
You must be very careful, that the Measures of your Copy are exactly the
same with those of the Vault, that the Net-work thrown into the Angles,
Arches and Lunettes of the Vault, may perfectly correspond with that of
your Copy. Lastly, if you would not run into inextricable Errors; assure
yourself, that all these Rules of horizontal Perspective are as strictly
to be observ’d in the Figures of Men or Animals, as in painting Columns,
Cornices, or the like.
_Ut Perspectivæ Tyronibus consulerem, qui fortasse non adeo facilè
percipient duodecim primas figurarum explicationes, totidem novas
explicationes hic addo._
For the greater Help to Beginners, and those who are less conversant in
the Art of Perspective, I here subjoin a farther Explanation of the first
twelve Figures of this Book.