The Notebooks of Leonardo Da Vinci (51 page)

_E. Studies for the Central Tower, or Tiburio of Milan Cathedral.

Towards the end of the fifteenth century the Fabbricceria del Duomo
had to settle on the choice of a model for the crowning and central
part of this vast building. We learn from a notice published by G.
L. Calvi [Footnote: G. L. CALVI, Notizie sulla vita e sulle opere
dei principali architetti scultori e pittori che fiorirono in
Milano, Part III, 20. See also: H. DE GEYMULLER, Les projets
primitifs etc. I, 37 and 116-119.—The Fabbricceria of the Duomo has
lately begun the publication of the archives, which may possibly
tell us more about the part taken by Leonardo, than has hitherto
been known.] that among the artists who presented models in the year
1488 were: Bramante, Pietro da Gorgonzola, Luca Paperio (Fancelli),
and Leonardo da Vinci.—

Several sketches by Leonardo refer to this important project:

Pl. XCIX, No. 2 (MS. S. K. III, No. 36a) a small plan of the whole
edifice.—The projecting chapels in the middle of the transept are
wanting here. The nave appears to be shortened and seems to be
approached by an inner "vestibolo".—

Pl. C, No. 2 (Tr. 21). Plan of the octagon tower, giving the
disposition of the buttresses; starting from the eight pillars
adjoining the four principal piers and intended to support the eight
angles of the Tiburio. These buttresses correspond exactly with
those described by Bramante as existing in the model presented by
Omodeo. [Footnote: Bramante's opinion was first published by G.
MONGERl, Arch. stor. Lomb. V, fasc. 3 and afterwards by me in the
publication mentioned in the preceding note.]

Pl. C, 3 (MS. Tr. 16). Two plans showing different arrangements of
the buttresses, which seem to be formed partly by the intersection
of a system of pointed arches such as that seen in **

Pl. C, No. 5 (MS. B, 27a) destined to give a broader base to the
drum. The text underneath is given under No. 788.

MS. B, 3—three slight sketches of plans in connexion with the
preceding ones._

Pl. XCIX, No.1 (MS. Tr. 15) contains several small sketches of
sections and exterior views of the Dome; some of them show
buttress-walls shaped as inverted arches. Respecting these Leonardo
notes:

758.

L'arco rivescio e migliore per fare spalla che l'ordinario, perche
il rovescio trova sotto se muro resistete alla sua debolezza, e
l'ordinario no trova nel suo debole se non aria

The inverted arch is better for giving a shoulder than the ordinary
one, because the former finds below it a wall resisting its
weakness, whilst the latter finds in its weak part nothing but air.

[Footnote: _Three slight sketches of sections on the same
leaf—above those reproduced here—are more closely connected with
the large drawing in the centre of Pl. C, No. 4 (M.S, Tr. 41) which
shows a section of a very elevated dome, with double vaults,
connected by ribs and buttresses ingeniously disposed, so as to
bring the weight of the lantern to bear on the base of the dome.

A sketch underneath it shows a round pillar on which is indicated
which part of its summit is to bear the weight: "il pilastro sara
charicho in . a . b." (The column will bear the weight at a b.)
Another note is above on the right side:
Larcho regiera tanto sotto
asse chome di sopra se
(The arch supports as much below it [i. e. a
hanging weight] as above it).

Pl. C, No. 1 (C. A. 303a). Larger sketch of half section of the
Dome, with a very complicated system of arches, and a double vault.
Each stone is shaped so as to be knit or dovetailed to its
neighbours. Thus the inside of the Dome cannot be seen from below.

MS. C. A. 303b. A repetition of the preceding sketch with very
slight modifications._]

[Figs. 1. and Fig. 2. two sketeches of the dome]

MS. Tr. 9 (see Fig. 1 and 2). Section of the Dome with reverted
buttresses between the windows, above which iron anchors or chains
seem to be intended. Below is the sketch of the outside._

_PI. XCIX, No. 3 (C. A., 262a) four sketches of the exterior of the
Dome.

C. A. 12. Section, showing the points of rupture of a gothic vault,
in evident connection with the sketches described above.

It deserves to be noticed how easily and apparently without effort,
Leonardo manages to combine gothic details and structure with the
more modern shape of the Dome.

The following notes are on the same leaf,_ oni cosa poderosa,
and
oni cosa poderosa desidera de(scendere);
farther below, several
multiplications most likely intended to calculate the weight of some
parts of the Dome, thus 16 x 47 = 720; 720 x 800 = 176000, next to
which is written:
peso del pilastro di 9 teste _(weight of the
pillar 9 diameters high).

Below:_ 176000 x 8 = 1408000;
and below:

Semjlio e se ce 80 (?) il peso del tiburio _(six millions six
hundred (?) 80 the weight of the Dome).

Bossi hazarded the theory that Leonardo might have been the
architect who built the church of Sta. Maria delle Grazie, but there
is no evidence to support this, either in documents or in the
materials supplied by Leonardos manuscripts and drawings. The sketch
given at the side shows the arrangement of the second and third
socle on the apses of the choir of that church; and it is remarkable
that those sketches, in MS. S. K. M. II2, 2a and Ib, occur with the
passage given in Volume I as No. 665 and 666 referring to the
composition of the Last Supper in the Refectory of that church._]

F. The Project for lifting up the Battistero of Florence and
setting it on a basement.

Among the very few details Vasari gives as to the architectural
studies of Leonardo, we read: "And among these models and designs
there was one by way of which he showed several times to many
ingenious citizens who then governed Florence, his readiness to lift
up without ruining it, the church of San Giovanni in Florence (the
Battistero, opposite the Duomo) in order to place under it the
missing basement with steps; he supported his assertions with
reasons so persuasive, that while he spoke the undertaking seemed
feasable, although every one of his hearers, when he had departed,
could see by himself the impossibility of so vast an undertaking."

[Footnote:
This latter statement of Vasari's must be considered to
be exaggerated. I may refer here to some data given by
LIBRI,
Histoire des sciences mathematiques en Italie (II, 216, 217): "On a
cru dans ces derniers temps faire un miracle en mecanique en
effectuant ce transport, et cependant des l'annee 1455, Gaspard Nadi
et Aristote de Fioravantio avaient transporte, a une distance
considerable, la tour de la Magione de Bologne, avec ses fondements,
qui avait presque quatre-vingts pieds de haut. Le continuateur de la
chronique de Pugliola dit que le trajet fut de 35 pieds et que
durant le transport auquel le chroniqueur affirme avoir assiste, il
arriva un accident grave qui fit pencher de trois pieds la tour
pendant qu'elle etait suspendue, mais que cet accident fut
promptement repare (Muratori, Scriptores rer. ital. Tom. XVIII, col.
717, 718). Alidosi a rapporte une note ou Nadi rend compte de ce
transport avec une rare simplicite. D'apres cette note, on voit que
les operations de ce genre n'etaient pas nouvelles. Celle-ci ne
couta que 150 livres (monnaie d'alors) y compris le cadeau que le
Legat fit aux deux mecaniciens. Dans la meme annee, Aristote
redressa le clocher de Cento, qui penchait de plus de cinq pieds
(Alidosi, instruttione p. 188— Muratori, Scriptores rer. ital.,
tom. XXIII, col. 888.—Bossii, chronica Mediol., 1492, in-fol. ad
ann. 1455). On ne concoit pas comment les historiens des beaux-arts
ont pu negliger de tels hommes." J. P. R.]

In the MS. C. A. fol. 293, there are two sketches which possibly
might have a bearing on this bold enterprise. We find there a plan
of a circular or polygonal edifice surrounded by semicircular arches
in an oblique position. These may be taken for the foundation of the
steps and of the new platform. In the perspective elevation the same
edifice, forming a polygon, is shown as lifted up and resting on a
circle of inverted arches which rest on an other circle of arches in
the ordinary position, but so placed that the inverted arches above
rest on the spandrels of the lower range.

What seems to confirm the supposition that the lifting up of a
building is here in question, is the indication of engines for
winding up, such as jacks, and a rack and wheel. As the lifting
apparatus represented on this sheet does not seem particularly
applicable to an undertaking of such magnitude, we may consider it
to be a first sketch or scheme for the engines to be used.

G. Description of an unknown Temple.

759.

Twelve flights of steps led up to the great temple, which was eight
hundred braccia in circumference and built on an octagonal plan. At
the eight corners were eight large plinths, one braccia and a half
high, and three wide, and six long at the bottom, with an angle in
the middle; on these were eight great pillars, standing on the
plinths as a foundation, and twenty four braccia high. And on the
top of these were eight capitals three braccia long and six wide,
above which were the architrave frieze and cornice, four braccia and
a half high, and this was carried on in a straight line from one
pillar to the next and so, continuing for eight hundred braccia,
surrounded the whole temple, from pillar to pillar. To support this
entablature there were ten large columns of the same height as the
pillars, three braccia thick above their bases which were one
braccia and a half high.

The ascent to this temple was by twelve flights of steps, and the
temple was on the twelfth, of an octagonal form, and at each angle
rose a large pillar; and between the pillars were placed ten columns
of the same height as the pillars, rising at once from the pavement
to a height of twenty eight braccia and a half; and at this height
the architrave, frieze and cornice were placed which surrounded the
temple having a length of eight hundred braccia. At the same height,
and within the temple at the same level, and all round the centre of
the temple at a distance of 24 braccia farther in, are pillars
corresponding to the eight pillars in the angles, and columns
corresponding to those placed in the outer spaces. These rise to the
same height as the former ones, and over these the continuous
architrave returns towards the outer row of pillars and columns.

[Footnote: Either this description is incomplete, or, as seems to me
highly probable, it refers to some ruin. The enormous dimensions
forbid our supposing this to be any temple in Italy or Greece. Syria
was the native land of colossal octagonal buildings, in the early
centuries A. D. The Temple of Baalbek, and others are even larger
than that here described. J. P. R.]

_V. Palace architecture.

But a small number of Leonardo's drawings refer to the architecture
of palaces, and our knowledge is small as to what style Leonardo
might have adopted for such buildings.

Pl. CII No. 1 (W. XVIII). A small portion of a facade of a palace
in two stories, somewhat resembling Alberti's Palazzo
Rucellai.—Compare with this Bramante's painted front of the Casa
Silvestri, and a painting by Montorfano in San Pietro in Gessate at
Milan, third chapel on the left hand side and also with Bramante's
palaces at Rome. The pilasters with arabesques, the rustica between
them, and the figures over the window may be painted or in
sgraffito. The original is drawn in red chalk.

Pl. LXXXI No. 1 (MS. Tr. 42). Sketch of a palace with battlements
and decorations, most likely graffiti; the details remind us of
those in the Castello at Vigevano._ [Footnote 1:
Count GIULIO
PORRO, in his valuable contribution to the
Archivio Storico
Lombardo, Anno VIII, Fasc. IV (31 Dec. 1881): Leonardo da Vinci,
Libro di Annotazioni e Memorie,
refers to this in the following
note:
"Alla pag. 41 vi e uno schizzo di volta ed accanto scrisse:
'il pilastro sara charicho in su 6' e potrebbe darsi che si
riferisse alla cupola della chiesa delle Grazie tanto piu che a
pag. 42 vi e un disegno che rassomiglia assai al basamento che oggi
si vede nella parte esterna del coro di quella chiesa."
This may
however be doubted. The drawing, here referred to, on page 41 of the
same manuscript, is reproduced on Pl. C No. 4 and described on page
61 as being a study for the cupola of the Duomo of Milan.
J. P. R.]

_MS. Mz. 0", contains a design for a palace or house with a loggia
in the middle of the first story, over which rises an attic with a
Pediment reproduced on page 67. The details drawn close by on the
left seem to indicate an arrangement of coupled columns against the
wall of a first story.

Pl. LXXXV No. 14 (MS. S. K. M. Ill 79a) contains a very slight
sketch in red chalk, which most probably is intended to represent
the facade of a palace. Inside is the short note 7 he 7 (7 and 7)._

MS. J2 8a (see pages 68 Fig. 1 and 2) contains a view of an unknown
palace. Its plan is indicated at the side.

In MS. Br. M. 126a(see Fig. 3 on page 68) there is a sketch of a
house, on which Leonardo notes; casa con tre terrazi (house with
three terraces).

Pl. CX, No. 4 (MS. L. 36b) represents the front of a fortified
building drawn at Cesena in 1502 (see No. 1040).

Here we may also mention the singular building in the allegorical
composition represented on Pl. LVIII in Vol. I. In front of it
appears the head of a sphinx or of a dragon which seems to be
carrying the palace away.

The following texts refer to the construction of palaces and other
buildings destined for private use:

760.

In the courtyard the walls must be half the height of its width,
that is if the court be 40 braccia, the house must be 20 high as
regards the walls of the said courtyard; and this courtyard must be
half as wide as the whole front.