ON THE LENGTH OF BEAMS.

That beam which is more than 20 times as long as its greatest
thickness will be of brief duration and will break in half; and
remember, that the part built into the wall should be steeped in hot
pitch and filleted with oak boards likewise so steeped. Each beam
must pass through its walls and be secured beyond the walls with
sufficient chaining, because in consequence of earthquakes the beams
are often seen to come out of the walls and bring down the walls and
floors; whilst if they are chained they will hold the walls strongly
together and the walls will hold the floors. Again I remind you
never to put plaster over timber. Since by expansion and shrinking
of the timber produced by damp and dryness such floors often crack,
and once cracked their divisions gradually produce dust and an ugly
effect. Again remember not to lay a floor on beams supported on
arches; for, in time the floor which is made on beams settles
somewhat in the middle while that part of the floor which rests on
the arches remains in its place; hence, floors laid over two kinds
of supports look, in time, as if they were made in hills [Footnote:
19 M. RAVAISSON, in his edition of MS. A gives a very different
rendering of this passage translating it thus: _Les planchers qui
sont soutenus par deux differentes natures de supports paraissent
avec le temps faits en voute a cholli_.]

Remarks on the style of Leonardo's architecture.

A few remarks may here be added on the style of Leonardo's
architectural studies. However incomplete, however small in scale,
they allow us to establish a certain number of facts and
probabilities, well worthy of consideration.

When Leonardo began his studies the great name of Brunellesco was
still the inspiration of all Florence, and we cannot doubt that
Leonardo was open to it, since we find among his sketches the plan
of the church of Santo Spirito[Footnote 1: See Pl. XCIV, No. 2. Then
only in course of erection after the designs of Brunellesco, though
he was already dead; finished in 1481.] and a lateral view of San
Lorenzo (Pl. XCIV No. 1), a plan almost identical with the chapel
Degli Angeli, only begun by him (Pl. XCIV, No. 3) while among
Leonardo's designs for domes several clearly betray the influence of
Brunellesco's Cupola and the lantern of Santa Maria del
Fiore[Footnote 2: A small sketch of the tower of the Palazzo della
Signoria (MS. C.A. 309) proves that he also studied mediaeval
monuments.]

The beginning of the second period of modern Italian architecture
falls during the first twenty years of Leonardo's life. However the
new impetus given by Leon Battista Alberti either was not generally
understood by his contemporaries, or those who appreciated it, had
no opportunity of showing that they did so. It was only when taken
up by Bramante and developed by him to the highest rank of modern
architecture that this new influence was generally felt. Now the
peculiar feature of Leonardo's sketches is that, like the works of
Bramante, they appear to be the development and continuation of
Alberti's.

_But a question here occurs which is difficult to answer. Did
Leonardo, till he quitted Florence, follow the direction given by
the dominant school of Brunellesco, which would then have given rise
to his "First manner", or had he, even before he left Florence, felt
Alberti's influence--either through his works (Palazzo Ruccellai,
and the front of Santa Maria Novella) or through personal
intercourse? Or was it not till he went to Milan that Alberti's work
began to impress him through Bramante, who probably had known
Alberti at Mantua about 1470 and who not only carried out Alberti's
views and ideas, but, by his designs for St. Peter's at Rome, proved
himself the greatest of modern architects. When Leonardo went to
Milan Bramante had already been living there for many years. One of
his earliest works in Milan was the church of Santa Maria presso San
Satiro, Via del Falcone[Footnote 1: Evidence of this I intend to
give later on in a Life of Bramante, which I have in preparation.].

Now we find among Leonardos studies of Cupolas on Plates LXXXIV and
LXXXV and in Pl. LXXX several sketches which seem to me to have been
suggested by Bramante's dome of this church.

The MSS. B and Ash. II contain the plans of S. Sepolcro, the
pavilion in the garden of the duke of Milan, and two churches,
evidently inspired by the church of San Lorenzo at Milan.

MS. B. contains besides two notes relating to Pavia, one of them a
design for the sacristy of the Cathedral at Pavia, which cannot be
supposed to be dated later than 1492, and it has probably some
relation to Leonardo's call to Pavia June 21, 1490[Footnote 2: The
sketch of the plan of Brunellesco's church of Santo Spirito at
Florence, which occurs in the same Manuscript, may have been done
from memory.]. These and other considerations justify us in
concluding, that Leonardo made his studies of cupolas at Milan,
probably between the years 1487 and 1492 in anticipation of the
erection of one of the grandest churches of Italy, the Cathedral of
Pavia. This may explain the decidedly Lombardo-Bramantesque tendency
in the style of these studies, among which only a few remind us of
the forms of the cupolas of S. Maria del Fiore and of the Baptistery
of Florence. Thus, although when compared with Bramante's work,
several of these sketches plainly reveal that master's influence, we
find, among the sketches of domes, some, which show already
Bramante's classic style, of which the Tempietto of San Pietro in
Montorio, his first building executed at Rome, is the foremost
example[Footnote 3: It may be mentioned here, that in 1494 Bramante
made a similar design for the lantern of the Cupola of the Church of
Santa Maria delle Grazie.].

On Plate LXXXIV is a sketch of the plan of a similar circular
building; and the Mausoleum on Pl. XCVIII, no less than one of the
pedestals for the statue of Francesco Sforza (Pl. LXV), is of the
same type.

The drawings Pl. LXXXIV No. 2, Pl. LXXXVI No. 1 and 2 and the ground
flour ("flour" sic but should be "floor" ?) of the building in the
drawing Pl. XCI No. 2, with the interesting decoration by gigantic
statues in large niches, are also, I believe, more in the style
Bramante adopted at Rome, than in the Lombard style. Are we to
conclude from this that Leonardo on his part influenced Bramante in
the sense of simplifying his style and rendering it more congenial
to antique art? The answer to this important question seems at first
difficult to give, for we are here in presence of Bramante, the
greatest of modern architects, and with Leonardo, the man comparable
with no other. We have no knowledge of any buildings erected by
Leonardo, and unless we admit personal intercourse--which seems
probable, but of which there is no proof--, it would be difficult to
understand how Leonardo could have affected Bramante's style. The
converse is more easily to be admitted, since Bramante, as we have
proved elsewhere, drew and built simultaneously in different
manners, and though in Lombardy there is no building by him in his
classic style, the use of brick for building, in that part of Italy,
may easily account for it._

_Bramante's name is incidentally mentioned in Leonardo's manuscripts
in two passages (Nos. 1414 and 1448). On each occasion it is only a
slight passing allusion, and the nature of the context gives us no
due information as to any close connection between the two artists._

_It might be supposed, on the ground of Leonardo's relations with
the East given in sections XVII and XXI of this volume, that some
evidence of oriental influence might be detected in his
architectural drawings. I do not however think that any such traces
can be pointed out with certainty unless perhaps the drawing for a
Mausoleum, Pl. XC VIII._

_Among several studies for the construction of cupolas above a Greek
cross there are some in which the forms are decidedly monotonous.
These, it is clear, were not designed as models of taste; they must
be regarded as the results of certain investigations into the laws
of proportion, harmony and contrast._

_The designs for churches, on the plan of a Latin cross are
evidently intended to depart as little as possible from the form of
a Greek cross; and they also show a preference for a nave surrounded
with outer porticos._

_The architectural forms preferred by Leonardo are pilasters coupled
(Pl. LXXXII No. 1; or grouped (Pl. LXXX No. 5 and XCIV No. 4), often
combined with niches. We often meet with orders superposed, one in
each story, or two small orders on one story, in combination with
one great order (Pl. XCVI No. 2)._

The drum (tamburo) of these cupolas is generally octagonal, as in
the cathedral of Florence, and with similar round windows in its
sides. In Pl. LXXXVII No. 2 it is circular like the model actually
carried out by Michael Angelo at St. Peter's.

The cupola itself is either hidden under a pyramidal roof, as in the
Baptistery of Florence, San Lorenzo of Milan and most of the Lombard
churches (Pl. XCI No. 1 and Pl. XCII No. 1); but it more generally
suggests the curve of Sta Maria del Fiore (Pl. LXXXVIII No. 5; Pl.
XC No. 2; Pl. LXXXIX, M; Pl XC No. 4, Pl. XCVI No. 2). In other
cases (Pl. LXXX No. 4; Pl. LXXXIX; Pl. XC No. 2) it shows the sides
of the octagon crowned by semicircular pediments, as in
Brunellesco's lantern of the Cathedral and in the model for the
Cathedral of Pavia.

Finally, in some sketches the cupola is either semicircular, or as
in Pl. LXXXVII No. 2, shows the beautiful line, adopted sixty years
later by Michael Angelo for the existing dome of St. Peter's.

It is worth noticing that for all these domes Leonardo is not
satisfied to decorate the exterior merely with ascending ribs or
mouldings, but employs also a system of horizontal parallels to
complete the architectural system. Not the least interesting are the
designs for the tiburio (cupola) of the Milan Cathedral. They show
some of the forms, just mentioned, adapted to the peculiar gothic
style of that monument.

The few examples of interiors of churches recall the style employed
in Lombardy by Bramante, for instance in S. Maria di Canepanuova at
Pavia, or by Dolcebuono in the Monastero Maggiore at Milan (see Pl.
CI No. 1 [C. A. 181b; 546b]; Pl. LXXXIV No. 10).

The few indications concerning palaces seem to prove that Leonardo
followed Alberti's example of decorating the walls with pilasters
and a flat rustica, either in stone or by graffitti (Pl. CII No. 1
and Pl. LXXXV No. 14).

By pointing out the analogies between Leonardo's architecture and
that of other masters we in no way pretend to depreciate his
individual and original inventive power. These are at all events
beyond dispute. The project for the Mausoleum (Pl. XCVIII) would
alone suffice to rank him among the greatest architects who ever
lived. The peculiar shape of the tower (Pl. LXXX), of the churches
for preaching (Pl. XCVII No. 1 and pages 56 and 57, Fig. 1-4), his
curious plan for a city with high and low level streets (Pl. LXXVII
and LXXVIII No. 2 and No. 3), his Loggia with fountains (Pl. LXXXII
No. 4) reveal an originality, a power and facility of invention for
almost any given problem, which are quite wonderful.

_In addition to all these qualities he propably stood alone in his
day in one department of architectural study,--his investigations,
namely, as to the resistance of vaults, foundations, walls and
arches._

_As an application of these studies the plan of a semicircular vault
(Pl. CIII No. 2) may be mentioned here, disposed so as to produce no
thrust on the columns on which it rests:_ volta i botte e non
ispignie ifori le colone. _Above the geometrical patterns on the
same sheet, close to a circle inscribed in a square is the note:_ la
ragio d'una volta cioe il terzo del diamitro della sua ... del
tedesco in domo.

_There are few data by which to judge of Leonardo's style in the
treatment of detail. On Pl. LXXXV No. 10 and Pl. CIII No. 3, we find
some details of pillars; on Pl. CI No. 3 slender pillars designed
for a fountain and on Pl. CIII No. 1 MS. B, is a pen and ink drawing
of a vase which also seems intended for a fountain. Three handles
seem to have been intended to connect the upper parts with the base.
There can be no doubt that Leonardo, like Bramante, but unlike
Michael Angelo, brought infinite delicacy of motive and execution to
bear on the details of his work._

_XIV._

_Anatomy, Zoology and Physiology._

_Leonardo's eminent place in the history of medicine, as a pioneer
in the sciences of Anatomy and Physiology, will never be appreciated
till it is possible to publish the mass of manuscripts in which he
largely treated of these two branches of learning. In the present
work I must necessarily limit myself to giving the reader a general
view of these labours, by publishing his introductory notes to the
various books on anatomical subjects. I have added some extracts,
and such observations as are scattered incidentally through these
treatises, as serving to throw a light on Leonardo's scientific
attitude, besides having an interest for a wider circle than that of
specialists only._

_VASARI expressly mentions Leonardo's anatomical studies, having had
occasion to examine the manuscript books which refer to them.
According to him Leonardo studied Anatomy in the companionship of
Marc Antonio della Torre_ "aiutato e scambievolmente
aiutando."_--This learned Anatomist taught the science in the
universities first of Padua and then of Pavia, and at Pavia he and
Leonardo may have worked and studied together. We have no clue to
any exact dates, but in the year 1506 Marc Antonio della Torre seems
to have not yet left Padua. He was scarcely thirty years old when he
died in 1512, and his writings on anatomy have not only never been
published, but no manuscript copy of them is known to exist._

_This is not the place to enlarge on the connection between Leonardo
and Marc Antonio della Torre. I may however observe that I have not
been able to discover in Leonardo's manuscripts on anatomy any
mention of his younger contemporary. The few quotations which occur
from writers on medicine--either of antiquity or of the middle ages
are printed in Section XXII. Here and there in the manuscripts
mention is made of an anonymous "adversary"_ (avversario) _whose
views are opposed and refuted by Leonardo, but there is no ground
for supposing that Marc Antonio della Torre should have been this
"adversary"._

_Only a very small selection from the mass of anatomical drawings
left by Leonardo have been published here in facsimile, but to form
any adequate idea of their scientific merit they should be compared
with the coarse and inadequate figures given in the published books
of the early part of the XVI. century.

William Hunter, the great surgeon--a competent judge--who had an
opportunity in the time of George III. of seeing the originals in
the King's Library, has thus recorded his opinion: "I expected to
see little more than such designs in Anatomy as might be useful to a
painter in his own profession. But I saw, and indeed with
astonishment, that Leonardo had been a general and deep student.
When I consider what pains he has taken upon every part of the body,
the superiority of his universal genius, his particular excellence
in mechanics and hydraulics, and the attention with which such a man
would examine and see objects which he has to draw, I am fully
persuaded that Leonardo was the best Anatomist, at that time, in the
world ... Leonardo was certainly the first man, we know of, who
introduced the practice of making anatomical drawings" (Two
introductory letters. London 1784, pages 37 and 39).

The illustrious German Naturalist Johan Friedrich Blumenback
esteemed them no less highly; he was one of the privileged few who,
after Hunter, had the chance of seeing these Manuscripts. He writes:
_Der Scharfblick dieses grossen Forschers und Darstellers der Natur
hat schon auf Dinge geachtet, die noch Jahrhunderte nachher
unbemerkt geblieben sind_" (see _Blumenbach's medicinische
Bibliothek_, Vol. 3, St. 4, 1795. page 728).

These opinions were founded on the drawings alone. Up to the present
day hardly anything has been made known of the text, and, for the
reasons I have given, it is my intention to reproduce here no more
than a selection of extracts which I have made from the originals at
Windsor Castle and elsewhere. In the Bibliography of the
Manuscripts, at the end of this volume a short review is given of
the valuable contents of these Anatomical note books which are at
present almost all in the possession of her Majesty the Queen of
England. It is, I believe, possible to assign the date with
approximate accuracy to almost all the fragments, and I am thus led
to conclude that the greater part of Leonardo's anatomical
investigations were carried out after the death of della Torre.

Merely in reading the introductory notes to his various books on
Anatomy which are here printed it is impossible to resist the
impression that the Master's anatomical studies bear to a very great
extent the stamp of originality and independent thought.

I.

ANATOMY.