The Notebooks of Leonardo Da Vinci (45 page)

On looking over the numerous studies in which the horse is not
galloping but merely walking forward, we find only one drawing for
the pedestal, and this, to accord with the altered character of the
statue, is quieter and simpler in style (Pl. LXXIV). It rises almost
vertically from the ground and is exactly as long as the pacing
horse. The whole base is here arranged either as an independent
baldaquin or else as a projecting canopy over a recess in which the
figure of the deceased Duke is seen lying on his sarcophagus; in the
latter case it was probably intended as a tomb inside a church.
Here, too, it was intended to fill the angles with trophies or
captive warriors. Probably only No. 724 in the text refers to the
work for the base of the monument.

If we compare the last mentioned sketch with the description of a
plan for an equestrian monument to Gian Giacomo Trivulzio (No. 725)
it seems by no means impossible that this drawing is a preparatory
study for the very monument concerning which the manuscript gives us
detailed information. We have no historical record regarding this
sketch nor do the archives in the Trivulzio Palace give us any
information. The simple monument to the great general in San Nazaro
Maggiore in Milan consists merely of a sarcophagus placed in recess
high on the wall of an octagonal chapel. The figure of the warrior
is lying on the sarcophagus, on which his name is inscribed; a piece
of sculpture which is certainly not Leonardo's work. Gian Giacomo
Trivulzio died at Chartres in 1518, only five months before
Leonardo, and it seems to me highly improbable that this should have
been the date of this sketch; under these circumstances it would
have been done under the auspices of Francis I, but the Italian
general was certainly not in favour with the French monarch at the
time. Gian Giacomo Trivulzio was a sworn foe to Ludovico il Moro,
whom he strove for years to overthrow. On the 6th September 1499 he
marched victorious into Milan at the head of a French army. In a
short time, however, he was forced to quit Milan again when Ludovico
il Moro bore down upon the city with a force of Swiss troops. On the
15th of April following, after defeating Lodovico at Novara,
Trivulzio once more entered Milan as a Conqueror, but his hopes of
becoming
Governatore
of the place were soon wrecked by intrigue.
This victory and triumph, historians tell us, were signalised by
acts of vengeance against the dethroned Sforza, and it might have
been particularly flattering to him that the casting and
construction of the Sforza monument were suspended for the time.

It must have been at this moment—as it seems to me—that he
commissioned the artist to prepare designs for his own monument,
which he probably intended should find a place in the Cathedral or
in some other church. He, the husband of Margherita di Nicolino
Colleoni, would have thought that he had a claim to the same
distinction and public homage as his less illustrious connection had
received at the hands of the Venetian republic. It was at this very
time that Trivulzio had a medal struck with a bust portrait of
himself and the following remarkable inscription on the reverse:_
DEO FAVENTE—1499—DICTVS—10—IA—EXPVLIT—LVDOVICV—SF—
(Sfortiam) DVC— (ducem) MLI (Mediolani)—NOIE
(nomine)—REGIS—FRANCORVM—EODEM—ANN —(anno) RED'T (redit)—LVS
(Ludovicus)—SVPERATVS ET CAPTVS—EST—AB—EO. _In the Library of
the Palazzo Trivulzio there is a MS. of Callimachus Siculus written
at the end of the XVth or beginning of the XVIth century. At the
beginning of this MS. there is an exquisite illuminated miniature of
an equestrian statue with the name of the general on the base; it is
however very doubtful whether this has any connection with
Leonardo's design.

Nos. 731-740, which treat of casting bronze, have probably a very
indirect bearing on the arrangements made for casting the equestrian
statue of Francesco Sforza. Some portions evidently relate to the
casting of cannon. Still, in our researches about Leonardo's work on
the monument, we may refer to them as giving us some clue to the
process of bronze casting at that period.

Some practical hints (706-709).

If you wish to make a figure in marble, first make one of clay, and
when you have finished it, let it dry and place it in a case which
should be large enough, after the figure is taken out of it, to
receive also the marble, from which you intend to reveal the figure
in imitation of the one in clay. After you have put the clay figure
into this said case, have little rods which will exactly slip in to
the holes in it, and thrust them so far in at each hole that each
white rod may touch the figure in different parts of it. And colour
the portion of the rod that remains outside black, and mark each rod
and each hole with a countersign so that each may fit into its
place. Then take the clay figure out of this case and put in your
piece of marble, taking off so much of the marble that all your rods
may be hidden in the holes as far as their marks; and to be the
better able to do this, make the case so that it can be lifted up;
but the bottom of it will always remain under the marble and in this
way it can be lifted with tools with great ease.

707.

Some have erred in teaching sculptors to measure the limbs of their
figures with threads as if they thought that these limbs were
equally round in every part where these threads were wound about
them.

708.

Divide the head into 12 degrees, and each degree divide into 12
points, and each point into 12 minutes, and the minutes into minims
and the minims into semi minims.

Degree—point—minute—minim.

709.

Sculptured figures which appear in motion, will, in their standing
position, actually look as if they were falling forward.

[Footnote:
figure di rilievo
. Leonardo applies this term
exclusively to wholly detached figures, especially to those standing
free. This note apparently refers to some particular case, though we
have no knowledge of what that may have been. If we suppose it to
refer to the first model of the equestrian statue of Francesco
Sforza (see the introduction to the notes on Sculpture) this
observation may be regarded as one of his arguments for abandoning
the first scheme of the Sforza Monument, in which the horse was to
be galloping (see page 2). It is also in favour of this theory that
the note is written in a manuscript volume already completed in
1492. Leonardo's opinions as to the shortcomings of plastic works
when compared with paintings are given under No. 655 and 656.]

Notes on the casting of the Sforza monument (710-715).

710.

Three braces which bind the mould.

[If you want to make simple casts quickly, make them in a box of
river sand wetted with vinegar.]

[When you shall have made the mould upon the horse you must make the
thickness of the metal in clay.]

Observe in alloying how many hours are wanted for each
hundredweight. [In casting each one keep the furnace and its fire
well stopped up.] [Let the inside of all the moulds be wetted with
linseed oil or oil of turpentine, and then take a handful of
powdered borax and Greek pitch with aqua vitae, and pitch the mould
over outside so that being under ground the damp may not [damage
it?]

[To manage the large mould make a model of the small mould, make a
small room in proportion.]

[Make the vents in the mould while it is on the horse.]

Hold the hoofs in the tongs, and cast them with fish glue. Weigh the
parts of the mould and the quantity of metal it will take to fill
them, and give so much to the furnace that it may afford to each
part its amount of metal; and this you may know by weighing the clay
of each part of the mould to which the quantity in the furnace must
correspond. And this is done in order that the furnace for the legs
when filled may not have to furnish metal from the legs to help out
the head, which would be impossible. [Cast at the same casting as
the horse the little door]

[Footnote: The importance of the notes included under this number is
not diminished by the fact that they have been lightly crossed out
with red chalk. Possibly they were the first scheme for some fuller
observations which no longer exist; or perhaps they were crossed out
when Leonardo found himself obliged to give up the idea of casting
the equestrian statue. In the original the first two sketches are
above l. 1, and the third below l. 9.]

711.

Make the horse on legs of iron, strong and well set on a good
foundation; then grease it and cover it with a coating, leaving each
coat to dry thoroughly layer by layer; and this will thicken it by
the breadth of three fingers. Now fix and bind it with iron as may
be necessary. Moreover take off the mould and then make the
thickness. Then fill the mould by degrees and make it good
throughout; encircle and bind it with its irons and bake it inside
where it has to touch the bronze.

Draw upon the horse, when finished, all the pieces of the mould with
which you wish to cover the horse, and in laying on the clay cut it
in every piece, so that when the mould is finished you can take it
off, and then recompose it in its former position with its joins, by
the countersigns.

The square blocks
a b
will be between the cover and the core, that
is in the hollow where the melted bronze is to be; and these square
blocks of bronze will support the intervals between the mould and
the cover at an equal distance, and for this reason these squares
are of great importance.

The clay should be mixed with sand.

Take wax, to return [what is not used] and to pay for what is used.

Dry it in layers.

Make the outside mould of plaster, to save time in drying and the
expense in wood; and with this plaster enclose the irons [props]
both outside and inside to a thickness of two fingers; make terra
cotta. And this mould can be made in one day; half a boat load of
plaster will serve you.

Good.

Dam it up again with glue and clay, or white of egg, and bricks and
rubbish.

[Footnote: See Pl. LXXV. The figure "40," close to the sketch in the
middle of the page between lines 16 and 17 has been added by a
collector's hand.

In the original, below line 21, a square piece of the page has been
cut out about 9 centimetres by 7 and a blank piece has been gummed
into the place.

Lines 22-24 are written on the margin. l. 27 and 28 are close to the
second marginal sketch. l. 42 is a note written above the third
marginal sketch and on the back of this sheet is the text given as
No. 642. Compare also No. 802.]

712.

All the heads of the large nails.

[Footnote: See Pl. LXXVI, No. i. This drawing has already been
published in the "
Saggio delle Opere di L. da Vinci
." Milano 1872,
Pl. XXIV, No. i. But, for various reasons I cannot regard the
editor's suggestions as satisfactory. He says: "
Veggonsi le
armature di legname colle quali forse venne sostenuto il modello,
quando per le nozze di Bianca Maria Sforza con Massimiliano
imperatore, esso fu collocato sotto un arco trionfale davanti al
Castello
."

713.

These bindings go inside.

714.

Salt may be made from human excrements, burnt and calcined, made
into lees and dried slowly at a fire, and all the excrements produce
salt in a similar way and these salts when distilled, are very
strong.

[Footnote: VASARI repeatedly states, in the fourth chapter of his
Introduzione della Scultura
, that in preparing to cast bronze
statues horse-dung was frequently used by sculptors. If,
notwithstanding this, it remains doubtful whether I am justified in
having introduced here this text of but little interest, no such
doubt can be attached to the sketch which accompanies it.]

715.

This may be done when the furnace is made [Footnote: this note is
written below the sketches.] strong and bruised.

Models for the horse of the Sforza monument (716-718).

7l6.

Messer Galeazzo's big genet

717.

Messer Galeazzo's Sicilian horse.

[Footnote: These notes are by the side of a drawing of a horse with
figured measurements.]

718.

Measurement of the Sicilian horse the leg from behind, seen in
front, lifted and extended.

[Footnote: There is no sketch belonging to this passage. Galeazze
here probably means Galeazze di San Severino, the famous captain who
married Bianca the daughter of Ludovico il Moro.]

Occasional references to the Sforza monument (719-724).

719.

Again, the bronze horse may be taken in hand, which is to be to the
immortal glory and eternal honour of the happy memory of the prince
your father, and of the illustrious house of Sforza.

[Footnote: The letter from which this passage is here extracted will
be found complete in section XXI. (see the explanation of it, on
page 2).]

720.

On the 23rd of April 1490 I began this book, and recommenced the
horse.

721.

There is to be seen, in the mountains of Parma and Piacenza, a
multitude of shells and corals full of holes, still sticking to the
rocks, and when I was at work on the great horse for Milan, a large
sackful of them, which were found thereabout, was brought to me into
my workshop, by certain peasants.

722.

Believe me, Leonardo the Florentine, who has to do the equestrian
bronze statue of the Duke Francesco that he does not need to care
about it, because he has work for all his life time, and, being so
great a work, I doubt whether he can ever finish it. [Footnote: This
passage is quoted from a letter to a committee at Piacenza for whom
Leonardo seems to have undertaken to execute some work. The letter
is given entire in section XXL; in it Leonardo remonstrates as to
some unreasonable demands.]