The Notebooks of Leonardo Da Vinci, Volume 2 by Leonardo Da Vinci

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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.]

723.

Of the horse I will say nothing because I know the times. [Footnote:
This passage occurs in a rough copy of a letter to Ludovico il Moro,
without date (see below among the letters).]

724.

During ten years the works on the marbles have been going on I will
not wait for my payment beyond the time, when my works are finished.
[Footnote: This possibly refers to the works for the pedestal of the
equestrian statue concerning which we have no farther information in
the MSS. See p. 6.]

The project of the Trivulzio monument.

725.

THE MONUMENT TO MESSER GIOVANNI JACOMO DA TREVULZO.

[2] Cost of the making and materials for the horse [5].

[Footnote: In the original, lines 2-5, 12-14, 33-35, are written on
the margin. This passage has been recently published by G. Govi in
Vol. V, Ser. 3a, of _Transunti, Reale Accademia dei Linea, sed. del
5 Giugno, 1881,_ with the following introductory note: _"Desidero
intanto che siano stampati questi pochi frammenti perche so che sono
stati trascritti ultimamente, e verranno messi in luce tra poco
fuori d'Italia. Li ripubblichi pure chi vuole, ma si sappia almeno
che anche tra noi si conoscevano, e s'eran raccolti da anni per
comporne, quando che fosse, una edizione ordinata degli scritti di
Leonardo."_

The learned editor has left out line 22 and has written 3 _pie_ for
8 _piedi_ in line 25. There are other deviations of less importance
from the original.]

A courser, as large as life, with the rider requires for the cost of
the metal, duc. 500.

And for cost of the iron work which is inside the model, and
charcoal, and wood, and the pit to cast it in, and for binding the
mould, and including the furnace where it is to be cast ... duc.
200.

To make the model in clay and then in wax......... duc. 432.

To the labourers for polishing it when it is cast. ....... duc. 450.

in all. . duc. 1582.

[12] Cost of the marble of the monument [14].

Cost of the marble according to the drawing. The piece of marble
under the horse which is 4 braccia long, 2 braccia and 2 inches wide
and 9 inches thick 58 hundredweight, at 4 Lire and 10 Soldi per
hundredweight.. duc. 58.

And for 13 braccia and 6 inches of cornice, 7 in. wide and 4 in.
thick, 24 hundredweight....... duc. 24.

And for the frieze and architrave, which is 4 br. and 6 in. long, 2
br. wide and 6 in. thick, 29 hundredweight., duc. 20.

And for the capitals made of metal, which are 8, 5 inches in. square
and 2 in. thick, at the price of 15 ducats each, will come to......
duc. 122.

And for 8 columns of 2 br. 7 in., 4 1/2 in. thick, 20 hundredweight
duc. 20.

And for 8 bases which are 5 1/2 in. square and 2 in. high 5 hund'..
duc. 5.

And for the slab of the tombstone 4 br. io in. long, 2 br. 4 1/2 in.
wide 36 hundredweight....... duc. 36.

And for 8 pedestal feet each 8 br. long and 6 1/2 in. wide and 6 1/2
in. thick, 20 hundredweight come to... duc. 20.

And for the cornice below which is 4 br. and 10 in. long, and 2 br.
and 5 in. wide, and 4 in. thick, 32 hund'.. duc. 32.

And for the stone of which the figure of the deceased is to be made
which is 3 br. and 8 in. long, and 1 br. and 6 in. wide, and 9 in.
thick, 30 hund'.. duc. 30.

And for the stone on which the figure lies which is 3 br. and 4 in.
long and 1 br. and 2 in., wide and 4 1/2 in. thick duc. 16.

And for the squares of marble placed between the pedestals which are
8 and are 9 br. long and 9 in. wide, and 3 in. thick, 8
hundredweight . . . duc. 8. in all. . duc. 389.

[33]Cost of the work in marble[35].

Round the base on which the horse stands there are 8 figures at 25
ducats each ............ duc. 200.

And on the same base there are 8 festoons with some other ornaments,
and of these there are 4 at the price of 15 ducats each, and 4 at
the price of 8 ducats each ....... duc. 92.

And for squaring the stones duc. 6.

Again, for the large cornice which goes below the base on which the
horse stands, which is 13 br. and 6 in., at 2 due. per br. ......
duc. 27.

And for 12 br. of frieze at 5 due. per br. ........... duc. 60.

And for 12 br. of architrave at 1 1/2 duc. per br. ....... duc. 18.

And for 3 rosettes which will be the soffit of the monument, at 20
ducats each .......... duc. 60.

And for 8 fluted columns at 8 ducats each ......... duc. 64.

And for 8 bases at 1 ducat each, duc. 8.

And for 8 pedestals, of which 4 are at 10 duc. each, which go above
the angles; and 4 at 6 duc. each .. duc. 64.

And for squaring and carving the moulding of the pedestals at 2 duc.
each, and there are 8 .... duc. 16.

And for 6 square blocks with figures and trophies, at 25 duc. each
.. duc. 150.

And for carving the moulding of the stone under the figure of the
deceased .......... duc. 40.

For the statue of the deceased, to do it well .......... duc. 100.

For 6 harpies with candelabra, at 25 ducats each ......... duc. 150.

For squaring the stone on which the statue lies, and carving the
moulding ............ duc. 20.

in all .. duc. 1075.

The sum total of every thing added together amount to ...... duc.
3046.

726.

MINT AT ROME.

It can also be made without a spring. But the screw above must
always be joined to the part of the movable sheath: [Margin note:
The mint of Rome.] [Footnote: See Pl. LXXVI. This passage is taken
from a note book which can be proved to have been used in Rome.]

All coins which do not have the rim complete, are not to be accepted
as good; and to secure the perfection of their rim it is requisite
that, in the first place, all the coins should be a perfect circle;
and to do this a coin must before all be made perfect in weight, and
size, and thickness. Therefore have several plates of metal made of
the same size and thickness, all drawn through the same gauge so as
to come out in strips. And out of [24] these strips you will stamp
the coins, quite round, as sieves are made for sorting chestnuts
[27]; and these coins can then be stamped in the way indicated
above; &c.

[31] The hollow of the die must be uniformly wider than the lower,
but imperceptibly [35].

This cuts the coins perfectly round and of the exact thickness, and
weight; and saves the man who cuts and weighs, and the man who makes
the coins round. Hence it passes only through the hands of the
gauger and of the stamper, and the coins are very superior.
[Footnote: See Pl. LXXVI No. 2. The text of lines 31-35 stands
parallel 1. 24-27.

Farther evidence of Leonardo's occupations and engagements at Rome
under Pope Leo X. may be gathered from some rough copies of letters
which will be found in this volume. Hitherto nothing has been known
of his work in Rome beyond some doubtful, and perhaps mythical,
statements in Vasari.]

727.

POWDER FOR MEDALS.

The incombustible growth of soot on wicks reduced to powder, burnt
tin and all the metals, alum, isinglass, smoke from a brass forge,
each ingredient to be moistened, with aqua vitae or malmsey or
strong malt vinegar, white wine or distilled extract of turpentine,
or oil; but there should be little moisture, and cast in moulds.
[Margin note: On the coining of medals (727. 728).] [Footnote: The
meaning of _scagliuolo_ in this passage is doubtful.]

728.

OF TAKING CASTS OF MEDALS.

A paste of emery mixed with aqua vitae, or iron filings with
vinegar, or ashes of walnut leaves, or ashes of straw very finely
powdered.

[Footnote: The meaning of _scagliuolo_ in this passage is doubtful.]

The diameter is given in the lead enclosed; it is beaten with a
hammer and several times extended; the lead is folded and kept
wrapped up in parchment so that the powder may not be spilt; then
melt the lead, and the powder will be on the top of the melted lead,
which must then be rubbed between two plates of steel till it is
thoroughly pulverised; then wash it with aqua fortis, and the
blackness of the iron will be dissolved leaving the powder clean.

Emery in large grains may be broken by putting it on a cloth many
times doubled, and hit it sideways with the hammer, when it will
break up; then mix it little by little and it can be founded with
ease; but if you hold it on the anvil you will never break it, when
it is large.

Any one who grinds smalt should do it on plates of tempered steel
with a cone shaped grinder; then put it in aqua fortis, which melts
away the steel that may have been worked up and mixed with the
smalt, and which makes it black; it then remains purified and clean;
and if you grind it on porphyry the porphyry will work up and mix
with the smalt and spoil it, and aqua fortis will never remove it
because it cannot dissolve the porphyry.

If you want a fine blue colour dissolve the smalt made with tartar,
and then remove the salt.

Vitrified brass makes a fine red.

729.

STUCCO.

Place stucco over the prominence of the..... which may be composed
of Venus and Mercury, and lay it well over that prominence of the
thickness of the side of a knife, made with the ruler and cover this
with the bell of a still, and you will have again the moisture with
which you applied the paste. The rest you may dry [Margin note: On
stucco (729. 730).] [Footnote: In this passage a few words have been
written in a sort of cipher--that is to say backwards; as in l. 3
_erenev_ for _Venere_, l. 4 _oirucrem_ for Mercurio, l. 12 _il
orreve co ecarob_ for _il everro (?) co borace_. The meaning of the
word before _"di giesso"_ in l. 1 is unknown; and the sense, in
which _sagoma_ is used here and in other passages is obscure.--
_Venere_ and _Mercurio_ may mean 'marble' and 'lime', of which
stucco is composed.

12. The meaning of _orreve_ is unknown.]

well; afterwards fire it, and beat it or burnish it with a good
burnisher, and make it thick towards the side.

STUCCO.

Powder ... with borax and water to a paste, and make stucco of it,
and then heat it so that it may dry, and then varnish it, with fire,
so that it shines well.

730.

STUCCO FOR MOULDING.

Take of butter 6 parts, of wax 2 parts, and as much fine flour as
when put with these 2 things melted, will make them as firm as wax
or modelling clay.

GLUE.

Take mastic, distilled turpentine and white lead.

On bronze casting generally (731-740).

731.

TO CAST.

Tartar burnt and powdered with plaster and cast cause the plaster to
hold together when it is mixed up again; and then it will dissolve
in water.

732.

TO CAST BRONZE IN PLASTER.

Take to every 2 cups of plaster 1 of ox-horns burnt, mix them
together and make your cast with it.

733.

When you want to take a cast in wax, burn the scum with a candle,
and the cast will come out without bubbles.

734.

2 ounces of plaster to a pound of metal;-- walnut, which makes it
like the curve.

[Footnote: The second part of this is quite obscure.]

735.

[Dried earth 16 pounds, 100 pounds of metal wet clay 20,--of wet
100,-half,- which increases 4 Ibs. of water,--1 of wax, 1 Ib. of
metal, a little less,-the scrapings of linen with earth, measure for
measure.] [Footnote: The translation is given literally, but the
meaning is quite obscure.]

736.

Such as the mould is, so will the cast be.

737.

HOW CASTS OUGHT TO BE POLISHED.

Make a bunch of iron wire as thick as thread, and scrub them with
[this and] water; hold a bowl underneath that it may not make a mud
below.

HOW TO REMOVE THE ROUGH EDGES FROM BRONZE.

Make an iron rod, after the manner of a large chisel, and with this
rub over those seams on the bronze which remain on the casts of the
guns, and which are caused by the joins in the mould; but make the
tool heavy enough, and let the strokes be long and broad.

TO FACILITATE MELTING.

First alloy part of the metal in the crucible, then put it in the
furnace, and this being in a molten state will assist in beginning
to melt the copper.

TO PREVENT THE COPPER COOLING IN THE FURNACE.

When the copper cools in the furnace, be ready, as soon as you
perceive it, to cut it with a long stick while it is still in a
paste; or if it is quite cold cut it as lead is cut with broad and
large chisels.

IF YOU HAVE TO MAKE A LARGE CAST.

If you have to make a cast of a hundred thousand pounds do it with
two furnaces and with 2000 pounds in each, or as much as 3000 pounds
at most.

738.

HOW TO PROCEED TO BREAK A LARGE MASS OF BRONZE.

If you want to break up a large mass of bronze, first suspend it,
and then make round it a wall on the four sides, like a trough of
bricks, and make a great fire therein. When it is quite red hot give
it a blow with a heavy weight raised above it, and with great force.

739.

TO COMBINE LEAD WITH OTHER METAL.

If you wish for economy in combining lead with the metal in order to
lessen the amount of tin which is necessary in the metal, first
alloy the lead with the tin and then add the molten copper.

How TO MELT [METAL] IN A FURNACE.

The furnace should be between four well founded pillars.

OF THE THICKNESS OF THE COATING.

The coating should not be more than two fingers thick, it should be
laid on in four thicknesses over fine clay and then well fixed, and
it should be fired only on the inside and then carefully covered
with ashes and cow's dung.

OF THE THICKNESS OF THE GUN.

The gun being made to carry 600 Ibs. of ball and more, by this rule
you will take the measure of the diameter of the ball and divide it
into 6 parts and one of these parts will be its thickness at the
muzzle; but at the breech it must always be half. And if the ball is
to be 700 lbs., 1/7th of the diameter of the ball must be its
thickness in front; and if the ball is to be 800, the eighth of its
diameter in front; and if 900, 1/8th and 1/2 [3/16], and if 1000,
1/9th.

OF THE LENGTH OF THE BODY OF THE GUN.

If you want it to throw a ball of stone, make the length of the gun
to be 6, or as much as 7 diameters of the ball; and if the ball is
to be of iron make it as much as 12 balls, and if the ball is to be
of lead, make it as much as 18 balls. I mean when the gun is to have
the mouth fitted to receive 600 lbs. of stone ball, and more.

OF THE THICKNESS OF SMALL GUNS.

The thickness at the muzzle of small guns should be from a half to
one third of the diameter of the ball, and the length from 30 to 36
balls.

740.

OF LUTING THE FURNACE WITHIN.

The furnace must be luted before you put the metal in it, with earth
from Valenza, and over that with ashes.

[Footnote 1. 2.: _Terra di Valenza_.--Valenza is north of
Alessandria on the Po.]

OF RESTORING THE METAL WHEN IT IS BECOMING COOL.

When you see that the bronze is congealing take some willow-wood cut
in small chips and make up the fire with it.

THE CAUSE OF ITS CURDLING.

I say that the cause of this congealing often proceeds from too much
fire, or from ill-dried wood.

TO KNOW THE CONDITION OF THE FIRE.

You may know when the fire is good and fit for your purpose by a
clear flame, and if you see the tips of the flames dull and ending
in much smoke do not trust it, and particularly when the flux metal
is almost fluid.

OF ALLOYING THE METAL.

Metal for guns must invariably be made with 6 or even 8 per cent,
that is 6 of tin to one hundred of copper, for the less you put in,
the stronger will the gun be.

WHEN THE TIN SHOULD BE ADDED TO THE COPPER.

The tin should be put in with the copper when the copper is reduced
to a fluid.

HOW TO HASTEN THE MELTING.

You can hasten the melting when 2/3ds of the copper is fluid; you
can then, with a stick of chestnut-wood, repeatedly stir what of
copper remains entire amidst what is melted.

_Introductory Observations on the Architectural Designs (XII), and
Writings on Architecture (XIII)._

_Until now very little has been known regarding Leonardo's labours
in the domain of Architecture. No building is known to have been
planned and executed by him, though by some contemporary writers
incidental allusion is made to his occupying himself with
architecture, and his famous letter to Lodovico il Moro,--which has
long been a well-known document,--in which he offers his service as
an architect to that prince, tends to confirm the belief that he was
something more than an amateur of the art. This hypothesis has
lately been confirmed by the publication of certain documents,
preserved at Milan, showing that Leonardo was not only employed in
preparing plans but that he took an active part, with much credit,
as member of a commission on public buildings; his name remains
linked with the history of the building of the Cathedral at Pavia
and that of the Cathedral at Milan._

_Leonardo's writings on Architecture are dispersed among a large
number of MSS., and it would be scarcely possible to master their
contents without the opportunity of arranging, sorting and comparing
the whole mass of materials, so as to have some comprehensive idea
of the whole. The sketches, when isolated and considered by
themselves, might appear to be of but little value; it is not till
we understand their general purport, from comparing them with each
other, that we can form any just estimate of their true worth._

_Leonardo seems to have had a project for writing a complete and
separate treatise on Architecture, such as his predecessors and
contemporaries had composed--Leon Battista Alberti, Filarete,
Francesco di Giorgio and perhaps also Bramante. But, on the other
hand, it cannot be denied that possibly no such scheme was connected
with the isolated notes and researches, treating on special
questions, which are given in this work; that he was merely working
at problems in which, for some reason or other he took a special
interest._

_A great number of important buildings were constructed in Lombardy
during the period between 1472 and 1499, and among them there are
several by unknown architects, of so high an artistic merit, that it
is certainly not improbable that either Bramante or Leonardo da
Vinci may have been, directly or indirectly, concerned in their
erection._

_Having been engaged, for now nearly twenty years, in a thorough
study of Bramante's life and labours, I have taken a particular
interest in detecting the distinguishing marks of his style as
compared with Leonardo's. In 1869 I made researches about the
architectural drawings of the latter in the Codex Atlanticus at
Milan, for the purpose of finding out, if possible the original
plans and sketches of the churches of Santa Maria delle Grazie at
Milan, and of the Cathedral at Pavia, which buildings have been
supposed to be the work both of Bramante and of Leonardo. Since 1876
I have repeatedly examined Leonardo's architectural studies in the
collection of his manuscripts in the Institut de France, and some of
these I have already given to the public in my work on_ "Les Projets
Primitifs pour la Basilique de St. Pierre de Rome", _P1. 43. In 1879
I had the opportunity of examining the manuscript in the Palazzo
Trivulzio at Milan, and in 1880 Dr Richter showed me in London the
manuscripts in the possession of Lord Ashburnham, and those in the
British Museum. I have thus had opportunities of seeing most of
Leonardo's architectural drawings in the original, but of the
manuscripts tliemselves I have deciphered only the notes which
accompany the sketches. It is to Dr Richter's exertions that we owe
the collected texts on Architecture which are now published, and
while he has undertaken to be responsible for the correct reading of
the original texts, he has also made it his task to extract the
whole of the materials from the various MSS. It has been my task to
arrange and elucidate the texts under the heads which have been
adopted in this work. MS. B. at Paris and the Codex Atlanticus at
Milan are the chief sources of our knowledge of Leonardo as an
architect, and I have recently subjected these to a thorough
re-investigation expressly with a view to this work._

_A complete reproduction of all Leonardo's architectural sketches
has not, indeed, been possible, but as far as the necessarily
restricted limits of the work have allowed, the utmost completeness
has been aimed at, and no efforts have been spared to include every
thing that can contribute to a knowledge of Leonardo's style. It
would have been very interesting, if it had been possible, to give
some general account at least of Leonardo's work and studies in
engineering, fortification, canal-making and the like, and it is
only on mature reflection that we have reluctantly abandoned this
idea. Leonardo's occupations in these departments have by no means
so close a relation to literary work, in the strict sense of the
word as we are fairly justified in attributing to his numerous notes
on Architecture._

_Leonardo's architectural studies fall naturally under two heads:_

_I. Those drawings and sketches, often accompanied by short remarks
and explanations, which may be regarded as designs for buildings or
monuments intended to be built. With these there are occasionally
explanatory texts._

_II. Theoretical investigations and treatises. A special interest
attaches to these because they discuss a variety of questions which
are of practical importance to this day. Leonardo's theory as to the
origin and progress of cracks in buildings is perhaps to be
considered as unique in its way in the literature of Architecture._

_HENRY DE GEYMULLER_

_XII._

_Architectural Designs._

_I. Plans for towns._

_A. Sketches for laying out a new town with a double system of high-
level and low-level road-ways._

_Pl. LXXVII, No. 1 (MS. B, 15b). A general view of a town, with the
roads outside it sloping up to the high-level ways within._

_Pl. LXXVII, No. 3 (MS. B, 16b. see No. 741; and MS. B. 15b, see No.
742) gives a partial view of the town, with its streets and houses,
with explanatory references._

_Pl. LXXVII, No. 2 (MS. B, 15b; see No. 743). View of a double
staircaise with two opposite flights of steps._

_Pl. LXXVIII, Nos. 2 and 3 (MS. B, 37a). Sketches illustrating the
connection of the two levels of roads by means of steps. The lower
galleries are lighted by openings in the upper roadway._

_B. Notes on removing houses (MS. Br. M., 270b, see No. 744)._

741.

The roads _m_ are 6 braccia higher than the roads _p s_, and each
road must be 20 braccia wide and have 1/2 braccio slope from the
sides towards the middle; and in the middle let there be at every
braccio an opening, one braccio long and one finger wide, where the
rain water may run off into hollows made on the same level as _p s_.
And on each side at the extremity of the width of the said road let
there be an arcade, 6 braccia broad, on columns; and understand that
he who would go through the whole place by the high level streets
can use them for this purpose, and he who would go by the low level
can do the same. By the high streets no vehicles and similar objects
should circulate, but they are exclusively for the use of gentlemen.
The carts and burdens for the use and convenience of the inhabitants
have to go by the low ones. One house must turn its back to the
other, leaving the lower streets between them. Provisions, such as
wood, wine and such things are carried in by the doors _n_, and
privies, stables and other fetid matter must be emptied away
underground. From one arch to the next

742.

must be 300 braccia, each street receiving its light through the
openings of the upper streets, and at each arch must be a winding
stair on a circular plan because the corners of square ones are
always fouled; they must be wide, and at the first vault there must
be a door entering into public privies and the said stairs lead from
the upper to the lower streets and the high level streets begin
outside the city gates and slope up till at these gates they have
attained the height of 6 braccia. Let such a city be built near the
sea or a large river in order that the dirt of the city may be
carried off by the water.

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