The author's intention to publish his MSS.
How by a certain machine many may stay some time under water. And
how and wherefore I do not describe my method of remaining under
water and how long I can remain without eating. And I do not publish
nor divulge these, by reason of the evil nature of men, who would
use them for assassinations at the bottom of the sea by destroying
ships, and sinking them, together with the men in them. Nevertheless
I will impart others, which are not dangerous because the mouth of
the tube through which you breathe is above the water, supported on
air sacks or cork.
[Footnote: The leaf on which this passage is written, is headed with
the words _Casi_ 39, and most of these cases begin with the word
'_Come_', like the two here given, which are the 26th and 27th. 7.
_Sughero_. In the Codex Antlanticus 377a; 1170a there is a sketch,
drawn with the pen, representing a man with a tube in his mouth, and
at the farther end of the tube a disk. By the tube the word
'_Channa_' is written, and by the disk the word '_sughero_'.]
The preparation of the MSS. for publication.
When you put together the science of the motions of water, remember
to include under each proposition its application and use, in order
that this science may not be useless.--
[Footnote: A comparatively small portion of Leonardo's notes on
water-power was published at Bologna in 1828, under the title: "_Del
moto e misura dell'Acqua, di L. da Vinci_".]
Admonition to readers.
Let no man who is not a Mathematician read the elements of my work.
The disorder in the MSS.
Begun at Florence, in the house of Piero di Braccio Martelli, on the
22nd day of March 1508. And this is to be a collection without
order, taken from many papers which I have copied here, hoping to
arrange them later each in its place, according to the subjects of
which they may treat. But I believe that before I am at the end of
this [task] I shall have to repeat the same things several times;
for which, O reader! do not blame me, for the subjects are many and
memory cannot retain them [all] and say: 'I will not write this
because I wrote it before.' And if I wished to avoid falling into
this fault, it would be necessary in every case when I wanted to
copy [a passage] that, not to repeat myself, I should read over all
that had gone before; and all the more since the intervals are long
between one time of writing and the next.
[Footnote: 1. In the history of Florence in the early part of the
XVIth century _Piero di Braccio Martelli_ is frequently mentioned as
_Commissario della Signoria_. He was famous for his learning and at
his death left four books on Mathematics ready for the press; comp.
LITTA, _Famiglie celebri Italiane_, _Famiglia Martelli di
Firenze_.--In the Official Catalogue of MSS. in the Brit. Mus., New
Series Vol. I., where this passage is printed, _Barto_ has been
wrongly given for Braccio.
2. _addi 22 di marzo 1508_. The Christian era was computed in
Florence at that time from the Incarnation (Lady day, March 25th).
Hence this should be 1509 by our reckoning.
3. _racolto tratto di molte carte le quali io ho qui copiate_. We
must suppose that Leonardo means that he has copied out his own MSS.
and not those of others. The first thirteen leaves of the MS. in the
Brit. Mus. are a fair copy of some notes on physics.]
Suggestions for the arrangement of MSS treating of particular
Of digging a canal. Put this in the Book of useful inventions and in
proving them bring forward the propositions already proved. And this
is the proper order; since if you wished to show the usefulness of
any plan you would be obliged again to devise new machines to prove
its utility and thus would confuse the order of the forty Books and
also the order of the diagrams; that is to say you would have to mix
up practice with theory, which would produce a confused and
I am not to blame for putting forward, in the course of my work on
science, any general rule derived from a previous conclusion.
The Book of the science of Mechanics must precede the Book of useful
inventions.--Have your books on anatomy bound! [Footnote: 4. The
numerous notes on anatomy written on loose leaves and now in the
Royal collection at Windsor can best be classified in four Books,
corresponding to the different character and size of the paper. When
Leonardo speaks of '_li tua libri di notomia_', he probably means
the MSS. which still exist; if this hypothesis is correct the
present condition of these leaves might seem to prove that he only
carried out his purpose with one of the Books on anatomy. A borrowed
book on Anatomy is mentioned in F.O.]
The order of your book must proceed on this plan: first simple
beams, then (those) supported from below, then suspended in part,
then wholly [suspended]. Then beams as supporting other weights
[Footnote: 4. Leonardo's notes on Mechanics are extraordinarily
numerous; but, for the reasons assigned in my introduction, they
have not been included in the present work.].
General introductions to the book on Painting (9-13).
Seeing that I can find no subject specially useful or
pleasing--since the men who have come before me have taken for their
own every useful or necessary theme--I must do like one who, being
poor, comes last to the fair, and can find no other way of providing
himself than by taking all the things already seen by other buyers,
and not taken but refused by reason of their lesser value. I, then,
will load my humble pack with this despised and rejected
merchandise, the refuse of so many buyers; and will go about to
distribute it, not indeed in great cities, but in the poorer towns,
taking such a price as the wares I offer may be worth. [Footnote: It
need hardly be pointed out that there is in this 'Proemio' a covert
irony. In the second and third prefaces, Leonardo characterises his
rivals and opponents more closely. His protest is directed against
Neo-latinism as professed by most of the humanists of his time; its
futility is now no longer questioned.]
I know that many will call this useless work [Footnote: 3. questa
essere opera inutile. By opera we must here understand libro di
pittura and particularly the treatise on Perspective.]; and they
will be those of whom Demetrius [Footnote: 4. Demetrio. "With regard
to the passage attributed to Demetrius", Dr. H. MULLER STRUBING
writes, "I know not what to make of it. It is certainly not
Demetrius Phalereus that is meant and it can hardly be Demetrius
Poliorcetes. Who then can it be--for the name is a very common one?
It may be a clerical error for Demades and the maxim is quite in the
spirit of his writings I have not however been able to find any
corresponding passage either in the 'Fragments' (C. MULLER, _Orat.
Att._, II. 441) nor in the Supplements collected by DIETZ (_Rhein.
Mus._, vol. 29, p. 108)."
The same passage occurs as a simple Memorandum in the MS. Tr. 57,
apparently as a note for this '_Proemio_' thus affording some data
as to the time where these introductions were written.] declared
that he took no more account of the wind that came out their mouth
in words, than of that they expelled from their lower parts: men who
desire nothing but material riches and are absolutely devoid of that
of wisdom, which is the food and the only true riches of the mind.
For so much more worthy as the soul is than the body, so much more
noble are the possessions of the soul than those of the body. And
often, when I see one of these men take this work in his hand, I
wonder that he does not put it to his nose, like a monkey, or ask me
if it is something good to eat.
[Footnote: In the original, the Proemio di prospettiva cioe
dell'uffitio dell'occhio (see No. 21) stands between this and the
preceding one, No. 9.]
I am fully concious that, not being a literary man, certain
presumptuous persons will think that they may reasonably blame me;
alleging that I am not a man of letters. Foolish folks! do they not
know that I might retort as Marius did to the Roman Patricians
[Footnote 21: _Come Mario disse ai patriti Romani_. "I am unable to
find the words here attributed by Leonardo to Marius, either in
Plutarch's Life of Marius or in the Apophthegmata (_Moralia_,
p.202). Nor do they occur in the writings of Valerius Maximus (who
frequently mentions Marius) nor in Velleius Paterculus (II, 11 to
43), Dio Cassius, Aulus Gellius, or Macrobius. Professor E.
MENDELSON of Dorpat, the editor of Herodian, assures me that no such
passage is the found in that author" (communication from Dr. MULLER
STRUBING). Leonardo evidently meant to allude to some well known
incident in Roman history and the mention of Marius is the result
probably of some confusion. We may perhaps read, for Marius,
Menenius Agrippa, though in that case it is true we must alter
Patriti to Plebei. The change is a serious one. but it would render
the passage perfectly clear.] by saying: That they, who deck
themselves out in the labours of others will not allow me my own.
They will say that I, having no literary skill, cannot properly
express that which I desire to treat of [Footnote 26: _le mie cose
.... che d'altra parola_. This can hardly be reconciled with Mons.
RAVAISSON'S estimate of L. da Vinci's learning. "_Leonard de Vinci
etait un admirateur et un disciple des anciens, aussi bien dans
l'art que dans la science et il tenait a passer pour tel meme aux
yeux de la posterite._" _Gaz. des Beaux arts. Oct. 1877.]; but they
do not know that my subjects are to be dealt with by experience
rather than by words [Footnote 28: See Footnote 26]; and
[experience] has been the mistress of those who wrote well. And so,
as mistress, I will cite her in all cases.
Though I may not, like them, be able to quote other authors, I shall
rely on that which is much greater and more worthy:--on experience,
the mistress of their Masters. They go about puffed up and pompous,
dressed and decorated with [the fruits], not of their own labours,
but of those of others. And they will not allow me my own. They will
scorn me as an inventor; but how much more might they--who are not
inventors but vaunters and declaimers of the works of others--be
And those men who are inventors and interpreters between Nature and
Man, as compared with boasters and declaimers of the works of
others, must be regarded and not otherwise esteemed than as the
object in front of a mirror, when compared with its image seen in
the mirror. For the first is something in itself, and the other
nothingness.--Folks little indebted to Nature, since it is only by
chance that they wear the human form and without it I might class
them with the herds of beasts.
Many will think they may reasonably blame me by alleging that my
proofs are opposed to the authority of certain men held in the
highest reverence by their inexperienced judgments; not considering
that my works are the issue of pure and simple experience, who is
the one true mistress. These rules are sufficient to enable you to
know the true from the false--and this aids men to look only for
things that are possible and with due moderation--and not to wrap
yourself in ignorance, a thing which can have no good result, so
that in despair you would give yourself up to melancholy.
Among all the studies of natural causes and reasons Light chiefly
delights the beholder; and among the great features of Mathematics
the certainty of its demonstrations is what preeminently (tends to)
elevate the mind of the investigator. Perspective, therefore, must
be preferred to all the discourses and systems of human learning. In
this branch [of science] the beam of light is explained on those
methods of demonstration which form the glory not so much of
Mathematics as of Physics and are graced with the flowers of both
[Footnote: 5. Such of Leonardo's notes on Optics or on Perspective
as bear exclusively on Mathematics or Physics could not be included
in the arrangement of the _libro di pittura_ which is here presented
to the reader. They are however but few.]. But its axioms being laid
down at great length, I shall abridge them to a conclusive brevity,
arranging them on the method both of their natural order and of
mathematical demonstration; sometimes by deduction of the effects
from the causes, and sometimes arguing the causes from the effects;
adding also to my own conclusions some which, though not included in
them, may nevertheless be inferred from them. Thus, if the Lord--who
is the light of all things--vouchsafe to enlighten me, I will treat
of Light; wherefore I will divide the present work into 3 Parts
[Footnote: 10. In the middle ages--for instance, by ROGER BACON, by
VITELLONE, with whose works Leonardo was certainly familiar, and by
all the writers of the Renaissance Perspective and Optics were not
regarded as distinct sciences. Perspective, indeed, is in its widest
application the science of seeing. Although to Leonardo the two
sciences were clearly separate, it is not so as to their names; thus
we find axioms in Optics under the heading Perspective. According to
this arrangement of the materials for the theoretical portion of the
_libro di pittura_ propositions in Perspective and in Optics stand
side by side or occur alternately. Although this particular chapter
deals only with Optics, it is not improbable that the words _partiro
la presente opera in 3 parti_ may refer to the same division into
three sections which is spoken of in chapters 14 to 17.].
The plan of the book on Painting (14--17).
ON THE THREE BRANCHES OF PERSPECTIVE.
There are three branches of perspective; the first deals with the
reasons of the (apparent) diminution of objects as they recede from
the eye, and is known as Diminishing Perspective.--The second
contains the way in which colours vary as they recede from the eye.
The third and last is concerned with the explanation of how the
objects [in a picture] ought to be less finished in proportion as
they are remote (and the names are as follows):
Linear Perspective. The Perspective of Colour. The Perspective of
[Footnote: 13. From the character of the handwriting I infer that
this passage was written before the year 1490.].
ON PAINTING AND PERSPECTIVE.
The divisions of Perspective are 3, as used in drawing; of these,
the first includes the diminution in size of opaque objects; the
second treats of the diminution and loss of outline in such opaque
objects; the third, of the diminution and loss of colour at long
[Footnote: The division is here the same as in the previous chapter
No. 14, and this is worthy of note when we connect it with the fact
that a space of about 20 years must have intervened between the
writing of the two passages.]
THE DISCOURSE ON PAINTING.
Perspective, as bearing on drawing, is divided into three principal
sections; of which the first treats of the diminution in the size of
bodies at different distances. The second part is that which treats
of the diminution in colour in these objects. The third [deals with]
the diminished distinctness of the forms and outlines displayed by
the objects at various distances.
ON THE SECTIONS OF [THE BOOK ON] PAINTING.
The first thing in painting is that the objects it represents should
appear in relief, and that the grounds surrounding them at different
distances shall appear within the vertical plane of the foreground
of the picture by means of the 3 branches of Perspective, which are:
the diminution in the distinctness of the forms of the objects, the
diminution in their magnitude; and the diminution in their colour.
And of these 3 classes of Perspective the first results from [the
structure of] the eye, while the other two are caused by the
atmosphere which intervenes between the eye and the objects seen by
it. The second essential in painting is appropriate action and a due
variety in the figures, so that the men may not all look like
[Footnote: This and the two foregoing chapters must have been
written in 1513 to 1516. They undoubtedly indicate the scheme which
Leonardo wished to carry out in arranging his researches on
Perspective as applied to Painting. This is important because it is
an evidence against the supposition of H. LUDWIG and others, that
Leonardo had collected his principles of Perspective in one book so
early as before 1500; a Book which, according to the hypothesis,
must have been lost at a very early period, or destroyed possibly,
by the French (!) in 1500 (see H. LUDWIG. L. da Vinci: _Das Buch van
der Malerei_. Vienna 1882 III, 7 and 8).]
The use of the book on Painting.
These rules are of use only in correcting the figures; since every
man makes some mistakes in his first compositions and he who knows
them not, cannot amend them. But you, knowing your errors, will
correct your works and where you find mistakes amend them, and
remember never to fall into them again. But if you try to apply
these rules in composition you will never make an end, and will
produce confusion in your works.
These rules will enable you to have a free and sound judgment; since
good judgment is born of clear understanding, and a clear
understanding comes of reasons derived from sound rules, and sound
rules are the issue of sound experience--the common mother of all
the sciences and arts. Hence, bearing in mind the precepts of my
rules, you will be able, merely by your amended judgment, to
criticise and recognise every thing that is out of proportion in a
work, whether in the perspective or in the figures or any thing
Necessity of theoretical knowledge (19. 20).
OF THE MISTAKES MADE BY THOSE WHO PRACTISE WITHOUT KNOWLEDGE.
Those who are in love with practice without knowledge are like the
sailor who gets into a ship without rudder or compass and who never
can be certain whether he is going. Practice must always be founded
on sound theory, and to this Perspective is the guide and the
gateway; and without this nothing can be done well in the matter of
The painter who draws merely by practice and by eye, without any
reason, is like a mirror which copies every thing placed in front of
it without being conscious of their existence.
The function of the eye (21-23).
INTRODUCTION TO PERSPECTIVE:--THAT IS OF THE FUNCTION OF THE EYE.
Behold here O reader! a thing concerning which we cannot trust our
forefathers, the ancients, who tried to define what the Soul and
Life are--which are beyond proof, whereas those things, which can at
any time be clearly known and proved by experience, remained for
many ages unknown or falsely understood. The eye, whose function we
so certainly know by experience, has, down to my own time, been
defined by an infinite number of authors as one thing; but I find,
by experience, that it is quite another. [Footnote 13: Compare the
note to No. 70.]
[Footnote: In section 13 we already find it indicated that the study
of Perspective and of Optics is to be based on that of the functions
of the eye. Leonardo also refers to the science of the eye, in his
astronomical researches, for instance in MS. F 25b '_Ordine del
provare la terra essere una stella: Imprima difinisce l'occhio'_,
&c. Compare also MS. E 15b and F 60b. The principles of astronomical
Here [in the eye] forms, here colours, here the character of every
part of the universe are concentrated to a point; and that point is
so marvellous a thing ... Oh! marvellous, O stupendous Necessity--by
thy laws thou dost compel every effect to be the direct result of
its cause, by the shortest path. These [indeed] are miracles;...
In so small a space it can be reproduced and rearranged in its whole
expanse. Describe in your anatomy what proportion there is between
the diameters of all the images in the eye and the distance from
them of the crystalline lens.
OF THE 10 ATTRIBUTES OF THE EYE, ALL CONCERNED IN PAINTING.
Painting is concerned with all the 10 attributes of sight; which
are:--Darkness, Light, Solidity and Colour, Form and Position,
Distance and Propinquity, Motion and Rest. This little work of mine
will be a tissue [of the studies] of these attributes, reminding the
painter of the rules and methods by which he should use his art to
imitate all the works of Nature which adorn the world.
Variability of the eye.
1st. The pupil of the eye contracts, in proportion to the increase
of light which is reflected in it. 2nd. The pupil of the eye expands
in proportion to the diminution in the day light, or any other
light, that is reflected in it. 3rd. [Footnote: 8. The subject of
this third proposition we find fully discussed in MS. G. 44a.]. The
eye perceives and recognises the objects of its vision with greater
intensity in proportion as the pupil is more widely dilated; and
this can be proved by the case of nocturnal animals, such as cats,
and certain birds--as the owl and others--in which the pupil varies
in a high degree from large to small, &c., when in the dark or in
the light. 4th. The eye [out of doors] in an illuminated atmosphere
sees darkness behind the windows of houses which [nevertheless] are
light. 5th. All colours when placed in the shade appear of an equal
degree of darkness, among themselves. 6th. But all colours when
placed in a full light, never vary from their true and essential
OF THE EYE.
Focus of sight.
If the eye is required to look at an object placed too near to it,
it cannot judge of it well--as happens to a man who tries to see the
tip of his nose. Hence, as a general rule, Nature teaches us that an
object can never be seen perfectly unless the space between it and
the eye is equal, at least, to the length of the face.
Differences of perception by one eye and by both eyes (26-29).
OF THE EYE.
When both eyes direct the pyramid of sight to an object, that object
becomes clearly seen and comprehended by the eyes.
Objects seen by one and the same eye appear sometimes large, and
The motion of a spectator who sees an object at rest often makes it
seem as though the object at rest had acquired the motion of the
moving body, while the moving person appears to be at rest.
Objects in relief, when seen from a short distance with one eye,
look like a perfect picture. If you look with the eye _a_, _b_ at
the spot _c_, this point _c_ will appear to be at _d_, _f_, and if
you look at it with the eye _g_, _h_ will appear to be at _m_. A
picture can never contain in itself both aspects.
Let the object in relief _t_ be seen by both eyes; if you will look
at the object with the right eye _m_, keeping the left eye _n_ shut,
the object will appear, or fill up the space, at _a_; and if you
shut the right eye and open the left, the object (will occupy the)
space _b_; and if you open both eyes, the object will no longer
appear at _a_ or _b_, but at _e_, _r_, _f_. Why will not a picture
seen by both eyes produce the effect of relief, as [real] relief
does when seen by both eyes; and why should a picture seen with one
eye give the same effect of relief as real relief would under the
same conditions of light and shade?
[Footnote: In the sketch, _m_ is the left eye and _n_ the right,
while the text reverses this lettering. We must therefore suppose
that the face in which the eyes _m_ and _n_ are placed is opposite
to the spectator.]
The comparative size of the image depends on the amount of light
The eye will hold and retain in itself the image of a luminous body
better than that of a shaded object. The reason is that the eye is
in itself perfectly dark and since two things that are alike cannot
be distinguished, therefore the night, and other dark objects cannot
be seen or recognised by the eye. Light is totally contrary and
gives more distinctness, and counteracts and differs from the usual
darkness of the eye, hence it leaves the impression of its image.