A singular fatality has ruled the destiny of nearly all the most
famous of Leonardo da Vinci’s works. Two of the three most important
were never completed, obstacles having arisen during his life-time,
which obliged him to leave them unfinished; namely the Sforza
Monument and the Wall-painting of the Battle of Anghiari, while the
third–the picture of the Last Supper at Milan–has suffered
irremediable injury from decay and the repeated restorations to
which it was recklessly subjected during the XVIIth and XVIIIth
centuries. Nevertheless, no other picture of the Renaissance has
become so wellknown and popular through copies of every description.

Vasari says, and rightly, in his Life of Leonardo, "that he labored
much more by his word than in fact or by deed", and the biographer
evidently had in his mind the numerous works in Manuscript which have
been preserved to this day. To us, now, it seems almost inexplicable
that these valuable and interesting original texts should have remained
so long unpublished, and indeed forgotten. It is certain that during
the XVIth and XVIIth centuries their exceptional value was highly
appreciated. This is proved not merely by the prices which they
commanded, but also by the exceptional interest which has been attached
to the change of ownership of merely a few pages of Manuscript.

That, notwithstanding this eagerness to possess the
Manuscripts, their contents remained a mystery, can only be accounted
for by the many and great difficulties attending the task of
deciphering them. The handwriting is so peculiar that it requires
considerable practice to read even a few detached phrases, much more to
solve with any certainty the numerous difficulties of alternative
readings, and to master the sense as a connected whole. Vasari observes
with reference to Leonardos writing: "he wrote backwards, in rude
characters, and with the left hand, so that any one who is not
practised in reading them, cannot understand them". The aid of a mirror
in reading reversed handwriting appears to me available only for a
first experimental reading. Speaking from my own experience, the
persistent use of it is too fatiguing and inconvenient to be
practically advisable, considering the enormous mass of Manuscripts to
be deciphered. And as, after all, Leonardo’s handwriting runs backwards
just as all Oriental character runs backwards–that is to say from
right to left–the difficulty of reading direct from the writing is not
insuperable. This obvious peculiarity in the writing is not, however,
by any means the only obstacle in the way of mastering the text.
Leonardo made use of an orthography peculiar to himself; he had a
fashion of amalgamating several short words into one long one, or,
again, he would quite arbitrarily divide a long word into two separate
halves; added to this there is no punctuation whatever to regulate the
division and construction of the sentences, nor are there any
accents–and the reader may imagine that such difficulties were almost
sufficient to make the task seem a desperate one to a beginner. It is
therefore not surprising that the good intentions of some of Leonardo s
most reverent admirers should have failed.

Leonardo’s literary labors in various departments both of Art
and of Science were those essentially of an enquirer, hence the
analytical method is that which he employs in arguing out his
investigations and dissertations. The vast structure of his scientific
theories is consequently built up of numerous separate researches, and
it is much to be lamented that he should never have collated and
arranged them. His love for detailed research–as it seems to me–was
the reason that in almost all the Manuscripts, the different paragraphs
appear to us to be in utter confusion; on one and the same page,
observations on the most dissimilar subjects follow each other without
any connection. A page, for instance, will begin with some principles
of astronomy, or the motion of the earth; then come the laws of sound,
and finally some precepts as to color. Another page will begin with his
investigations on the structure of the intestines, and end with
philosophical remarks as to the relations of poetry to painting; and so
forth.

Leonardo himself lamented this confusion, and for that reason
I do not think that the publication of the texts in the order in which
they occur in the originals would at all fulfill his intentions. No
reader could find his way through such a labyrinth; Leonardo himself
could not have done it.

Added to this, more than half of the five thousand manuscript
pages which now remain to us, are written on loose leaves, and at
present arranged in a manner which has no justification beyond the
fancy of the collector who first brought them together to make volumes
of more or less extent. Nay, even in the volumes, the pages of which
were numbered by Leonardo himself, their order, so far as the
connection of the texts was concerned, was obviously a matter of
indifference to him. The only point he seems to have kept in view, when
first writing down his notes, was that each observation should be
complete to the end on the page on which it was begun. The exceptions
to this rule are extremely few, and it is certainly noteworthy that we
find in such cases, in bound volumes with his numbered pages, the
written observations: "turn over", "This is the continuation of the
previous page", and the like. Is not this sufficient to prove that it
was only in quite exceptional cases that the writer intended the
consecutive pages to remain connected, when he should, at last, carry
out the often planned arrangement of his writings?

What this final arrangement was to be, Leonardo has in most
cases indicated with considerable completeness. In other cases this
authoritative clue is wanting, but the difficulties arising from this
are not insuperable; for, as the subject of the separate paragraphs is
always distinct and well defined in itself, it is quite possible to
construct a well-planned whole, out of the scattered materials of his
scientific system, and I may venture to state that I have devoted
especial care and thought to the due execution of this responsible
task.

The beginning of Leonardo’s literary labors dates from about
his thirty-seventh year, and he seems to have carried them on without
any serious interruption till his death. Thus the Manuscripts that
remain represent a period of about thirty years. Within this space of
time his handwriting altered so little that it is impossible to judge
from it of the date of any particular text. The exact dates, indeed,
can only be assigned to certain note-books in which the year is
incidentally indicated, and in which the order of the leaves has not
been altered since Leonardo used them. The assistance these afford for
a chronological arrangement of the Manuscripts is generally self
evident. By this clue I have assigned to the original Manuscripts now
scattered through England, Italy and France, the order of their
production, as in many matters of detail it is highly important to be
able to verify the time and place at which certain observations were
made and registered. For this purpose the Bibliography of the
Manuscripts given at the end of Vol. II, may be regarded as an Index,
not far short of complete, of all Leonardo’s literary works now extant.
The consecutive numbers (from 1 to 1566) at the head of each passage in
this work, indicate their logical sequence with reference to the
subjects; while the letters and figures to the left of each paragraph
refer to the original Manuscript and number of the page, on which that
particular passage is to be found. Thus the reader, by referring to the
List of Manuscripts at the beginning of Volume I, and to the
Bibliography at the end of Volume II, can, in every instance, easily
ascertain not merely the period to which the passage belongs, but also
exactly where it stood in the original document. Thus, too, by
following the sequence of the numbers in the Bibliographical index, the
reader may reconstruct the original order of the Manuscripts and
recompose the various texts to be found on the original sheets–so much
of it, that is to say, as by its subject-matter came within the scope
of this work. It may, however, be here observed that Leonardo’s
Manuscripts contain, besides the passages here printed, a great number
of notes and dissertations on Mechanics, Physics, and some other
subjects, many of which could only be satisfactorily dealt with by
specialists. I have given as complete a review of these writings as
seemed necessary in the Bibliographical notes.

In 1651, Raphael Trichet Dufresne, of Paris, published a
selection from Leonardo’s writings on painting, and this treatise
became so popular that it has since been reprinted about two-and-twenty
times, and in six different languages. But none of these editions were
derived from the original texts, which were supposed to have been lost,
but from early copies, in which Leonardo’s text had been more or less
mutilated, and which were all fragmentary. The oldest and on the whole
the best copy of Leonardo’s essays and precepts on Painting is in the
Vatican Library; this has been twice printed, first by Manzi, in 1817,
and secondly by Ludwig, in 1882. Still, this ancient copy, and the
published editions of it, contain much for which it would be rash to
hold Leonardo responsible, and some portions–such as the very
important rules for the proportions of the human figure–are wholly
wanting; on the other hand they contain passages which, if they are
genuine, cannot now be verified from any original Manuscript extant.
These copies, at any rate neither give us the original order of the
texts, as written by Leonardo, nor do they afford any substitute, by
connecting them on a rational scheme; indeed, in their chaotic
confusion they are anything rather than satisfactory reading. The
fault, no doubt, rests with the compiler of the Vatican copy, which
would seem to be the source whence all the published and extensively
known texts were derived; for, instead of arranging the passages
himself, he was satisfied with recording a suggestion for a final
arrangement of them into eight distinct parts, without attempting to
carry out his scheme. Under the mistaken idea that this plan of
distribution might be that, not of the compiler, but of Leonardo
himself, the various editors, down to the present day, have very
injudiciously continued to adopt this order–or rather disorder.

I, like other enquirers, had given up the original Manuscript
of the Trattato della Pittura for lost, till, in the beginning of 1880,
I was enabled, by the liberality of Lord Ashburnham, to inspect his
Manuscripts, and was so happy as to discover among them the original
text of the best-known portion of the Trattato in his magnificent
library at Ashburnham Place. Though this discovery was of a fragment
only–but a considerable fragment–inciting me to further search, it
gave the key to the mystery which had so long enveloped the first
origin of all the known copies of the Trattato. The extensive
researches I was subsequently enabled to prosecute, and the results of
which are combined in this work, were only rendered possible by the
unrestricted permission granted me to investigate all the Manuscripts
by Leonardo dispersed throughout Europe, and to reproduce the highly
important original sketches they contain, by the process of
"photogravure". Her Majesty the Queen graciously accorded me special
permission to copy for publication the Manuscripts at the Royal Library
at Windsor. The Commission Centrale Administrative de ‘Institut de
France, Paris, gave me, in the most liberal manner, in answer to an
application from Sir Frederic Leighton, P. R. A., Corresponding member
of the Institut, free permission to work for several months in their
private collection at deciphering the Manuscripts preserved there. The
same favor which Lord Ashburnham had already granted me was extended to
me by the Earl of Leicester, the Marchese Trivulsi, and the Curators of
the Ambrosian Library at Milan, by the Conte Manzoni at Rome and by
other private owners of Manuscripts of Leonardo’s; as also by the
Directors of the Louvre at Paris; the Accademia at Venice; the Uffizi
at Florence; the Royal Library at Turin; and the British Museum, and
the South Kensington Museum. I am also greatly indebted to the
Librarians of these various collections for much assistance in my
labors; and more particularly to Monsieur Louis Lalanne, of the
Institut de France, the Abbate Ceriani, of the Ambrosian Library, Mr.
Maude Thompson, Keeper of Manuscripts at the British Museum, Mr.
Holmes, the Queens Librarian at Windsor, the Revd Vere Bayne, Librarian
of Christ Church College at Oxford, and the Revd A. Napier, Librarian
to the Earl of Leicester at Holkham Hall.

In correcting the Italian text for the press, I have had the
advantage of valuable advice from the Commendatore Giov. Morelli,
Senatore del Regno, and from Signor Gustavo Frizzoni, of Milan. The
translation, under many difficulties, of the Italian text into English,
is mainly due to Mrs. R. C. Bell; while the rendering of several of the
most puzzling and important passages, particularly in the second half
of Vol. I, I owe to the indefatigable interest taken in this work by
Mr. E. J. Poynter R. A. Finally I must express my thanks to Mr. Alfred
Marks, of Long Ditton, who has most kindly assisted me throughout in
the revision of the proof sheets. The notes and dissertations on the
texts on Architecture in Vol. II I owe to my friend Baron Henri de
Geymuller, of Paris. I may further mention with regard to the
illustrations, that the negatives for the production of the
"photo-gravures" by Monsieur Dujardin of Paris were all taken direct
from the originals.

It is scarcely necessary to add that most of the drawings here
reproduced in facsimile have never been published before. As I am now,
on the termination of a work of several years’ duration, in a position
to review the general tenor of Leonardo’s writings, I may perhaps be
permitted to add a word as to my own estimate of the value of their
contents. I have already shown that it is due to nothing but a
fortuitous succession of unfortunate circumstances, that we should not,
long since, have known Leonardo, not merely as a Painter, but as an
Author, a Philosopher, and a Naturalist. There can be no doubt that in
more than one department his principles and discoveries were infinitely
more in accord with the teachings of modern science, than with the
views of his contemporaries. For this reason his extraordinary gifts
and merits are far more likely to be appreciated in our own time than
they could have been during the preceding centuries. He has been
unjustly accused of having squandered his powers, by beginning a
variety of studies and then, having hardly begun, throwing them aside.
The truth is that the labors of three centuries have hardly sufficed
for the elucidation of some of the problems which occupied his mighty
mind.

Alexander von Humboldt has borne witness that "he was the
first to start on the road towards the point where all the impressions
of our senses converge in the idea of the Unity of Nature" Nay, yet
more may be said. The very words which are inscribed on the monument of
Alexander von Humboldt himself, at Berlin, are perhaps the most
appropriate in which we can sum up our estimate of Leonardo’s genius.