The Notebooks of Leonardo Da Vinci — Complete
neighbouring rivers, by washing down the shores; and if you chose to
say that there were several deluges to produce these rifts and the
shells among them, you would also have to affirm that such a deluge
took place every year. Again, among the fragments of these shells,
it must be presumed that in those places there were sea coasts,
where all the shells were thrown up, broken, and divided, and never
in pairs, since they are found alive in the sea, with two valves,
each serving as a lid to the other; and in the drifts of rivers and
on the shores of the sea they are found in fragments. And within the
limits of the separate strata of rocks they are found, few in number
and in pairs like those which were left by the sea, buried alive in
the mud, which subsequently dried up and, in time, was petrified.
991.
And if you choose to say that it was the deluge which carried these
shells away from the sea for hundreds of miles, this cannot have
happened, since that deluge was caused by rain; because rain
naturally forces the rivers to rush towards the sea with all the
things they carry with them, and not to bear the dead things of the
sea shores to the mountains. And if you choose to say that the
deluge afterwards rose with its waters above the mountains, the
movement of the sea must have been so sluggish in its rise against
the currents of the rivers, that it could not have carried, floating
upon it, things heavier than itself; and even if it had supported
them, in its receding it would have left them strewn about, in
various spots. But how are we to account for the corals which are
found every day towards Monte Ferrato in Lombardy, with the holes of
the worms in them, sticking to rocks left uncovered by the currents
of rivers? These rocks are all covered with stocks and families of
oysters, which as we know, never move, but always remain with one of
their halves stuck to a rock, and the other they open to feed
themselves on the animalcules that swim in the water, which, hoping
to find good feeding ground, become the food of these shells. We do
not find that the sand mixed with seaweed has been petrified,
because the weed which was mingled with it has shrunk away, and this
the Po shows us every day in the debris of its banks.
Other problems (992-994).
992.
Why do we find the bones of great fishes and oysters and corals and
various other shells and sea-snails on the high summits of mountains
by the sea, just as we find them in low seas?
993.
You now have to prove that the shells cannot have originated if not
in salt water, almost all being of that sort; and that the shells in
Lombardy are at four levels, and thus it is everywhere, having been
made at various times. And they all occur in valleys that open
towards the seas.
994.
>From the two lines of shells we are forced to say that the earth
indignantly submerged under the sea and so the first layer was made;
and then the deluge made the second.
[Footnote: This note is in the early writing of about 1470--1480. On
the same sheet are the passages No. 1217 and 1219. Compare also No.
1339. All the foregoing chapters are from Manuscripts of about 1510.
This explains the want of connection and the contradiction between
this and the foregoing texts.]
VII.
ON THE ATMOSPHERE.
Constituents of the atmosphere.
995.
That the brightness of the air is occasioned by the water which has
dissolved itself in it into imperceptible molecules. These, being
lighted by the sun from the opposite side, reflect the brightness
which is visible in the air; and the azure which is seen in it is
caused by the darkness that is hidden beyond the air. [Footnote:
Compare Vol. I, No. 300.]
On the motion of air (996--999).
996.
That the return eddies of wind at the mouth of certain valleys
strike upon the waters and scoop them out in a great hollow, whirl
the water into the air in the form of a column, and of the colour of
a cloud. And I saw this thing happen on a sand bank in the Arno,
where the sand was hollowed out to a greater depth than the stature
of a man; and with it the gravel was whirled round and flung about
for a great space; it appeared in the air in the form of a great
bell-tower; and the top spread like the branches of a pine tree, and
then it bent at the contact of the direct wind, which passed over
from the mountains.
997.
The element of fire acts upon a wave of air in the same way as the
air does on water, or as water does on a mass of sand --that is
earth; and their motions are in the same proportions as those of the
motors acting upon them.
998.
OF MOTION.
I ask whether the true motion of the clouds can be known by the
motion of their shadows; and in like manner of the motion of the
sun.
999.
To know better the direction of the winds. [Footnote: In connection
with this text I may here mention a hygrometer, drawn and probably
invented by Leonardo. A facsimile of this is given in Vol. I, p. 297
with the note: _'Modi di pesare l'arie eddi sapere quando s'a
arrompere il tepo'_ (Mode of weighing the air and of knowing when
the weather will change); by the sponge _"Spugnea"_ is written.]
The globe an organism.
1000.
Nothing originates in a spot where there is no sentient, vegetable
and rational life; feathers grow upon birds and are changed every
year; hairs grow upon animals and are changed every year, excepting
some parts, like the hairs of the beard in lions, cats and their
like. The grass grows in the fields, and the leaves on the trees,
and every year they are, in great part, renewed. So that we might
say that the earth has a spirit of growth; that its flesh is the
soil, its bones the arrangement and connection of the rocks of which
the mountains are composed, its cartilage the tufa, and its blood
the springs of water. The pool of blood which lies round the heart
is the ocean, and its breathing, and the increase and decrease of
the blood in the pulses, is represented in the earth by the flow and
ebb of the sea; and the heat of the spirit of the world is the fire
which pervades the earth, and the seat of the vegetative soul is in
the fires, which in many parts of the earth find vent in baths and
mines of sulphur, and in volcanoes, as at Mount Aetna in Sicily, and
in many other places.
[Footnote: Compare No. 929.]
_XVII._
_Topographical Notes._
_A large part of the texts published in this section might perhaps
have found their proper place in connection with the foregoing
chapters on Physical Geography. But these observations on Physical
Geography, of whatever kind they may be, as soon as they are
localised acquire a special interest and importance and particularly
as bearing on the question whether Leonardo himself made the
observations recorded at the places mentioned or merely noted the
statements from hearsay. In a few instances he himself tells us that
he writes at second hand. In some cases again, although the style
and expressions used make it seem highly probable that he has
derived his information from others-- though, as it seems to me,
these cases are not very numerous--we find, on the other hand, among
these topographical notes a great number of observations, about
which it is extremely difficult to form a decided opinion. Of what
the Master's life and travels may have been throughout his
sixty-seven years of life we know comparatively little; for a long
course of time, and particularly from about 1482 to 1486, we do not
even know with certainty that he was living in Italy. Thus, from a
biographical point of view a very great interest attaches to some of
the topographical notes, and for this reason it seemed that it would
add to their value to arrange them in a group by themselves.
Leonardo's intimate knowledge with places, some of which were
certainly remote from his native home, are of importance as
contributing to decide the still open question as to the extent of
Leonardo's travels. We shall find in these notes a confirmation of
the view, that the MSS. in which the Topographical Notes occur are
in only a very few instances such diaries as may have been in use
during a journey. These notes are mostly found in the MSS. books of
his later and quieter years, and it is certainly remarkable that
Leonardo is very reticent as to the authorities from whom he quotes
his facts and observations: For instance, as to the Straits of
Gibraltar, the Nile, the Taurus Mountains and the Tigris and
Euphrates. Is it likely that he, who declared that in all scientific
research, his own experience should be the foundation of his
statements (see XIX Philosophy No. 987--991,) should here have made
an exception to this rule without mentioning it?_
_As for instance in the discussion as to the equilibrium of the mass
of water in the Mediterranean Sea--a subject which, it may be
observed, had at that time attracted the interest and study of
hardly any other observer. The acute remarks, in Nos. 985--993, on
the presence of shells at the tops of mountains, suffice to
prove--as it seems to me--that it was not in his nature to allow
himself to be betrayed into wide generalisations, extending beyond
the limits of his own investigations, even by such brilliant results
of personal study._
_Most of these Topographical Notes, though suggesting very careful
and thorough research, do not however, as has been said, afford
necessarily indisputable evidence that that research was Leonardo's
own. But it must be granted that in more than one instance
probability is in favour of this idea._
_Among the passages which treat somewhat fully of the topography of
Eastern places by far the most interesting is a description of the
Taurus Mountains; but as this text is written in the style of a
formal report and, in the original, is associated with certain
letters which give us the history of its origin, I have thought it
best not to sever it from that connection. It will be found under
No. XXI (Letters)._
_That Florence, and its neighbourhood, where Leonardo spent his
early years, should be nowhere mentioned except in connection with
the projects for canals, which occupied his attention for some short
time during the first ten years of the XVIth century, need not
surprise us. The various passages relating to the construction of
canals in Tuscany, which are put together at the beginning, are
immediately followed by those which deal with schemes for canals in
Lombardy; and after these come notes on the city and vicinity of
Milan as well as on the lakes of North Italy._
_The notes on some towns of Central Italy which Leonardo visited in
1502, when in the service of Cesare Borgia, are reproduced here in
the same order as in the note book used during these travels (MS.
L., Institut de France). These notes have but little interest in
themselves excepting as suggesting his itinerary. The maps of the
districts drawn by Leonardo at the time are more valuable (see No.
1054 note). The names on these maps are not written from right to
left, but in the usual manner, and we are permitted to infer that
they were made in obedience to some command, possibly for the use of
Cesare Borgia himself; the fact that they remained nevertheless in
Leonardo's hands is not surprising when we remember the sudden
political changes and warlike events of the period. There can be no
doubt that these maps, which are here published for the first time,
are original in the strictest sense of the word, that is to say
drawn from observations of the places themselves; this is proved by
the fact--among others--that we find among his manuscripts not only
the finished maps themselves but the rough sketches and studies for
them. And it would perhaps be difficult to point out among the
abundant contributions to geographical knowledge published during