'Describe landscapes with wind and water and at the setting and rising of the sun! 

Within the spaces between the rain one sees the redness of the sun ; that is of the clouds interposed between the sun and the rain. 

The waves interposed between the rain and the eye never reveal to the eye the image of the darkness of this rain, and this is due to the fact that the side of the wave is not seen nor does it see the rain. And the clouds are of dark purple. c.a. 38 r. b 


Of things seen through the mist the part which is nearest to the extremities will be less visible, and so much less when they are more remote. c.a. 76 r. b 

A mountain that stretches above a city which raises dust in the form of clouds, but the colour of this dust is varied by the colour of these clouds; and, where the rain is thickest, the colour of the dust is least visible; and, where the dust is thickest, the rain is least visible; and, where the rain is mingled with the wind and the dust, the clouds created by the rain are more transparent than those of the dust. 

And when the flames of the fire are mingled with clouds of smoke and steam this creates dark and very thick clouds. 

The rest of this discourse will be treated of clearly in the book of painting. 

[With drawing] 

The trees, smitten by the course of the winds, bend towards the place where the wind is moving, and after the wind has passed they bend in the opposite movement, that is in the reflex movement. 

The mighty fury of the wind, driven by the avalanches of the mountains above the yawning caverns, by means of the avalanches of the mountains which formed a covering to these caverns. c.a. 79 r. c 


When rain is falling from broken clouds one sees the shadows of these clouds upon the earth interrupted by the part of the earth that is illuminated by the sun. 


When the sun is lower the arc has a larger circle, and when it is 
higher it will be the contrary. 

When the sun is in the west, hidden behind some small and thick 
cloud, then this cloud will be surrounded by a ruddy splendour. 

c.a. 97 v. a 

Why towers and campaniles at a great distance, although of uni- 
form thickness, seem like inverted pyramids. 

This arises from the fact that the lower tracts of air being thick and 
misty veil them more completely, and the more an object is veiled 
the more the perception of its extremities is lost, and consequently the 
perception of the object tends to concentrate about its central line. 

c.a. 130 v. b 


In the houses of a city, where one observes that the divisions between 
them are clear when it is misty below, if the eye is above the level of 
the houses the lines of vision, as they descend in the space that is 
between house and house, plunge into mist which is more dense and 
therefore, being less transparent, seems whiter; and if one house is 
higher than another the reality is more to be discerned in the thinner 
air, and therefore they seem more indistinct in proportion as they are 
less 1 elevated. c.a. 160 r. a 

This came about by reason of the clouds interposed between the 
earth and the sun, wherefore being in the west it grew red and with 
its ruddy glow lit as with a haze all the things visible to it, but so 
much more or less in proportion as these things were nearer or more 
remote. c.a. 165 v. b 

At the first hour of the day the atmosphere in the south near to the 
horizon has a dim haze of rose-flushed clouds; towards the west it 
grows darker, and towards the east the damp vapour of the horizon 

1 MS. piu. 



shows brighter than the actual horizon itself, and the white of the 
houses in the east is scarcely to be discerned, while in the south, t he- 
farther distant they are, the more they assume a dark rose-flushed 
hue, and even more so in the west; and with the shadows it is the 
contrary, for these disappear before the white. 

[....] in the east, and the tops of the trees are more visible than 
their bases, since the atmosphere is thicker lower down, and the struc- 
ture becomes more indistinct at a height. 

And in the south, the trees may scarcely be distinguished by reason 
of the vapour which darkens in the west and grows clear in the east. 

c.a. 176 r. b 


If between the eye and the horizon there intervenes the slope of a 
hill that drops towards the eye, and the eye finds itself at about the 
middle of the height of the slope then the hill will acquire darkness 
with every stage of its length. This is proved by the seventh of this 
which says; that plant will show itself darker which is seen more be- 
low; therefore the proposition is confirmed, because the hill shows 
from the centre downwards all its plants in the parts which are as 
much illumined by the brightness of the sky, as the part which is 
in shade is shaded by the darkness of the earth. For which reason it 
is necessary that these plants should be of moderate darkness, and 
from this point on towards the bases of the hills the plants are con- 
tinually becoming brighter through the converse of the seventh propo- 
sition, for by this seventh proposition the nearer such plants are to the 
summit of the hill the more of necessity they become darker. And it 
follows that this darkness is not proportionate to the distance, from the 
eighth proposition which says: that thing will show itself darker which 
finds itself in finer air; and by the tenth: that will show itself darker 
which borders on the brighter background. c.a. 184 v. c 


Buildings seen at a great distance in the evening or morning through 
mist or heavy atmosphere, have only such portions in light as are 



illuminated by the sun which is then near the horizon, and the parts 
of those buildings which are not exposed to the sun remain almost the 
same dim neutral colour as the mist. 

Why the higher things situated at a distance are darker than the 
lower ones even though the mist is of uniform thickness: 

Of the things situated in mist or any other dense atmosphere, 
whether this arise from vapour or smoke or distance, that will be 
most visible which is the highest, and of things of equal height that 
will seem darkest which is against a background of the deepest mist. 
As happens with the eye h, which beholding a b c, towers of equal 
height, sees c the summit of the first tower at r, situated below in the 
mist at two degrees of depth, and sees the summit of the centre tower 
b in only one degree of mist; therefore the summit c will show itself 
darker than the summit of the tower b. e 3 v. 



The landscapes which occur in representations of winter should not 
show the mountains blue as one sees them in summer, and this is 
proved by the fourth part of this [chapter], where it is stated that of 
the mountains seen at a great distance that will seem a deeper blue 
in colour which is in itself darker; for when the trees are stripped of 
their leaves they look grey in colour, and when they are with their 
leaves they are green, and in proportion as the green is darker than 
the grey, the green will appear a more intense blue than the grey; 
and by the fifth part of this [chapter], the shadows of trees which are 
clad with leaves are as much darker than the shadows of those trees 
which are stripped of leaves as the trees clad with leaves are denser 
than those without leaves; and thus we have established our propo- 

The definition of the blue colour of the atmosphere supplies the 
reason why landscapes are a deeper shade of blue in summer than in 

The shadows of trees set in landscapes do not seem to occupy the 
same positions in the trees on the left as in those on the right, and this 
especially when the sun is on the right or the left. This is proved by 



the fourth which states: — opaque bodies placed between the light 
and die eye will show- themselves entirely in shadow; and by thr 
fifth: — the eye that is interposed between the opaque body and the 
light sees the opaque body all illuminated; and by the sixth: — when 
the eye and the opaque body are interposed between the darkness 
and the light the body will be seen half in shadow and half in light. 

e 19 r. 


The object wall appear more or less distinct at the same distance, in 
proportion as the atmosphere interposed between the eye and this 
object is of greater or less clearness. 

Since therefore you are aware that the greater or less quantity of 
atmosphere interposed between the eye and the object causes the out- 
lines of these objects to seem more or less blurred to the eye, you 
should represent the stages of loss of definition of these bodies in the 
same proportion to each other as that of their distances from the eye 
of the beholder. e 79 v. 

When the smoke from dry wood comes between the eye of the 
observer and some dark space it appears blue. 

So the atmosphere appears blue because of the darkness which is 
beyond it; and if you look towards the horizon of the sky you will see 
that the atmosphere is not blue, and this is due to its density; and so, 
at every stage as you raise your eye up from this horizon to the sky 
which is above you, you will find that the atmosphere will seem 
darker, and this is because a lesser quantity of air interposes between 
your eye and the darkness. 

And if you are on the top of a high mountain the atmosphere will 
seem darker above you, just in proportion as it becomes rarer between 
you and the said darkness; and this will be intensified at every succes- 
sive stage of its height, so that at the last it will remain blue. 

That smoke will appear the bluest which proceeds from the driest 
wood, and is nearest to the place of its origin, and when it is seen 
against the darkest background with the light of the sun upon it. 

f 18 r. 



The smoke that penetrates through the air if it is thick, and rises 
out of great flame which is fed by damp wood, does not mingle with 
it but makes itself seem denser above than in the centre, and does this 
the more when the air is chilly; and the faint gleam that penetrates the 
air is always warm and always becoming fainter, and of the dust 
which passes through the air the finest rises the highest. f 88 r. 

Although leaves with a smooth surface are for the most part of the 
same colour on the right side as on the reverse, it so happens that 
the side exposed to the atmosphere partakes of the colour of the at- 
mosphere, and seems to partake of its colour more closely in propor- 
tion as the eye is nearer to it and sees it more foreshortened. And the 
shadows will invariably appear darker on the right side than on the 
reverse, through the contrast caused by the high lights appearing 
against the shadow. 

The under side of the leaf, although its colour in itself may be the 
same as that of the right side, appears more beautiful; and this colour 
is a green verging upon yellow; and this occurs when the leaf is inter- 
posed between the eye and the light which illumines it from the op- 
posite side. Its shadows also are in the same positions as those on the 
opposite side. 

Therefore, O painter, when you make trees near at hand, remember 
that when your eye is somewhat below the level of the tree you will 
be able to see its leaves some on the right side and some on the reverse; 
and the right sides will be a deeper blue as they are seen more fore- 
shortened, and the same leaf will sometimes show part of the right side 
and part of the reverse, and consequently you must make it of two 
colours. g 3 r. and 2 v. 

When there is one belt of green behind another, the high lights on 
the leaves and their transparent lights show more strongly than those 
which are against the brightness of the atmosphere. 

And if the sun illumines the leaves without these coming between 
it and the eye, and without the eye facing the sun, then the high lights 
and the transparent lights of the leaves are extremely powerful. 

It is very useful to make some of the lower branches, and these 
should be dark, and should serve as a background for the illuminated 
belts of green which are at some little distance from the first. 



Of the darker greens seen from below, that part is darkest which is 
nearest to the eye, that is to say which is farthest from the Luminous 
atmosphere. g 4 r. 

Never represent leaves as though transparent in the sun, because 
they are always indistinct; and this comes about because over the 
transparency of one leaf there will be imprinted the shadow of an- 
other leaf which is above it; and this shadow has definite outlines and 
a fixed density. And sometimes it is the half or third part of the leaf 
which is in the shadow, and consequently the structure of such a leaf 
is indistinct, and the imitation of it is to be avoided. 

The upper branches of the spreading boughs of trees keep nearer to 
the parent bough than do those below. 

That leaf is less transparent which takes the light at a more acute 
angle. g 4 v. 


Of the plants which take their shadows from the trees which grow 
among them, those which are in front of the shadow have their stalks 
lighted up against a background of shadow, and the plants which are 
in shadow have their stalks dark against a light background, that is 
against a background which is beyond the shadow. 


Of the trees which are between the eye and the light, the part in 
front will be bright, and this brightness will be diversified by the 
ramification of the transparent leaves — as seen from the under side — 
with the shining leaves seen from the right side, and in the back- 
ground, below and behind, the verdure will be dark, because it is cast 
in shadow by the front part of the said tree; and this occurs in trees 
which are higher than the eye. g 9 v. 


When the leaves are interposed between the light and the eye, then 
that which is nearest to the eye will be the darkest, and that farthest 



away will be the lightest, if they are not seen against the atmosphere; 
and this happens with leaves which are beyond the centre of the tree, 
that is in the direction of the light. g io v. 



The true method of practice in representing country scenes, or I 
should say landscapes with their trees, is to choose them when the 
sun in the sky is hidden, so that the fields receive a diffused light and 
not the direct light of the sun, for this makes the shadows sharply de- 
fined and very different from the lights. guv. 


The shadows of verdure always approximate to blue, and so it is 
with every shadow of every other thing, and they tend to this colour 
more entirely when they are farther distant from the eye, and less in 
proportion as they are nearer. 

The leaves which reflect the blue of the atmosphere always present 
themselves edgewise to the eye. 


The part illuminated will show more of its natural colour at a great 
distance when it is illuminated by the most powerful light, g 15 r. 


When the sun is in the east and the eye is looking down upon a city 
from above, the eye will see the southern part of the city with its roofs 
half in shadow and half in light, and so also with the northern part; 
but the eastern part will be all in shadow and the western part all in 


Landscapes ought to be represented so that the trees are half in light 
and half in shadow; but it is better to make them when the sun is 



covered by clouds, for then the trees are lighted up by the general light 
of the sky and the general shadow of the earth; and these are so much 
darker in their parts, in proportion as these parts are nearer to the 
middle of the tree and to the earth. c. 19 v 


When the sun is in the east, the trees in the south and north are 
almost as much in light as in shadow, but the total amount in light is 
greater in proportion as they are more to the west, and the total 
amount in shadow is greater in proportion as they are more to the 


When the sun is in the east, the grasses in the meadows and the 
other small plants are of a most brilliant green, because they are trans- 
parent to the sun. This does not happen with the meadows in the 
west, and in those in the south and north the grasses are of a moderate 
brilliance in their green. g 20 v. 


When the sun is in the east all the parts of trees which are illu- 
minated by it are of a most brilliant green; and this is due to the fact 
that the leaves illuminated by the sun within half our hemisphere, 
namely the eastern half, are transparent, while within the western 
semicircle the verdure has a sombre hue and the air is damp and 
heavy, of the colour of dark ashes, so that it is not transparent like that 
in the east, which is refulgent, and the more so as it is more full of 

The shadows of the trees in the east cover a large part of the tree, 
and they are darker in proportion as the trees are thicker with leaves. 

g 21 r. 


When the sun is in the east the trees seen towards the east will 
have the light surrounding them all around their shadows, except 
towards the earth, unless the tree has been pruned in the previous 



year; and the trees in the south and in the north will be half in 
shadow and half in light, and more or less in shadow or in light ac- 
cording as they are more or less to the east or to the west. 

The fact of the eye being high or low causes a variation in the 
shadows and lights of trees, for when the eye is above, it sees the trees 
with very little shadow, and when below with a great deal of shadow. 

The different shades of green of plants are as varied as are their 
species. g 21 v. 


When the sun is in the east the trees towards the west will appear 
tx> the eye with very little relief and of almost imperceptible grada- 
tion, on account of the atmosphere which lies very thick between the 
eye and these trees, according to the seventh [part] of this [treatise]; 
and they are deprived of shadow, for although a shadow exists in each 
part of the ramification, it so happens that the images of shadow and 
light which come to the eye are confused and blended together, and 
cannot be discerned through the smallness of their size. And the high- 
est lights are in the centre of the trees and the shadows are toward 
their extremities, and their separation is marked by the shadows in 
the spaces between these trees when the forests are dense with trees; 
and in those which are more scattered the contours are but little seen. 

g 22 r. 


When the sun is in the east the trees in that quarter are dark towards 
the centre, and their edges are in light. 



The smoke is seen better and more distinctly in the eastern than in 
the western quarter when the sun is in the east. This is due to two 
causes: the first is that the sun shines with its rays through the par- 
ticles of the smoke, and lightens these up and renders them visible; 
the second is that the roofs of the houses seen in the east at this hour 
are in shadow, because their slope prevents them from being lighted 
by the sun; the same happens with the dust, and both the one and the 



other are more charged with light in proportion as they are thicker; 

and they are thickest towards the middle. 


G 22 V. 



When the sun is in the east the smoke of cities will not be visible in 
the west, because it is neither seen penetrated by the solar rays nor 
against a dark background, since the roofs of the houses turn the same 
side to the eye that they show to the sun, and against this bright back- 
ground the smoke will be scarcely visible. But dust when seen under 
the same conditions will appear darker than smoke, because it is 
thicker in substance than smoke, which is made up of vapour. 

g 23 r. 

[Of trees penetrated by the air] 


The intervening region of the air within the bodies of trees, and the 
spaces between the trees within the air at a great distance, do not 
reveal themselves to the eye, for where it requires an effort to discern 
the whole it would be difficult to distinguish the parts. But it forms a 
confused mixture, which derives most from that which forms the 
greatest mass. The open spaces of the tree being made up of particles 
of illuminated air, and being much less than the tree, one therefore 
loses sight of them much sooner than one does of the tree; but it does 
not therefore follow that they are not there. Hence of necessity there 
comes about a blending of air and of the darkness of the shaded tree, 
which float together to meet the eye of the beholder. 


That part of the tree will show fewer open spaces when it has be- 
hind it, between the tree and the air, the greater mass of another tree. 
So with the tree a the open spaces are not covered, nor in b, because 
there are no trees behind. But in c there is only open space in the half, 
that is to say that c is covered by the tree d, and part of the tree d is 



covered by the tree e, and a little beyond this all the open spaces within 
the circumference of the trees are lost, and only those at the sides 
remain. g 25 v. 


What outlines do trees show at a distance against the atmosphere 
which serves as their background ? The outlines of the structure of trees 
against the luminous atmosphere, as they are more remote, approach 
the spherical more closely in their shape, and as they are nearer, so 
they display a greater divergence from the spherical form. 

So the first tree a l as being near to the eye displays the true form of 
its ramification, but this is somewhat less visible in b, and disappears 
altogether in c, where not only can none of the branches of the tree be 
seen, but the whole tree can only be recognised with great difficulty. 

Every object in shadow — be it of whatever shape you please — will 
at a great distance appear to be spherical; and this occurs because if an 
object be rectangular, then at a very short distance its angles become 
invisible, and a little farther of? it loses more than it retains of the lesser 
sides, and so before losing the whole it loses the parts, since these are 
less than the whole. 

So with a man when so situated, you lose sight of the legs, arms and 
head, before the trunk, and then the extremities of the length become 
lost before those of the breadth, and when these have become equal 
there would be a square 2 if the angles remained, but as they are lost 
there is a sphere. g 26 v. 

In the representation of trees in leaf be careful not to repeat the 
same colour too often, for a tree which has another tree of the same 
colour as its background, but vary it by making the foliage lighter or 
darker, or of a more vivid green. g 27 v. 


The lights on such leaves as are darkest in colour will most closely 
resemble the colour of the atmosphere reflected in them; and this is due 

1 MS. contains a sketch of a row of trees seen in perspective. 

2 I have followed Dr. Richter in interpreting a tiny figure in the text as a square. 
M. Ravaisson-Mollien reads it as ci. 



to the Eact that the brightness of the illuminated part mingling w ith the 
darkness tonus ot itscll a blue colour; and this brightness proceeds from 
the blue of the atmosphere, which is reflected in the smooth surface oi 
these leaves, thereby adding to the blueness which this light usually 
produces when it falls upon dark objects. 



But leaves of yellowish green do not when they reflect the atmosphere 
create a reflection which verges on blue; for every object when seen in 
a mirror takes in part the colour of this mirror; therefore the blue of 
the atmosphere reflected in the yellow of the leaf appears green, because 
blue and yellow mixed together form a most brilliant green, and there- 
fore the lustre on light leaves which are yellowish in colour will be a 
greenish yellow. 


The trees, illuminated by the sun and by the atmosphere, which 
have leaves of a dark colour, will be illuminated on one side by the 
atmosphere alone, and in consequence of being thus illuminated will 
share its blueness; and on the opposite side they will be illuminated 
both by the atmosphere and the sun, and the part which the eye sees 
illuminated by the sun will be resplendent. g 28 v. 

The extremities of the branches of trees if not dragged down by the 
weight of their fruit turn towards the sky as much as possible. 

The upper sides of their leaves are turned towards the sky in order 
to receive nourishment from the dew that falls by night. 

The sun gives spirit and life to plants, and the earth nourishes them 
with moisture. In this connection I once made the experiment of leav- 
ing only one small root on a gourd and keeping this nourished with 
water; and the gourd brought to perfection all the fruits that it could 
produce, which were about sixty gourds of the long species; and I set 
myself diligently to consider the source of its life, and I perceived that 
it was the dew of the night which steeped it abundantly with its mois- 



ture through the joints of its great leaves, and thereby nourished the tree 
and its offspring, or rather the seeds which were to produce its off- 

The rule as to the leaves produced on the last of the year's branches 
is that on twin branches they will grow in a contrary direction, that is, 
that the leaves in their earliest growth turn themselves round towards 
the branch, in such a way that the sixth leaf above grows over the sixth 
leaf below; and the manner of their turning is that if one turns towards 
its fellow on the right, the other turns to the left. 

The leaf serves as a breast to nourish the branch or fruit which grows 
in the succeeding year. g 32 v. 


The dark colours of the shadows of mountains at a great distance 
take a more beautiful and purer blue than those parts which are in 
light, and from this it follows that when the rock of the mountains is 
reddish the parts of it which are in light are fawn-coloured, and the 
more brightly it is illuminated the more closely will it retain its natural 
colour. 1 48 r. 


Smoke enters into the air in the form of a wave, like that which 
v/ater makes when its force causes it to burst through other water. 

1 106 [58] r. 

Reeds in the light are scarcely visible, but between the light and the 
shade they stand out well. 

To represent landscapes, choose when the sun is at the meridian and 
turn to the west or the east, and then begin your work. 

If you turn to the north every object placed on that side will be 
without shadow, and especially those nearest to the shadow cast by your 
head, and if you turn to the south every object upon that side will be 
entirely in shadow. 

All the trees which are towards the sun and which have the atmos- 
phere for their background will be dark, and the other trees which 
have this darkness for their background will be black in the centre and 
lighter towards the edges. l 87 r. 




Low, tall, thin, thick, that is with leaves, dark, light, yellow, red, 
with branches pointing upwards, with branches that meet the eye, with 
branches that point downwards, with trunks white, those transparent 
in the air, those not, those massed together, those spread out. 

L 87 V. 

The line of equality and that of the horizon are the same. 

m 36 v. 

Landscapes are of a more beautiful azure when in fine weather the 
sun is at noon, than at any other hour of the day, because the atmos- 
phere is free from moisture; and viewing them under such conditions 
you see the trees beautiful towards their extremities and the shadows 
dark towards the centre; and in the farther distance the atmosphere 
which is interposed between you and them appears more beautiful 
when beyond it there is some darker substance, and consequently the 
azure is most beautiful. 

Objects seen from the side on which the sun is shining will not show 
you their shadows. But if you are lower than the sun you will see what 
was not seen by the sun, and that will be all in shadow. 

The leaves of the trees which are between you and the sun are of 
five principal shades of colour, namely a green most beautiful, shining 
and serving as a mirror for the atmosphere which lights up objects that 
cannot be seen by the sun, and the parts in shadow that only face the 
earth, and those darkest parts which are surrounded by something other 
than darkness. 

Trees in the open country which are between you and the sun seem 
much more beautiful than those which have you between the sun and 
themselves; and this is the case because those which are in the same 
direction as the sun show their leaves transparent towards their 
extremities, and the parts that are not transparent, that is at the tips, 
are shining; it is true that the shadows are dark, because they are not 
covered by anything. 

The trees when you place yourself between them and the sun will 
only show themselves to you in their clear and natural colour, which is 
not of itself very conspicuous, and besides this certain reflected lights, 



which, owing to their not being against a background that offers a 
strong contrast to their brightness, are but little in evidence; and if you 
are at a lower altitude than these, such parts of them may be visible as 
are not exposed to the sun, and these will be dark. 



But if you are on the side from whence the wind is blowing, you will 
see the trees looking much lighter than you would see them from the 
other sides; and this is due to the fact that the wind turns up the reverse 
sides of the leaves, which are in all cases much paler than their right 
sides; and especially will they be very light if the wind blows from the 
quarter where the sun happens to be, and if you have your back turned 
to it. b.m. 113 v. 

All trees seen against the sun are dark towards the centre; this dark- 
ness will take the shape of the tree when it stands apart from others. 

The shadows cast by trees on which the sun is shining are as dark 
as that of the centre of the tree. 

The shadow cast by trees is never less in mass than the mass of the 
tree; but it is larger in proportion as the place where it is thrown slopes 
more towards the centre of the earth. 

A shadow will be thickest towards the centre of a tree when it has 
fewest branches. 

Every branch gets the middle of the shadow of every other branch 
and as a consequence of all the tree. 

The shape of every shadow of branch or tree is clothed with a bright 
part on the side from which the light comes; this brightness will be of 
the same shape as the shadow and may extend for a mile from the side 
where the sun is. 

If it should happen anywhere that a cloud casts a shadow on some 
part of the hills, the trees there will undergo less change than in the 
distances or plains; for the trees upon the hills have their branches 
thicker because their growth each year is less than in the plains; there- 
fore as they are of the number of those naturally dark and full of shade 
the shadows of the clouds cannot make them any darker, and the level 
spaces that come between the trees which have not lost any shadow 



vary very much in tone, and especially those which arc other than 
green, such as cultivated lands or the havoc of mountains or their 
barrenness or ruggedness. 

Where trees are on the skyline they seem of the same colour, unless 
they are very close together and with thick-set leaves like the pine and 
similar trees. 

When you see trees on the side on which the sun lights them you 
will see them of almost uniform brightness, and the shadows which are 
within them will be covered by the illuminated leaves which come 
between your eye and the shadows. 

When trees come between the sun and the eye beyond the shadows 
which spread out from their centre you will see the green of the leaves 
in transparence; but this transparence will be broken in many places 
by the leaves and branches in shadow which come between you and 
them, and in the upper portions it will be accompanied by many 
reflections from the leaves. b.m. 114 r. 

When the sun is covered by clouds, objects have a low degree of 
visibility; because there is but little difference between the lights and 
shadows of the trees and buildings, through them being illuminated 
by the spaciousness of the atmosphere, which surrounds the objects in 
such a way that the shadows are few, and these few become fainter and 
fainter so that their extremities become lost in mist. 

The trees in landscapes are of various different shades of green; for 
in some, such as firs, pines, cypresses, laurels, box and the like, it bor- 
ders on black; others such as walnuts and pears, vines and young foli- 
age approximate to yellow; others to darker shades of yellow, such as 
chestnuts, oaks and the like, others redden towards the autumn, these 
are sorbs, pomegranates, vines and cherry trees; others such as willows, 
olives, bamboos, and others like these, tend to become white. 

b.m. 114 v. 


All the leaves which hang down towards the ground as the twigs 
bend, owing to the branches being turned over, straighten themselves 



in the current of the winds; and here their perspective is inverted, for 
if the tree is between you and the quarter from which the wind is 
coming, the tips of the leaves which are towards you take their natural 
position, and those opposite which should have their tips the contrary 
way, from the fact of their being upside down, will be turned with their 
tips towards you. 

Trees in a landscape do not stand out distinctly one from another, 
because their illuminated parts border on the illuminated parts of those 
beyond them, and so there is little difference between the lights and 
the shadows. 

When clouds come between the sun and the eye all the edges of their 
rounded masses are clear, and they are dark towards the centre, and this 
happens because towards the top these edges are seen by the sun from 
above while you are looking at them from below; and the same hap- 
pens with the positions of the branches of the trees; and moreover the 
clouds, like the trees, through being somewhat transparent are partly 
bright, and at the edges show themselves thinner. 

But when the eye finds itself between the cloud and the sun, the 
appearance of the cloud is the contrary of what it was before, for the 
edges of its rounded masses are dark and they are bright towards the 
centre. And this comes about because you are looking at that part 
which is also facing the sun, and because these edges have a degree of 
transparency and reveal to the eye the part that is hidden beyond them, 
and this not being visible to the sun as are the parts which are turned 
towards it is necessarily somewhat darker. It may also be that you see 
the details of these rounded masses from the underside while the sun 
sees it from above, and since they are not so situated as to give back the 
brightness of the sun as in the former instance, therefore they remain 

The black clouds which are often visible above those that are bright 
and illuminated by the sun, are thrown into shadow by the other clouds 
which are interposed between them and the sun. 

Again the rounded masses of the clouds that face the sun show their 
edges dark, because they are silhouetted 1 against a bright background; 
and to see the truth of this you should observe the top of a cloud which 

1 MS. canpegiano. 



is entirely light because it is silhouetted against the blue of the atmos- 
phere whieh is darker than the cloud. b.m. 172 v. 


I ask whether the true movement of the clouds can be recognised by 
the movement of their shadows, and similarly by the movement of the 
sun. Forster 11 46 r. 

The sun will appear greater in moving water or when the surface is 
broken into waves than it does in still water. An example is of the light 
reflected on the strings of the monochord. Windsor: Drawings 12350 


The clouds do not display their roundnesses except in those parts 
which are seen by the sun : other roundnesses are imperceptible because 
they are in the parts in shadow. 

If the sun is in the east and the clouds are in the west, the position 
of the eye being between the sun and the cloud, it sees the edges of the 
roundnesses which are the component parts of these clouds as dark, 
and the portions which are surrounded by these darknesses become 
light. And this proceeds from the fact that the edges of the rounded 
forms of these clouds face the sky above and around them, so that it is 
mirrored in them. 

The cloud and the tree display no roundness in those of their parts 
which are in shadow. Windsor: Drawings 12388 

The shadows of clouds are lighter in proportion as they are nearer 
to the horizon. Windsor: Drawings 12391 

That part of a tree which is against a background of shadow is al] 
of one tone, and where the trees or branches are thickest there it is 
darkest because there is less perforation by the air. But where the 
branches are on a background of other branches there the luminous 
parts show themselves brighter and the leaves more resplendent, 
because of the sun which illumines them. 

Windsor: Drawings 12431 v. 




The density of smoke below the horizon appears white and above 
the horizon dark, and even though the smoke is in itself of uniform 
colour this uniformity will seem to vary, according to the difference 
of the space in which it is found. Windsor mss. r 878