UNDER this head I shall attempt shewing what it
is that gives the appearance of that hollow or
vacant space in which all things move so freely; and in
what manner light, shade and colours, mark or point
out the distances of one object from another, and oc-
casion an agreeable play upon the eye, called by the
painters a fine keeping, and pleasing composition of
light and shade. Herein my design is to consider this
matter as a performance of nature without, or before
the eye; I mean, as if the objects with their shades, &c.
were in fact circumstanced as they appear, and as the
unskill'd in optics take them to be. And let it be re-
marked throughout this chapter, that the pleasure arising
from composition, as in a fine landskip, &c. is chiefly
owing to the dispositions and assemblages of light and
shades, which are so order'd by the principles called
OPPOSITION, BREADTH and SIMPLICITY, as to produce
a just and distinct perception of the objects before us.
Experience teaches us that the eye may be subdued
and forced into forming and disposing of objects even
quite contrary to what it would naturally see them, by

the


[107]

the prejudgment of the mind from the better autho-
rity of feeling, or some other persuasive motive. But
surely this extraordinary perversion of the sight would
not have been suffer'd, did it not tend to great and ne-
cessary purposes, in rectifying some deficiences which it
would otherwise be subject to (tho' we must own at the
same time, that the mind itself may be so imposed
upon as to make the eye see falsely as well as truly) for
example, were it not for this controul over the sight,
it is well known, that we should not only see things
double, but upside down, as they are painted upon the
retina, and as each eye has a distinct sight. And then
as to distances; a fly upon a pane of glass is sometimes
imagined a crow, or larger bird afar off, till some cir-
cumstance hath rectified the mistake, and convinced us
of its real size and place.
Hence I would infer, that the eye generally gives its
assent to such space and distances as have been first
measured by the feeling, or otherwise calculated in
the mind: which measurements and calculations are
equally, if not more, in the power of a blind man, as
was fully experienced by that incomparable mathemati-
cian and wonder of his age, the late professor Sanderson.
By pursuing the observation of the faculties of the
mind, an idea may be formed of the means by which
we attain to the perception or appearance of an im-
mense space surrounding us; which cavity, being subject
to divisions and subdivisions in the mind, is afterwards

P 2 fashioned


[108]

fashioned by the limited power of the eye, first into a
hemisphere, and then into the appearance of different
distances, which are pictured to it by means of such dis-
positions of light and shade as shall next be described.
And these I now desire may be looked upon, but as so
many, marks or types set upon these distances, and
which are remember'd and learnt by degrees, and when
learnt, are recurred to upon all occasions.
If permitted then to consider light and shades as
types of distinctions, they become, as it were, our mater-
rials, of which prime tints are the principal; by these,
I mean the fixed and permanent colours of each object,
as the green of trees, &c. which serve the purposes of
separating and relieving the several objects by the diffe-
rent strengths or shades of them being opposed to each
other *.
The other shades that have been before spoken of,
Serve and help to the like purposes when properly op-
posed; but as in nature they are continually fleeting and
changing their appearances, either by our or their situa-
tions, they sometimes oppose and relieve, and sometimes
not, as for instance; I once observed the tower-part of
a steeple so exactly the colour of a light cloud behind
it, that, at the distance I stood, there was not the least
distinction to be made, so that the spire (of a lead-
colour) seemed suspended in the air; but had a cloud of
the like tint with the steeple, supplied the place of the
white one, the tower would then have been relieved

and

* Fig. 86.
T. p. 2.


[109]

and distinct, when the spire would have been lost in
the view.
Nor is it sufficient that objects are of different co-
lours or shades, to shew their distances from the eye, if
one does not in part hide or lay over the other, as in
Fig. 86.
For as fig.* the two equal balls, tho' one were black
and the other white, placed on the separate walls, sup-
posed distant from each other twenty or thirty feet, ne-
vertheless, may seem both to rest upon one, if the tops
of the walls are level with the eye; but when one ball
hides part of the other, as in the same figure, we begin
to apprehend they are upon different walls, which is
determin'd by the perspective I: hence you will see the
reason, why the steeple of Bloomsbury-church, in com-
ing from Hamstead, seems to stand upon Montague-
house, tho' it is several hundred yards distant from it.
Since then the opposition of one prime tint or shade
to another, hath so great a share in marking out the re-
cessions, or distances in a prospect, by which the eye is
led onward step by step, it becomes a principle of con-
sequence enough to be further discussed, with regard to
the management of it in compositions of nature, as well
as art. As to the management of it, when seen only

I The knowledge of perspective is no small help to the seeing objects truly, for which purpose Dr. Brook Taylor's Linear perspective made easy to those who are unacquainted with geometry, proposed to be pub- lish'd soon by Mr. Kirby of Ipswich, may be of most service.

from

* Fig. 90.
T. p. 2.


[110]

from one point, the artist hath the advantage over nat-
ure, because such fix'd dispositions of shades as he hath
artfully put together, cannot be displaced by the altera-
ion of light, for which reason, designs done in two
prime tints only, will sufficiently represent all those re-
cessions, and give a just keeping to the representation
of a prospect, in a print; whereas, the oppositions in
nature, depending, as has been before hinted, on acci-
dental situations and uncertain incidents, do not always
make such pleasing composition, and would therefore
have been very often deficient, had nature worked in
two colours only; for which reason she hath provided
an infinite number of materials, not only by way of
prevention, but to add lustre and beauty to her works.
By an infinite number of materials, I mean colours
and shades of all kinds of degrees; some notion of
which variety may be formed by supposing a piece of
white silk by several dippings gradually dyed to a
black; and carrying it in like manner through the
prime tints of yellow, red and blue; and then again,
by making the like progress through all the mixtures
that are to be made of these three original colours. So
that when we survey this infinite and immense variety,
it is no wonder, that, let the light or objects be situated
or changed how they will, oppositions seldom miss; nor
that even every incident of shade should sometimes be
so completely disposed as to admit of no further beauty.
as to composition; and from whence the artist hath

by


[111]

By observation taken his principles of imitation, as in
the following respect.
Those objects which are intended most to affect the
eye, and come forwardest to the view, must have large,
strong, and smart oppositions, like the fore-ground in
fig.* , and what are designed to be thrown further off,
must be made still weaker and weaker, as expressed in
figure 86, which receding in order make a kind of
gradation of oppositions; to which, and all the other
circumstances already described, both for recession, and
beauty, nature hath added what is known by the name
of aerial perspective; being that interposition of air,
which throws a general soft retiring tint over the whole
prospect; to be seen in excess at the rising of a fog.
All which again receives still more distinctness, as well
as a greater degree of variety, when the sun shines
bright, and casts broad shadows of one object upon
another; which gives the skilful designer such hints for
shewing broad and fine oppositions of shades, as give
life and spirit to his performances.
BREADTH of SHADE is a principle that assists in
making distinction more conspicuous; thus fig.†, is
better distinguish'd by its breadth or quantity of shade,
and view'd with more ease and pleasure at any distance,
than fig. ‡, which hath many, and these but narrow
shades between the folds. And for one of the noblest
instances of this, let Windsor-castle be viewed at the
rising or setting of the sun.

Let

* Fig. 89. T. p. 2.

† Fig. 87. L. P. I.

‡ Fig. 88. L. P. I.

[112]

Let breadth be introduced how it will, it always
gives great repose to the eye; as on the contrary, when
lights and shades in a composition are scattered about
in little spots, the eye is constantly disturbed, and the
mind is uneasy, especially if you are eager to under-
stand every object in the composition, as it is painful
to the ear when any one is anxious to know what is
said in company, where many are talking at the same
time.
SIMPLICITY (which I am last to speak of) in the dis-
position of a great variety, is best accomplished by fol-
lowing nature's constant rule, of dividing composition
into three or five parts, or parcels, see chap. 4. on sim-
plicity: the painters accordingly divide theirs into fore-
ground, middle-ground, and distance or back-ground;
which simple and distinct quantities mass together that
variety which entertains the eye; as the different parts
of base, tenor, and treble, in a composition in music,
entertain the ear.
Let these principles be reversed, or neglected, the
object will appear as disagreeable as fig. *, whereas,
was this to be a composition of lights and shades only,
properly disposed, tho' ranged under no particular fi-
gures, it might still have the pleasing effect of a picture.
And here, as it would be endless to enter upon the dif-
ferent effects of lights and shades on lucid and transpa-
rent bodies, we shall leave them to the reader's observa-
tion, and so conclude this chapter.

C H A P.

* Fig. 91.
T. p. 2.