one process having a tendency to sharpen edges
rather monotonously.

This quality is everywhere to be found in nature. If you regard any
scene pictorially, looking at it as a whole and not letting your eye
focus on individual objects wandering from one to another while being
but dimly conscious of the whole, but regarding it as a beautiful
ensemble; you will find that the boundaries of the masses are not hard
continuous edges but play continually along their course, here melting
imperceptibly into the surrounding mass, and there accentuated more
sharply. Even a long continuous line, like the horizon at sea, has some
amount of this play, which you should always be on the look out for. But
when the parts only of nature are regarded and each is separately
focussed, hard edges will be found to exist almost everywhere, unless
there is a positive mist enveloping the objects. And this is the usual
way of looking at things. But a picture that is a catalogue of many
little parts separately focussed will not hang together as one visual
impression.

[Illustration: Plate XLIV.

PART OF THE SURRENDER OF BREDA. BY VELAZQUEZ

Note the varied quantity of the edge in white mass of tunic. (The
reproduction does not unfortunately show this as well as the original.)

_Photo Anderson_]

In naturalistic work the necessity for painting to one focal impression
is as great as the necessity of painting in true perspective. What
perspective has done for drawing, the impressionist system of painting
to one all-embracing focus has done for tone. Before perspective was
introduced, each individual object in a picture was drawn with a
separate centre of vision fixed on each object in turn. What perspective
did was to insist that all objects in a picture should be drawn in
relation to one fixed centre of vision. And whereas formerly each object
was painted to a hard focus, whether it was in the foreground or the
distance, impressionism teaches that you cannot have the focus in a
picture at the same time on the foreground and the distance.

Of course there are many manners of painting with more primitive
conventions in which the consideration of focus does not enter. But in
all painting that aims at reproducing the impressions directly produced
in us by natural appearances, this question of focus and its influence
on the quality of your edges is of great importance.

Something should be said about the serrated edges of masses, like those
of tr