e of actuality and vividness beside which the traditionary
practice seemed absolutely fanciful and mechanical.

Applying Manet's method, his invention, his discovery, to the painting
of out-of-doors, the _plein air_ school immediately began to produce
landscapes of astonishing reality by confining their effort to those
values which it is in the power of pigments to imitate. The possible
scale of mere correspondence being of course from one to one hundred,
they secured greater truth by painting between twenty and eighty, we may
say. Hence the grayness of the most successful French landscapes of the
present day--those of Bastien-Lepage's backgrounds, of Cazin's pictures.
Sunlight being unpaintable, they confined themselves to the
representation of what they could represent. In the interest of truth,
of reality, they narrowed the gamut of their modulations, they attempted
less, upheld by the certainty of accomplishing more. For a time French
landscape was pitched in a minor key. Suddenly Claude Monet appeared.
Impressionism, as it is now understood, and as Manet had not succeeded
in popularizing it, won instant recognition. Monet's discovery was that
light is the most important factor in the painting of out-of-doors. He
pushed up the key of landscape painting to the highest power. He
attacked the fascinating, but of course demonstrably insolvable, problem
of painting sunlight, not illusorily, as Fortuny had done by relying on
contrasts of light and dark correspondent in scale, but positively and
realistically. He realized as nearly as possible the effect of
sunlight--that is to say, he did as well and no better in this respect
than Fortuny had done--but he created a much greater illusion of a
sunlit landscape than anyone had ever done before him, by painting those
parts of his picture not in sunlight with the exact truth that in
painting objects in shadow the palette can compass.

Nothing is more simple. Take a landscape with a cloudy sky, which means
diffused light in the old sense of the term, and observe the effect upon
it of a sudden burst of sunlight. What is the effect where considerable
portions of the scene are suddenly thrown into marked shadow, as well as
others illuminated with intense light? Is the absolute value of the
parts in shadow lowered or raised? Raised, of course, by reflected
light. Formerly, to get the contrast between sunlight and shadow in
proper scale, the painter would have painted the shadows da