The coming landscape-painter will be a four-hour man, of thorough knowledge, one who has most intimate and close acquaintance with nature, one who can select and then seize the salient features of the landscape, at a glance arranging them upon the square of his canvas, in other words, composing them, the basis being the most expansive and most picturesque grouping of the several details of the subject, extracting at the same moment, at the same instant, with one sweep of his eye, the whole scheme of local color, and then surely, clearly, lovingly, and reverently making it breathe upon his canvas for other souls to live by.
And how noble the ambition!
In our present civilization some men are moved to philanthropy, some to science, some to be rulers of men. Some men are brimful and running over with harmonies that will live forever. Other men's hearts beat in unison with the symphonies of the spheres, and Homer and Milton and Dante become household words. You seek another expression of the good that is in you. You will be painters and sculptors. Color, form, and mass are to you what the pen, the sword, and the lute are to those others who have gone before, or are now around you. Your mission is as distinct as theirs, and it is as imperative that you should fulfil it. Paint what you see and as you see it. Nothing more nor less. See only the beautiful, and if you cannot reach that content yourself with the picturesque. It is a first cousin but once removed.
MASS
The difference between composition and mass is that a composition is a mere outline of pen or pencil, each object taking its proper place in the square of a canvas, while mass is the filling in between these outlines either of varied color or in lights or darks, their gradations but so many guides to the spectator's eye marking not only its perspective, form and atmosphere, but, if skilfully done, telling the story of your subject at a glance.
To do this the student must find the lightest light and darkest dark in the subject before him and, having found it, adhere to it to the end of his work. For as the sun dominates the sky and earth so do its rays dominate parts of the whole, making more luminous than the rest only one object upon which its light falls. To make this more explicit it is only necessary to look at an egg upon a white table-cloth. Here is a natural object devoid of local color except in reflected lights, and yet you will find that where the round of the egg reflects the light the highest light is found, while in the edge of the shadow, where the egg turns into the round—between that high light and the reflected light from the table-cloth, I mean—is found its darkest dark. But only one portion of that shadow, a point as large as the point of a pin, is the darkest dark. Everything else is gradation, from the highest light to the lowest light, the lowest light being almost a shadow; and from its darkest dark to its lightest dark the lightest dark again being almost a light.
In landscape art these problems are greatly simplified. The sun is always the strongest light, and whatever comes against it, church tower, rock, palace, or ship under full sail, is the darkest object. In addition to this there is always some one point where the outdoor painter can find a lesser supplementary light and near it a lesser supplementary dark. Moreover, throughout the rest of the composition these same lights and darks are echoed and re-echoed in constantly decreasing gradations.