IF you want a fairly easy yet interesting subject to sketch, choose a mass of trees or a range of hills against a twilight sky. Do not admit too much into the picture. Sketch it over and over. The cloud or sky effect, at any rate, will be different each time; and then, on one evening the outline may be studied, on another the values. After making three or four drawings of the one subject, one's last sketch of it looks quite masterly compared with the first. You have learned what is important in that subject and what is not.

In regard to sketching in colour, an important point, frequently forgotten by beginners, is that of the general tone. Whether they are studying a marine or a woodland subject, a snow scene or an autumn forest, they begin in the same manner, upon a white or greyish ground. It is well to do so in making a thorough study; but in sketching it is important to get the general tone and effect as quickly as possible. Many clever painters use coloured paper when sketching, which gives them some approximation to the tone. Blue-grey serves well on which to sketch a marine, all sea and clear sky; olive green for a wood scene; brown for a barn-yard. On these the sketcher may begin to work with a lighter tone first, as the old masters frequently did. The great French landscape painters did not often indulge in all the colours of the sunset or of autumn woods; but they seldom let slip an opportunity to note the effect of grey clouds and green woods, of the reddish brown of newly ploughed fields, and the tender blue and white of a spring sky, or the pale, ochreous colour of a muddy roadway contrasting with the grass along its edges. The more brilliant colours are more difficult to harmonize, and a slight error is more apt to be remarked.

Effects of shadow are often extremely picturesque and very interesting, but they do not last long enough for the uncertain draughtsman. Still he may find his troubles much lightened by proceeding as above, leaving the shadows to the last, and then dashing the colour into the middle of the shade and leading it out carefully to the edges. The edge of the shadow is what tells in a subject of this kind, and inexperienced sketchers frequently spend so much time in outlining it, that the shade has shifted before they can get their outline clone. By beginning with the lights, the position of the shadow is determined before anything is clone to it; and working from the middle out, it is much easier to arrive at the true edge so quickly that it will not have time to change. We say and feel that shadows are formless; but practically it is' the shadows that define the forms of objects seen in direct light. A clever draughtsman will sometimes indicate a whole scene by touching in the shadows only, but the amateur should work up to them from the lights, for if they are wrongly placed and badly drawn it is to little purpose that anything else in the drawing is right.

We come at last to sketches made for the sake of the special character of the scene. This depends on some peculiar arrangement of landscape forms, or rocks, hill-slopes, water-courses, woods, fields, and buildings.

As with colour, it is a natural gift to perceive characteristic forms or arrangements of form quickly and surely. But a great deal may here be done by training. Landscape painters almost invariably draw more or less from the figure, though they may never exhibit a figure subject. They find that the practice which they thus gain in rendering precise and well-known forms cultivates in them the sense of form and enables them to work much more surely after nature. Corot painted many figures, and Diaz for a time made his living by painting figure subjects. But it may not be possible for the reader to study from the model or from casts. In that case he can do no better than to make serious studies of still life, subjects of permanent forms and hues, which can be arranged in an unvarying light, and which will wait day after day to be painted. The habits of exact observation, of comparing forms, measuring proportions, and judging values, are applied almost unconsciously in sketching, yet make a very noticeable difference in the result.