To a great extent, one may show in an outline drawing the character and texture of surfaces. Our main object should be to train the boys and girls to observe in order to acquire a correctness of perception, for "education amongst us consists too much in telling, not enough in training." [Illustration: _Fig. 211. The American Elm, one of the most typical of vase-form trees._] One of the greatest difficulties is to impress upon the minds of beginners the fact that they must think while they look and draw. Insist upon the pupil's looking repeatedly at the object. It is better to observe for five minutes and draw for one, than to observe for one and draw for five. Make the drawing lesson more interesting by telling the class something about the object which they are to draw, involving in the story facts that will impress upon their minds some of the most salient characteristics of the object. Encourage the children to discuss the object, drawing out facts for their own observation. Certain kinds of trees, like certain races of people, have a general similarity, yet every single tree has an individuality of its own. Apply a few essential questions that will help to determine at least the kind of tree it is, the race to which it belongs; for first we must get its general character, seeing its big proportions and shape; and later must search for its individualities. Is it tall for its greatest width? How far does the trunk extend before dividing? At what height do the lowest branches arise? What is their general direction? Do they appear to radiate from the trunk? How do they appear to radiate from the trunk? How do the main branches compare in size with the trunk? Are they crooked or straight? The manner of branch growth must be studied carefully. We see in our elm (Fig. 211) that the trunk divides at about a fourth of its height into several main branches, while in the case of the pepperidge (Fig. 207) the trunk extends to the very top of the tree, the branches being small in proportion to the trunk, not varying much in size, and taking an oblique downward direction. Notice the weird expression of these trees with their crookedly bent tops, one side of each trunk being almost devoid of branches. The trunk of the sassafras (Fig. 208) continues nearly to the top of this tree, while the large branches, though unsymmetrical, give it a well-balanced appearance. Again in our picture of the thorn-apple (Fig. 209), we are at once impressed with its irregular form, the branches on the left taking a more oblique direction than those of the other side, the trunk dividing a little short of half the height of the tree. For an example, let our subject be an elm tree (Fig. 211); our drawing to be rendered in outline. [Illustration: _Fig. 212. Blocking-in the elm tree (Fig. 211). The first work which the artist does when he draws the tree._]