The cylinder feels something like the sphere and something like the cube. Study by Touch and by Sight Put the models on the desk or table-experiment with each separately as to rest or motion. The sphere will roll. The sphere will stand. The cube will not roll; it will slide and will stand. The cylinder will roll, it will slide and will stand. The sphere will roll in every direction and however placed. The cylinder will not roll when it is upright; when it is lying down, it will roll, but not in all directions like the sphere. Examine each model as to dimensions-how do its different dimensions compare with each other? In the sphere, the width from left to right, the width from front to back, and the height are equal. In the cube, the width from left to right, the width from front to back, and the height are equal. In the upright cylinder, the width from left to right and the width from front to back are equal, but the height is greater than the width. For older children. After the children have passed the kindergarten age,. it is desirable to introduce new features and greater variety. The sphere and cube cannot be changed in proportion; but the cylinder may vary very much in the proportion of the height to the other two dimensions. By using a cylinder higher than wide, two new elements are introduced, that of proportion and that of greater beauty of form. The cylinder in which the height varies from the width is much more beautiful than the cylinder in which these dimensions are equal. It will be noticed that cylindric objects having the three dimensions equal are very rare; but that those objects in which the height is greater or less than the width are very frequent. Fig. 6 In considering the elements of proportion in the cylinder at this stage, it is desirable to choose a proportion easily appreciated. Therefore, the cylinder given for primary work has the very simplest proportion, that of 1 to 2. Build up the sphere, cube, and cylinder, and new revelations will be made concerning them. Try the arrangements illustrated and any others which may occur to you. What do you learn? Fig. 7 The sphere can have but one position. The cube and cylinder can have several positions. The sphere and the horizontal cylinder cannot be used as foundations in building. Study by Arrangement Try now to arrange the solids in rows; seek for pleasing arrangement. You will find yourselves, perhaps, working for an orderly and symmetrical arrangement, Fig. 8. Fig. 8 Study by Sight Hold each model up before you, Figs. 9 and 10; turn it in any way you please. How much of it do you see? The sphere cannot be held so that more than half can be seen; neither can it be held so that less than half is visible. The cube and cylinder cannot be held so that more than half can be seen*; but they can be held so that less than half can be seen. Figs. 11 and 12. *These statements need a little modification when very small models are used. 2, 3. Study as to Surface and Face Surface in its geometric signification means simply length and breadth without thickness. But Definitions. when applied to objects, it is used differently. The surface is the whole outside of a thing. A face is a limited part of a surface. Classification of surfaces. The ordinary and general classification of surfaces and faces is into two kinds, plane and curved. This is a broad classification; but for the purposes of Form-study, a more specific classification is necessary. Take the sphere in your hand; turn it over, you will find that it is round all over. If you apply a rule or any other straight edge to it, the rule will touch the sphere at but one point. And moreover this surface or face is continuous; turn the sphere as you will, you will find the surface unbroken by an edge. Such a urface or face is called round. Round and Looking over your solids you will find another resembling the sphere in part but having two faces; rounding. one of these faces is round in character as far as it goes, but it is not completely round and is limited by an edge. Such surfaces or faces, being in some ways like a sphere, are called rounding. A ruler applied to any one of them will touch at but one point. Do Fig. 13 Take now the cylinder; applying the ruler to its length, you find that the ruler touches the cylinder throughout its entire length. Turn the ruler and apply it across the same face and it touches at but one point. You will find also another solid among the twelve that has a similar face. Such faces, that are round one way and straight one way are called curved Now study the objects in the illustration, Fig. 15, with reference to the kinds of faces. Remember that all Form-study should be carried on from the typesolids to its application in objects. |