I have grouped the model aeroplanes into four divisions, but before we proceed it will be well to notice the various classes of large machines. There is the monoplane or one plane type; the biplane or two planes, one above the other; and the multiplanes in which several planes are used. The first two have survived, and form the very large percentage of all that are attempted these days. I should like to make clear that I do not recommend, even discourage, any attempt at gliders large enough to carry the maker, and the aeroplane in which a motor engine is to be placed. There is too much danger connected with them, and our lives and limbs are too precious a gift to be trifled with in such unnecessary ventures. The little models, however, are harmless and yet are very fascinating, even when there is no thought of their embodiment in a large machine. =In group A=, where the worker seeks to imitate a large machine in miniature, the joy of the undertaking lies in the processes involving very accurate work and nicety of finish. There is a fascination for young people in the making of things in miniature. The models made in group A are usually larger than in group D, as the pieces of the framework need a little more material to work to advantage, while in D, the parts must be kept light. Weight is not so much of an item in group A. [Illustration: FIG. 207.] [Illustration: FIG. 208.] The photograph of the Curtis model, Fig. 207, has a clock spring works in it, but it is of no service. This is a very fine piece of work and has been admired by many. Outside of the clock works the model is all handmade. Little turn buckles for tightening the guy wires were made, as well as the little metal attachments to which the ends of the guy wires are attached. The silk covering was stretched and oiled on the frame. An equally well made model is shown in Fig. 208. In this monoplane all the curving of ribs and trussing of frame were very accurately done. It will be recognized that this is a very excellent piece of work and the outlines of the planes are very beautiful and well proportioned. The planes are supported at the outer ends by careful adjustment of wires above and below the wings. Notice the two little braces above the center of the framework to which the guy wires are attached. Turn-buckles are used on this model also. The horizontal and vertical planes to the rear of the model, but to the front in the picture, were ideas original with the maker, altho I have seen pictures similar to this since. Some make up these models in good shape for the purpose of using them as attractions in show windows. Merchants will sometimes give a rental for a good model. Very often when used as a display, an electric motor is installed in them so as to run the propellers.