=A biplane= is shown in Fig. 211, one with bowed cross-pieces in Fig. 212, and one with bent up tips on the upper plane in Fig. 213. The folded paper glider made by the children soars excellently; try an aeroplane kite on that plan, Fig. 214. Another modification of Fig. 214 is the bird aeroplane kite, Fig. 215. In this a plane is placed about half way from front to back. The ends of the wings get their curve from the back stick, a piece of heavy reed, and the outline of the bird is also of reed. By drawing the shape on a board the reed can be bent to the shape. The reed should be wet and tacks should be driven at each side to keep the shape until dry. This kite, if well made, should glide for a very long distance. It would take too much space to go into details with each design, but the drawings I think will be sufficient for most readers who may be planning these models, especially where framework and finished kite are both given. CHAPTER XIV. GLIDERS. =In group C= is to be found the most profitable source of study for the self-propelling model aeroplane. The glider has no motor and no propeller, but is made on the plan of the motored model in the construction and adjustments. The glider is usually made smaller at first, increasing the size to the actual model later. The glider is more useful for study, if it is made heavier in comparison with the motored model. The glider can be thrown by the hand as if it were a spear, Fig. 216, or it can be thrown by a rubber cord, Fig. 217, or by a springy stick, Fig. 218. [Illustration: FIG. 216.] All experiments except those intended for adverse conditions, should be made either indoors where there is no wind, or away from buildings far enough to be out of reach of the whirls that are always present near buildings. Heavy paper can be used for planes in some of the experimenting, and even much may be learned by the use of paper models thruout the whole construction, but a little stiffening with small thin strips as reinforcement is better in most cases. [Illustration: FIG. 217.]