The two kites just described may be modified in a number of ways as follows:--Two square kites side by side will give Fig. 69, and three side by side Fig. 70; these might be increased in both directions until a kite like Fig. 71 might be evolved. But there is no great gain and much hindrance in some of these complications. If there is insufficient room between upper and lower surface, not all of the surface is exposed and there is skin friction, again if there is not space enough between the fore and back cells, the front cuts off the air pressure to some extent on the back cells. So Fig. 72 is not high enough, while Fig. 73 has the fore and back cells too close together. Fig. 74 is very unstable in the air. [Illustration: FIGS. 69, 70, 71, 72, 73, 74.] [Illustration: FIGS. 75, 76, 77, 78, 79.] The triangular cross-section has the advantage of a bracing framework and is easy in combination. The bridle is attached to one of the long sticks and the kite rides on a keel, Fig. 75. Three braces about the middle of each cell keep the corner sticks out to place. These can be put in at the field, thus allowing the kite to be rolled for transportation. The triangular kite is sometimes lengthened so as to use three cells, Fig. 76, and again two kites are placed side by side, Fig. 77, and this may be increased by placing another below both, as in Fig. 78. In the last combination we have a large kite to the outside and a smaller one to the inside which can be lengthened so as to give three cells in length, Fig. 79, and many other combinations can be made. [Illustration: FIG. 80.] [Illustration: FIG. 81.] [Illustration: FIG. 82.] [Illustration: FIG. 83.]