250 The National Geographic Magazine 



three of its five faces covered. The 

 open spaces between the cells are tetra- 

 hedral in form. 



4. Kite shown in No. 3 flying with 

 its rectangular side up. 



5. Kite shown in No. 3 flying with 

 its rectangular side down. 



6. Kite shown in No. 3 with the 

 covering removed from the two mid- 

 dle pentahedral cells — rectangular side 

 down. 



7. Same kite shown in No. 6 flying 

 with the rectangular side up. In this 

 picture the short white line in the margin 

 of the photograph indicates the direction 

 of the flying cord. 



Plate XI. — Experiments to determine 

 the relation of center of gravity to cen- 

 ter of surface in a flying structure by 

 shifting the cellular superstructure to 

 different parts of the body frame. 



1 . Superstructure over first body cell ; 

 center of gravity too far back. 



2. Superstructure over second body 

 cell. 



3. Superstructure over third body 

 cell. 



4. Superstructure over fourth body 

 cell ; center of gravity too far forward ; 

 kite dived, superstructure smashed. 



Plate XII. — Experiments with kites 

 having two sets of cells in the super- 

 structure : 



1. Superstructure over second and 

 fourth body cells. 



2. Just rising in the air. 



3. Flying by cord attached to front 

 of first body cell. 



4. Bringing the kite down while 

 anchored by a bow-line. 



5. Superstructure over first and fifth 

 body cells. Flying line attached to 

 front of first body cell. The apparent 

 smallness of the kite shows that it is 

 at a considerable elevation in the air. 



6. Kite being landed from a distance. 

 Allowed to fall on a slack line, but 

 checked momentarily as it nears the 

 ground to reduce the rate of fall. 

 Again allowed to fall and the cord 



reeled in so as to give the kite headway 

 at the moment of contact with the 

 ground, thus causing the stern to strike 

 only a glancing blow. A bow- line, how- 

 ever, is a great safeguard against injury. 

 Plate XIIJ. — The photographs illus- 

 trate the nature of experiments made 

 to test the effect of varying the number 

 and position of sets of triangular cells 

 upon a body framework : 



1. Two sets of cells near bow, and 

 one stern set as a tail. 



2. Kite shown in No. 1 at a great 

 elevation in the air. 



3. Same kite shown in No. 1 with the 

 stern set of cells removed. The photo- 

 graph shows very clearly the bow-line 

 used to facilitate the handling of kites 

 in the air. Flying by the bow-line re- 

 duces enormously the strain upon the 

 structure when the kite first begins to 

 rise in the air. This strain gradually 

 eases off as the kite rises, and when it 

 is at a considerable elevation the bow- 

 line is made slack while the kite is held 

 by the other, or "flying-cord," which 

 in this case is attached to the rear edge 

 of the first set of cells, when the kite 

 rises still higher. The bow-line is 

 again used in bringing the kite down, 

 for the body then becomes practically- 

 horizontal as it nears the ground. 

 This is advantageous, for it reduces the 

 risk of injury to the kite upon landing. 

 In good flying kites anchored by the 

 bow the bow-line can be overrun by 

 the hand, or by a grooved roller, until 

 the kite is reached and grasped by the 

 hand without allowing the kite to touch 

 the ground at all. 



5. Same kite shown in No. 3, but the 

 sets of cells separated as far as possible 

 upon the body. 



6. Kite shown in No. 5 nearing the 

 ground after an experiment. It is 

 flying by the bow-line, and the photo- 

 graph shows the other line blown back 

 by the wind, or perhaps held in the 

 hands of an assistant. 



4. A kite with eight sets of cells. 



