TETRAHEDBAL KITES. 



i35 



To 



t^' 



D. 



B. A Four-celled TetrahedralKite. 

 A Sixty-four-celled Tetrahedral Kite. 



wing-surface. The ratio of weight to surface, therefore, is the same for the larger liites as for the 

 smaller. In the middle of the kites there is an empty space, octahedral in form, which seems 

 to have the same function as the space between the two cells of the Hargrave box kite. The 

 tetrahedral kites that have the largest central spaces preserve their equilibrium best in the air. 



twelve sides, and cells of various other shapes were devised, tried and 

 thrown away. 



Finally the triangular cell was hit upon. It immediately proved 

 an immense advance over the rectangular Hargrave, being stronger 



