THE CELLULAR KITE.—Following out the suggestion of the Hargreaves kite, numerous forms embodying the principle of the box structure were made and put on the market before the aeroplane became a reality.
Fig. 42. Cellular Kite.
A structure of this form is illustrated in Fig. 42. Each box, as A, B, has therein a plurality of vertical and horizontal partitions, so that a number of cells are provided, the two cell-like boxes being held apart by a bar C, axially arranged.
This type is remarkably stable, due to the small cells, and kites of this kind are largely used for making scientific experiments.
THE TETRAHEDRAL KITE.—Prof. Bell, inventor of the telephone, gave a great deal of study to kites, which resulted in the tetrahedral formation, as shown in Fig. 43.
Fig. 43. Tetrahedral Kite.
The structure, apparently, is somewhat complicated, but an examination of a single pair of blades, as shown at A, shows that it is built up of triangularly-formed pieces, and that the openings between the pieces are equal to the latter, thereby providing a form of kite which possesses equilibrium to a great degree.
It has never been tried with power, and it is doubtful whether it would be successful as a sustaining surface for flying machines, for the same reasons that caused failure with the box-like formation of the Voison Machine.
THE DELTOID.—The deltoid is the simplest, and the most easily constructed of all the kites. It is usually made from stiff cardboard, A-shaped in outline, as shown in Figs. 44 and 45, and bent along a central line, as at A, forming two wings, each of which is a right-angled triangle.
Fig. 44. and 45. Deltoid Formation.