A new form of kite was invented a few years ago by Mr. Hargrave, an Australian inventor, who is devising a flying-machine. A picture of a Hargrave kite floating in the air, taken from a photograph made by Mr. Alexander McAdie, is shown in the illustration. In this kite the wind acts on a number of thin strips rather than on a single broad surface, and at the same time it gets steadiness of flight by putting the planes in pairs in two directions, and adding side planes. The general principles to be remembered are to have the width of the kite five-sixths of its length, the width of the cells a little less than a third of the length of the kite, and the depth of the cells the same as their width. The description of Hargrave's improved kite appeared in 1895. Since then numerous forms having something of his principle have been invented. The most interesting are Lamson's multiplane and schooner kites, Potter's diamond kite, and Hammon's hemispherical kite, all shown in the illustrations. No tails are used with any of these kites.
Mr. Hargrave's kite is complex, and not easy to build. Simpler forms of the frame have been used at Blue Hill, but probably the simplest and best frame is that devised by Mr. S. C. Keith, Jun., and described here for the benefit of those boys who may wish to try one.
The cells have the same shape and appearance as Hargrave's kite, shown in the picture, but the frame is different.
Fig. 6 is a plan of the kite; Fig. 7 is a side view; and Fig. 8 an end view. In Figs. 6 and 7 the stick M N is 66 inches long, and has a cross-section of ½ by 3/8 of an inch. At C D and A B are cross-sticks, two at each place. An end view, at A B, is shown in Fig. 8. The cross-sticks A F and B E are 33 inches long, and 3/8 inch square, or even smaller. Small screw-eyes like those used in hanging pictures are screwed into the ends of each stick. Pass a strong wire or cord—steel piano-wire is best—through the screw-eyes at A B E and F (Fig. 8), and fasten it firmly at the corners by a cord, or otherwise, making A E and B F 14 inches, and A B and E F about 30 inches. Next pass a wire from M through the screw-eyes at C and A to N (Fig. 6), and then on through F and G (Fig. 7) to M again, and fasten it. Pass a similar wire on the opposite side of the kite from M through D B N, etc., to M, and fasten it. These wires, and also the wire around A B E and F (Fig. 8), should be light. It is best to have turn-buckles at some point in each wire, so that it can be tightened after it is in place. Since the sticks at A E F B and C D G are liable to slip along the wire, it is necessary to hold them by stays tied to M and N. The cells are made of cloth (nainsook being the best). After the cloth is folded over at the edges, and hemmed or pasted, it is in two strips, each 14 inches wide and 90 inches long, so that the strips will pass entirely around the kite-frame and form two cells, D P and R B (Fig. 7). The distances from the line B F to N, and from the line D G to M, is 9 inches, and the distance P to R is 20 inches. The cloth, after being fastened around the kites, should be tight and smooth. This can be obtained best by putting lacing-strings in the edges, and making the cloth 3 or 4 inches shorter than the measure given above—say 86 inches. The cloth should then be fastened to the corners of the sticks, and also to the wire which passes around the kite at C D and A B. Next, the edges of the two cells should be laced together all around by cords running across from one to the other, as shown by the dotted lines in Fig. 6. To fly the kite, tie a strong cord at M, and also at the other end, where M N joins the cross-sticks which run from B and F. (See the broken line in Fig. 7) Tie a ring or a loop-knot at O at the rear edge of the cell D P (Fig. 7). Or the hanger may be tied at M, and brought down under the cell D P. In that case the ring O should come farther forward. It also insures steadiness to run two strings from O, one to F, and the other to E. The kite-string is tied in O.
The best material for the construction of a kite is straight-grained spruce. The best covering is bond paper, nainsook, or silk.