August 14, 1003.] 



SCIENCE. 



205 



that Professor Alexander Graham Bell has 

 joined the band of experimenters and is 

 lending his inventive genius to the cause. 

 Professor Bell has been for several years 

 experimenting Avith kites, led to this line 

 of experiments, he thinks, because of the 

 intimate connection of the subject with the 

 problem of the flying machine.* Professor 

 Bell began his experiments with the box- 

 kite of Hargrave, whom he recognizes as the 

 pioneer in modern kite-construction. His 

 objections to the box-kite are that, "It re- 

 quires additions to the framework of va- 



even if made of the finest wire, so as to 

 Ije insignificant in weight, all comes in the 

 way of the wind, increasing the head- 

 resistance without counterbalancing ad- 

 vantages. ' ' 



These remarks of Professor Bell con- 

 cerning guys, etc., do not apply to the orig- 

 inal Hargrave kites which have no guys, 

 but only to a style of Hargrave kite in- 

 vented and patented by me. This style 

 is the one which has come into universal 

 use under the name of the Hargrave kite, 

 and is the one with which Professor Bell 



rious sorts to give it sufficient strength to 

 hold the aeroplane surfaces in their proper 

 relations and prevent distortions of the 

 kit<3-frame under the action of the wind. 

 Unfortunately the additions required to 

 give rigidity to the framework all detract 

 from the efficiency of the kite: first, by 

 rendering the kite hea\aer, so that the 

 ratio of weight to surface is increased ; and, 

 secondly, by increasing the head-resistance 

 of the kite. A rectangular cell like A 

 (Fig. l)f is strueturallj'' weak, as can 

 readily be demonstrated by the little force 

 required to distort it into the form shown 

 at B. In order to remedy this weakness, 

 internal bracing is advisable of the char- 

 acter shown at C. This internal bracing, 



* His experiments are described in a communi- 

 cation made to the National Academy of Sciences, 

 in Washington, D. C, April 23, 1903. Also 

 Xalional Geographical Magazine for June, 1903. 



t The numbers of the figures differ from the 

 original because many of the figures are omitted 

 here. 



began his experiments rather than with the 

 original Hargrave structure, few of which 

 have been made. 



Continuing, Professor Bell says: "In 

 looking back over the line of experiments 

 in my own laboratory I recognize that the 

 adoption of a triangular cell was a step in 

 advance, constituting indeed one of the 

 milestones of progress, one of the points 

 that stand out clearly against the hazy 

 background of multitudinous details. The 

 following (Pig. 2) is a drawing of a typ- 

 ical, triangular-celled kite, made upon the 

 same model as the Hargrave box kite. 

 * * * A triangle is by its very structure 

 perfectly braced in its own plane, and in 

 a triangular-celled kite, like that shown in 

 Fig. 2, internal bracing of any kind is 

 unnecessary to prevent distortion of a 

 kind analogous to that referred to above in 

 the case of the Hargrave rectangular cell 

 (Fig. 1). The lifting power of such a 

 triangular cell is probably less than that 



