214' 



AERONAUTICS. 



The model was forced by its propellers along a wire at a 

 great speed, but, so far as I could determine from observa- 

 tion, failed to lift itself notwithstanding its extreme lightness 

 and the comjtaratively very great power employed 



The idea embodied by Henson, Wenham, and Stringfellow 

 is plainly that of a boy's kite sailing upon the wind. 'The 

 kite, however, is a more perfect flying apparatus than that 

 furnished by Henson, Wenham, and Stringfellow, inasmuch 

 as the inclined plane formed by its body strikes the air at 

 various angles — ^the angles varying according to the length of 

 string, strength of breeze, length and weight of tail, etc. 

 Henson's, Wenham's, and Stringfellow's methods, although 

 carefully tried, have hitherto failed. The objections are 

 numerous. In the first place, the supporting planes (aero- 

 planes or otherwise) are not flexible and elastic as wings 

 are, but rigid. This is a point to which I wish particularly 

 to direct attention. Second, They strike the air at a given 

 angle. Here, again, there is a departure from nature. Third, 

 A machine so constructed must be precipitated from a height 

 or driven along the surface of the land or water at a high 

 speed to supply it with initial velocity. Fourth, It is un- 

 fitted for flying with the wind unless its speed greatly exceeds 

 that of the wind. Fifth, It is unfitted for flying across 

 the wind because of the surface exposed. Sixth, The sus- 

 taining surfaces are comparatively very large. They are, 

 moreover, passive or dead surfaces, i.e. they have no power 

 of moving or accommodating themselves to altered circum- 

 stances. Natural wings, on the contrary, present small flying 

 surfaces, the great speed at. which wings are propelled con- 

 verting the space through which they are driven into what 

 is practically a solid basis of support, as explained at pp. 1 1 8, 

 119, 151, and 152 {vide figs. 64, 65, 66, 82, and 83, pp. 139 

 and 158). This arrangement enables natural wings to seize 

 and utilize the air, and renders them superior to adventitious 

 currents. Natural wings work up the air in which they move, 

 but unless the flying animal desires it, they are scarcely, if at 

 all, influenced by winds or currents which are not of their 

 own forming. In this respect they entirely difler from the 



^ Mr. Stringfellow stated that his machine occasionally left the wire, and 

 was sustained by its superimposed planes alone. 



