THE PEOBLEM OF FLYING * 



By Otto Lilienthal. 



While tlieoretically no difficulty of any considerable importance pre- 

 cludes tlight, the problem can not be considered solved until the act of 

 flying- has been ac(*ora])lished by niau. In its application, liowever, 

 unforeseen difficulties arise of which the theorist can have no concep- 

 tion. 



The first obstacle to be overcome by the practical constructor is that 

 of stability. It is an old adage that '^ Wasser hatkehte Ballcen.''^ What 

 then, shall be said of air? 



Leaving- out of the question propelling mechanisms which re(jnire 

 more than ordinary refinements of construction, theory teaches that a 

 pro])erly constructed fiying apparatus may be brought to sail in a suffi- 

 ciently strong wind; while in still air, such a machine amy be made to 

 glide downward upon a slightly inclined path. In the practical ap])li- 

 catiou of these two methods, however, it is found that while the api)a- 

 ratus is supported by moving air, it is also subjected to the whims of 

 the wind, which often places it in uncomfortable positions, overturns 

 it, or carries it into higher regions and then precipitates it, headfore- 

 most, to the ground. Lowering- of the center of gravity is of little 

 avail, nor does the most ingenious change of the wings or the steering- 

 surfaces alter the case. There is still no trace of the majestic soaring 

 of the bird, for the wind is a treacherous fellow, who follows his own 

 inclinations and laughs at our art. Therefore let us try the second 

 method, the oblique descent in still air. 



According to computation the apparatus should descend at a small 

 angle, reaching the ground at a considerable distance, but this experi- 

 ment is a success only in short flights. Beyond these the apparatus 

 becomes unmanageable, darts vertically up, turns about, comes to a 

 full stop, stands on its head, and descends with uncomfortable rapidity 

 to the ground, the contact with which will probably have demolished 

 the machine, if it do not turn a lucky somersault and land upon its 



* Translated abstract of a paper from Frometheun, No. 205, 1893, vol. iv, pp. 709-774. 

 t Water lias uo rafters. 



189 



