178 



NATURE 



[December 20. 1894 



flapping their wings ; and second, to apply to his 

 apparatus such dynamical means that will enable 

 him, when sailing in a calm atmosphere, to prolong his 

 flights. 

 To carr\- out these experiments he has thrown up, in 



Fig. 



the neighbourhood of Berlin, a large conical mound, 

 fifteen metres in height ; this mound he uses as a 

 starting-point for his flights. In Fig. i the operator 

 is shown just commencing one of these flights. 



sails off until he alights again on the earth. Fig. 2 

 shows him just about to alight. It will be noticed that 

 to come down easily and softly, he puts on the brake by 

 offering to the air a greater expanse of wing, whereby 

 his velocity is at once reduced. 



Ry experience Herr Lilienthal has found that although 

 in quiet weather he can manipulate his craft very easily, 

 in windy weather the operator has to be more careful. 

 The investigations in this direction have, however, been 

 satisfactorily made, and he can now by an adroit move- 

 ment of his body and that of the apparatus sustain his 

 equilibrium, and sail successfully. 



In his article on this subject [Piomcllicus, No. 261, 

 p. 7), from which these references to his new experi- 

 ments have been taken, he states that sometimes, when 

 a strong wind was blowing, he has been surprised by 

 sudden gusts, which, before he had time to make the 

 necessary movements to sustain his equilibrium, had 

 carried him high up in such a manner as to often take 

 his breath away. 



Fig. 3 illustrates the operator receiving such a sudden 

 shock ; it will be seen at once that to jcontend with 

 these new conditions he has had to bring his sail up to 

 the direction of the blast, and to meet it if possible, 

 while at the saine time he has altered his whole centre 

 of gravity by a movement of the lower part of his body. 



Such movements as these cannot yet be made quite 

 instantaneously, owing to lack of experience ; but, as he 

 justly remarks, with more practice he will no doubt be 

 able to make them instinctively, just as the bicycle- 

 rider does. 



To attain his second object, that is, to employ some 

 mechanical aid to help him to sustain himself for 

 longer intervals of time in the air, he has constructed a 



m^. 



yT' 





Fig, 4. 



With a tight grip of the framework with his hands, 

 he runs quickly down the slope until he has attained a 

 sufficient velocity to raise him and his apparatus off the 

 ground. When such conditions have been obtained, he 



NO. I312, VOL. 51] 



new apparatus, somewhat, but not quite, similar to that 

 up till now used. .\ good idea of this can be obtained 

 from the accompanying illustration (Fig. 4). 



A comparison of this /lying machine with the sailing 



