300 



NA TURE 



[January 30, 1896 



LILIENTHALS EXPERIMENTS ON FLYING. 



T^HERE are many of us, no doubt, who are watching 



-*■ with great interest the experiments of Herr Otto 



LiHenthal in his " Fliegesport and Fliegepraxis." These 



' Uebungen," which he is making from a hill thrown up 

 in the neighbourhood of Berlin, have, from the very 

 beginning, been rewarded with a distinct success ; and it 

 seems that, given time, he may present us, if not with a 

 method of flying, then with an approximation to it, 

 which perhaps at some later date may be more fully 

 developed. 



His experiments have, up to the present, shown that, 

 by means of such an apparatus as he employs, fairly 

 long flights may be indulged in with perfect safety, 

 provided the operator does not attempt to do too much 



at the beginning, but contents himself with mastering the 

 first elements of sustaining his equilibrium. 



In a previous article (Nature, vol. li. p. 177), a short 

 account was given of Herr Lilienthal's earlier experiments 



NO. 1370, VOL. 53 



on this subject, and it was then mentioned that falls must 

 be expected in the preliminary trials, until the operator 

 becomes accustomed to the many new conditions which 

 make themselves apparent at every step, before they can 

 be mastered instinctively. 



Similar difficulties have, for instance, 

 to be contended with when learning 

 to ride a bicycle. The beginner is 

 at first unable to keep his equili- 

 brium, and so wobbles here and 

 there with the loss of much power, 

 until he eventually finds himself on the 

 ground. This is simply because he is 

 doing something unusual, and is not 

 accustomed to the new conditions. 

 An adept rider, on the other hand, 

 never thinks of the possibility of fall- 

 ing, and quite unconsciously keeps his 

 equilibrium without any exertion or loss 

 of power on his part. So it is with this 

 sailing machine, and it is only with 

 practice that the required head can be 

 obtained and success assured. 



In the above-mentioned article, the 

 machine Lilienthal employed consisted 

 of a wing-shaped framework of a slightly 

 curved nature, the advantage of the 

 curved form, both as regards the amount 

 and direction of the resistance, having 

 been previously proved. The tail con- 

 sisted also of two plane surfaces, one 

 being at right angles to that of the 

 horizontal framework, and lying in the direction of 

 movement, and the other more generally in that 

 horizontal plane, but capable of movement about a 

 fixed point in it. 



With the wind blowing at a moderate and more or 

 less constant rate this machine has been found to be 

 very satisfactory, and flights of comparatively long 

 duration have been made with it. 



Lilienthal's ambition, however {Prometheus, No. 322, 

 p. 148), does not end here ; but he looks further ahead 

 than this, and wishes to be able to practise in such strong 

 winds that he can be carried along with 

 them. He, however, remarks that the 

 size of the apparatus puts a certain 

 limit to this ; for if the spread of the 

 wings be too large, then the whole 

 arrangement becomes extremely awk- 

 ward and hard to manage. 



Up to the present, although he has 

 practised in moderately rough weather, 

 and had to perform fantastic feats in 

 the air to keep his equilibrium, he has 

 been fortunate in obtaining on nearly 

 every occasion a safe landing. Experi- 

 ence has, however, convinced him that 

 before trying to compete against strong 

 winds in future, he must modify his 

 machine to some extent, in order to 

 make it easier to handle under these 

 more trying circumstances. 



To this end experiments were made 



with wings of various shapes ; but these 



were given up, as it was found that the 



employment of a new principle, suddenly 



discovered, gave the required results 



with satisfaction that was scarcely 



dreamt of. The idea consisted in using, 



instead of one large framework covered 



with some light material, two smaller ones, placed parallel 



one above the other. These, of course, would, when 



sailing through the air, have a similar lifting effect ; but, 



besides affording a simple means of increasing the sail- 



