284 



DISCOVERY 



that these experiments took place about the time 

 when the brothers \\'right were perilously edging 

 round corners on their first power-driven machine and 

 inquiring into the mystery of its tendency to side-slip 

 and " stall " while doing so. A further commentary 

 is afforded by the accident in September this year to 

 Herr Klempferer, one of the most successful present- 

 day exponents of gliding in Germany, who was released 

 in his glider from a kite-balloon at a height of 4,000 feet 

 and fell to the ground without gaining control of his 

 machine. 



In view of these amazing performances, which are 

 well authenticated, it seems extraordinary that one 

 has never seen a reference to Montgomery in any of 



spent in the air and distance covered are concerned, 

 is due to the advance that has been made in the 

 intervening years in the aerodynamic efficiency of 

 machines, combined with the increased skill of the 

 pilots. It must be remembered that the pioneers 

 were using gliders in the effort to teach themselves 

 the art of maintaining equilibrium in the air. The 

 present-day experimenter, on the other hand, comes 

 to the sport with all the accumulated experience of 

 many hundreds of hours spent in the air in aeroplanes, 

 and the resulting confidence, and knowledge of what 

 to do in an emergency. So far as concerns the 

 efficiency of machines, even down to the days of the 

 Wrights, little was known of the characteristics of 



IIG. 2.— A MODERN GERM.iN GLIDER. 

 Shoning the type of couutrj' suitable for gliiling. 



the numerous articles on gliding which have been 

 published recently. 



It is not proposed to deal here at any length with 

 the work of Wilbur and OrvUle Wright which eventu- 

 ally led to the successful development of the aeroplane 

 as we now know it, since a detailed account alreadv 

 exists in a readable and accessible form.' But readers 

 of Discovery may probably not be aware of the 

 fact that in 1911 Orville \\'right set up a world's 

 record for soaring by remaining in the air over the same 

 spot for 10 minutes i second, which possibly remains 

 unequalled as a demonstration of control by all the 

 long gliding and circling flights, up to three hours in 

 duration, made in Germany during August this year. 



The improvement in performance, so far as time 



1 The Life and Work of Wilbur Wright, published by the 

 Royal -Aeronautical Society, London. 



wing-forms or the amount of resistance offered by 

 different-shaped bodies. And yet these are points 

 of vital importance to the gliding angle of the machine, 

 which decides how many feet it will tra^■el forward 

 for each foot it drops towards the earth under the 

 influence of gravity. In the average aeroplane of 

 to-day this rate of descent, with engine cut-off, is in 

 the neighbourhood of i in 11, while some of the most 

 successful recent German gliders are said to have a 

 gliding angle of i in 16 in calm air compared with the 

 I in 6 of Lilienthal. In its simplest form gliding is 

 analogous to " coasting " on a bicycle down a steep 

 hill, the slope being provided in the case of the glider 

 by the passage of the air along the wings. In the 

 more complicated examples of gliding flight it is 

 important to remember this cardinal principle ; that 

 the machine is always gliding downwards through the 



