THE NATURAL LIMITS TO HUMAN FLIGHT 



By H. E. Wimpekis, C. B., C. B. E., D. Eng., F. R. Ae. S. 



[With one plate] 

 INTRODUCTORY 



The more I think about the subject chosen for this address, the 

 rasher does it seem. To proclaim limits to human flight is to do two 

 things. To say what can be done, and to suggest what cannot. 

 Now, though there may be little rashness in the one, there is much 

 in the other. If I say that such and such a thing can be done and 

 someone in the distant years points out that actually it has not been 

 done, my shade has the easy reply that achievement requires effort 

 and that my critics should use their brains. But if I suggest that 

 certain boundaries cannot be crossed, what fun for the coming race 

 of engineers who cross them (if they do), than to poke fun at the 

 memory of your lecturer to-night! 2 



It must be rash since wise men have diligently avoided such issues. 

 Can one think of any engineer who has endeavored to lay down for 

 all time, what is the height of the highest skyscraper than can be 

 built, or the longest bridge there can ever be thrown across a river, 

 or the fastest motor car that the world will see? Again, does any 

 ship builder dare specify a natural limit to the size of future ships 

 or to the power of the engines they will carry? 



Why in the field of aeronautics is this rashness found? It must, I 

 submit, either be because the subject is so well knit to its scientific 

 foundations that prophecy is tempting, or else, I tremble to say it, 

 that the impetuous youthfulness of aeronautics blows caution to the 

 winds. But if impetuosity be the key to the answer, I urge that by 

 assembling this row of aeronautical ninepins, I encourage the resource- 

 fulness of coming generations by providing them with the zest of 

 knocking them down. And that, I think, is worth doing. 



The globe on which we live is a nearly spherical ball 8,000 miles 

 across. Its highest mountain, like its deepest sea, is about 5 miles 



1 Presidential address delivered before The Royal Aeronautical Society on Monday, April 26, 1937. Re- 

 printed by permission from The Journal of the Royal Aeronautical Society, vol. 41, No. 324, December 1937. 

 • And when I use the word "flight," I mean flying with wings and not the flight of a projectile. 



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