PIONEER WIND TUNNELS 



By N. H. RANDERS-PEHRSON 

 Assistant, Division of Aeronautics, Library of Congress 



(With 4 Plates) 



In a paper read before the Royal Society in 1759 John Smeaton 

 presented the following very neat outline of the various methods that 

 may be used for aerodynamic research : ^ 



In trying experiments on wind mill sails, the wind itself is too uncertain 

 to answer the purpose ; we must have recourse to an artificial wind. This 

 may be done two ways ; either by causing the air to move against the machine, 

 or the machine to move against the air. To cause the air to move against the 

 machine, in a sufficient volume, with steadiness and the requisite velocity, is 

 not easily put in practice : To carry the machine forward in a right line 

 against the air, would require a larger room than I could conveniently meet 

 with. What I found most practicable, therefore, was to carry the axis, whereon 

 the sails were to be fixed, progressively round in the circumference of a large 

 circle. 



Technical difificulties prevented Smeaton from using a wind tunnel 

 and prompted him to adopt the whirling machine, invented in 1746 

 by Ellicott and Robins. This and other inferior methods of research 

 were in use long after wind tunnels had been constructed and found 

 satisfactory. Thus, Eiffel spent much time dropping plates from the 

 tower bearing his name before adopting the wind-tunnel method ; 

 Langley and others used whirling machines, while many used natural 

 wind, which Smeaton had already found to be unreliable. 



F. H. WENHAM 



The distinction of being the first to introduce the wind tunnel be- 

 longs to Francis Herbert Wenham, founder member of the Aero- 

 nautical Society of Great Britain, who read at its opening meeting 

 his classical paper on " Aerial Locomotion ". In 1871 this Society 

 desired to undertake systematic aerodynamic experiments to obtain 

 " data on which a true science of aeronautics can be founded ". A 

 subscription fund was established ; an instrument designed by Wenham 



^ Smeaton, John, Experimental enquiry concerning the natural powers of 

 wind and water, p. 38, London, 1794. 



Smithsonian Miscellaneous Collections, Vol. 93, No. 4 



