NO. 4 



PIONEER WIND TUNNELS RANDERS-PEHRSON 



for his " aerial steamer ", the first large power-driven airplane model 

 to rise from the ground in tethered flight/ 



Twenty-five years later Wenham expressed the wish that he might 

 have an opportunity to build a large tunnel that would convey a current 

 " at rates varying from a gentle breese, up to a tornado that could rip 

 the clothes off your back, or blow you away like a feather, but no 

 flying man should mind this effect." In 1900, at the age of yd, he 

 actually rigged up a fan blower for experiments ; it ran at 1,700 revolu- 

 tions per minute and gave a current of 25 miles per hour. Apparently 

 it was driven by hand, as he says : ^ 



I could not get beyond this as it absorbed all my strength to work it, still 

 the current was definite and steady with proper arrangement to measure lift 

 and drift [i. e., drag]. I attached various models in the blast, consisting of 

 different forms of supporting surfaces. 25 miles an hour would be a sufficient 

 speed to begin to fly with. 



HORATIO PHILLIPS 



Next to use a wind tunnel was another Englishman, Horatio 

 Phillips. He produced his air current by means of a steam jet, hoping 

 in that way to avoid the fluctuations of the wind which had marred 

 Wenham's experiments. 



Sbaion nn lim A.S 



Phillips' tunnel was 17 inches square and 6 feet long. Attached to 

 one end was " an expanding delivery tube of sheet-iron ", which was 

 6 feet long, 12 inches wide where it entered the box, contracting to 

 8 inches, and again expanding to 2 feet. In its narrowest part was 

 introduced a ring of iron pipe pierced with holes, through which steam 

 was fed from a large boiler under 70 pounds pressure. This produced 

 by suction an air current in the square part of the tunnel. In order to 

 increase the speed of the current, the square box was partly closed by a 



^Aeronautical Society of Great Britain, 6th Ann. Rep., pp. 75-78, 1871 ; 

 7th Ann. Rep., pp. 6-12, 1872; 9th Ann. Rep., pp. 6-7, 1874. 



^ Unpubhshed letters from F. H. Wenham to Octave Chanute, now in the 

 Library of Congress. 



