[PATTERSON] 



CANADIAN STANDARD ANEMOMETER 



93 



given mean velocity of the wind, excluding thunderstorm squalls. 

 The results were smoothed in the same way as before by taking the 

 mean of three successive readings as the value for the middle reading. 

 The pressure tube anemometer readings were not corrected at first to 

 true readings, but the final results were all corrected. On subtracting 

 the mean maximum velocity from the highest maximum velocity the 

 results given in the column "A-B" were obtained, and from them it 

 would appear as if this difference was fairly constant above 25 miles 

 per hour and equal to about 1 1 . Using the curve 



Vg = 3 + l-26 Vm 

 for the most probable gust velocity it would give 



Vg=14+l-26Vm (3) 



as the possible extreme gust velocity that might be recorded for mean 

 velocities above 25 miles per hour, or if one assumes that the differ- 

 ence is not constant, the equation takes the form 



Vg = 3 + l-64Vm (4) 



This result gives higher values of Vg than equation (3). The Equa- 

 tions (3) and (4) are plotted in Fig. 4. There are unfortunately not 

 enough observations on mean velocities above 30 miles an hour 

 available to determine with accuracy the correct form of the equation. 



Table VII 



