132 THE ROYAL SOCIETY OF CANADA 



Section IV. Notes on the Use of this Pitot Tube with Reference to 

 Gustiness. 



The use of such a Pitot Tube for the detection and 

 measurement of gustiness was demonstrated. The 

 relation between the mean gust velocity, the mean lull 

 velocity, and the mean velocity, was investigated for 

 velocities up to 20 mis/hr. Checks were made on the 

 methods by (1) watching the behaviour of a tethered 

 pilot balloon (2) by comparing with the record of a 

 Dines Microbaragraph and (3) by counting the suc- 

 cessive dark regions which were caused on the surface 

 of the water on a day when the gustiness was marked. 



Section V. The Use of the Hot-Wire Anemometer Under Open Air 

 Conditions. 



The linear Hot-Wire Anemometer as developed 

 by Dr. L. V.King, was tested under open air conditions 

 and appeared to be the most promising of anemo- 

 meters, from the standpoint of precision. The claims 

 of its designer seem fully to be justified. 



Section VI. The Kata-Thermometer Used as an Anemometer. 



The dry bulb Kata-Thermometer used as ^n 

 anemometer, gave very good results for velocities less 

 than 20 mis/hr. As it is an instrument with many 

 valuable uses, its additional application as an anemo- 

 meter was of special interest. 



