IMoCliclland and Kennedy — The Lnrcjelons in the Ahnosphere. 77 



satnration can be reached with moderate voltages, the current obtained from 

 voltages far away from saturation will be too small for accurate measurement. 

 Further, it is desirable to make observations as rapidly as possible on 

 account of the variable nature of the atmospheric ionisation. The method of 

 procedure,, therefore, was to make a separate examination of the part of the 

 curve remote from saturation, using an air-blast consideraloly greater than 

 that used when it is desirable to obtain saturation. Fig. 4 shows this portion 

 Average\<dociiy of MrBlast "=16-7 Cmsji&rSto. 



9D 



.•S 8D 

 fO 7D 



•■y 50 



K 3D 

















































































_--- 















""^ 













^^.^-^ 



'^ 











>-- 



--"^ 











^,0 





^^^-^ 



■^ 













-^ 

















YoZts 

 Fio. 5. 



of the curve. Here the value of (? was such that the curve includes a range of 



voltages that would saturate ions of mobilities varying from -J^ to j-^ cm./ see. 



Ai/u'cui&Vtlociiy of Air Blast = 53-5 Cms per Sec 



^ 7D 

 S GO 























































^ 















^^ 



.^--^ 

















^ 

















-^ 















^^^-^ 

































^---^ 

















-^"^ 



















a 1 



lO 3 



00 4 



50 G 



DO 7 



9 



a 10 



so 1 



00 



There is no evidence of any bend in this portion. Again, the curve (tig. (5) gives 

 the relation between voltage and current for a range of voltages that would 

 saturate ions of mobilities ranging from jJ-u tOy^Vo cm./sec, and(fig. 6) the 



