Wilson- Gerdien Theory of Thunderstorm Electricity. 6 ID 



Equation (33) like the more exact form (32) has to be solved 

 by trial and error. 



The final results are given in the first four columns of the 

 following table, the last four columns are from Prof. Callendar's- 

 paper : — 





Our re 



suits. 





Prof. Callendar's re 



suits. 



Concentration in 

 grams per litre. 



Diff. 



per cent. 



Concentration in 

 grams per litre. 



Diff. 





At bottom. 



At top. 



At top. At bottom. 



per cent 



750-6 



676-7 



73-9 



9-85 



760* 900 



140 



184 



660-5 



598-6 



61-9 



9 06 



660 741 



81 



123 



5404 



4909 



49-5 



9-16 



510 600 



60 



111 



420-3 



385-2 



35-1 



8-35 



420 460 



40 



95 



3002 



2789 



21-3 



7-10 



300 32.') 



25 



8-3 



180-1 



1700 



101 



5-61 



180 193 



13 



7-3 



* It is probable that this number is copied from a misprint in Lord 

 Berkeley's paper on van cler Waals' equation (Proc. Roy. Soc. Series A, 

 vol. lxxix. p. 126). 



Prof. Callendar deduces from his results that if the numbers 

 in the last column appear to indicate a systematic error in 

 the experimental numbers for strong solutions/'' On com- 

 paring the two sets of figures it will be seeu that those 

 calculated from the more accurate formula do not bear out 

 Prof. Callendar's deduction. 



H 



LV. On the WiUon-Gerdien Theory of Thunderstorm 

 Electricity. By George .. Simpson, D.Sc, Meteorological 



Department, Government of India*. 



rN 1900 Mr. C. T. P. Wilson put forward a theory to 

 account for the electrical phenomena connected with 

 thunderstorms based on his well-known experiments on the 

 condensation of water vapour from supersaturated air upon 

 negative ions. Judoino- from a number of references to this 

 theory in recent articles in scientific journals it would appear- 

 that it has obtained considerable acceptance, both in England 

 and on the continent. It therefore appeared to me desirable 

 that the theory should be subjected to a critical examination, 

 and I propose in this paper to undertake such an examination 



* Communicated by the Author 



