L. VEGARD. M.-N. Kl. 



The total electric charge Er inside the sphere is given by the equation; 



r 



Er ^= Eo + A :t \ O r^ d r 



\- 



where Eo is the total charge inside some arbitrary sphere with radius ro. 

 Then .• 



r 



F-=^ + ^\or^dr (2) 



We suppose that the usual relation between pressure and density of 

 a gas also holds in an electrified atmosphere, or that: 



M is the molecular weight and R the gas constant. 

 Combining equation (1), (2) and (3) we get: 



RT , 



M - 



o Eo Ana 



.Tøf , 



dr 



Puttinsf : 



RT 



M 



r 

 CI 1 d Ct O P 1 C 



^JL^ + I^i__£^_4,^ [of^dr (4) 



o d r o J 



Difterentiating with respect to r and remembering that q and o are functions 

 of r, the equation takes the form: 



1 d^ g L ^ ^ I (2l 4- A.\ _L ^L^ ^i?<^ö 2 g g ^TTrj 



o d )^ o^ dr d y \r a j o d r a o^ d r aar a 



The equation contains two unknown quantities g and o, and to solve 

 the problem one equation more should be required. 



This second relation depends on the way in which the atmosphere is 

 brought into its charged state. 



In the previous papers it was pointed out that the atmosphere might 

 be positively charged through the photo-electric effect produced by X- or 

 7-rays from the sun, but even if this was the only cause of the charged 

 state of the atmosphere we are not in possession of sufficient data to find the 

 charge given to the atmosphere in this way. 



