82 Prof. L. Vegard : Results of JSforthlight Investigations 

 Now we further have the condition that the quantity 



mv __ M v_ 

 "E ~" N"«« 



must be smaller than a quantity a which gives 



Nena 



v< -it 



v < 10^- 



This gives for the range 



x < 10~ 15 ^a 3 cm. 



We see that for a given value of a the range of the ray is 

 proportional to its charge and inversely proportional to the 

 square of the mass. Putting a = 2*5 . 10 4 , we get 



fi 



x < 1*56 . 10" 2 . =|p cm. 



The quantity to the right gives us the maximum ranges of 

 these rays which are consistent with our view with regard to 

 the distribution of luminosity, and which are able to produce 

 the very narrow streamers. Probably the above value of a 



is too large. Putting a=10 4 , we find ^=10~ 3 -^p cm. 



The greatest penetrating power we should get for hydrogen 

 atoms for which both M and n are =1, and which for 

 <2 = 2'5.10 4 and v = 2'5.10 8 give a range in nitrogen of 

 - 16 mm., which is indeed a quantity of nearly the same 

 order of magnitude as that earlier given from the estimates 

 of Glinime and Pausch von Traubenberg ; but remembering 

 that the range in nitrogen at atmospheric pressure is nearly 

 equal to the air equivalent, we see from fig. 7 and Table X. 

 that if H 2 and He were not present, and with the distribution 

 of N 2 in the atmosphere given by Wegener, even a hydrogen 

 ray which has the proper magnetic deflectibility could only 

 get down to a height of about 118 km., and an a-particle 

 that moves in accordance with the above conditions cannot 

 have a penetrating power greater than that responding to 

 the air equivalent found at the height of 130 km. A Ca-atom 



