﻿218 



Mr. L. Yegard on the Properties of 



claim great accuracy, but we shall use Wegener's numbers 

 as probably being of the right order of magnitude. 



The relation between velocity and height is calculated for 

 the following two cases : — 



1. The matter traversed is air, velocity Y«. 



2' „ „ hydrogen, velocity Y H . 



The results are given in the following table : — 



Table I. 



h. 



V H . 



km. 



500 



300 



200 



100 



60 



20 







mm. 





cm . 'sec. 





cm. /sec. 



0-00162 



0-62 V 



1-24X10 9 



0-97 V 



1-94X10 9 



0-00329 



0-79 „ 



1-58 „ 



1-24 ,, 



2-48 „ 



0-00581 



0-96 ., 



192 „ 



1-50 „ 



3-0 „ 



0128 



1-24 „ 



2-48 ,. 



194 „ 



3-9 ., 



0-106 



1-51 „ 



502 „ 







41-7 



(18-4) „ 



(36-8) „ 







760 



(48-4) „ 



(96-8) „ 



1 





V is the velocity of a-particles from Ra C, and is put equal 

 to 2-0xl0 9 cm. sec." 1 



Fig. 3. 



ye. 



eoo 



500 



VaV* 



■T ■ 



1 



L -L i 











"1 



YRn a 



















Ud.C 



1 L-7Z.~ D 

















400 



^300 



« 



5: 



— R 



R t 























SVft 



















200 

 160 



"AM 











! 







^^4^ — 













i 





| I 





12 



14 



2 4 6 8 iO 



Ve/occ?</ 



The velocities corresponding to various values of (h) 



are illustrated in fig. 3. On each curve are marked a 



number of points corresponding to the range of the a-rays 



IS CTji.sar 



