122 



THE ROYAL SOCIETY OF CANADA 



were found by repeated observ^ations and the values shown in Table 11 

 as "Average Range" are accurate probably to 0.01 gm. per sq. cm. 

 A correction was necessary due to the permanent base of the electro- 

 scope, and the values obtained after this has been made are given 

 under the heading "Corrected Range." 



TABLE II 

 Effective R.\nge of ;Ô-Rays from Ra.E. 



The values here shown can only be considered as the result of 

 preliminary experiments v^^hich the writer hopes to continue at some 

 future date. 



MASS OF A0SO/7BS/? /// QMS / CM.^ 



Fig. 7 



