142 



THE ROYAL SOCIETY OF CANADA 



(c) Intensity of primary rays 23-0, Lead Lj, 2-58 cms. 



TABLE 2. 



Angle of scattering 110° 



(a) Intensit}^ of primary rays, 100. Lead Lj, 0-0 mms. thick. 



(b) Intensity of primary rays 60. Lead La, 0-74 cms. thick. 



(c) Intensity of primary rays, 32-5. Lead Lj, 1-84 cms. thick. 



