Smithsonian Report. 1935. — Johnson 



Plate 2 



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1. Cloud photograph by Anderson of an iS-milhon volt negative electron curved by a magnetic field of 

 12.000 gauss. The direction and amount of the curvature and the density of the track are data useful 

 in determining what the ray is. 



2. Track of an alpha particle by Anderson illustrating the greater density resulting from the higher charge 

 and mass as compared with that of the electron of plate 2, figure 1. 



