ERATE W 
MINERAL ONE WEEK Two Days One Day ON Hour 
Uraninite 
North Carolina 
Gummite 
North Carolina 
Thorianite 
Ceylon 
Uranophane 
North Carolina 
Thorite | 
Norway | No result 
Fergusonite 
No result 
Norway > 
Carnotite 
ч No result 
Colorado 
Samarskite No result 
North Carolina 
ES o 
RADIOGRAPHS—COMPARATIVE EXPOSURES 
