490 



The Hottle Spring has remained almost constant, while the Illinois 

 Central has fallen from 600. X 10- 12 curies to almost zero. Four readings 

 taken on another (J. C. S.) spring are added. Taken all together it is 

 noted that in May there was a low value and an increase during Sep- 

 tember and another decrease October and December. In a rough way an 

 increase coincides with a season of rain and a decrease with dry weather. 

 It may be that due to a small flow there is more splashing and trickling 

 over rocks near the mouth of the spring and the emanation is lost. 



Indiana University, 



December 21. 191'/. 



