CONTENTS 



Original Papers 



Page 

 Physics. — Criteria for gray radiation. Paul D. Foote 573 



Geology. — Clay derived from volcanic dust in the Pierre in South Dakota. 

 Edgar T. Wherry 576 



Abstracts 



Geodesy 584 



Physics 584 



Geology 586 



Ornithology 586 



Proceedings 



Botanical Society 591 



Philosophical Society 592 



