CONTENTS. 



Number 237. 



Page 



Art. XX. — A Shaler Memorial Study of Coral Reefs ; by 



W. M. Davis ..223 



XXL— Notes on Black Shale in the Making; by W. H. 



TWENHOFEL 272 



XXII. — Anodic Potentials of Silver : I. The Determination 

 of the Reaction Potentials of Silver and their Signifi- 

 cance ; by J. H. Reedy 281 



XXIII. — Use of Compensators, Bounded by Curved Surfaces, 



in Displacement Interferometry ; by C. Barus 299 



XXIV. — Radioactivity of Spring Water ; by R. R. Ramsey 309 



XXV. — Stream Piracy of the Provo and Weber Rivers, 



Utah ; by G. E. Anderson 314 



SCIENTIFIC INTELLIGENCE. 



Geology — Geological Survey of West Australia, 316. — Physiographic Geology 

 of West Australia, J. T. Jutson, 317. 



Miscellaneous Scientific Intelligence — The Social Problem ; a Constructive 

 Analysis, C. A. Ellwood, 317. — Societal Evolution ; a study of the Evo- 

 lutionary Basis of the Science of Society, A. G. Keller : British Associa- 

 tion for the Advancement of Science : American Association for the 

 Advancement of Science, 318. 



