188 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Geology. 



1. The Tidal and Other Problems — Contributions to Cos- 

 mogony and the Fundamental Problems of Geology / by T. C. 

 Chamberlin, F. R. Moulton, C. S. Slichter, W. D. MacMillan, 

 Aethue C. LuNNand Julius Stieglitz. Pp. 264. Washington, 

 D. C, 1909. (Published by the Carnegie Institution of Wash- 

 ington.) — In the department of science to which they relate, this 

 series of papers will doubtless take rank among the most import- 

 ant ever published. Not a little of their value is due to the fact 

 that the plans of the investigations have been controlled by a 

 leading geologist on the one hand and a master of celestial 

 mechanics on the other, while many of the detailed problems 

 have been handled by men who were specialists in the respective 

 lines of research involved. By this collaboration the premises 

 and results have been checked with the known details of earth 

 history and celestial relations, and a greater degree of reliance 

 reached in regard to the methods of investigation which were 

 employed. Within the limits of this review, only the more 

 important conclusions can be given, and it is hoped that the result 

 will be to produce a wider study of the volume itself. The first 

 large subject treated under six papers is that of the tidal problem 

 with its bearings on the former rate of the earth's rotation, its 

 influence on the modes of crustal deformation, the initial relations 

 of the earth and moon, and also the problem of the origin of 

 binary stars through fission. 



The opening paper is by Chamberlin, and in an introductory 

 portion he gives a synopsis of previous work, followed by a redis- 

 cussion of tidal phenomena. The geological evidences are also 

 considered, this topic being treated along the lines followed in 

 Chamberlin and Salisbury's geology. His conclusion is that : 



" The application of the most radical and the most rigorous 

 method of estimating the frictional value of the present water- 

 tides, a method which brings to bear practically all the friction 

 of these tides as a retardative agency, irrespective of their 

 positions or directions of motion, seems to show that they have 

 only a negligible effect on the earth's rotation. 



" From the best available evidence I conclude that the tides of 

 the lithosphere are chiefly elastic strains and have little retarda- 

 tive value, while the tides of the atmosphere are too small to be 

 measured. 



" The accelerative influences seem to be also negligible, so far 

 as geological applications are concerned. 



" In close accord with these deductions, the geological evidences 

 indicate that there has been no such change in the rate of the 



