Reviews and Book Notices 



A Register 0} National Bibliography, with a Selection of the Chief 

 Bibliographical Books and Articles Printed in Other Countries. 

 By William Prideaux Courtney. 2 vols., 8vo. Pp. viii + 639. 

 London: Archibald Constable & Co., 1905. 



This book is not on geology, but it contains so much of value to ge- 

 ologists, mineralogists, and paleontologists that it seems well worth while 

 to call attention to it. It is a bibhography of bibliographies, and though 

 one might infer from the title that it was confined to British bibhographies» 

 this is far from being the case. The author hves in London, and for some 

 twenty years he worked more or less at this task, while during the last 

 four years he devoted his time entirely to it. He has besides had the aid 

 of many persons interested in special Hnes of bibliographic research, to 

 say nothing of purely clerical work provided by himself. 



The general titles are arranged in alphabetic order, and besides these 



there is at the end a full index covering seventy pages of closely printed 



names and subjects. Under the head of geology, besides the general bibh- 



ographies, there are given bibliographies of over one hundred countries, 



states, and special topics. 



J. C. Branner. 



The Dynamics of Faulting. By Ernest M. Anderson. (Transac- 

 tions of the Edinburgh Geological Society, Vol. VIII, Part III 

 [1905], pp. 387-403-) 



By treating the subject in a mathematical and theoretical method the 

 following conclusions are drawn : 



Faults may be grouped roughly into three classes, known as reversed 

 faults, normal faults, and wrench-planes. 



a) Reversed faults and thrust-planes originate when the greatest pres- 

 sure in the rock mass is horizontal, and the least pressure vertical. They 

 "strike" in a direction perpendicular to that of the greatest pressure, and 

 dip in either direction at angles of less than 45°. 



h) Normal faults originate when the greatest pressure is vertical, and 

 the least pressure in some horizontal direction. They ' ' strike " in a direction 

 perpendicular to that of least pressure, and dip in either direction at angles 

 of more than 45°. 



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