Reviews. 



Great Valley of Califorfiia ; a Criticism of the Theory of Isostasy, by 



F. Leslie Ransome : Univ. California, Bull. Geol. Dept., 



Vol. I, pp. 371-428, 1896. 

 British Geology, by T. Mellard Reade : Geological Magazine, 



Dec. 4, Vol. II, pp. 557-565. 1895. 

 Notes on the Gravity Determinations Reported by Mr. G. R. Put?iam, 

 • by Grove Karl Gilbert : Bull. Philos. Soc. Washington, 



Vol. XIII, pp. 61-76, 1895. 

 Three papers have been issued recently which have a direct bear- 

 ing upon the theory of isostasy. Two are of the nature of criticisms \ 

 one being the outcome of. studies conducted in this country, and the 

 other of inquiries instituted in England. The third introduces some 

 new complications which the advocates of the hypothesis would hardly 

 expect. 



The first memoir is of more than ordinary interest in being an 

 attempt to practically test the theory from a purely geological stand- 

 point, and to apply the principles to a particular limited region unusu- 

 ally favorably situated for obtaining tangible results. The paper had 

 its origin in a review of the literature bearing upon the theory of "con- 

 servation of equilibrium in the earth's external form, which Button has 

 named Isostasy, and which has come into prominence mainly through 

 the labors of that illustrious group of American geologists to whom 

 geology is so deeply indebted for certain broad views and far-sighted 

 generalizations, which in spirit and expression recall the wide regions 

 and clear atmosphere in which the authors worked." 



Accordinglv the discussion is appropriately subdivided into five 

 distinct parts, (i) a description of the Great Valley as it is today, (2) 

 an outline of the geological evolution through which it has arrived at 

 its present form, (3) an account of the development of the so-called 

 "doctrine of isostasy" as a working hypothesis, (4) a discussion of the 

 applicability of this hypothesis to the Great Valley, and (5) a more 



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