Davis — Framework of the Earth. 231 



belts vary in dimensions, in pattern, and in arrange- 

 ment. If the framework of the earth's crust is modeled 

 on a geometrical plan, the departures from the plan are 

 more conspicuous than the plan itself. Thus while clearly 

 setting forth the dominant structural features of the 

 actual earth, Suess exhibited a fine scientific prudence 

 in not following the Procrustean habit of some of his 

 predecessors, who have attempted to force the frame- 

 work of the earth to fit a systematic and more or less 

 preconceived scheme. The chapter in which the "Anal- 

 yses" are summarized must indeed be disappointing to 

 those who expected to find in it the specifications of a 

 patent earth. This restraint from over-generalization is 

 wise: it goes well with the marvellous marshalling of 

 geological records from all parts of the world, in view 

 of which we repeat that Suess 's volumes constitute the 

 greatest geological work ever published. 



One of the most remarkable features of the work is 

 that its fundamental thesis regarding the asymmetrical 

 structure of mountain chains, which is now supported by 

 so vast a body of evidence, was well developed in the 

 author's epoch-making essay on "Die Entstehung der 

 Alpen," published in 1875, before "Das Antlitz der 

 Erde" was begun. Various phrases from that essay 

 might be repeated with little modification in the chapter 

 on "Analyses," which forms a closing part of the later 

 three-volume work. Indeed, it is perhaps because of the 

 great success of his main thesis that the author has been 

 led to hold with too great tenacity to certain other early- 

 formed opinions, which find less confirmation in later 

 and wider study. Masterful as the work is, repeated 

 examination of its successive volumes as they appeared 

 has aroused the question whether the adopted method of 

 treatment was sufficiently mobile for so rapidly expand- 

 ing a science as geology. The enormous erudition of 

 the author and his unending capacity for analysis and 

 synthesis are most admirable; but his mind seems to 

 have been ponderous rather than nimble. Alternative 

 solutions are not always treated with equal hospitality. 

 The method of multiple working hypotheses is not 

 conspicuously employed in the solution of disputable 

 problems. 



It is concluded, for example, that Laurentia and other 

 ancient areas have been long undisturbed because they 



