October 23, 1903.] 



SCIENCE. 



539 



of a geographic cycle, little has been at- 

 tempted. The significance of the great geo- 

 graphic lines of a region, the breaks in the 

 continuity of mountain ranges, the direction 

 of cliS lines, the position of cataracts in rela- 

 tion to one another (in a unique instance 

 called a 'fall line'), the relation in direction 

 of strong topographic lines to water courses, 

 and, above all, to geologic boundaries — in 

 fact, the more impressive manifestations of 

 nature through surface configuration, seem 

 not to have been included in the field of study 

 of physiography. This neglected field is no 

 doubt quite as much within the province of 

 the student of the consolidated crust of the 

 lithosphere — the worker upon the ' hard geol- 

 ogy ' — who, from his knowledge of mountain 

 structure, is the one best fitted to cope with 

 the problems involved in the interpretation 

 of these complex phenomena. It need, there- 

 fore, be no reflection upon the modern phys- 

 iographer that he has left almost untouched 

 this department of physiography strictly so- 

 called ; and the rather sharp differentiation of 

 structural from physiographic geology is 

 doubtless responsible for the fact that ex- 

 ploitation of this frontier of physiography is 

 now only beginning. 



The neglected field of study sketched in the 

 above paragraph may be described as the in- 

 quiry into the configuration of the earth's 

 surface, and particularly that of its rock base- 

 ment, as this is related to rock composition 

 and structure. In contrast with physiography, 

 as that term is now applied, it discusses the 

 relation of earth physiognomy to orogeny, 

 rather than to epeirogeny. It gives compara- 

 tively little attention to the characters of 

 erosional contours, but endeavors to decipher 

 beneath those obscuring curves, as upon a 

 weather-worn and moss-grown monument, the 

 partly effaced characters which have been 

 chiseled in an earlier period. The attention 

 is focused, therefore, upon the direction — the 

 orientation — of the earlier lines. The ques- 

 tions asked are not whether for a given 

 province an infantile or a mature stage of 

 erosion or one of rejuvenation, is indicated; 

 but rather what are the cardinal directions of 

 lineaments, and how are they related to geo- 



logic boundaries and to other structure planes 

 within the lithosphere. It is, in a word, the 

 architecture of the earth's surface — the 

 tectonic geography — that is considered, as has 

 been happily expressed by a recent French 

 writer (Barre, ' L'architecture du sol de la 

 France,' Paris, 1903). The increasing fre- 

 quency with which the term orography has 

 been used by continental writers for studies 

 bordering upon this field (vide especially Koto, 

 ' An Orographic Sketch of Korea,' Tokyo, 

 1903) suggests the appropriateness of a gen- 

 eral term to designate this division of phys- 

 iography or geomorphology. The term orol- 

 ogy (the science of mountain chains), which 

 was used with special fitness by Gilbert in 

 connection with his classical studies of the 

 basin ranges of the western United States, 

 would appear, however, better adapted for tlie 

 purpose than orography, for it may be pre- 

 sumed that physiology, rather than physiog- 

 raphy would have come into use save for the 

 limitations already placed upon that term. 

 Both these terms fail, however, to emphasize 

 sufficiently the importance of physiographic 

 development, and as indicating the respective 

 provinces of the two widely different lines 

 of investigation the terms epeirogenic phys- 

 iography and orogenic physiography may be 

 better employed. 



Studies upon which the writer has been en- 

 gaged for a number of years within the 

 province of southwestern New England have 

 been directed toward the discovery of methods 

 by which the relationships of physiographic 

 lineaments to tectonic structures may be dis- 

 closed. The results, when reviewed in their 

 relations to the more marked physiographic 

 features of the Atlantic coast region, are com- 

 prised in a forthcoming monograph of the 

 United States Geological Survey, and indicate 

 that for a large area the earth's physiognomy 

 is the outward expression of its internal struc- 

 ture. These conclusions have followed from 

 extension of the pregnant generalizations of 

 Professor Edouard Suess, of Vienna — gen- 

 eralizations which have already borne such 

 rich fruit upon the other side of the Atlantic. 

 It is the writer's belief that the exploitation 

 of this frontier region of orogenic physiog- 



