JOHN WKSLEY POWELL DAVIS 



placed in these two essays by an elaborate, sometimes an ex- 

 travagant, manner of statement little suited to school teachers. 

 They are literal readers, and must have been mystified by sucIT~ 

 sentences as : "The purple cloud is painted with dust, and the 

 sapphire sky is adamant on wings;" or, "With the revolving 

 moon the tides sweep back and forth across the surface of the 

 sea, and alternately lash the shores with their crested waves ;" 

 and it was certainly disappointing to those who had labored 

 to introduce the principles of uniformitarian geology into 

 geography to find the authority of Powell back of a statement 

 telling "how fire, earthquake, and flood have been involved in 

 fashioning the land and sea." The small attention given to 

 marine processes in Powell's official reports, written in the en- 

 vironment of a broad continental interior, was natural enough ; 

 but the scanty systematic treatment that these processes re- 

 ceived in comparison with the attention given to rain and 

 rivers in the essay on "Physiographic Processes" was as little 

 appropriate as the insufficient discussion of river work and the 

 exaggerated consideration of marine processes by certain ear- 

 lier transatlantic writers of a more insular environment. 



The third essay of this series, on the "Physiographic Re- 

 gions of the United States," is better than the other two. The 

 subdivisions of our country into provinces, as there presented, 

 has been often used by later writers, and must in its larger 

 features be permanently adopted, because it is based on under- 

 ground structure as the prime element in physiographic classi- 

 fication, rather than on an empirical examination of surface 

 features, independent of their origin, such as had been ac- 

 cepted in earlier years when geographers and geologists hardly 

 had a speaking acquaintance with one another. \ The correla- 

 tion of structure and form in the Plateau region had been 

 admirably set forth in the Uinta report by means of a block 

 diagram (facing p. 14), which marked an immense advance 

 over the black-bodied profiles then in common use, and even 

 today unhappily not extinct. The same report had clearly 

 separated the Basin Ranges, the Plateaus, and the Rocky Moun- 

 tains : "first, desert valleys between naked ridges ; second, high 

 plateaus severed by profound gorges, and, third, massive high 

 mountains with shining snow-fields" (Uinta, 8). This is sup- 



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