878 RE VIE WS AND ABS TRA C TS 



One of the chief objects to be attained by the systematic treatment 

 of physical geography by the state surveys is educational It is in 

 every way desirable to disseminate accurate information among the 

 people, and to have the information in such form that it will stimulate 

 independent study. Another object is to furnish professional 

 geographers with accurate knowledge of the region studied. Mr. 

 Marbut's report must be looked upon as more successful from the 

 standpoint of geographers, than from the standpoint of those who are 

 not. Judged from the standpoint of the reader who is not posted in 

 the principles and nomenclature of modern geography, the report is 

 in danger of seeming unnecessarily technical and so of not being 

 understood. This danger is enhanced by the fact that it occasionally 

 lacks in clearness, both because the language is obscure, and because 

 of the lack, at some points, of adequate illustration. Another defect 

 in the same line appears in the frequent references to places which no 

 accompanying map locates. From the standpoint of the geographer 

 these defects may not be serious, but from the standpoint of the citizen 

 who is not a geographer, it is to be feared that they will too often 

 cause the report to remain unread. It goes without saying that it is 

 much easier to point out these shortcomings than to remedy them. 



A question is here raised, by way of suggestion, rather than of 

 criticism, concerning one of the statements of the report. On page 76 

 it is said that the upper Mississippi probably assumed its present loca- 

 tion in late Cretaceous time. There is some reason, though at present 

 by no means conclusive, for suspecting that the present location of 

 this stream was selected at a much later date, possibly as late as the 

 Tertiary.' If it shall prove to be true that the isolated remnants of 

 preglacial gravels, occurring at high levels at various points in the 

 Mississippi basin are Tertiary, the development of the present physio- 

 graphic features of the Mississippi basin, including the valley of the 

 master stream, must date from a still later time. R. D. S. 



Geologic Atlas of the United States. Folio 18, Smartsville, Calif oriiia, 

 1895. 



This folio consists of four pages of text, signed by Waldemar Lind- 

 gren and H. W. Turner, geologists, and G. F. Becker, geologist in 

 charge ; a topographic sheet (scale i : 1 25,000), a sheet of areal geology, 

 one of economic geology, and one of structure sections. 



Topography. — The district of country represented lies between the 



I 



