Fereuaey 10, 1899.] 



SCIENCE. 



215 



first in our reading to one of the later chapters, 

 entitled ' The Life History of a River,' in 

 which Professor Eussell has given lis a de- 

 lightful summary of a river history as seen by 

 a supposed being sufficiently long-lived to have 

 outlived the river. In spite of the imagination 

 demanded for the writing or reading, or per- 

 haps better, because of the necessary imagina- 

 tion, the chapter in question is of exceptional 

 value In emphasizing the comparative lives of 

 man and earth forms, and the difficulty of gain- 

 ing proper ideas of time. It is, however, a 

 chapter that should be read as a summary and 

 not as an introduction by a beginner ; for a 

 body of facts is necessary in order to have such 

 & broad view properly understood and appre- 

 ciated. 



The plan of the book is very logical and 

 practical, the first seven chapters being devoted 

 to a careful account of the details of river 

 work under the following larger headings : 

 The Disintegration and Decay of Rocks, Laws 

 ■Governing the Streams, Influence of Inequali- 

 ties in the Hardness of Rocks on Riverside 

 Scenery, Material Carried by Streams in Sus- 

 pension and in Solution, Stream Deposits, 

 Stream Terraces and Stream Development. 

 The last two chapters are devoted to consider- 

 ing the more important American rivers, and 

 the Life History of a River, in which a summary 

 use is made of the principles that have been 

 previously developed. 



The first chapter is devoted to a consideration 

 of the processes of mechanical and chemical dis- 

 integration and the consequences of such work, 

 and forms a natural and necessary introduction 

 to the especial treatment of rivers, which 

 really begins in Chapter II. Here we find a 

 good treatment of the processes and results of 

 river erosion and transportation, and the impor- 

 tant controls of such river work. Especial 

 and perhaps a little too emphatic emphasis is 

 given to the effect of the rotation of the earth 

 upon river cutting, particularly as seen on 

 Long Island. From such a forceful exposition 

 of this control the beginner might uncon- 

 sciously gather an erroneous impression of its 

 importance in general. 



The chapter devoted to the loads of rivers is 

 very detailed and one of the most important of 



the book. In spite of numerous analyses and 

 tables, the text does not lose its interest, and 

 the treatment is not above the ability of the 

 average reader. The chapter is sufficiently 

 inclusive for general needs, and yet free from 

 the mathematical difficulties that scare the 

 student so frequently in text-book considera- 

 tions of this difficult subject. 



In the consideration of river deposits the 

 author gives a whole chapter to one group, 

 namely, terraces, which, although of great 

 interest, are not of such world-wide significance 

 as the other greater groups considered together 

 in Chapter V. In spite of this seeming divorce 

 of related subjects, the arrangement is good, 

 because the more normal conditions of river 

 deposition can thus be considered in exteuso, 

 without too serious modification of the idea of 

 a river's life cycle. We are glad to see the 

 river deposits treated causally and inclusively. 

 The consideration of deltas is particularly help- 

 ful and to the point. The classification is good, 

 clear and workable, and one to be commended. 

 The influences of climate, elevation and de- 

 pression are treated at length, and the chapter 

 closes with a summary devoted to the cross and 

 longitudinal profiles of rivers illustrated with 

 a few clear diagranis. 



The most helpful chapter in the book is that 

 devoted to stream development. Here we have 

 for the first time available for public use the 

 theory and the details of the newer classifica- 

 tion of land forms. The questions of stream 

 development and adjustment, the stages in 

 river history and the topographic forms to be 

 found in the various instances are considered 

 concisely and clearly. The newer terminology 

 is used with discretion and success. Only those 

 terms that have to a certain extent been estab- 

 lished by usage are included, and these are not 

 given dogmatically in technical language. The 

 author has not written his chapter to explain 

 the terms to be found in the literature of his 

 subject, as is so often the case, but has given 

 each suggested term at the close of a clear ex- 

 position of a composite fact as a shorthand 

 method 'of indicating the composite. The 

 student reader of this chapter would not, we 

 think, be led to use any term with quotation 

 marks, either oral or written, but would avoid 



