Apkil 7, 1916] 



SCIENCE 



497 



SCIENTIFIC BOOKS 



A Text-hooh of Geology, in two parts. Part 



I., Physical Geology. By L. V. PmssoN. 



Part II., Historical Geology. By Chaeles 



ScHUCHERT. John Wiley & Sons. 1915. 



Separately, Part I., $2.25; Part II., $2.75. 



Parts I. and II. bound in one volume, $4.00. 



It is most fitting that this book, issued by 

 two members of the Tale University Geolog- 

 ical Department, should be " Dedicated to the 

 memory of James Dwight Dana, Explorer, 

 Geologist, ISTaturalist, Professor in Tale Uni- 

 versity"; to the man who first made this de- 

 partment so famous. 



This book of 1,060 pages, with 522 illustra- 

 tions and 40 plates, is divided into two parts. 

 Part I., by Professor Pirsson, consists of 404 

 pages, and deals with physical geology. Part 

 II., by Professor Schuchert, discusses histor- 

 ical geology and has 647 pages. It is an excel- 

 lent plan to issue the parts separately, as well 

 as combined. They are similar in size and 

 binding to Bowman's " Forest Physiography '' 

 and Ries & Watson's " Engineering Geology." 

 The binding is well done, the type is good, the 

 illustrations are well produced and there are 

 practically no typographic errors. The pub- 

 lishers and authors are to be congratulated 

 upon this production. 



Part I. is an excellent presentation of the 

 fundamental facts and principles of physical 

 geology. The subject is treated under two 

 main captions, namely. Dynamical Geology 

 and Structural Geology. In view of the state- 

 ment made in the preface, that the author has 

 attempted to produce a text-book which should 

 have " a balance more even in the subject- 

 matter composing it, than is to be found in 

 available texts," the reader may question the 

 space allotment assigned to the different chap- 

 ters, as follows: Introduction, 5 pp.; General 

 Considerations and Work of the Atmosphere, 

 22 pp.; Rain and Running Water, 42 pp.; 

 Lakes and Interior Drainage, 10 pp.; The 

 Ocean and Its Work, 27 pp.; Ice as a Geolog- 

 ical Agency, 34 pp.; Underground Water, 17 

 pp. ; The Geological Work of Organic Life, 23 

 pp. (is there such a thing as inorganic life?); 



Igneous Agencies, and Volcanoes and Hot 

 Springs, 38 pp.; Movements of the Earth's 

 Outer Shell, 23 pp. These chapters belong 

 under Dynamical Geology. The structural 

 side is treated in the remaining chapters : Gen- 

 eral Structure and Properties of the Earth, 11 

 pp.; Sedimentary Rocks, 39 pp.; Igneous 

 Rocks, 21 pp.; Metamorphic Rocks, 18 pp.; 

 Fractures and Faulting of Rocks, 17 pp.; 

 Mountain Ranges, 31 pp.; and. Ore Deposits, 

 24 pp. Unless the reviewer is mistaken, he 

 understands that the "balance" was obtained 

 by averaging the space given to each subject 

 by authors of older text-books of general geol- 

 ogy- 



In putting dynamical geology before struc- 

 tural geology the writer leads his readers 

 from the known to the unknown. In many 

 respects this is far more satisfactory for be- 

 ginner's classes than the philosophical order 

 according to which the masses operated upon 

 by geologic forces should be described before 

 considering the action of these forces. 



An elementary text-book should excel, first 

 and foremost, in the clearness of its exposi- 

 tion and in the choice of its illustrations. In 

 both respects, "Physical Geology" is deserv- 

 ing of high praise. Almost without exception 

 the language is lucid and concise, although we 

 do read of " pouring dry dune sand from San 

 Francisco" (p. 15). The haK- tones are well 

 chosen and excellently printed. With refer- 

 ence to the line diagrams perhaps a word of 

 criticism may be said. Fig. 13 is incorrectly 

 drawn; Figs. 74, 225, 227, 230 and 231 are 

 misleading; and the perspective is faulty in 

 Figs. 129 and 149. More uniformity might 

 have been attained had the block diagrams 

 been constructed either in perspective or in 

 isometric projection, or, preferably, in cabi- 

 net projection. Thus, the blocks shown in 

 Figs. 271, 272 and 273 might have been drawn 

 in similar positions instead of being tilted at 

 various angles. 



There are a few places in the text where 

 statements are misleading or incorrect. On 

 p. 11 we find that, in a classification of work 

 performed by the atmosphere, the chemical 



