496 



SCIENCE 



[N. S. Vol. LIV. No. 1403 



made with the maps by Schuchert, and by 

 Chamberlin and Salisbury. Some of the old 

 and crude woodcuts that have done service 

 in the literature for over half a century 

 might be honorably retired; for example. 

 Figs. 79, 128, 311, 593. 



The publisher's part has been well done. 

 More care in the matter of ink and press- 

 work might improve the quality of the half- 

 tones, some of which are poor. 



In the order of topics the author does not 

 follow the usual practise of beginning with de- 

 scription of geologic processes open to observa- 

 tion, surficial geology, but uses the philosoph- 

 ical or deductive order of cause and effect. 

 Three short chapters on the nature and scope 

 of the science are succeeded by chapters on the 

 materials composing the earth's crust, miner- 

 alogic and chemic geology, and volcanism. This 

 is discussed in the interesting preface. 



The many subjects in dynamic and struc- 

 tural geology are covered in the remaining 14 

 chapters of Part I. ; the author's more original 

 matter being on saline deposits (Chapter 11) ; 

 organic deposits (Chapters 12, 13) ; and on the 

 deposition, classification and structure of the 

 clastic rocks (Chapters 16-18). 



Historical Geology, Part II., does not offer 

 much opportunity for any original treatment. 

 The life history of the past is well emphasized. 



The author is strong on classification and 

 terminology, and in consequence of his refined 

 classification some topics are subdivided and 

 treated under different heads. For example, 

 glaciers are discussed in at least four places in 

 the first volume. The student who wishes to 

 find what the book contains on a subject may 

 have to consult the index many times. 



A favorite subject of the author is the prob- 

 lems of sedimentation; marine transgression 

 and regression, overlap and offlap, origin of 

 saline deposits, etc. He discusses these in a 

 masterly way. But he does not clearly distin- 

 guish between accepted fact and his own plaus- 

 ible philosophy. An elementary text-book in 

 science should contain very little beyond estab- 

 lished fact and generally accepted principles. 

 In a comprehensive work like this, intended for 

 advanced students, new theories and perhaps 



even subjects under sharp discussion may be 

 admitted, but such should be distinctly stated 

 as tentative. This matter needs to be specially 

 guarded by an author who is active in scientific 

 debate. It will be recognized as bad form for 

 an author to use a text-book for propaganda. 

 Students should realize that scientific truth 

 comes by observation and experiment, not by 

 mere thinking. Theorizing is helpful as it 

 points the way for induction. Grabau's discus- 

 sion of sedimentation, especially as it relates to 

 Paleozoic stratigraphy, will provoke debate and 

 will be stimulating to advanced students. 



The work makes very large use of foreign 

 material and of illustrations from foreign liter- 

 ature. Indeed, on many topics the description 

 of foreign features and phenomena is in excess. 

 The work should be a satisfactory text for 

 European students. But American students 

 will be disappointed in the meager discussion 

 and illustration of some interesting features of 

 American geology. Some topics having very 

 inadequate treatment, as noted in the rapid re- 

 view, are: American geysers with only a few 

 words, but four pages, including four cuts, of 

 geysers in general ; two pages on petroleum and 

 rock gas ; the glacial lakes and tilted shorelines 

 in the basin of the Great Lakes and the Hud- 

 son-Champlain valley receive only a few lines 

 (page 695) ; only three pages on coal; only four 

 lines to drumlins. 



What may be regarded as a defect in the 

 work is the entire absence of references to the 

 geologic literature. Some reference to the more 

 important articles on topics only briefly dis- 

 cussed in the work would be very useful to 

 the reader. And for subjects on which other 

 authorities may differ references to the litera- 

 ture are necessary for impartial study. 



The work is too full and too large to be used 

 as a test for beginners. The author evidently 

 had laboratory use in mind. Only the test of 

 actual use can prove its value in competition 

 with other excellent works. The time has 

 passed when all of geologic general science, 

 even for our continent, can be usefully gath- 

 ered into one or two volumes. That was fairly 

 done by Dana, fifty years ago. Fifteen years 

 ago Chamberlin & Salisbury had to make three 



