JXJNE 4, 1909] 



SCIENCE 



897 



ence to the different classes of students fol- 

 lowing the course, the point being that stu- 

 ents looking forward to engineering ostensibly 

 need a text-book different in character from 

 that best fitted for other students. The 

 difficulties of satisfying these requirements 

 by any one text-book are insuperable. At the 

 very best the author must make certain com- 

 promises and must adapt his book to certain 

 actual conditions, and to the classes with 

 which he is most familiar. It is not an easy 

 matter to prepare a text-book in physics which 

 shall satisfy the obvious pedagogical require- 

 ments for physics as a subject in general edu- 

 cation and at the same time meet the require- 

 ments mentioned above. It is not to be ex- 

 pected that aU. teachers of physics should feel 

 satisfied with all text-books of physics, from 

 the standpoint either of general purpose or of 

 detail, but the two books under review are 

 certainly admirable in many respects, and are 

 sure to have a well-deserved popularity among 

 American colleges. 



The author of the present review is not cer- 

 tain as to the object of such an article. It 

 certainly should not be to point out typo- 

 graphical errors, or even to refer to what may 

 seem to him to be misstatements of facts or 

 of theory. On the contrary, perhaps the best 

 result may be secured by noting both the ob- 

 vious facts concerning the book and the points 

 by which each differs from other well known 

 books. 



Professor Crew's book is a beautiful piece 

 of book-making; the paper, type, wood-cuts 

 and binding are all that could be desired. It 

 contains 515 pages, of which 182 are devoted 

 to mechanics and properties of matter, 64 

 to wave motion and sound, 61 to heat, 115 to 

 magnetism and electricity and about 100 pages, 

 the rest of the book, to light. The balancing 

 of the various subjects, as shovsm by this sub- 

 division, is admirable. One would expect that 

 this text-book would prove most satisfactory 

 to any college class; the references to the 

 historical development of the science are most 

 interesting and inspiring; the various ma- 

 chines or experimental facts which are given 

 as illustrations of the general theories are 

 well selected and described with enthusiasm; 



in fact, the whole book is permeated with a 

 certain charm thoroughly characteristic of all 

 of Professor Crew's own enthusiasm as a 

 teacher and investigator. Another excellent 

 point about the book is the selection of prob- 

 lems. These contain not only useful arith- 

 metical illustrations, but also questions which 

 require the exercise of reasoning as apart from 

 any use of f ormulse or numbers. It is only in 

 a few places that the author seems to intro- 

 duce matter which is too far removed from 

 the elementary character of the general book. 



The text-book edited by Professor Duff is 

 a compilation of seven sections prepared by 

 different authors as follows: Mechanics, by 

 Professor Duff himself; Heat, by Professor 

 Guthe ; Wave Motion and Sound, by Professor 

 Hallock; Light, by Professor E. P. Lewis; 

 Electricity and Magnetism, by Professor 

 Goodspeed; Electromagnetic Induction, by 

 Professor Carman, and Conduction of Elec- 

 tricity through Gases and Radioactivity, by 

 Professor McClung. 



In attempting to prepare a book in this 

 manner there are no unavoidable difficulties 

 provided the general editor is one who- has cer- 

 tain executive powers, and certainly in this 

 case the publishers are fortunate in having 

 persuaded a man of Professor Duff's ability 

 to assume the task. As is to be expected in 

 such a compilation, there is a certain degree 

 of inequality, but in this particular illustra- 

 tion it is reduced to a minimum. In fact, the 

 work is admirably done from the standpoint 

 of the general editor. The book contains 666 

 pages and is divided into the seven sections 

 referred to; 177 being devoted to mechanics 

 and properties of matter, 102 to heat, 45 to 

 wave motion and sound, 143 to light, 154 to 

 electricity and magnetism, including electro- 

 magnetic induction, 136 to conductivity of 

 gases, etc. At the end of the various sections 

 there are sets of problems which in the major- 

 ity of cases are admirably selected. The il- 

 lustrations are clear, but lack the charm of 

 those of Professor Crew's book; the tjTpe and 

 paper are satisfactory, although not so good 

 as to demand special attention. 



It is not easy to decide as to the class of 

 students for which this book is designed, be- 



