282 Scientific Intelligence, 



adopted in some technical schools in which it is no longer possible 

 to base the teaching of physics upon the mathematical courses to 

 the extent that may have been done heretofore. As might be 

 expected, these text books are strongly stamped with the individ- 

 uality of the author — or authors — even to the appearance of the 

 pages, on which varying degrees of emphasis are marked by seven 

 or eight different fonts of type, fortississimo being indicated by 

 10-point bold face capitals. More important than the superficial 

 appearance of the text is the purpose of the authors toward the 

 teaching of physics. In this volume they express the opinion 

 that the function of physics teachers is to aid in the important 

 and difficult matter of mathematical training and accordingly the 

 calculus methods are introduced from the beginning without pre- 

 suming previous knowledge of these powerful mathematical 

 methods on the part of the student. 



The form of presentation is intended to facilitate class room 

 work. Each topic is introduced with a definite statement, or 

 definition, of the physical meaning of the idea propounded, and 

 so developed as to lead to illustrative numerical problems which 

 are very numerous. Descriptive material has been reduced to a 

 minimum. The figures are well conceived but too sketchy — one 

 might even say scratchy. The chapter headings run through the 

 gamut of Statics, Motion of Translation, Motion of Rotation, 

 Hydrostatics, Hydraulics, Elasticity, and Waves in Elastic Bodies. 

 Three appendices are devoted to Measurements, to Errors, and 

 to Equations of analogous form in Translation, Rotation and Elec- 

 tricity. Controversial subjects are not avoided but as might be 

 anticipated the bull is taken by the horns. To help the student 

 through the slough of gravitational and absolute units the pound 

 mass is denominated the sugar-pound and the pound force is dis- 

 tinguished as the pull-pound or when occurring alone as ' ' pound ' ' 

 in quotation marks. The unit of mass in the gravitational sys- 

 tem is always taken as the slug which is the attraction of the 

 earth upon the mass di\4ded by the acceleration of weight. 



As far as it is possible for a book to do it the student who has 

 worked through these lessons in mechanics should have been 

 helped to form sound concepts of the physical ideas, to give clear 

 interpretations of mathematical symbols, and to state results free 

 from confusion in the units. f. e. b. 



10. Lessons in Electricity and Magnetism; by William S. 

 Franklin and Barry ]\L4cNutt. Pp. XIV, 254. Bethlehem, 

 Pa., 1919 (Franklin and Charles) .—This is the second volume 

 of the series mentioned above and might be called ' ' Things which 

 the beginner in electrical engineering should know. ' ' The mode 

 of presentation is peculiar, being developed from the standpoint 

 of electro-mechanics, i. e. instead of starting with the relatively 

 simpler phenomena and proceeding to the more complex, the 

 authors purposely ignore the nature of everything, and postulate 

 the existence of magnets, and of electric currents with the Joule, 



