REVIEWS. 



light and Sound. By William S. Franklin and Barry MacNutt. Cloth. Pp. 

 vn-344. Price, $1.60 net. New York: The MacMillan Company. London: 

 MacMffian & Co., 1909. 



This book is the third one of a series written by these authors on 

 special subjects in physics. It professes to be a text-book for colleges 

 and technical schools. It is evident that the primary object of the 

 authors has been to write a popular book. Many things which seem 

 vital to the reviewer have been sacrificed by the authors in an attempt 

 to make the subject interesting. 



The subject is treated in a very elementary manner and with the use 

 of very little mathematics. As physics is essentially a mathematical 

 science, the reviewer believes there will never be in the future any great 

 physicst who will not be able to think in the terms of mathematics ; and 

 even a beginning course in physics should lay the foundation for 

 mathematical thinking. 



• The authors state that the main object of the book is to develop "a 

 simple living interest in science on the part of all plain people." As a 

 popular and accurate reading book of selected practical chapters on 

 Light and Sound, the volume is excellent. A text book of physics should 

 develop the subject from a mathematical point of view, and if such a 

 treatment is dry and lacks interest, the latter must be developed through 

 the lectures and discussions of the class room and especially through the 

 enthusiasm and personality of the teacher. 



The subjects selected cover only such parts of the fields of light and 

 sound as are commonly met with in every day experience and have 

 evidently been so chosen by the authors because of the greater interest 

 and ease of treatment by practical illustrations. There is only an exceed- 

 ingly limited discussion of recent theories of light, and after stating that 

 the electric magnetic theory of light is the one generally accepted by scien- 

 tists^ the authors, for reasons of simplicity, in most parts of the book use 

 the elastic solid theory in their explanations of light phenomena. 



There are ten chapters on light. The wave theory as applied to light 

 is illustrated and made quite simple by the use of water waves. The 

 chapters on Lenses and Lens Systems, Simple Optical Instruments, and 

 Lens Imperfections and their Compensation, are three of the most prac- 

 tical in the book. They explain in a simple manner the various phenom- 



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