PRACTICAL PHYSICS FOR 

 SECONDARY SCHOOLS 



By N. HENRY BLACK, of the Roxbury Latin School. Bo 8 ton. and 

 Prof. HARVEY N. DAVIS, of Harvard University 



Cloth, l2mo., illustrated, 488 pages, list price, $1 .25 



"In preparing this book," say the authors in the Preface, "we have tried 

 to select only those topics which are of vital interest to young people, 

 whether or not they intend to continue the study of physics in a col- 

 lege course. 



"In particular, we believe that the chief value of the informational 

 side of such a course lies in its applications to the machinery of daily life. 

 Everybody needs to know something about the working of electrical 

 machinery, optical instruments, ships, automobiles, and all those labor- 

 saving devices, such as vacuum cleaners, tireless cookers, pressure cookers, 

 and electric irons, which are found in many American homes. We have, 

 therefore, drawn as much of our illustrative material as possible from 

 the common devices in modern life. We see no reason why this should 

 detract in the least from the educational value of the study of physics, 

 for one can learn to think straight just as well by thinking about an 

 electrical generator, as by thinking about a Geissler tube 



"To understand any machine clearly, the student must have clearly 

 in mind the fundamental principles involved. Therefore, although we 

 have tried to begin each new topic, however short, with some concrete 

 illustration familiar to young people, we have proceeded, as rapidly as 

 seemed wise, to a deduction of the general principle. Then, to show how 

 to make use of this principle, we have discussed other practical applica- 

 tions. We have tried to emphasize still further the value of principles, 

 that is, generalizations, in science, by summarizing at the end of each 

 chapter the principles discussed in that chapter. In these summaries 

 we have aimed to make the phrasing brief and vivid so that it may be 

 easily remembered and easily used." 



The new and noteworthy features of the hook are the admirable 

 selection of familiar material used to develop and apply the principles 

 of physical science, the exceptionally clear and forceful exposition, 

 showing the hand of the master teacher, the practical, interesting, 

 thought-provoking problems and the superior illustrations. 



THE MACMILLAN COMPANY 



64-66 Fifth Avenue, NEW YORK CITY 



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CHICAGO SAN FRANCISCO 



