The mere falling of a stone is wonderful past 

 all speaking.^^ 



FUNDAMENTAL CONCEPTS 

 of PHYSICS 



By PAUL R. HEYL, PH. D. 



Physicist of the Bureau of Standards, Washington, D. C. 



A book simply written, concerning the stuff of 

 which the universe is made — and what our ideals 

 about it have been and are. It tells of the ante- 

 cedents of our present concepts during the "century 

 of materialism" (the eighteenth) and the "century 

 of correlation" (the nineteenth) and depicts the 

 present era as the "century of hope." 



"/« the deielopment of our latter day physical con- 

 cepts there has been more of evolution and less of 

 revolution than is commonly supposed.^' 



Price $2.00 



THE WILLIAMS & WILKINS COMPANY 



Publishers of Scientific Books and Periodicals 



BALTIMORE, U.S.A. 



