PHYSICS 275 



are that he will be somewhat surprised at the role which 

 the investigators of France have continuously played. 

 For the features of a landscape upon which a people live 

 are not more permanent than the intellectual character 

 of that people. 



As regards Mechanics: Father MERSENNE investi- 

 gated the dynamics of vibrating strings as early as 1636 

 six years before the birth of Newton. VARIGNON shares 

 with Newton the credit of introducing the new dynamics 

 now called the Newtonian dynamics. His "Project" 

 appeared in the same year with Newton's "Principia" 

 and quite independently of it. 



Students of Mechanics can never forget the three 

 brilliant contemporaries D'ALEMBERT, LAGRANGE, and 

 LAPLACE who were living in Paris when Benjamin 

 Franklin was there, so ably representing the American 

 cause. A half century later POINSOT created our rota- 

 tional dynamics; later this was followed by the experi- 

 mental researches of FOUCAULT on the pendulum and 

 gyrostat. Eminent contributions to the theory of 

 elasticity and wave-motion came from POISSON and 

 CAUCHY; work along the same line being carried on to- 

 day by BOUSSINESQ and HADAMARD. 



In the domain of vibrating bodies, the names of 

 LAGRANGE, FOURIER, LISSAJOUS, and KOENIG at once come 

 up. A distinct and important contribution to thermal 

 science is recognized at the mention of each of the follow- 

 ing men, CARNOT, CLAPEYRON, DULONG and PETIT, 

 REGNAULT, BECQUEREL, POUILLET, AMAGAT, CHAPPUIS, 

 GUILLAUME. The wave theory of light the theory of 

 transverse vibrations was created and established 

 largely by FRESNEL, ARAGO, CAUCHY, JAMIN, FIZEAU, 

 FOUCAULT, CORNU, and MASCART. 



Just as the quantitative side of Electrostatics was 

 set forth by COULOMB, so the quantitative description 



