THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[SIXTH SERIES.] 



OCTOBER 1903. 



L. On the Worh done hy Forces Operative at one or more 

 Points of an Elastic Solid. By Lord Rayleigh, O.M., 

 F.E.S.^ 



4 N investigation of the waves generated in an isotropic 

 jTjl elastic solid by a periodic impressed force, localized ir 



LC 



ni 

 the neighbourhood of a point, was first given by Stokes f. 

 A simpler treatment of the problem will be found in my 

 paper " On the Light from the Sky, &c/' J, and more fully 

 in ' Theory of Sound,' § 378. It will be desirable to re 

 capitulate the principal steps. 



If a, 13, y be the displacements at any point of the sohd, 

 X', Y', Z' the impressed forces reckoned per unit of mass, we 

 have equations such as 



in which a and h are the velocities of dilatational and 

 transverse waves respectively, and 8 represents the dilatation 

 expressed by 



doc djB dy .^. 



dx dy clz 



* Communicated by the Author. 



t Camb. Phil. Trans, vol. ix. p. 1 (1849) ; Collected Works, vol. ii. 



^' X Phil. Mag. xli. pp. 107, 274 (1871) ; Scientific Papers, i. p. 96 

 PhiL Mag. S. 6. Vol. 6. No. 34. Oct. 1903. 2 C 



