I91S.] INTERIOR OF THE EARTH. 297 



We can say in conclusion, that the transmission of transverse 

 earthquake waves shows that the earth is sohd, at least to a great 

 depth below the surface; and that experiments on the deflection of 

 the vertical show that it is quite as rigid and as viscous as steel. 

 There are still difficulties in the interpretation of the observations, 

 but their elucidation cannot alter the general character of the 

 conclusions. 



