Earthquake waves through the earth. 361 



probably increase in passing through the deeper parts of the 

 interior. 



Besides these two types of wave there is a third, supposed to 

 be of a gravitational character, which does not fall within the 

 limits of the present enquiry. 



I cannot but think that many geologists, like myself, would 

 be pleased to be permitted to regard the interior of the earth as 

 liquid, and if what I have now written is a step in that direction 

 I shall be satisfied. 



VOL. XII. pt. v. 24 



