494 



SCIEN'GE. 



LVoL. IX., No. 224 



ing upon the total energy and the depth below the shock deeply seated, or to a less energetic one 

 surface. The intensity at any point on the sur- nearer the surface. The criterion is soon given, 

 face will therefore depend upon these two quan- It is obvious that in any shock there is some 



150SE1SMALS 



OF THE 



CHARLESTON EARTHQUME 



R0351-FOREL SCALE 



-^^^ 



^ 



titles, — energy and depth. It still remains to point at some particular distance from the epi- 

 find some means of discriminating whether the centre at which the rate of diminution of surface 

 intensity at any point is due to a more energetic intensity has a maximum value. As we leave the 



