THE USEFULNESS OF EARTHQUAKES. 233 



when we consider fairly the share which time had in 

 those ancient processes of change, when we see that 

 while mountain-ranges were being upheaved or valleys 

 depressed to their present position, race after race and 

 type after type appeared on the earth, and lived out 

 the long lives which belong to races and to types, we 

 are recalled to the remembrance of the great work 

 which the earth's subterranean forces are still engaged 

 upon. Even now, continents are being slowly de- 

 pressed or upheaved ; even now mountain-ranges are 

 being raised to a new level, table-lands are in process 

 of formation, and great valleys are being gradually 

 scooped out. It may need an occasional outburst such 

 as the earthquake of August, 1868, to remind us that 

 great forces are at work beneath the earth's surface. 

 But, in reality, the signs of change have long been 

 noted. Old shore-lines shift their place, old soundings 

 vary ; the sea advances in one place and retires in 

 another ; on every side Nature's plastic hand is at 

 work modelling and remodelling the earth, in order 

 that it may always be a fit abode for those who are to 

 dwell upon it. 



(From Fraser^s Magazine, July, 1870.) 



THE USEFULNESS OF EARTHQUAKES. 



have lately had fearful evidence of the energy 

 of the earth's internal forces. A vibration which, 



