Physical Geography as a Popular Study. 67 



power over the earth, becomes most apparent, and enters into 

 rivalry with natural forces in producing modification. For 

 immense periods it is probable that, on the whole, the amount 

 of natural force at work to effect alterations of the earth's 

 surface has been tolerably uniform in amount ; but we who 

 live in regions lying a little way out of the existing lines of 

 maximum disturbance from action of fire, ice, or water, are apt 

 to underrate the work that is going on from day to day. 

 Wonderful is the amount of that work when fairly surveyed, 

 and the time may arrive when fresh changes in the direction 

 of disturbing forces may occur, and our own quiet regions may 

 again be torn by earthquakes, fire -deluged by the volcano, or 

 modified by glacial ice. 



