184 THE PALMS OF THE ANCIENT WORLD. 



Sir Charles Lyell has advanced a beautiful 

 theor}', Avhich shows that these changes of 

 chmate may be accounted for by reference 

 to one cause, which is still in daily operation 

 on our globe. It is well known to every 

 one who is even but slightly acquainted 

 -with geological facts, that the land is not 

 always that stable, fixed, and unalterable thing 

 which it is usually looked upon as being. In 

 various parts of the world, by some marvellous 

 action of the internal forces of the earth, pro- 

 bably analogous to those which produce earth- 

 quakes, the land is raised up to a greater 

 elevation above the sea-level, or it is depressed 

 lower than before. And not only has this been 

 the case, but it is a process continually going 

 on, sometimes suddenly, but more often gra- 

 dually and slowly, though certainly. Thus, in 

 some parts of Norway the land has been slowly 

 rising at the steady rate of about four feet in a 

 century. In many parts of the southern ocean 

 its bed is as certainly, yet slowly sinking ; and 

 coral islands that now are but just level with 

 the water, will probably become a sunken reef 

 of dancrerous rocks. In South America the 

 land has been rising, till what were once beaches 

 are now great distances inland.* On one occa- 



• Sec Darwin's " Nntuiul History of tlie Voyage of the 

 Bcngle," 



I 



