PRESENT CHANGES IN THE EARTH. 



121 



ancient cities, with their temples and palaces, are found 

 covered in the sand. 



206. Alteration of Levels. Besides the depressions 

 and elevations which, as you have seen, have been pro- 

 duced violently and suddenly by earthquakes, there are 

 other changes of a similar character which have been 

 very gradual. There is ample proof that in Sweden 

 there have been extensive alternate elevations and de- 

 pressions, which have gone on so slowly that no disturb- 

 ances have resulted. One of the most interesting evi- 

 dences of change of level is found in the pillars of what 

 has been supposed to be the Temple of Jupiter Serapis, 

 near Naples. They are represented in Fig. 47. You 



Fig. 47. 



see some way up the pillars a roughness of the surface. 

 This results from a collection of just such perforations 

 as are known to be made by certain sea mollusks called 



F 



