THEORY OF THE EARTH. 53- 



It has been asserted that the sea is subject to a 

 continual diminution in its level, and proofs of this 

 are said to have been discovered in some parts of 

 the shores of the Baltic. Whatever may have been 

 the cause of these appearances, we certainly know 

 that nothing of the kind has been observed upon 

 our coasts ; and, consequently, that there has been 

 no general lowering of the waters of the ocean. 

 The most ancient sea-ports still have their quays 

 and other erections at the same height above the 

 level of the sea as at their first construction. 



Certain general movements have been supposed 

 in the sea from east to west, or in other directions ; 

 but no where has any person been able to ascertain 

 their effects with the least degree of precision. 



17. Of Volcanoes. 



The operation of volcanoes is still more limited 

 and local than that of any of the agents which have 

 yet been mentioned. Although we have no idea 

 of the means employed by nature for feeding these 

 enormous fires from such vast depths, we can judge 

 decidedly, by their effects, of the changes which 

 they were capable of producing upon the surface 

 of the earth. When a volcano announces itself 

 after some shocks of an earthquake, it forms for it- 

 self an opening. Stones and ashes are thrown to 

 a great distance, and lava is vomited forth. The 

 more fluid part of the lava runs in long streams, 



