CONSTANT LEVEL OF SEAS. 101 



retiring again, carrying devastation over a greater or less extent 

 These impetuous movements of advance and retreat, accompanied 

 by sudden dislocations caused by subterraneous commotions: in the 

 solid crust of the globe, may occasion frightful havoc. The his- 

 tory of the Grecian archipelago, of the islands of Japan, and of a 

 multitude of places, is full of disasters produced by these catas- 

 trophes. 



The various effects produced by earthquakes under our eyes, and those 

 cited in the most authentic narrations, tend to confirm what is transmitted 

 to us from the most remote times, although we might state the facts in other 

 terms. Who dares formally to contradict Pliny, relating, according to the 

 historians, that Sicily was separated from Italy by an earthquake ; that the 

 island of Cy'prus was seperaled from Syria by the same means ; and that of 

 Eubce'a (Negropont) from IkeotLi, &c.? We would not even positively deny 

 the existence of the Atlantis, swallowed by the waters, according to Egyp- 

 tian tradition, in a day and a night. Let us rather declare, that the assem- 

 blage of observations we have, evidently slio.vs that immense upheavals and 

 subsidences have for a long time formed part of the mechanism of nature, in 

 bringing (he surface of the earth to the configuration we now observe. 



7. Constant level of seas. We have just admitted the subsid- 

 ence and upheaval of coasts, and laid down the principle that the 

 level of seas is invariable : but this last assertion being contrary to 

 opinions commonly received by the world, it is necessary to sup- 

 port it by demonstration. The laws of hydrostatics teach us that 

 a mass of liquid cannot be permanently elevated or depressed at 

 one point of its surface, but that a level must be established after 

 oscillation, great or small, ceases. Hence it follows that the levei 

 of the sea cannot be stationary at one point, without its being so 

 throughout, and thaUthe waters cannot be elevated or depressed in 

 one spot, without similar changes being experienced at all points 

 of the same basin. Now we know thousands of localities where 

 the surface of the sea has not undergone the least variation since 

 the most remote historic times ; therefore the level has not changed, 

 and its constancy is the most positive fact we are aware of, be- 

 cause it has been subject to the proof of all ages. On the other 

 hand, if we could be led to suppose, like the inhabitants of Chile, 

 seeing the manifest change on their coast, that the sea has sub- 

 sided there, we must also conclude, with the inhabitants of Cali- 

 fornia, Peru, Brazil, &c., that in those places it underwent no 

 variation. It must also be admitted that the sea has risen at th-3 

 bottom of the Gulf of Arabia, as it has done, in different epochs, on 

 the roasts of Portugal, in the Straits of Messina, &c. All these 

 circumstances are incompatible with each other, and opposed to 

 the laws of hydrostatics; and hence we conclude, that instead of 

 the immutability of the ground, which an error, analogous to the 

 idea of immobility of the globe, has created, we must admit immu- 



7. Does the sea always maintain the same level ? What reasons lead to 

 the opinion that the level of seas is always the same? 







Of THE 



