( ^52 ) 



quantities of fiich fand and (lime into the fea ; whereby, at tlie 

 mouths of thofe rivers many levels of marfli land are produced, while 

 on the other hand, moft countries far diftant from the fea are moun- 

 tainous. 



If we tlien conclude, that, by all thefe rivers, a great quantity of 

 fand and earth, and whatever is heavier than the water, is dcpofited 

 in the fea, it necelTaril}^ follows, that the feamufl: from time to time 

 be inore elevated. Again, by earthquakes, large portions or tra61:s of 

 land ai'e buried in the fea, leaving nothing but lakes in their place ; 

 and we have inftances of a volcano or burning mountain cafting fo 

 many rocks and flones into the fea, as to raife illands where before 

 it had been deep water. 



In the year 1692, by an earthquake in the ifland of Jamaica, a 

 large fpace of land was fwallowed up, and converted into a lake ; and, 

 at the dillance of thirty miles from the fea, two hills, by the fide of 

 a river were thrown down, caufing the river to take another courfe ; 

 from which new channel, a great quantity of earth muft have been 

 carried into tire fea : and although the coafi; of Norway, and that of 

 Ireland, Scotland, and part of England, are rocky cliiTs, yet their 

 rivers muft continually carry much folid or heavy matter with their 

 waters, and, tlie beating of the waves againft the cliffs, will carry 

 thefe kinds of fubftances into the bottom of the fea, and fo elevate 

 its furface. 



To fome perfons this aflertion may feem ftrange, as judging that 

 the great extent of the fea bears no proportion to the fmall quantity 

 of earth which the rivers wafli into it ; and that therefore, the fea 

 cannot be fo much elevated, as to make any peixeptible diif erence in 

 feveral hundred years. 



In order to fet this matter in a true point of view, I have made a 

 quellion with myfclf : Suppofing the mountain called the Peak of 

 Teneriffe, to be funk in the fea, what elevation would it produce in 



