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distance, where they sink in the form of a sediment, and 

 form the first, stratum, which will soon be covered by 

 another, and so with more and more. Hence in time a 

 mountain v\ill be formed in the bottom of the sea, en- 

 tirely like what we set on the land. 



Such eminences, lying in the same direction with the 

 waves that produced them, form by degrees a chain of 

 mountains. "But how come mountains, -whose top is 

 composed of rock, to have only earth or sand for their 

 base, which may often be seen in the neighbouring plains, 

 to a considerable distance T We answer, the water first 

 transported the sand that formed the first layer at the 

 bottom of the sea. Afterward the more firm and 

 weighty substances were attacked, and brought by the 

 waters in an impalpable powder. And this powder of 

 stone formed the rocks which now cover these eminences. 



These causes act with more force under the equator, 

 as the winds are there more uniform, aud the tides more 

 violent : and accordingly the greatest chain of mountains 

 is near the equator. Those of Africa and Peru are the 

 highest we know, which after traversing whole conti- 

 nents, stretch to very considerable distances, under the 

 waters of the ocean. The mountains of the north are 

 not equal to these. Moreover the number of isles in the 

 northern seas is inconsiderable, while there is a vast quan- 

 tity under the torrid zone : and an ; island* is no more 

 than the top of a mountain. 



It is then doubtless the general flux and reflux of the 

 sea, which has produced the greatest mountains. But 

 others we may ascribe to currents, winds, and other irre- 

 gular agitations of the sea, which must by their various 

 combinations .infinitely vary the direction of the tides. 

 They are the smallest of all which owe their rise to earth- 

 quakes, or other accidental causes. 



But how shall we account for the formation of the 

 Iron Mountain, near Taberg, in Sweden ] It is situated 

 in a mountainous part of the country, covered with sand, 

 near forty leagues from the sea. It is an entire mass of 

 .rich irun ore, the perpendicular height whereof is above 



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