ADVERTISEMENT. IX 



teen days, which amounts to more than fix leagues, 

 a day, *' with the affiftance," fays he, *' of the 

 *' counter-currents, which have always a velocity 

 *' equal to the principal Current." This is the 

 only obfervation which I have added, on account 

 of it's importance, and out of the refpedt which I 

 bear to it's Author. 



Thus the general effed of the tides is placed in 

 the cleared light, by the inftance of the lateral 

 counter-currents of our bafons, into which fources 

 difcharge themfelves, by thofe of the lakes which 

 receive rivers, and by thofe of rivers themfelves, 

 notwithflanding their confiderable declivities, with- 

 out any neceffity for a particular ftrait, to produce 

 thofe re-a6\ions along the whole extent of their 

 (hores, though ftraits confiderably increafe thefc 

 fame counter-currents, or eddies. 



The courfe of our tides toward the North ia 

 winter, it mud be admitted, cannot be explained 

 as an effeft of the lateral counter-currents of the 

 Atlantic Ocean, which defcends from the North, 

 for at that feafon it's general Current comes from 

 the South-Pole, the ices of which are then in fu- 

 fion by the heat of the Sun. But the courfe of 

 thofe tides toward the North, may be conceived 

 flill more eafily, from the dired: effed of the ge- 

 neral Current of the South Pole, which runs ftraight 



North» 



