IXX ADVERTISEMENT. 



It's return, therefore, is to be calculated only 

 from the month of Oftober, when I fuppofe it to 

 be in the vicinity of the Line, the calms of which 

 may have flopped it, till it felt the influence of the 

 South Pole, which does not acquire aftivity, in our 

 Hemifphere, till toward the month of December. 

 At that epoch, the courfe of the Atlantic, which 

 goes to the North, being the fame with that of our 

 tides, it might have been brought near our fhores, 

 and there expofed to many retardations, by the 

 difgorging of the rivers which croffed it*s courfe, 

 as they threw themfelves into the Sea, but chiefly 

 by the re-adion of the tides : for if their flux fees 

 in toward the North, their reflux carries back to 

 the South. 



It is of efi"eniial importance, therefore, to make 

 experiments of this kind in the open Sea, and efpe- 

 cially to pay attention to the diredion of the Cur- 

 rent of the Ocean, for fear of conveying fouthward 

 intelligence defigned for the North, At the feafon 

 when that Current is not favourable, advantage 

 might be taken of the tides, which frequently run in 

 the contrary diredion ; but as I have juft obferved, 

 there is this great inconveniency, that jf their flux 

 fets in northward, their reflux carries back again 

 teward the South. 



The 



