ADVERTISEMENT. XlX 



of the Seas, with the diurnal Tides on our coafts, 

 are the effeâîs'--. Accordingly, if fome perfons 

 before me, have affirmed, that the Tides are pro- 

 duced by the melting of the polar ices, which I am 

 to this hour ignorant that any one ever did, I, ac 

 leaft, am the firft who demonftrated it. Other 

 Europeans, prior to ChriJIophe)- Columbus, faid that 



* It will be a matter of fome difficulty for many perfons, 

 to conceive how our Tides fliould poffibly, m Summer, re- 

 afcend toward the North Pole, at the very feafon when the 

 Current which produces them is rufliing down from that Pole. 

 They may fee a very fenfible image of thefe retrograde effeéls of 

 running waters, at the bridge of Notre-Dame, at the opening 

 of the arch which is fupported by the Quay Pelletier. The 

 Current of the Seine, direfted obliquely by a kind of dam, 

 againfl: a pile of that arch, produces there a counter-current, 

 which conflantly re-afcends againft the courfe of the river, up 

 to the very bubbling over of the dam. In like manner, the 

 meltings of the northern ices defcend, in Summer, fi-om the 

 bays adjacent to the polar Circle, going at the rate of from 

 eight to ten leagues an hour, according to EUis, Lin/^fchotten, and 

 Barents ; they flow toward the South, in the middle of the At- 

 lantic Ocean ; but coming to meet on their fliores, almofl ia 

 front, Africa and America, where they proje6l on both fides, a 

 violent reflux is produced, to right and left, along the coafts of 

 both Continents, which is forced northward above the Capes 

 BoYador and St. Auguftin, which are rendered famous by their 

 Currents. Now, as the fources from which they iflue have an 

 intermittent flux of acceleration and retardation, occafioned by 

 the diurnal and noclurnal aftion of the Sun on the ices of the 

 eaftern and weftern Hemifphere of the Pole, their lateral coun- 

 ter-currents, that is, their Tides, have likevvife a fimilar inter- 

 mittent flux. 



b 2 there 



