AÎ>VERTISEMENT. XXXI 



heat of thofe luminaries, which melt, for fix 

 months alternately, ihe ices of each Pole. 



I have afterwards adduced two very curious ob- 

 fervations, in proof of the exiftenceof a fimilar al- 

 ternate and half-yearly Current in the Atlantic 

 Ocean, in which, till now, no fuch thing had been 

 fufpeded. The firfi: is that of Rennefort, who 

 found, in the month of July 1666, on leaving the 

 Azores, the Sea covered with the wrecks of a na- 

 val engagement, which had taken place nine days 

 before, between the EngliOi and Dutch, off 

 Oftend. Thefe wrecks had been carried along, 

 in nine days, more than 275 leagues to the South, 

 which is confiderably above 30 leagues a day: and 

 this is a fifth nautical experiment, which proves, 

 from the rapidity of the Currents of the North, 

 the confiderable elevation of that Pole above the 

 Horizon of the Seas. 



IX. My llxth nautical experiment demonftrates 

 particularly the elevation of the South-Pole, from 

 the extent of it's Currents, which, in winter, force 

 their way up to the extremities of the Atlantic. It 

 is the obfervation of Mr. Pennant, the celebrated 

 Englifli Naturalift, who relates, that the Sea threw 

 on the coafts of Scotland, the maft of the Tilbury- 

 man of war, which was burnt in the road of Ja- 

 maica j and that they every year pick up on the 



Uiores 



