*44 Examination of St. Plcfre's Hypothecs 



fea; their retardations and accelerations on thefe fhoresj 

 their directions, fometimes eaftward, fometimes weftward, 

 according to the monfoons ; finally, their elevation, which 

 increafes in proportion as we approach the poles, and di- 

 miniihes in proportion to the diftances from it, even between 

 the tropics, demonftrate that their focus is not -under the 

 line. The caufe of their motions depends not on the attrac- 

 tion or prefiure of the fun and moon on that part of the 

 ocean, for their forces would undoubtedly acl there with the 

 greateft energy, and in periods as regular as the courfe of the 

 two luminaries. 



Why, then, are the tides between the tropics fo feeble 

 and fo much retarded under the direcf. influence of the 

 moon ? 



Why does the moon, by her attraction, give us two tides 

 every 24 hours in the Atlantic ocean, and produce only one 

 in manv parts of the South fea, which is incomparably 

 broader ? 



Why do the tides take place there con flan tly at the fame 

 hours, and rife to a regular height almoft all the year round ? 



Why do fome rife at the quarters juft the fame as at the 

 full and change ? 



Why arc they always ftronger as you approach the poles, 

 and frequently fet in toward the line, contrary to the principle 

 of lunar impulfion ? 



Thefe problems, which it is impoffible to explain by the 

 lunar theory, admit an eafv folution on the hypothefis of the 

 alternate fufion of the polar ices. 



Such are the moft material objections adduced to invali- 

 date the lunar theory. How far they are conclufive, fhall 

 be left to future inveftigation. 



But St. Pierre is not content with demolifhing the old 

 itru&ure ; he has judged proper to ere6l a new one; and a 

 fair expofition of this fyftem will enable us to determine, by 

 comparifon, to which we fhall give our fuffrage. 



It is well known that Sir Ifaac Newton and Caflini differed 

 in their opinion refpefting the figure of the earth : the former 

 conceiving it to be an oblate fpheroid, flattened at the poles ; 

 the latter contending it mull be oblong, or elongated at the 



poles. 



