XVlll ADVERTISEMENT. 



dated much more cordially in praife of them, had 

 they not gone much too far in praife of me. Ne- 

 verthelefs, gratitude conftrains me to fay, that 

 they are the produdion of Mr. Therejfe, Counfellor 

 at Law, who favoured me a year ago, in the month 

 of January, with this particular teftimony of his 

 friendfliip, and of his fuperior talents. 



Let us return to the point in which the Acade- 

 micians are principally interefted. In order to ac- 

 quire conviftion that the Poles of the Earth are 

 drawn out lengthwife, there is not the leaft occa- 

 lion for folving fome tranfcendant geometrical 

 problem, hedged round and round with equations, 

 fuch as the quadrature of the circle ; it is fufficient 

 to poflefs the moft trivial notions of geometry and 

 of phyfics. Before I proceed to coUeâ: the proofs 

 which have already been produced, and to confirm 

 thefe by the produdion of others altogether new, I 

 beg leave to fay a word or two on the means which 

 may be employed for afcertaining the truth, as 

 much for the fake of my own inftrudion, as for 

 that of my critics. 



We are in the bofomof ignorance, like mariners 

 in the midft of a fea without (hores. We perceive 

 in it, here and there, fome truths fcattered about 

 like illands. In order to hit, and to diftinguifli, 

 iflands in the open Sea, it is not fufficient to know 



their 



