Ch. ir. SOUTH AMERICA. jji 



the eaftward of his reckoning. The captain of the 

 Louis Erafme found the difference nearly the fame as 

 the captain of the tViarqvñs d'Antin, who nvjde ufe of 

 an equation. Both, as i have already cbferved, found- 

 ed their correciioMS on the variations; differing very 

 confiderably from that delineated on the chai ts. 



The great variety of currents met' with in failing 

 round Cape Horn, being fometimes ftrong, fometimes 

 moderate, and at others fcarce perceivable, induces 

 me to think that they v/ere not confiderable in corretSt- 

 ing the account. For their velocity being uncertain, 

 it is in fadl only committing a voluntary error; and 

 as the variAcions enable Ub to gnefs at our longitude 

 within two or three degrees; and as after making ufe of 

 the equation, the place of the ihip cannot be known 

 nearer the truth, the correction is entirely ufelefs ; and 

 the inference drawn from obferving the variation, is a- 

 bundantly fufficient for fecurity. I fay, that the place 

 of the fliip may be known {o within two or three de- 

 grees; and a more exatl conformity between the cor- 

 rected reckoning and the time of making land would 

 be rather fortuitous than the effed: of accuracy, in 

 making the correélion. The difference of one or two 

 degrees in the variations, an error unavoidable, may 

 produce in the longitude an error of three or four de- 

 grees, or even more, according to the place of the 

 lliip. Every one on board the three frigates, found 

 their reckoning to the weftward of the ihip's true place, 

 though they had made an allowance for the currents, 

 and the diíFerence between fome of their accounts was 

 not frnall, as I have already noticed *. This was ow- 

 ing to the like uncertainty in the journals of other 



* There is a ilrong current to the W. in thefe feas, and by the 

 beit obicrvations I could in^ike (at a mean) ic is about one niiia 

 per hour, but in fome places much more, eipcciali) near the muuch 

 of tlie river Amazon. 



N B. I generally founJ the above allowance to anfwer from 

 Ut. 4S. to 54 S. A. 



X 4 voyages 



