XXlV 



INTRODUCTION. 



4late of the Southern hemifphere, and can pronounce with 

 certainty, that the equilibnm7i of the globe is effectually 



, preferved, 



<juantity as that which M. Le Monier refts his whole caufe upon ; and if fo, his argu- 

 ments, which depend wholly on a fuppofition, that not only they, but M. Bouvet's 

 alfo, were capable of determining it with the utmoft exadtnefs, muft fall to the 

 •ground. 



I ft, It appears, from various inftances, that the variations obferved by the fame 

 compafs would d*ffer 3" to 5", 6", and fometimes even 10°, from no other caufe what- 

 ever, but putting the fliip's head a contrary way *. 



2d, That the fame compafs, in the fame fituation in every refpeft, within a few 

 .miles, but at two different times of the fame day, would give variations differing from 

 ■one another, 3°, 4.% 5°, 6% and even f \. 



3d, That the fame compafs, on the fame day, and in the hands of the fame obferver, 

 will give variations differing from one another by 5°, on board the feme ftip, whea 

 under fail, and when at anchor in a road-ftead J. 



4th, Compaffes, made by the fame artift, at the fame time and place, "but on board 

 different fhips, differed 3", 4°, and even 5° in the variation §. 



eth. The fame Compaffes, on board the fame fliip, and within a few miles of the 

 .fame fituation, but at different times of our being there, gave variations differing by 

 4° and s°, or upwards ||. 



6th, Different 



• Seethe Original Aftronomical Obfervations, made in the fecond Voyage, March 11, 

 1773. P- 372- January 24, 177+.?- 375- and July 28, p. 378. 



-f- obfervations in the fecond Voyage, Febriiary J, 1773. P-37'' and January 19, 1775, 

 ,p. 382. Alfo Obfervations in laft Voyage, July 17, 177b, p. 179. Augult 30, p. 181. Ja- 

 nuary 24, 1777. p. 192. and September 15, 177S, p. 205. 



X Aftronomical obfervations of fecond Voyage, July 14, 1775, p. 585. 



§ Compare the Aftronomical Obfervations, made in the fecond Voyage, Augnft ^, and 9, 

 and September 4, 1772, p. 181. with thofe of t!ie f.. me dates, p. 369. Thole of January 

 II, and 14, and Febru2ry7, 177;, p. )8z, with thofe of the fame dates, p. 371. Alfo 

 Aftronomical Obfervations, made in the lail Voyage, of December 27, i>76, p. 191. Fe- 

 bruary 22, 1778, p. 201. IViay 5, and 8, p. 1C2. July 9, and 64, 1779, p. 209. and. 

 January 16, l7iiO, p. 212. v.'ith thtfe of the fame dates, p. 191, 295, 294, 297, 

 and 298. 



II Compare Aftronomical Obfervations, made in the fecond \'oyage, February 10, 

 .?■ 37;- '^'''^ Obfervations of December ii, 1774, p. 381. Alfo ObfervaciLns, made 

 "iu the lall Voyng , M..y 3, and June 18, 1779, p. 208. 



