VOYAGE TO THE PACIFIC OCEAN. 5 



the globe is effectually preserved, though the pro- 

 portion of sea actually sailed through, leaves no 



3d, That the same compass, on the same day, and in the hands 

 of the same observer, will give variations differing from one another 

 by 5, on board the same ship, when under sail, and when at 

 anchor in a road-stead. * 



4th, Compasses made by the same artists at the same time and 

 place, but on board different ships, differed 3, 4, and even 5 in 

 the variation, -f- 



5th, The same compasses, on board the same ship, and within 

 a few miles of the same situation, but at different times of our 

 being there, gave variations differing by 4 and 5, or upwards, t 



6th, Different compasses, at the same time, on -board the same 

 ship, and in every respect under the same circumstances, will gi\e 

 variations differing from one another, 3, 4, 5, and 6. 



These differences, several of which happened very near the 

 place in question, are all of them at least equal to, most of them 

 much greater, and some of them double that which M. Le Monier 

 founds his argument on, even according to his own account of it, 

 which I have already shown is by no means admissible, and, there- 

 fore, totally invalidate it. To allege that the instruments made 

 use of in Captain Cook's two voyages were bad, or that the ob- 

 servers were not expert in the use of them, will answer no pur- 

 pose : they are the instruments and observers which M. Le Mo- 

 nier's argument must rest on ; and, therefore, let those of the 

 French, or any other navigator, have been ever so much better 

 than they were (which few will be hardy enough to assert, and 

 fewer still found weak enough to believe), it will avail nothing to 

 the point in dispute, which must evidently fall to the ground, if 

 the observations made for finding the variation in Captain Cook's 

 voyage are not sufficient to support it. What then must become 

 of it, if M. Bouvefs observations, of this kind, were liable to an 



* Astronomical Observations of second voyage, July 14. 1775, p. 385. 



+ Compare the Astronomical Observations, made in the second voyaize, August 

 3. and 9. and September 4. 1772, p. 181., with those of the same dates, p. 369. 

 Those of January 11. and 14. and February 7. 1773, p. 182., with those of the 

 same dates, p. 371. Also Astronomical Observations, tiiade in the last voyage, of 

 December 27. 1776, p. 191, February 22. 1778, p. 201., May 5. and 8. p. 102, 

 July 9. and 24. 1779, p. 209-, and January 15. 1780, p. 212., with those of the 

 same dates, p. 29L, 293., 294., 2!) 7 , and 298. 



Observations made in the second Voyage, February 2. 1773. p. 

 1 8. p. 372. , and January 24. 1 774, p. 575. See also Observations made last Voyage, 

 August 18. 1776, p. 180. October 7. and 14. p. 189, and 190. December 12. 

 p. ibid. January 24. 1777, p. 192. March 10. p. 195. July 9. and 17. 1779, 

 p. 209. January 16. 17S0, p. 212. March 21. p. 213. and May 19. p. 214. 



