to the Strait of Magellan, 



3 



of the Dock-yard, completely equipped, with provisions for 

 eight months, and wood and water for five ; and, as the for^ 

 tunate conckision of all sea-expeditions must, in great measure, 

 depend on the health and comfort of the seamen, it was the com- 

 mander's principal care to use every precaution for that effect. 



He therefore sent on-board, not only an ample supply of 

 additional warm clothing for the crew, but also ail such medi- 

 cines, and other preservatives, as the experience of former 

 navigators had shown to be essentially useful. 



Whilst the commander was thus employed, the two officers, 

 charged with the nautical observations, carried on-board twa 

 marine watches or time-pieces, (Nos. 15 and 16 of Berthoud,) 

 which belonged to the Observatory of Cadiz, and also No. 71 

 of Arnold, a small one belonging to Lieut. Belmonte ; and, by 

 means of observations on-shore, and signals on-board the frigate, 

 began to ascertain their several rates of motion, and to form the 

 corresponding tables. 



At the same time was carried on-board a complete collection 

 of instruments, chosen from those procured by order of His 

 Catliolic Majesty in London, under the inspection of Mr. 

 Jacinto Magellan, and from the hands of the most eminent 

 artists of England. In removing them from the Observatory to 

 the ship, the glass tube of the marine barometer suddenly burst, 

 without its having received any blow or other injury, — so that 

 the mercury was lost, — occasioned probably by the mercury 

 having been but imperfectly purified, or perhaps not in the 

 just quantity; so that we were under the necessity of proceed- 

 ing on our voyage without tiiat most valuable but delicate in- 

 strument. 



Amongst these instruments were the best English quintants 

 and sextants that could be procured : for if, by the aid of the 

 time-pieces, we hoped to be able to ascertain every day the 

 errors occasioned in our reckoning, by its own unavoidable un- 

 certainty, as well as by the setting of tides and currents; so, by 

 constant observations of the distance of the moon from the sua 

 or stars, performed with these excellent instruments of reliec- 

 tion, by two distinct observers, it was to be expected, as it was 

 afterwards experienced, that in each lunation we might disco- 

 ver what confidence ought to be plaeed in these time-pieces, 

 supposing them to preserve one uniform motion : and, from 

 such comparisons and calculations, we made no doubt of ob- 

 taining satisfactory results. 



Lastly, as ever}^ information that could be collected respect- 

 ing the object of the voyage must be useful, eitiier as furnishing 

 advice to be foliov»^ed, or as pointing out what was to be 

 avoided, the several ofiicers of the frigate made it their business 



B 2 



