to the Strait of Magellan. 



5 



Canary and TenerifFe. At 7^ hours a.m. we took observations 

 of the sun's altitude, in order to determine our longitude ; and 

 at the same time found the Pic of Teyde, in Teneriife, bearing^ 

 from us W. 3° S. and the W. point of Grand Canary, 8. 14° 

 W. from which observation we ascertained our phice on the 

 chart, making use of that of M. Verdun de la Crenne : and the 

 latitude so pointed out agreed with that observed the following- 

 noon ; when allowances had been made for a reckoning care- 

 fully kept during the interval of four-and-a-half hours, and for 

 the setting of the waters to the souihward; which, by observing 

 the bearings of the island, we found had been the case. We 

 livere therefore at that time, according to the above-mentioned 

 chart, in N, lat. 2S° 1B'2(/, and in long. W. from Cadiz, 9» 

 28' 48". The time-piece. No. l6 of Berthoud, indicated 2' 7", 

 and No. 71 of Arnold 3' 4" more to the westward : differences 

 so inconsiderable on a course of such extent, as to give great 

 hopes of reaping the highest advantages from those machines ; 

 whilst we entirely abandoned No. 15 of Berthoud, of whose 

 accuracy we had all along been very suspicious. The errors in 

 our ship's reckoning had been so compensated one by another, 

 that it differed only a few minutes from the place laid down on 

 the chart.* 



All this day we continued under sail, with light Avinds, be- 

 tween the Grand Canary and I'eneriffe, whose peak disap- 

 peared to us soon after midnight ; nor did we see it anymore 

 on the following day, on account of the fresh weather. With 

 tolerably fresh breezes we stood on to the S.S.W. that we 

 might the sooner get out of the calms so often met with to 

 leeward of the Canaries. 



* It is necessary here to remark, that all the bearinf!:s mentioned in this accouat 

 are corrected for the variation; and that tlie lougitiuie is counted from the me- 

 ridian of the Royal Marine Observatory at Cadiz 6° 16' W. from Greenwich. 



In the account of the lasl Voyage of the celebrated Captain Cook, an attempt 

 is made to prove, that the position of the Road of Santa Cruz, in TenerifFe, is 

 14' 30" to the westward of that assigned by Captain Don Joseph Varela ; who 

 was employed, with Messrs. Yerdun de la Crenne and Korda, in constructing tlie 

 above chart. The observations of the Spanish astronomer must be preferable to 

 those of Captain Cook, as being absolute, and independent of any errors occa- 

 sioned by a time-piece. However, as much pains are taken in the above voyage 

 to show that Varela was mistaken, we will here compare two positions, as laid 

 down by Cook, with those assigned by two distinct astronomers; which, joined 

 to Cook's remark on the Cape of Good Hope, which he lays down 8' 25" to the 

 W. of the truth, will demonstrate that his tmie-piece went out of England with a 

 positive error ; or that, in a few days, it contracted that error. 



Isle of Guessant (Ushant), according to Cook W. from Paris 7° 37' 37" 



Ditto, according to M. M. Verdun and Borda 7 24 30 



Cook to the westward 0 ]3 0-1 



Cape Finisterre, according to Cook, W. from Cadiz . . .3 12 00 



Pitto, according to Don Vicente Tofino 2 55 54 



Cook to t!ie westward ... o.. 0 16 06 



