106 A VOYAGE TO AUG. 



pitched on the pier head, where they made their ob- 

 servations, and compared their watches, every day 

 at noon, with the clock on shore, by signals. These 

 signals the Chevalier very obligingly communicated 

 to us ; so that we could compare our watch at the 

 same time. But our stay was too short to profit 

 much by his kindness. 



The three days' comparisons which we made, 

 assured us that the watch had not materially, if at 

 all, altered her rate of going ; and gave us the same 

 longitude, within a very few seconds, that was ob- 

 tained by finding the time from observations of the 

 sun's altitude from the horizon of the sea. The 

 watch, from a mean of these observations, on the 1st, 

 2d, and 3d of August, made the longitude 16 31' 

 west ; and, in like manner, the latitude was found to 

 be 28 3(Y IF north. 



Mr. Varila informed us, that the true longitude 

 was 18 35' 30", from Paris, which is only 16 16' 

 30" from Greenwich ; less than what our watch gave 

 by 14/ 30". But, far from looking upon this as an 

 error in the watch, I rather think it a confirmation 

 of its having gone well ; and that the longitude by it 

 may be nearer the truth than any other. It is farther 

 confirmed by the lunar observations that we made in 

 the road, which gave 16 3T 10". Those made be- 

 fore we arrived, and reduced to the road by the watch, 

 gave 16 33' 30". And those made after we left it, 

 and reduced back in the same manner, gave 16 28'. 

 The mean of the three is 16 30' 40". 



To reduce these several longitudes, and the lati- 

 tude, to the Pic of Teneriffe, one of the most noted 

 points of land with geographers (to obtain the true 

 situation of which, I have entered into this particular 

 discussion), I had recourse to the bearing, and a few 

 hours of the ship's run after leaving Santa Cruz road ; 

 and found it to be 12" 11" south of the road, and 29' 

 30" of longitude west of it. As the base, which 

 helped to determine this, was partly estimated, it is 



