SAIL FROM TENERIFE. 35 



which at present beset geographers in attempting 

 to delineate this unknown land, will not soon again 

 present itself. 



Having completed the necessary magnetic obser- 

 vations, and rated the chronometers, we sailed from 

 Tenerife, on the evening of the 23rd. It should 

 be noticed that the results obtained from our obser- 

 vations for the dip of the needle, differed very mate- 

 rially from those given by former observers : the 

 experiments made by Lieutenant Grey in different 

 parts of the island, satisfied us that the variation 

 could not be imputed to merely local causes. 



As in obedience to our instructions we had to 

 examine and determine the hitherto doubtful posi- 

 tion of certain rocks near the Equator, about the 

 meridian of 20° W. longitude, we were obliged to 

 take a course that carried us far to the eastward of 

 the Cape de Verd Islands ; for this reason we had 

 the N. E, trade wind very light ; we finally lost it on 

 the 30th, in lat. 13" 0' N., and Ion. 14° 40' W. ; it 

 had been for the two previous days scarcely per- 

 ceptible. 



The S.E. trade reached us on the 8th of August, 

 lat. 3° 30' N. long. 17° 40' W., and on the morning 

 of the 10th we crossed the Equator in long. 22° 0' 

 W. : when sundry of our crew and passengers under- 

 went the usual ceremonies in honour of old Father 

 Neptune. A close and careful search within the 

 limits specified in our instructions justified us in 

 certifying the non-existence of the rocks therein 



D 2 



