390 APPENDIX. 



by the inequality of the bottom. There is, however, great 

 objection to nearing the land eastward of Cape Horn, in con- 

 sequence of the velocity with which the current sets through 

 Strait Le Maire, particularly with a southerly wind. This 

 does not obtain to the westward of Diego Ramirez, in which 

 direction I see no objection to approaching the coast within 

 forty or sixty miles. Cook ranged this shore very close in 

 December, and on more than one occasion fovmd the current 

 setting offshore, and at other times slowly along it to the S.E. 



In the first part of this passage the currents ran to N.W., 

 but after passing the latitude of 40o S. they set to the east- 

 ward ; and when we arrived off Cape Horn the ship was 

 S. 400 E. 116 miles of her reckoning. 



While we were in the neighbourhood of Diego Ramirez 

 there was little or no current, but to the westward it ran to 

 the W.N.W. It however, soon after changed, and on our 

 arrival off Conception the whole amount of current was 

 N. 490 E. 147 miles. In rounding Terra del Fuego with a 

 southerly wind full four points must be allowed for variation 

 and current. For in this high latitude there will, in most ships, 

 be found ten or twelve degrees more variation with the head 

 west than east ; and though the true variation be but 24o E., 

 at least 29o or 30o must be allowed going westward. 



We found the barometer in this passage an invaluable 

 instrument : upon no occasion did it deceive us. In passing 

 these latitudes my attention was drawn to the changes in tlie 

 temperature of the water, which I usually found to precede a 

 shift of wind from south to north, and vice versa, even before 

 that of the temperature of the air. I subjoin a short state- 

 ment of these changes, for the satisfaction of such as may feel 

 interested in them. 



On the 29th of August, at eight a.m. the temperature of the 

 surface was 58'>, the weather moderate and cloudy, and the 

 wind W. N.W.; from this time to midnight it gradually fell 

 imtil it stood at 48°. The wind now increased, and the next 

 morning shifted to S.W. and S.S.W., and blew fresh gales: 

 the breeze continuing, on the 31st the temperature of the sur- 

 face underwent a further fall of 3^" ; and we had hard squalls. 



