OF THE POLAR SEA. 



19 



went down four hundred and fifty fathoms. 

 The change in temperature, shewn by the 

 register thermometer during the descent, 

 was from 52° to 40.5°; and it stood at the 

 latter point, when taken out of the tin case. 

 The temperature of the water brought up 

 in the bottle was 41°, being half a degree 

 higher at four hundred and fifty than at six 

 hundred and fifty fathoms, and four degrees 

 colder than the water at the surface, which 

 was then at 45°, whilst that of the air was 

 46°. This experiment in shewing the 

 water to be colder at a great depth than at 

 the surface, and in proportion to the increase 

 of the descent, coincides with the observa- 

 tions of Captain Ross and Lieutenant Parry, 

 on their late voyage to these seas, but is 

 contrary to the results obtained by Captain 

 Buchan and myself, on our recent voyage 

 to the north, between Spitzbergen and 

 Greenland, in which sea we invariable found 

 the water brought from any great depth to 

 be warmer than that at the surface. 



On the 28th we tacked, to avoid an ex- 

 tensive stream of sailing ice. The tempe- 

 c 2 



