46 Temperature of Sea. 



fathoms of line out. I brought into use on this 

 occasion the Casella thermometer with which the Hy- 

 drographer had kindly supplied me, and ascertained 

 that the temperature at that depth was 30°, whilst 

 at the surface it was 34°, the air at the same time 

 being 39". This result must at once put a stop to 





/ • M 



^p s=»s_ 





Iceberg. 



any idea that may be entertained of a warm current 

 flowing up Davis' Straits. 



This evening we forced our way through several 

 wide and apparently hnpervious streams of ice, 

 which kept the men incessantly at work, either 

 throwing everything aback to avoid a collision with 

 an unusually large and heavy floe, or else backing 

 the main-topsail only, to deaden the ship's way. 



