162 INCREASE OF SEA TEMPERATURE. \April., 



bottle by a plug of loose cotton : the lead (14 Ibs.) being- 

 attached, carried it too rapidly to the bottom to admit of 

 any ice entering. It is evident that the pressure below 

 would force the cotton, and when the bottle became full 

 the cotton would resume its position in the neck. By 

 reference to page 178, Vol. I., it will be seen that similar 

 experiments determined that the sea during winter is 

 constantly charged with minute crystals of ice ; this had 

 now ceased ; the water, on examination, was found to be 

 perfectly transparent and free from any such crystals ; 

 moreover the temperature, during its very short passage 

 from the floe to my cabin, had risen to 36. These facts 

 satisfy my mind that from this date we may safely calcu- 

 late on the water penetrating, and, acting on any fissures 

 which may offer, aiding in the destruction of the heavy 

 pack. 



An occurrence at this moment forcibly impressed on 

 our minds the effect resulting from any sudden shock 

 communicated to the ice, and the result on the ship. It 

 was found necessary to enlarge the fire-hole alongside the 

 ship; and to aid in effecting this, the Boatswain employed 

 one of the heavy loggerheats (oblong shot) supplied for 

 breaking the light bay ice (its weight was two hundred- 

 weight). This was allowed to fall from a height of about 

 thirty feet, the ice on which he was acting being four 

 feet in thickness, but previously cut free on three sides 

 by the ice saw. 



The concussion to the ship at the stern, where I was 

 seated, sixty feet distant, was fully equal to 20 Ibs. of 

 gunpowder, and caused everything on the table to vi- 

 brate. Nor could I be brought to believe for some 



