CHAP. IV.] INFLUENCE OF SUN. 207 



in the experiment fired a pistol ball of that metal 

 into a piece of wood which had been long ex- 

 posed to the cold. 



Now, as before, we found there was more grind- 

 ing during the prevalence of calms, or light airs, 

 than in a breeze ; for, the greater part of the even- 

 ing and night of the 1st February, there was a fear- 

 ful noise outside and even at the edge of the floe, 

 and on examination the next day I ascertained 

 that a further encroachment had been made ; 

 and, from the uplifted waves of ice, and the con- 

 fused and massive heaps thrown up or partly 

 crushed, it was evident the force must have been 

 irresistible. Many lanes of water were visible on 

 the morning of February 2nd ; and though the ther- 

 mometer was still low, the sun whose altitude was 

 8° 39' 45 /7 at noon, began to produce some effect 

 on the southern thermometer exposed on board 

 though surrounded with snow, the difference be- 

 tween this and the northern one amounting to 

 15°. If any thing, the ship had gone a little 

 nearer the shore. The variation was 60° 45' 

 west. On walking round the floe, I observed 

 that some one had cut the figure of a cross on 

 the overhanging and inner face of a huge wave 

 of ice, left by a former pressure in that menacing 

 attitude. 



The wind having got round from N. E. to 



