Arctic Natural History. 75 



which was securely closed also with firm snow, one had to 

 call out in quite a stentorian voice before a reply could be 

 obtained. The thickness of the slab of snow which closed 

 the doorway was not above nine inches. This is at once a 

 proof of the bad conductor of sound we have in snow. It is 

 very probable that the property of conducting sound dimi- 

 nishes with the density from ice down to the softest snow. — 

 (Sutherland's Journal.) 



5. The Breaking up of an Iceberg. 



When an immense iceberg begins to tumble to pieces 

 and change its position in the water, the sight is really 

 grand, — perhaps one that can vie with an earthquake. 

 Masses inconceivably great, four times the size of St 

 Paul's Cathedral, or Westminster Abbey, are submerged 

 in the still blue water to appear again at the surface, 

 rolling and heaving gigantically in the swelling waves. 

 Volumes of spray rise like clouds of white vapour into the 

 air all round, and shut out the beholder from a scene 

 too sacred for eyes not immortal. The sound that is 

 emitted is not second to terrific peals of thunder, or the dis- 

 charge of whole parks of artillery. The sea, smooth and 

 tranquil, is aroused, and oscillations travel ten or twelve 

 miles in every direction ; and if ice should cover its surface 

 in one entire sheet, it becomes broken up into detached 

 pieces, in the same manner as if the swell of an extensive 

 sea or ocean had reached it ; and before a quiescent state is 

 assumed, probably two or three large icebergs occupy its 

 place, the tops of some of which may be at an elevation of 

 upwards of two hundred feet, having, in the course of the 

 revolution, turned up the blue mud from the bottom at a 

 depth of two to three hundred fathoms. 



6. Refrigerating power of Icebergs. 



When we lost sight of this iceberg, or, I should rather 

 say, of its ruins, a state of perfect rest had not been ac- 

 quired. One half of it had but turned over upon its side, 

 so that the pinnacled top had become the one side, while 

 the bottom bad become the other ; and the other half ap- 



