228 ACCOUNT OF THE ARCTIC REGIONS. 



vated. It is kept dov/ii by some larger mass ; from 

 beneath which, it shows itself on one side. I have 

 seen a calf so deep and broad, that the ship sailed 

 over it without touching, when it might be observed 

 on both sides of the vessel at the same time ; such 

 an experiment, however, is attended with consider- 

 able danger, and necessity alone can warrant it, 

 as calves, when disturbed by a ship sailing over 

 them, have not unfrequently been called from their 

 sub-marine situation to the surface, and with such 

 an accelerated velocity, as to damage the vessel, or 

 even to occasion shipwreck. 



10. A tongue is a point of ice projecting nearly 

 horizontally from a part that is under water. Ships 

 have sometimes run aground upon tongues of ice. 



11. A pack is a body of drift-ice of such magni- 

 tude, that its extent is not discernible. A pack is 

 said to be open, when the pieces of ice, though very 

 near each other, do not generally touch ; or closer 

 when the pieces are in complete contact. 



12. A patch is a collection of drift or bay-ice of 

 a circular or polygonal form. In point of magni- 

 tude, a pack corresponds with a field, and a patch 

 with a floe. 



13. A stream is an oblong collection of drift or 

 bay-ice, the pieces of which are continuous. It is 

 called a sea-stream, when it is exposed on one side 

 to the' ocean, and affords shelter from the sea, to 

 whatever is within it. 



