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horizon. Field ice usually varies in thickness from 5 to 20 feet. 

 Its surface is usually covered by a large deposit of snow, which 

 usually melts during the summer, forming many fresh-water pools. 

 Generally the field is covered by long ridges or hummocks, some 

 of which are often very high. 



A "floe" is a collection of sheets of ice, mere or less connected by 

 freezing. The pieces vary from one-half to one mile in diameter. 

 The extent of the ice can usually be seen. When the pieces of ice are 

 smaller, the ice is called "drift ice." 



"Floe berg," a large mass of ice broken off from floes of great 

 thickness usually built up by rafting and freezing and forced on 

 shore. 



''Ground ice," ice formed on the rivers and inlets before the general 

 freeze up. 



"Growler," a small piece of glacial ice dangerous to navigation, 

 usually caused by the capsizing and disintegration of an iceberg. 



"Iceberg," a large mass of glacial ice. 



"Ice foot," floe ice frozen fast to shore. 



"Land ice," comparatively thin ice attached to shore. 



"Lane" or "lead," a narrow track of open water between floes or 

 pack ice. 



"Nipped," when a vessel is pressed by ice floes on both sides. 



"Pan," a large sheet of ice thicker at the edges than in the middle. 



"Pack," a large collection of heavy ice closely packed together 

 and usually impossible of navigation, ordinarily of such extent that 

 its limits can not be seen. When the individual pieces do not touch, 

 an "open pack" exists; when they are pressed together, a "close 

 pack" exists. 



"Patch," a small collection of drift ice. 



"Rotten ice," old ice that has been subjected to the disintegrating 

 forces apd is well honeycombed. 



"Rafting," piling up of sheet on sheet of ice by the action of the 

 wind and sea. 



"Stream," a drifting line of drift ice. 



"Sheet ice," a large sheet of floe or bay ice adrift at sea. 



"Shore ice," the original ice formed along the shore, free from 

 motion due to tide and sea. 



"Sludge," a field of brash ice. 



"Slob ice," loose broken ice that collects in bays and along edges 

 of floes, usually more or less discolored. 



"Tongue," a projecting point of ice from a berg under the water. 



"Young ice," ice that forms in the open sea early in the autumn, 

 when the temperature is sufficiently low, usually a film of ice. When 

 the ice becomes very thick it is called "bay ice." 



