•100 
VOYAGE TO GREENLAND. 
arising from thedriftiiig of heavy ice, I shall refer to 
Captain Scoresby’s account of the tremendous con- 
cussion of fields. He observes that the occasional 
rapid motion of ice fields, attended with the de- 
structive effects, which are produced on any op- 
posing substance, exhibits one of the most striking, 
and, at the same time, one of the most terrific 
sights, which Greenland produces. These bodies 
not unfrequently acquire a rotary motion, by Avhich 
their circumference attains a velocity of several 
miles an hour. If a field, thus in motion, comes in 
contact with another at rest, or more especially in 
a contrary direction of movement, the shock is 
dreadful. Some faint idea may, indeed, be con- 
ceived of the consequences which must ensue, when 
a body of more than ten thousand millions of tons 
in weight^ encounters resistance to its motion. 
The weaker field is crushed to atoms, with an 
awful noise ; sometimes the destruction is mutual ; 
pieces of huge dimensions, are not unfrequently 
piled to the height of twenty or thirty feet upon 
the top, whilst, doubtless, a proportionate quantity 
is depressed beneath. These stupendous effects, 
when viewed in safety, exhibit a picture sublimely 
grand ; but where there is danger of being over- 
^ Captain Scoresby estimates .that a field containing thirty 
nautical square miles in surface, with a thickness of thirteen feet, 
would weigh more than is here mentioned, allowing it to dis- 
place the water in which it floats to the depth of eleven feet. 
The weight would appear to be 10,182,857,142 tons, nearly in 
the proportion of a cubic foot of s^a water to sixty-four pounds. 
