POLAR ICE. 437 
discovered at a great distance, by that singular appearance on 
the verge of the horizon which the Dutch seamen have termed 
ice-blink. It is a stratum of lucid whiteness, occasioned evi- 
dently by the glare of light reflected obliquely from the sur- 
face of the ice against the opposite atmosphere. This shining 
streak, which looks always brightest in clear weather, indi- 
cates to the experienced navigator, twenty or thirty miles be- 
yond the limits of direct vision, not only the extent and figure, 
but even the quality of the ice. The blink from packs of ice 
appears of a pure white, while that which is occasioned by 
snow-fields has some tinge of yellow. 
The mountains of hard and perfect ice are the gradual pro- 
duction, perhaps, of many centuries. Along the western coast 
of Greenland, prolonged into Davis's Strait, they form an im- 
mense rampart, which presents to the mariner a sublime spec- 
tacle, resembling, at a distance, whole groups of churches, 
mantling castles, or fleets under full sail. Every year, but 
especially in hot seasons, they are partially detached from 
their seats and whelmed into the deep sea. In Davis's Strait 
those icebergs appear the most frequent ; and about Disco 
Bay, where the soundings exceed 300 fathoms, masses of 
such enormous dimensions are met with that the Dutch sea- 
men compare them to cities, and often bestow on them the 
familiar names of Amsterdam and Flaerlem. They are car- 
ried toward the Atlantic by the current which generally flows 
from the north-east, and after they reach the warmer water 
of the lower latitudes they readily dissolve, and finally disap- 
pear, probably in the space of a few months. 
The blocks of fresh-water ice appear black as they float ; 
but show a fine emerald or beryl hue when brought up on the 
deck. Though perfectly transparent like crystal, they some- 
times enclose threads or streamlets of air-bubbles, extricated 
in the act of congelation. This pure ice, being only a fif- 
teenth part lighter than fresh water, must consequently project 
about one-tenth as it swims on the sea. An iceberg of 2000 
feet in height would therefore, after it floated, still rise 200 
above the surface of the water. Such, perhaps, may be con- 
sidered as nearly the extreme dimensions. Those mountains 
of ice may even acquire more elevation at a distance from 
land, both from the snow which falls on them, and from the 
copious vapors which precipitate and congeal on their sur- 
face. But in general they are carried forward by the cur- 
rent which sets from the north-east into the Atlantic, where, 
bathed in w^armer fluid, they rapidly waste and dissolve. It 
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