trembling noise, according as the degree of pressure was diminished or
increased, until it had risen as high as the deck. After about two hours
the motion ceased, and soon afterwards the two sheets of ice receded
from each other nearly as rapidly as they had before advanced. The ship
in this case did not receive any injury; but, had the ice only been half
a foot thicker, she might have been wrecked." Other navigators have not
been so fortunate; and the annual loss of whaling vessels in the polar
seas is considerable, the Dutch having had as many as seventy-three sail
of ships wrecked in one season. Between the years 1669 and 1778, both
inclusive, or a period of one hundred and seven years, they sent to the
Greenland fishery fourteen thousand one hundred and sixty-seven ships,
of which five hundred and sixty-one, or about four in the hundred, were
lost.

Every one will remember the intense and mournful interest occasioned by
the loss of the President steamer which left New York in the year 1841
to cross the Atlantic, but perished in the passage, without leaving a
survivor to tell the story of her fate. It has been deemed highly
probable that this vessel got entangled in the ice, and was destroyed by
collision with its masses; for during that year, in the month of April,
the Great Western steamer encountered a field extending upwards of a
hundred miles in one direction, surrounded with an immense number of
floes and bergs, and had great difficulty in effecting its passage by
this floating continent in safety.

Another form under which the ice appears in the ocean is that of bergs,
which differ from the ice-fields in shape and origin. They are masses
projecting to a great height above the surface of the water, and have
the appearance of chalk or marble cliffs and mountains upon the deep.
They have been seen with an elevation of two hundred feet--a