The Portland gazette. [volume] (Portland, Me.) 1818-1824, 1818-11-10

where the soundings exceed 900 faith.
oms, masses of such enormous dimen-
sions are met with, that the Dutch sea-
men compare them to cities and often be
stow on them the familiar names of I'm
sterdam or Eacrlem. They are carried
towards the Atlantic by the current,
which generally flows from the north
east and after they reach the lower lat
itudes, they rapidly dissolve, and finally
disappear, probably in the space Of few
months.
The blocks of fresh water ice appear
black, as they swim IN the sea but show
fine emerald or beryl hue, when
brought up on tbs deck Il hough per-
ftctly transparent like crystal. they some
times inclose threads, or streamlets, Of
air bubbles. extricated il the act of con
gelation. This pure ice being only a
fifteenth part lighter than fresh water,
must consequently project about one
tenth as it swims on the sea. An ice
berg of 1000 feet in height, would there
fore, after it Aoa,ed, still rise 400 feet
bovc tie surface of the water. Such
perhaps may be considered as nearly the
extreme dimensions. Those mountains
of ice may even acquire more elevation
at distance from land, both from the
snow which falls on them and from the
copious vapours which precipitate and
CONCEAL on their surface. But in gener
al, they are carried forwards by the cur
rent which sets from the southeast into
The Atlantic, where, bathed in warmer
fluid, they rapidly waste and dissolve.
1t may be shown, by experiment, that if
the water IN which they float had only
the temperature of A, the mass of ice
would lose the thickness of an inch every
hour, or two feet in day. Surprising
the surface OF the sea 10 be at 81, the
daily elimination of thickness would be
double, and would therefore amount to
-four feet. IN iceberg, having 600 feet
of total elevation would hence, on this
probable estimate, require $50 DAYS for
It's dissolution. But the melting of the
ice would be greatly accelerated, if the
mass was impeiled through the water by
the action OF winds. a velocity of only
mile in an hour would triple The ordi
nary effect. Hence, though large bodies
of ice are often found near the banks OF
Newfoundland. they seldom advance
farther, or pass beyond the 46th degree
of latitude. Within the Arctic regions,
those stupendous blocks remain, by their
mere inertia, SO fixed on the water, as
commonly to serve for the mooring of
vessels employed in the whale fishery
In such cases, however, it is necessary
PROBATION to lengthen out the cables ana
ride at some distance from the frozen
cliff because the fragments of ice which
the seamen term caves, are frequently de
tached from the under part of the mass,
and darling upwards, acquire such vel
ocity in their ascent, that they would in
failibly strike holes into the ships bot
tom.
AS heat is absorbed in the process Of
thawing, so it is again evolved in the act
OF eongelstion The annual formation
and destruction of ice within the arctic
Circle, is hence beautiful provision of
nature, for mitigating the excessive inc
quality of temperature. Had only dry
land been there opposed TO the sun, il
would have been absolutely scorched by
his incessant beams in fummer, and
pinched In the darkness of winter by the
intense and penetrating cold. None of
the animal or vegetable tribes could at all
have supported such extremes. But in
the actual arrangement, the surplus heat
of summer is spent in melting away the
ice /; and It's deficiency in winter is part
ly supplied by the influence of the pro
gress of congelation, AS long as ice re
mains to -tlfaw, or water to freeze, the
temperature of the atmosphere can new
or vary beyond certain limits. such is
the harmony of the system and all ex-
perience and observation forbid US to be
lieve il TO be subject to any radical
change. Some years may chance to form
more ice than Others, or to melt more a.
way, but it were idle to.expect any thing
like general permanent disruption of
the glacia crust which binds the regions
Of the north. But even were this ice
once removed, a similar collection would
soon succeed, since it is always the ef1ecr,
and not the cause, of the disposition of
the atmosphere, which it really serves to
temper. We should be guilty of the |