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

fome cafes may be deemed potable.
10 CONCEAL fra water of the ordi. |
nary faItness, or containing nearly the
goth part # is weight of iaIine matter,
itreqsires NOT an extreme cold, this pro
GETS taking effect about the 27th degree
OF Fahrenheit's fcale, or only degrees
bslew tile freezing point of freih water
Within the .4rctic circle, therefore, the
iurface of the ocean being never much
warmer. is. in the decline of the summer,
foon cooled down to the limit a which
congeation commences. About the end
of Jelly, or the beginning Of Augulf, a
iheet of ice in the space of single night
10 formed, perhaps an inch thick he
5froit now maintains It's ascendencY, and
fhoots its increasing energy in all direc,
tions, till it has covered the whole
extent of thole feas with fold vault TO
the depth Of feyeral feet But, on the
retura of fpring, the penetrating rays of
the sun gradually melt or foften that icy
floor, and render Its subltance friable,
and easily disrupted II he hrf hrong
wind, Creating swell in the ocean, then
breaks up the vaf continent into large
fields, which are afterwards fhrivslls in
70 fragments by their mutual collision
This generally happens early in the month
of June; and few weeks are common
ly sufficient to disPerie and dlholve the
floating ice. The fea Is at lait open,
for fhort and dubious interval, 10 the
purfuits of the adventurous mariner.
While iccbergs are thus the slow
growth of ages, the fields or shoals of sa-
line ice are annually formed and destroy
ed The ice generated from melted snow,
is hard, pellucid, and often swells to en-
ormous height and dimensions But the
concretion of salt water wants soli6ity,
clearness and strength, and never rises TO
any very considerable thickness: 1t sci
dom floats during more than part of the
year. though in some cold seasons the
scattered fragments may be surprised by
the early frost, and preserved Ill the fol
lowing summer.
The whale fishers cnumerate several
varieties Of salt water ice. A very wide
expanse of it they call field, and one
of smaller dimensions foe. When a
field is discovered by subaqueous or grown
swell, it breaks into numerous pieces, sell
dom exceeding 20 or 50 yards in diam
eter, which, taken collectively, are term
ed pack. This pack again, when of a
broad shape is called patch, and when
much elongated a stream. The packs
Of ice are crowded and heaped together
by violent winds, but they again separate,
and spread asunder iii calm weather
IF a ship can sail freelythrough the float
inc pieces of ice it is called drift ice !;
and the ice itself is said TO be loose or
open. When, from the effect of abra
sion, the larger blocks of ice are crpm
bled into minute fragments, this collec
ton is called brash ice. n portion of zee
rising above the common level, is termed
q hummock. being produced by the
squeezing Of one piece over another.
These hummocks of protuberances break
the uniform surface of the ice, and gives
it a most,diversi6ed and fantastic appear.
ance. They are numerous in the heavy
packs and along the edges of ice fields,
reaching to the height Of thirty feet.
The term sludge is applied by the sailors
to the soft and ncoherent chrystal which
the frost forms when it FIRST attacks the
rufIled surface of the ocean. AS these
increase, they have some effect like oil,
10 still the secondary waves but they
are prevented, from coalescing into con-
tinuous sheet. by the agitation which still
prevails; and they form small discs, roun-
ded by continual attrition, and scarcely
three inches in diameter, called pancakes
Sometimes these again unite into circu.
lar pieces. perhaps foot thick, and ma.
ny yards in circumfessrce.-
Inc FIELDS, and other collections Of
floating ice, are often discovered great
distance by that singular appearance on
the verge of the horizon, which the
Dutch seamen have termed ice blink. 1t
is stratum Of lucid whiteness, occasion
&c evidently by the glare of light rehec-
ted obliquely from the surface of the ice
against The opposite atmosphere. This
shining streak which looks always bright
eet in clear weather indicates, to the ex-
perienced navigator. 20 or go miles be-
vond the limit of direct vision, not only
the extent and figure but even the quality
of the ice. he blink from packs of ice,