The Delta independent., 1890-08-19
THE NORTH ATLANTIC ICE.
Ensign Rodman Tells of I.!s Observation
OF Icebergs and Fields.
Ensign Hugh Rodman, United States


at the thirty-ninth meeting of the
National Geographic society in the
assembly-hall of the Cosmos club, says
the Washington Star. His topic was
'1cebergs and Field-Ice in the North
Atlantic" he having just returned
from . trip into the ice-making regions
of Labrador and Newfoundland on
special mission on behalf of the HYDRO
gen Office for the purpose of obtaining
Information that might lead to more
accurate knowledge in relation to the
formation and movements of ice around
the lines of regular ocean travel.
His lecture was illustrated with
lantern slides from views taken by him
during his trip. Newfoundland and
the mouth of the St. Lawrence river
yearly send out miles of ice that is ex-
tremely dangerous to navigation. In
deep waters the course of ice can be
easily traced. but in shoal water this
becomes difficult. The movements of
the ice depend in a great measure upon
the various currents that traverse the
ocean in this vicinity, as we'll as upon
great variety of other forces, and
little can be said with any degree Of
defniteness as to the probable move-
ments of ice beforehand. Hundreds OF
vessels have been lost from ignorance
of the local path of the ice, and many
are damaged severely yearly on the
same account.
Greenland is the great factory for the
formation of icebergs, and the most of
those that make an annual appearance
in the northern waters are from this
region. 1t is large island. entirely
covered with ice. that flows down to
nd l.
and tielus. Each glacier produces
annual output of ice that has been esti-
mated at 250. 900, 900, 900 of cubic feet,
or. calculating at the rate of five
pounds day for every man, woman,
and child in the United States, enough
to supply this country for at least 100
years. But only small proportion of
the years production OF bergs ever
reach the transatlantic steamer lines.
for many are melted, but more are
broken up before they get into the
.nayigable waters. OF the Grand
= banks the bergs are the most plentiful
during the spring months.
There is great difference in the
rates at which bergs travel. One may
reach the southern waters the same
year in which it is produced, while
another may be several years going
the same distance. The ice-tields are
great obstacle to the progress of the
bergs. smashing them up and causing
their disintegration. The ice of the
bergs is very brittle, and sometimes q
sharp blow of an ak will shatter q
berg and they are often demolished
by the conclusion of the report of
cannon. They break up with loud re-
ports that can be heard for some dis
tance. Water often melts in crevices
Of the bergs and then. by some change
Of temperature. freezes again. and then
1t often happens that, by reason Of the
expansion and contraction due to the
change in the condition of the water.
the ice is split, and thus bergs are fire.
quently destroyed.
They melt away as they get into
the warmer water of the south, and are
ground against tie field and broken
ice that they meet on the way. Some OF
them last for several years. They quite
often have long, outlying spurs pro,
jecting under the surface of tho water
that are very dangerous to ships. as
they are invisible and may pierce the
side of vessel. Bergs are. as rule,
nicely balanced and are quite apt to
tumble over if they are disturbed. On
a clear day berg can bA seen for
fohg distance on account Il its brilliant
whitcness and at night from its reful.
gence.
In fog bergs may be detected by
their apparent backness. but more
often by the echo which they throw of
: from any such sound as fog-horn or
whistle. An instrument on deck
catches the echo waves, and by a per-
fected mechanism their lengths may be
measured. thus giving. the mariner
some idea rs to the distance he is away
from his danger. Field ice is con.
stantly drifting and seems to have o
motion within itself that is always
carrying it on in some direction. It
often breaks up. drifts and freezes
again the same day. Two vessels
caught in the ice near each other may,
in few days, be many miles apart
although there is not time when one
could not walk from one to the other.
The Arctic ice takes several seasons to
make, while that made further south
forms each season. The latter is softer
and does not last as long as the other
sort. Only an nveragc-sized berg can
get across the banks owing to the
great depth of water which they draw,
and many are grounded there to melt
slowly away.
The cod follow the ice down and feed
nnder it, while the seal. the sort that
b hunted for its leather and not its fur,
eakes the ice its breeding ground.
This furnishes lively industry to
2 oany fishermen of the north. who go
cut in fleets as soon as the ice begins
to come down and race for the bergs
and fields. The catch averages about
$1,000. 600 worth each year, but the
business is perilous and the risks are
great. 1t is a peculiar fact that has
been lately demonstrated, that all ice
does not form on the surface of the
water. but often makes in from ten to
fifteen fathoms down. Articles that
have been lost overheard have been
found in cakes of ice months or years
after. As they are heavier than the
water and could not float. this is ac-
counted for by the explanation that
there are spots in the under-current Of
the water that arc colder than on top
and ice forms when it could not do SO
above.
The photographic Office has been do
ing great deal to get reliable infor-
nation about the movements of ice in