The record-union., 1897-01-24
THE OCEANS FLOOR.
Normal Depth Of the Atlantic Nearly
Three Miles.

Interesting Discoveries Made While
Laying the Different Ocean
Cables.
An expedition which was undertaken
by the Silvertown Company, to survey
a cable route down the west coast of
Africa, revealed some interesting facts
with regard to the ocean bed in that
quarter. A spot called on the Admi-
ralty charts The Bottomless Pit ly-
ing off Little Bassam, ON the Ivory
Coast, was explored, and a depth of 10
fathoms in close proximity to forty
seven and sixty y-Seven fathomS on
either side of it was found. This form
ed, perhaps, at one time the mouth OF
the river Akba. Along the eastward
end of the Guinea Coast the descent
from the 1OO-fathom line is we'll mark
ed, but on nearing the area influenced
by the outflow of the Niger and the
Congo the slope becomes abnormally
gentle. Nine-tenths of the rivers of AT
rica empty themselves into the Gulf of
Guinea, and the sand and mud brought
steep descent to a slowly shelving
bank. The water too, of these rivers,
which drain district remarkable for
its heavy rainfall, causes the gulf to be
less salt than any other portion of
ocean water in the world. While sound
ing off the Congo. a submarine canyon
or gully two miles broad and 242 feet
deep was discovered. This canyon was
formed, not like land canyon, by the
wearing away of the river bed, burt by
the heaping up of the mud brought
down by the stream into banks on
either side. The current was SO strong
here that during soundings the ship s
engines had to be kept halfspeed
ahead, and with a hemp line it would
have been impossible TO get reliable re-
suits
THE DEEPEST SOUNDING.
The information gathered from vari-
Gus scientific and telegraphic expedi-
t1or.S goes to prove that the normal
depth of the Atlantic Ocean is about
1000 fathons, or nearly three miles In
Sc me parts, however. it is almost twice
as deep, for off Porto Rico, in the West
IECieS the Blake found a depth of
i 4,361 fathoms, or nearly five and a
quarter miles. One of the deepest ca
hles in the Atlantic is that of the South
American Company, which in one part,
between Senegal and the island of Fer
rando Noronha, lies in $3.50 fathoms,
or little more than three miles. When
laying a lime in this depth it is calcu
lated that, with the ship steaming at
eight knots an hour, the length of cable
he. cfa of ha oh m hQ
where it touches the ground is over
twenty five miles, and that it takes a
particular point In the cable more than
two hours and half to reach the bot
t. m from the time that it first enters
the water The deepest sounding yet
recorded was taken early in the present
year by H. NJ. S. Penguin in the South
eastern Pacific, about so miles to the
northwest of New Zealand. This gave
D, 155 fathoms, or depth Of nearly six
miles
AS a result of these numerous sur
veys, much valuable information has
been obtained with regard to the con-
fguration Of ocean beds Contrary to
the opinion formerly held, the bottom
of the sea does not present SO many
striking irregularities as the surface
of the earth. Except for islands of vol
canic origin and some coral patches,
the bed of the Atlantic is an undulating
plain of fairly uniform fatness, and
may be better compared to a tray with
a sharply descending rim than to ba-
SIN. The slope of the land, as a gen
eral rule, is continued out into the sea
Until it reaches a depth of about 100
fathoms, and then 1t increases rapidly
to 800 and 1000 fathoms, reaching
finally the normal depth of $500 faith
oms. The area between the 100fathom
line and the shore-usually known as
the continental Platforms really sub
merged land, and if the sea level were
suddenly lowered to that extent, Eng
land would be connected by dry land
to Denmark. Holland, Belgium, France,
Ireland, Orkney and Shetland. Nearly
the whole of the North Sea, with the
exception of some of the Norwegian
fords would be laid bare, while the
coast of Ireland would be extended 100
miles to the westward On the other
hand the raising of the sea level to
the extent of 100 fathoms would put a
large portion of Europe under water
as, indeed, has been several times the
case with that continent. Not only in
the Atlantic, but in the Pacific, ON the
west coast of North America especially
the continental platform rises abruptly
from the margins of the real oceanic
depressed areas, and this phenomenon
is one of the strongest arguments i'm
favor of the theory of the permanence
of the great ocean beds.
TEMPERATURE OF THE WATER.
The temperature at the bottom of the
ocean is nearly down to freezing point
and sometimes actually below Dt There
is a total absence of light, as far as
sunlight rs concerned, and there is an
enurmIous pressure, reckoned about one
ton to the square inch in every 1,000
fatboms, which is 160 times greater
than that of the atmosphere we live in
At 1000 fathorns the pressure is thirty
times more powerful than the steam
pressure of locomotive when drawing
a train. AS la.e as 1880 a Ieading zool-
oGist explained the existence of deep
sea animals at such depths by assum-
ing that their bodies were composed of
solids and liquids of great density, and
contained no air. This, however, is
no. the case with deep sea fish, which
are provided with air-inflated swim
ming bladders If one of these fish.
in full chase after its prey, happens to
ascend beyond a certain level, its blad-
der becomes dtstended with the de-
creased pressure, and carries it, in spite