Year: 1874

seemed 10 make all LIE impossible. The
general impression was that the water be-
came denser in proportion to the depth
and the consequent pressure upon it, and
that all loose things tloated in it at level
determined by their weight; pieces Of
board and such light substances in one
place, the skeletons of men and animals
in another, iron still lower. and ''last OF
all, the broad gold pieces, lost in the
wreck of many Il galleon on the Spanish
main, the whole forming kind of false
bottom to the ocean, beneath which lay all
the depth OF clear, still water, which was
heavier than molten gold" But water is
almost lncompressible, and at the depth of
twelve thousand feet it is scarcely denser
than at the surface, although the pressure
upon spot the size of a mans body is
equal to that Of twenty locomotives, each
with long train of cars loaded with pig
IRON Yet, surprising as it seems. the
bottom OF the ocean is peopled by forms
ct animal lite Of extreme aelicacy.


1t may appear at first thought, an easy
matter to measure the depth of the ocean
and to bring substances from the bottom,
but it is in reality a work Of great difficulty.
The taking of soundings is as old as nayi-
CATION, and in shallow water it is easily
done with a lead and line From the re-
cords of these soundings, charts Of coasts
have been made of all degrees Of excel
lence from the rude maps used by ancient
mariners to the elaborate charts Of the
nlted States Coast Survey. TO the mere
measurement of the water has been added,
gradually, notes on other subjects, such as
the temperature, tides, winds, and cur
rents; and thus has grown up the science
known as Physical Geography of the Sea.
But all this dealt only with the surface of
the water, and with such characteristics of
the coasts as concerned the safety of YES
i sells. The bottom of the ocean at Il dis
tance from land was a matter Of utter
ignorance. Occasional curoSties were.
indeed, brought up by soun,ling-li lines and
III the nets of fishermen, but so little We're
they priced that, unless they promised to
be OF market value, they were thrown back
INTO the water. In 1119, the first drcdgc
for collecting specimens was sent down by
the naturalist Otho Friedrich Muller 1t
was only a square-mouthed bag. and does
not appear to have been used ut depth
Of more than one hundred and eighty
feet.


1t was not until the question OF the pos
slbllity of laying the Atlantic cable was
raised that the work Of surveying and map
ping the bottom of the Atlantic began in
earnest. The cable was laid, broken and
flshcd up again. and the possibility OF
reaching the bottom of the ocean, and OF
bringing up substances being thus proved.
4 new field of fourteen million square
mllcS IN extent was opened to the natural
l>t, and Its exploration was eagerly begun


There were two serious difficulties to be
ovcrcome,-the getting of the weight
down, and the getting of it up again to
measure the line. In shallow water this
is easily done, for all that is necessary is
to tasten piece Of lead to rope and let
1t sink until the line stops paying out, and
then pull it in again. But in deep water
the friction upon the rope causes much re
slstance to its passage in either direction.
Amy one who has seen the log thrown
at sea and the amount of strength eXertcl
in drawing the cord into the ship again,
will realize this. \ lead which is heavy
enough to overcome the resistance of the
water and reach the bottom. will snap the
rope when its weight is added to the tric-
tion encountered in the attempt to draw
1t up again. On the other hand, ii the
! rope be even 4 trie lighter than the
water, it will buoy up the lead and float
about instead Of sinking. and if heavier, 1t
will cOntnue to run off from the reel after
the weight is at rest Many kinds of ap-
paratus have been invented in the hope of
overcoming these difficulties, one of the
most simple and ingenious Of which was
contrlved by 4 Mr.. Brooks, an officer in
the American navy He fastened Il cannon
ball to the end of the rope in such u way
that the moment it touched the bottom II
| spring opened, the ball fell out of the
socket in which it was held and the rope
could be drawn up without it The
most common deep-sea lead is u block
about two feet long, and weighing from
eighty to one hundred and twenty pounds
the lower end is cup-shaped, and filled
with tallow, to which cling specimens of
| the mud, shells and gravel, that it touches
The scoops used for bringing up ooze are
mostly some modification of the oyster
dredge, but where the water is not very
deep, open-mouthed bags are used 10 the
| lower edge of these it has been found use
full to fasten hempen tassels to which cling
many small substances which would not
be likely to be caught in the bag itself
| Great interest is now felt in the discov-
cries that are beng made, and several eN-
| pedltions have been recently made under
the command of scientific men for the pur-
pose of studying the deep sea. Last De-
cember the largest and best equipped of
them all started from England on board
the NJ S. Challenger. 1t is to make a yoy-
age lasting three or four years, crossing
| and recrossng the Atlantic, rounding the
Cape of Good Hope, and cruising among
the islands Of the Pacific and Indian oceans
She is fitted for her work in the most
thorough manner, that the foresight of her
commanders could suggest, and already
there have been received encouraging ac-
counts of her success. Among other things
| discovered, are a transparent lobster, and
a little fish, not only totally blind, but alb
solutely without eyes, it having been tax
en- from a depth to which no light could
| penetrate. The same species was found
near the surface with well developed eyes,
the organs of vision diminishing in power
and construction rs the depth OF its dwell
| ling increased, until these little eyelcss
creatures We're discovered Similar blind
fish are found in the dark caverns Of the
Mammoth Cave


The dredge Of the Challenger has also
brought from a depth of four thousandfa
oms, nearly five statue miles, a tube build
ing mnelid, q delicate worm heretofore
found only in shallow water, thus answer
ing the question whether these delicate
organisms can withstand the pressure at
great depths.


The Atlantic has been the most thorough
ly sounded Of the oceans, both because OF
the number Of telegraph lines laid across
it and the amount shipping sailing up
on it. Its average depth is not more than
twelve thousand feet, and there are few
places where it exceeds fifteen or twenty
thousand In the Arctic sea the water is
nine thousand feet deep. Then comes q
huge plateau, extending from the coast of
Norway to beyond Iceland in the west,
and to the coast of France in the south,
where the depth scarcely exceeds three
thousand feet. Then comes another deep
valley, after which is another shoal, show
ing that the bottom Of the ocean varies in
4 manner similar to the dry land There
are various deep channels in which appear