Democratic messenger. [volume] (Snow Hill, Md.) 1869-1973, 1913-10-11
WATER PRESSURE
Tremendous Force Exerted at
the Bottom Of the Sea.
AIR THERE COULD NOT RISE.
II Would Be Compressed to Such a
Degree OF Density by the Enormous
Weight That the Water Would Float
Upon lt--Limits Of Diving Depths.


( Upon lt--Limits OF Diving Depths.
j From ordinary considerations Il
would seem that there is no limit to
the depths TO which a diver or sub
marine bout might 20. Such. how
ever. Is not the case What prevents
diving to great depths Is the enormous.
" increasing pressure Of water. No
diver without suit can 90 over 100
feet. because the pressure on the body
IS then about five tons 10 the square
foot on his body. Eardrums would be
STAYED IN and other fearful difficulties
would result
To remedy this the diving suit was
invented. but there Is a limit also TO
its depth ~ depth OF one mile the
pressure due to the water alone is l65
tons 90 the square foot. Even II div
Ing suit was devised 10 withstand this
enormous pressure trouble would be
found in getting n pipe line that long
and withstanding the pressure That
would not break OF its own weight.
In the case of submarine boat Il
Is slightly different Here only the
strength of the boat Is the necessary
thing But to be strong the walls have
TO be thickened and this ndds TO the
weight. consequently adding to the
load TO be pulled through the water.
and so NJ last the limit of the engine
propellinG the boat is reached II n
larger engine is procured Il itself
weighs more. larger quarters are need
cd for II. etc So there Is a well de-
fined limit 90 a marine boats diving
Let us take the extreme depth of the
sea so far found. that of five miles. and
find the pressure TO the square foot on
the bottom As water is comparative
~ incompressible. n cubic foot of II
weighs practically the same on the
surface ms AT the bottom OF the sea.
In the case of fresh water this is sixty.
two and half pounds. Salt water
weighs slightly more. So all one has
10 do to find the pressure due To the
water Mt any depth is to multiply the
depth In feet by sixty-two and half.
and the answer is apparent Mt once in
pounds.
At depth of FIVE miles. the number
Of feet being 26,4O0. we have that num-
Der OF cubic feet TO multiply by sixty
two and a half. The answer il ESQ.,
600 pounds. or SOB tons. TO the square
foot pressure No known hollow YES
sci can withstand this
While on the subject OF increasing
water pressure number of interesting
observations can be made In connec-
ton with air comprcssibility. Air Is
very compressible. the volume decreas-
Ing as the pressure increases. II bot
tie is tightly corked IL will contain air
at ordinary pressure OF fifteen pounds
TO the square inch. and that Is the
pressure II cxerts Then tie weight
to the bottle and let II down In the sea
by means of string on bringing II
TO the top again II will be found that
the stopper has been forced into the
bottle by the water pressure. II the
bottle Is filed with water and stop
pered and let down no such thing takes
place. showing that water is not com
prcSSlble 10 any great extent
II by any means some air could be
placed M the bottom of sen five miles
deep 10 would not rise to the top. for IL
would be- deuscr that Is would weigh
more 20 the cubic foot than water
and the water would have to tloat on
the air: hence no man knows II the
bottom OF our seas Is wet or not.
There Is only one thing that would
prevent the air from becoming this
dense. and that is II IL was cold enough
II would l!quefy. However. IL Is al
most imposSiblc-is in fact. impossible
for anything nj the bottom OF the sea
TO be colder than I degrees C.. for If IL
got colder the water around IL would
become colder aud larger and eonse-
quently tighter ANA rise. and lis place
would be taken hy | degree water.
which world bring the object to that
temperature So wc have no argument
against the suggestion. for the temper
azure M or below which air liqueics II
between l0n aud 300 degrees below
zero L.
Some people seem TO think that
stone thrown into the sen can sink
only 10 n certain depth aud i there
held suspended on account of the pres.
sure OF water \ body immersed In
nuid Is buoycd M only by the weight
OF the fluid displaced We have found
that water is practically incumpress.
ible. So II the stone diSplaccs cubic
foot of water that water weighs the
same. or practically 50. at the top or
M the bottom OF the sea. So the stone
would Toe buoycd up only by that con
slant force and would be carried down
by lis weight Thus the difference In
the forces would he always downward.
aud the stone would sink to the bot
tom
In fact. II the stone Is nj all com
prcsSihle the tendency Is for Il 10 get
heavier pei unit volume as II goes
down for We have the same weight