The Hartford herald. [volume] (Hartford, Ky.) 1875-1926, 1913-10-15
WATER PRESSURE
Tremendous Force Exerted at
the Bottom of the Sea.
AIR THERE COULD NOT RISE.
u Would Be Compressed to Such q
Degree Of Density by the Enormous
Weight That the Water Would Float
Upon It-limits Of Diving Depths.

From ordinary considerations II
would seem that there is no limit to
the depths to which a diver or q sub
marine boat might go. Such. how
ever Is not the case. What prevents
diving to great depths Is the enormous
ly increasing pressure Of water. No
diver without suit can go over 150
feet. because the pressure on the body
Is then about five tons to the square
foot on his body. Earlrunls would be
STAYED In. and other fearful difficulties
would result.
To remedy this the diving suit was
invented. but there Is II limit also to
its depth. At n depth of one mile the
pressure due to the water alone Is 1GJ
tons to the square foot. Even II n div
ing suit was devised to withstand this
enormous pressure trouble would he
found in getting II pipe line that long
and understanding the pressure that
would not break of its own weight.
In the case Of submarine boat IT
is slightly different. Here only the
strength Of the boat Is the necessary
thing But TO lie strong the walls have
to be thickencd. and this adds to the
weight. consequently adding to the
load to be pulled through the water,
and so ut last the limit Of the engine
prOpelling the boat Is reached. II n
larger engine is procured It itself
weighs more, larger quarters are need
ed for 1t. etc. So there IL a well de-
fined limit TO marine boats diving.
Let us take the extreme depth of the
sea so far found. that of five miles. and
find the pressure rs the square feet or
the bottom. As water is comparative
ly incOmpressible. n cubic foot of it
weighs practically the same on the
surface ms ut the bottom Of the sea.
In the case of fresh water this Is sixty
two and II half pounds. Salt water
weighs slightly more. So all one has
to do to find the pressure due to the
water at any depth Is To multiply the
depth in feet lily sixty-two and Il half.
and, the answer Is apparent mt once in
pounds. ~---------~
At depth of five miles. the number
of feet being 26.4OO we have that num-
Der of cubic feet to multiply by sixty
two and half The answer Is so
900 pounds. or So tons. to the square
foot pressure. No known hollow YES
sci ran withstand this.
While on the subject Of increasing
water pressure a number of Interesting
nh. In. I'm.
ton with air compressibillty. Air is
very compressibe. the volume decreas-
ing us the pressure increases. III II bot
tie is tightly corked 1t will contain air
ut ordinary pressure OF fifteen pounds
to the square inch. and that is the
pressure 1t exerts. Then tie II weight
to the hottie and let it down in the sea
by means of string. On bringing 1t
to the top again it 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
piacc. showing that water Is not com
pressiblc To amy great extent.
IL by any means some air could he
placed III the bottom of n sea five miles
deep il would not rise To the top. for 1t
would he dcnser--that Is. would weigh
more To the cubic foot than water
and the water would have to teat ON
the air; hence no man knows II thc
bottom OF our seas is wet or not.
There is only one thing that wouhi
prevent the air from becoming this
dense. and that is II ii was cold enough
ii would liquefy. However. 1t Is al-
most impossible-is. in fact. impossible
for anything nj the bottom of the sea
Ia he colder than 1 degrees c.. for il II
got colder The water around ii would
become colder and larger aud consc-
qucntly lighter and rise. and its place
would be taken by 4 degree water.
which would bring the object to that
temperature. So we have no argument
against the suggestion, for the temper
AZURE ut or below which air liqucfies j.
between IOO and 100 degrees below
zero 4.
Some people seem TO think that
stone thrown into the sea can sink
Vh's w ''itNii hfi'h - 'Hs''
held suspended on account of the pres
sure Of water 4 body immersed la
fluid is bnoyed NJ only by the weight
Of the iiull displaced. We have found
that water is practically incompress-
ible. So II the stone displnces a cubic
foot of water that water weighs the
same. ar practically 81. at the top ar
at the bottom OF the sea. So the stone
would he luoyed up only by that con
stant farce and would be carried down
by its weight Thus the difference ia
the forces would be always downward.
and the stone would sink Ia the hot
tom.
In fact. II the stone l. at all cont
presslble the tendency Is fnr II Ia get
heavier per unit volume ms 1t goes
down. for we have the same weight
In n smaller space. II will he ren,er'-
bcrcd that this Is what happens Ia IN.
air II we take II IN II rubber bag nnde"
the surface az the sea. The volume
gets lass and less. consequently weigh
iutr lllnra slflI mara mar pnif x..llt,..