The Butler County press. [volume] (Hamilton, Ohio) 1900-1946, 1913-10-31
WATER PRESSURE:
Tremendous Force Exerted at
the Bottom OF the Sea.
AIR THERE COULD NOT RISE.
1t Would Be Compressed to Such
Degree of Density by the Enormous
Weight That the Water Would Floas
Upon It-Linnits of Diving Depths.

"Oufd seem IudL JueFe Is no unit TO
the depths to which a diver or a 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 20 over $50
feet, because the pressure on the body
is then about five tons to 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. At depth of one mile the
pressure due to the water alone is 1856
tons to the square foot Even if a div
ing suit was devised to withstand this
enormous pressure trouble would be
found in getting n pipe line that long
and withstanding the pressure that
would not break of It's own weight.
In the case Of a submarine boat it
is slightly different Here only the
strength Of the boat is the necessary
thing But to be strong the walls have
to be tbickened, and this adds to the
weight, consequently adding to the
load to be pulled through the water,
and so at last the limit of the engine
propeling the boat is reached IF a
larger engine is procured it itself
weighs more, larger quarters are need
ed for it. etc. So there is a well de-
fined limit 70 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
ly incompressibe, a cubic foot of it
weighs practically the same on the
surface as at the bottom of the sea
In the case Of fresh water this is sixty
two and a 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 by sixty-two and a half
and the answer is apparent at once in
pounds.
At a depth OF five miles. the number
Of feet being q, 400, we have that mum
ber of cubic feet to multiply by sixty
two and a half. The answer is ], $50
600 pounds, or S25 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 compressibility. Air is
very compressible, the volume decreas-
ing as the pressure increases. If bot
tie is tightly corked it Will contain air
at ordinary pressure of fifteen pounds
to the square inch, and that is the
pressure it eXerts. Then tie a weight
to the bottle and let it down in the sea
by means Of a string, On bringing it
to the top again it viii be found that
the stopper has been forced into the
bottle by the water pressure. If the
bottle is filed with water and stop
pered ana let down no such thing takes
place. showing that water is not com
pressible to any great extent.
If By any means some air could be
deep ii would not rise to the top, for it
would be dPnser-that is. would weigh
more to the cubic foot than water
and the water would have to fioat on
the air: hence no man knows if 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 if it was cold enough
it would liquefy. However, it is al
most impossible-is, in fact, impossible
for anything at the bottom Of the sea
to be colder than 4 degrees c., for if it
got colder the water around it would
become colder and larger and conse-
quently 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
ature at or below which air liquefles is
between 100 and 200 degrees below
zero c.
Some people seem to think that
stone thrown into the sea can sink
O4llg " q Vel tam uGpCH anu ID lhNAC
held suspended on account of the pres
sure of water A body immersed in
fluid is buoyed up only by the weight
of the fluid displaced We have found
that water is practically incompress-
ible, so if the stone dispaces a cubic
foot of water that water weighs the
same, or practically so, at the top or
at the bottom of the sea. So the stone
would be buoyed up only by that con
stant force and would be carried down
by its weight. Thus the difference in
the forces would be always downward,
and the stone would sink to the bot
tom.
In fact, if the stone is at all COM
pressible the tendency is for it to get
heavier per unit volume as ii goes
down, for we have the same weight
in smaller space Ii will be remem-
bered that this is what happens to the
air if we take it in rubber bag under
the surface Of the sea. The volume
gets less and less consequently weigh
Ing more and more per unit volume
and displacing less and less water and
being buoyed up less and less until at
last place is reached where the air
weighs more volume for volume than
does the water aud It will not rise
Lawrence Hodges In Chicago Record