South Bend news-times. (South Bend, Ind.) 1913-1938, 1917-06-26
Why Ships Haze 10 Go to the Bottom
There No Halfway Stopping Place Them Wa
ter Gets InSde-PrinCpleS of Bouyancy Applied
to ShipSS, Submarines and Balloons.

to the seabed in the deepest parts
Of the ocean.
The underlying principle which
everybody ought to learn in order
not 10 fall into mistakes on this sub
iect is that whenever body IS
wholly or partly immersed in water
it is buoyed upward with q force
equal TO the weight Of the water
displaced by it. If the body is. bulk
for bulk, lighter than water IL will
sink only far enough TO displace a
quantity of water equal in weight
TO its Cthe body's) own weight.
If it is. bulk for bulk, heavier
than water. i. e, denser. it will be-
come wholly immersed and will sink
To the bottom. IN this case, too, the
| body viii experience an upward
force equal 10 the weight Of the dis
placed water, and by that amount
its weight Will be diminished. only
in the case where the body is. bulk
for bulk. equal in weight, i. e., equal
in density 10 water, will il remain in
equilibrium. totally immersed but
not tending TO sink farther.
Wood is. with very few excep-
tions, lighter than water, and con-
sequently il becomes only partly
/ immersed, the depth 10 which it
sinks being proportional to its rela-
/ tive density as compared with the
| density of water. Metals, including
! aluminium, are much heavier than
| water. and if thrown into il become
totally immersed and sink TO the
bottom. though in every case their
weight is diminished by an amount
equal TO the weight of the water
| displaced by them.
A submarine is a water balloon
and a Zeppelin is an air-hsh. The
one diminishes its buoyancy TO get
below and the other increases It's
| buoyancy to get above. When the
total weight of the submarine is
slightly less tnan the weight of an
equal bulk of water il can be made
10 descend and to remain at a chos-
en- depth by the action Of planes re-
sembling in their function those OF
airships. Even an aerOplane de
ponds for its support upon the prin-
ciple Of buoyancy, the weight of the
machine. which would bring it down
lif il remained motionless. beins
| counterbalanced by the reaction OF
the air upon the sloping planes dri =
en- swiftly through IL Thus an arti-
fetal buoyancy is produced.
\ balloon floats because the great
size Of its distended gas bag enables
il 10 displace an amount Of air ex-
ceeding in weight all the materials
OF which the balloon is composed
the consequence being that the air
presses upward on il with a force
greater than the downward pull OF
gravity In the same way an iron
ship floats because its concavlty en-
ables it 10 occupy a space which if il
we're hlled with water. would con
tain a greater weight Than the actual
weight OF the ship.
But explode the balloon or open
the hull of the ship and both OF
them go 10 the bottom. since the ali
in one case and the water in the
other now fills the space from which
IL was excluded. There is one very
important difference, however. at
fecting the buoyancy OF air a. com
pared with that OF water. Air l.
very compressible. the consequence
being that. unlike water. il Is much
denser near the bottom than the
top. Thus a a balloon cannot float
/ equally well at all attitudes