The Pensacola journal. (Pensacola, Fla.) 1898-1985, 1916-06-25


officers having accomplished that feat
during a series of tests carried on by
the British admiralty in 1907. For
the benefit of those who do not ap-
preciate the difficulty of diving to
such depths it may be stated that at
a depth of 10 feet below the surface
the pressure is 4.33 pounds per square
inch of surface of the body submerged.
This pressure increases proportionate-
", and at a depth of 100 feet it has
increased to 43.3 pounds and at a
depth of 300 feet to 1898 pounds.
notwithstanding this tremendous
pressure, the expert divers of the u.
S. navy have succeeded in not only
reaching a depth of 800 to 305 feet,
but in remaining at that depth from
5 to 20 minutes at a time, making
examinations and observations in re-
gard to a sunken vessel that made its
subsequent salvage possible. This
work was done in connection with the
raising of the United States subma-
rine F-4, which, it Will be remembered,
plunged to the bottom of the sea Just
off the harbor of Honolulu on March
25, 1915. Not only did the divers
establish a new worlds record for
deep-sea diving upon that occasion,
but the subsequent raising and recov-
cry of the Fla is the only instance in
history where sunken vessel was re-
covered from a depth of 300 feet"
The writer thereupon gives brief
sketch of the history of diving as a
useful art from the time of Aristotle
down to the present, and after de-
scribing modern diving outfit and
explaining in some detail the matter
of the divers being subjected to two
pressures, viz, the pressure of the air
inside the helmet and suit and the ex-
ternal pressure of the water, contin-
ues, as follows:
''The necessity of having the air
pressure within the diving dress com
pensate the external water pressure,
thus subjecting the diver to pressure
directly proportional to the depth to
which he descends, is the dangerous
element in deep-sea diving. At a
depth, for instance, of 100 feet, diver
must be subjected to pressure of 4
atmospheres, or go pounds per square
inch, in order to compensate the ex-
ternal water pressure. Exposure to
such pressure is apt to be followed
by dangerous physiological effects,
commonly known as "caison disease, =
the symptoms of which include pain
in the muscles and joints, commonly
called "bends," deafness, embarrassed
breathing, vomiting, fainting, etc.
sometimes resulting in death. They
do not appear while the pressure is
being raised nor so long as it is con-
tinued, but only after it has been re-
moved; and the view now accepted is
that they are due to the rapid eff,
fervescence of the gases which are
absorbed in the body fluids during ex-
posure to pressure. Experiment has
proved that when the pressure is sud.
denly relieved the gas is liberated II
bubbles within the body, and that
these do the harm. Set free in the
spinal cord, for instance, they may
cause partial paralysis, or in the
heart lead to stoppage of the circu.
lation. 1t has been found, however
that if the pressure is relieved grad
ually the bubbles are not formed, be-
cause the gas comes out of solution
slowly and is got rid of by the heart
and lungs. To prevent these effects
the withdrawal of the air pressure
in other words, the decomposition
should be slow. Tence the divers
ascent must be regulated accordingly
and the deeper he has been the slower
and longer must be the periods fol
decomposition. It was particularly il
regard to this matter of decompres
sion that the experiments of the U
S. Navy Department in 1914, led tt
improved methods enabling the diver!
to descend to 800 feet below the sur
face. Being able to safely observe
and direct work of rescue at such {
depth, and with modern lifting appa
ratus, who can say that the recover!
of ancient treasures of sunken Span
ish galleons, of hundreds or more re