historical chronicles are described varieties of projects of constructing
self-contained breathing apparatuses but they were impracticable – their
design opposed to the laws of physics and physiology. One of the earliest
attempts was a primitive device – an animal bladder or a leather bag (in
which air was stored) and a stone to help the diver sink. The supply of
air was enough only for several inhalations.
von Drieberg designed an apparatus that was worn on the diver’s back and
was surface-supplied with compressed air. This device, called “Triton”,
was of no practical use but it gave the idea of compressed air being applied
French inventors Benoit Rouquayrol and Augustus Denayrouse developed an
autonomous open-circuit breathing apparatus. It consisted of a steel bottle
for air reservoir and a valve regulator connected to a mouthpiece. The
regulator served to provide air under pressure, equal to the pressure in
the outside. A hose delivered fresh air from the surface to the bottle
but the diver could disconnect from that system and dive only with the
bottle for a couple of minutes. The valve was a remarkable discovery because
it allowed the diver to have a breath of air in case of emergency. This
equipment referred to as “Aerophore” was even described in Jules Verne’s
classic – “Twenty Thousand Leagues under the Sea”.
the diver is carrying electric
this year, divers with scuba equipment exhaled straight into the surrounding
water and thus, much air was wasted. In 1879, Henry Fleuss invented a “closed-circuit
oxygen rebreather scuba” with a totally new principle of operation.
The diver breathed air, rich in O2 . CO 2 from the exhaled air was
soaked by an absorber and enriched with oxygen by a balloon; afterwards,
exhaled air can be re-breathed. Despite depth limitations (pure oxygen
is hazardous below a definite sea level), this device allowed long bottom
|Another closed-circuit breathing
apparatus, which worked with pure oxygen, was constructed by the Frenchman
Davis in 1890. The exhaled gas mixture was purified chemically and was
used again. Consequently, this device was developed and in 1911, it was
employed in the French Navy to rescue ships from sunken ships or boats.
Yves Le Prieur and Fernez patented a self-contained diving apparatus. Its
main elements are a steel cylinder with compressed air on diver’s back,
air hose leading to the mouthpiece, goggles and a noseclip. The trouble
with it was that it did not have a demand valve.
Improved models allowed
the diver to swim for 30 min at a depth of 7 meters or for 10 min at 12
|Because closed-circuit breathing
apparatuses do not permit bubbles to enter water (when exhaled air is rebreathed),
they were widely-used in Second-World-War-military operations. Divers were
camouflaged and could not be detected by the enemy. During the war, belligerents
developed intensively underwater equipment. Due to their inconspicuousness
and autonomy, divers were dangerous and hopeful weapons against enemy
ships, in battle reconnaissance, in mining and unmining of targets.
Cousteau and Emile Gagnan invented their “Aqualung” and revolutionized
underwater exploration. They designed a self-contained underwater breathing
apparatus (SCUBA) with two or three cylinders with compressed air. This
device uses a demand valve regulator which does not allow air-waste during
inhalation. It was the first automatic autonomous diving suit with a pressure
regulator and compressed-air bottles that provided the diver with absolute
freedom of movement.
Its simplicity of design
and perfectness of construction make it less dangerous for underwater activities
and sport diving. The new type diving apparatus received world acknowledgement
and made diving descents safe and accessible for everyone.
The same year Cousteau,
Gagnan and two other men experienced over five hundred dives with the aqualung
and greatly contributed to underwater investigation.