Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1920-02-06

study, SO that when spring comes
they can launch their offensives'
without loss of time.
With all of our boosted ingenui-
ty and progress in the art of sal
vaging. We still have far to go be-
fore We can sweep the ocean bed
OF all its booty Systematic salvage
dates back only century or two
Before that, divers wore no special
costumes, and stayed under water
only so long as they could hold
their breath-at the most two or
three minutes at a time. Then in
the 18th century came a leather
diving suit, and after that the rub
Der and canvas suit with its steel
helmet and tubes to supply air.
The rubber suit is still worn by
river and shallow water divers, as
it is easy to work in, and allows
the wearer considerable use of
hands and feet The main disad-
vantage is that the diver must be
let down and raised very slowly be-
cause Of the changes in pressure.
The pressure of the atmosphere at
sea level is Is pounds to the square
inch. At 100 feet below the sea
the pressure of the water is SO
pounds to square inch, while at
200 feet it is 81 pounds. A diver
wearing a rubber suit cannot de-
scend far below 100 feet, as the suit
is likely to collapse and cause his
instant death.
The rubber equipment is now
supplanted by rigid armor for deep
sea diving. The diving suit was
weighted down only by sufficient
lead to keep the diver submerged.
The armor weighs around 500
pounds, and it is rather like the
metal upholstery Of feudal knight.
the big difference being that the
knight could stand up in his trap
pings, whereas the diver is abso-
lutely helpless in his until some of
the weight is Offset by few tons
of water pressure.
After he is slung down to two or
three hundred feet the armored
diver can walk about stiffly, and
even bend his arms. He does not
have to worry about water pres
sure, because the armor withstands
| it just as a submarines armor does.
Nor is he concerned with air trou-
bles, for the most modern patents
include an air generating plant,
somewhat like a gas mask canister.
This does away with pumping air
down to the diver, always a dan
gerous business, as tubes are apt
to spring leak or be cut by sharks.
The one drawback to the human
tank idea is the stiffness of the ar
NOR which necessitates use of hooks
instead of hands, and limits the
divers work on the wreck. How
ever, he can stay down comfortably
two or three hours, feat impossi-
BILE with the rubber suit, and he
can make full observations and tel
ephone to the surface boat reports
as to needed repairs or work to be
done. The telephone attachment in
the helmet, which permits divers to
communicate with each other and
with the surface, is one of the most
valuable inventions of submarine
engineering.
The armored diver locates the
leak in the ship and plans repairs
and methods of raising the hull
When the hull is mended, the ship
lis raised, usually by pontoons. Steel
cables are slung under the hull and
attached to barges on the surface.
| Compressed air is forced into the
holds to take the place of the wa
ter. This lightens the ship. so that
it rises, guided by the barge pom
i ICONS, and is then towed to shore
/ If the armored diver is to help
raise a ship, he is often sent down
in a submarine bell of some sort.
One of the latest devices is very
like U-boat, in that it is steel
encased chamber with motors to
carry it about the ocean floor. : 1t
is let down by cables and diver
opens the door of compartment
shut off from the main cabin, and
closes the door behind him. He
puts on an armored suit, and water
is let into the compartment to off
set the weight of the armor. He
then opens an outside door to the
compartment and steps out onto
the ocean floor. This adaptation of
the submarine was contrived by
Simon Lake, the inventor of the
modern submarine. Mr.. Lake is
himself interested in salvage prof.
etcs, and expects to recover by sub
marine what his original invention
sent to the bottom of the sea-