The St. Mary banner. (Franklin, Parish of St. Mary, La.) 1889-1931, 1912-12-14

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than to build a new ship.
Her value as old iron. on the other
hand, would not pay for raising and
! breaking up. She may. however, be In
the way of other ships, a danger to
navigation generally, and then she is
sometimes blown to pieces by judi
ciously placed charge of dynamite.
1t is usually worth while, however
to save parts of wreck. IL by any
means they can be got at. Brass
work. for example. is Of sufficient
value to be worth getting. and. OF
course, II gold or silver-either in the
form Of coins or bars-be part OF
the cargo, then 1t is certainly warth
an attempt
Sometimes even that Is impossible.
because of the depth at which the
wreck lies. AS diver descends the
water pressure increases, and to keep
him from being crushed by it the pres
sure of air in his dress has to be In
creased to the same extent, and there
is limit to the amount Of air pres
6QI "HiSu Gail L lie
main trouble is that his blood becomes
aerated under the pressure
Its condition becomes like that Of
soda water In a corked bottle. and as
soon as he commences to ascend and
the pressure is reduced it becomes
like soda water with the cork out.
The nitrogen which was forced into
It by the pressure comes bubbling out
as the pressure falls. and II this be
allowed to occur too vigorously 1t will
result in the divers death.
About thirty-five fathoms is the
limit below which man cannot 70,
and even at that. II the diver has to
stay down any lengthof time, he must
ascend again by easy stages with long
intervals OF rest for his blood to get
rid Of the absorbed air; so that his
ascent will take as much as four
hours. Four hours spent In coming
to the surface after but one hours
work belOw-f1ve or more hours
wages for one hours work to an ex-
pensive man like diver, to say moth
ing If the wages OF his attendants
makes deep water diving an expensive
matter, and beyond the limit men,
toned Is out OF the question alto
gether.
Diving In Strong Currents.
Then there is the trouble caused BY
strong tides and undercurrents. The
diver when In the water is the plav.
thing Of the currents. Robert Louis
Stevenson, who once ventured on a
diving expedition. describes himself as
being blown sideways like a leaf"
when In the water. Even large, heavy
bodies like ships Of iron are some
times carried to long distances by
the currents. 1t Is said that the naval
authorities have thus lost entirely an
CID submarine which they sank for
she purpose OF trying salvage expert
ments
They knew the spot where it went
down. but when they tried to salve It
1t was not there. The under current
had carried it away. 1t is obvious.
therefore, that diving in places where
tide or current runs strongly is very
difficult
And most salvage operations depend
upon the diver Suppose that
A ship is sunk in collision. He first
goes down and examines the wreck.
Upon his report it is decided whether
t Is worth while to attempt to salve
he ship as whole. 1t not, he may be
old to salve the brass fittings, so down
lie will go again and again. with tools
suitable for the work and will remove
rom the ship and send up all that he
IAN procure that Is worth saving.
II there be treasure on board he 10