m*- w - Clpdigital.org

directs placing the submarine fort in a
position favorable for raising the sunken
ship. I le makes his observations through
portholes and is aided by a powerful
searchlight which is supplied with current
from the towing vessel. In some
respects an operator in the bottom of the
inner cylinder is comparable to a diver in
an old-fashioned diving bell. Any system
of signals previously agreed upon can be
used. By the time the pontoon base has
RAISING SUNKEN SHIPS 883
such is the case, the cables may be swept
under the hull by means of an auxiliary
force in the cylinders, or the main power
derived by pumping out the water, or,
if necessary, a "sand-sucker" or propeller
may be employed for tunneling.
Finally the other end of the network of
cables is fastened to the top of the inner
buoyant chamber of another fort located
on the opposite side of the wreck.
Now everything is in readiness for
RECLAIMING THE OCEAN'S LOST TREASURES
We ''lay expect tosee this apparatus used soon by parties searching for every type of sunken bullion vessel, from the
Spanish galleons of 6ld to the new victims of German undersea pirates.
. . .«• .
filled with' water it is resting evenly on raising the submerged vessel without re­
tiie ocean bed. In this location it is not moving its valuable cargo. Seacocks
affected by ocean currents. ' Nor is the have been opened to admit water into the
buoyant chamber, now upright in posi­ inner cylinder which is then forced out
tion, affected by the movement of the through an opening at the top by motor-
water any more than an upright spar is. •
The next operation is getting the network
of cables under the vessel One
end is made fast in a clutch at the top
of the outer cylinder. Then the cables
are passed under the bow or s r ern of the
wreck, which is rarely difficult since it is
seldom that any ship settles into the sand
so that both fore and aft are buried. It-
driven pumps. This makes the inner
cylinder lighter and. therefore, it begins
to rise. At the same time this operation
tightens the hawser passing under the
shipwrecked vessel. As a rule the buoyant
chambers raise the shipwreck from
25 to 50 feet, after which they are refilled
with water, lowered, and another
bee on the cables is taken.