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374 ILLUSTRATED WORLD
A "CLOSE-UP" OF THE APPARATUS
This is the steam air compression plant of a modern salvage expedition, with storage tanks for the divers.
objects to any further trifling with the
physical limits of endurance which she
has set.
l*"or instance, after a diver has got that
far down in the realms of ocean deeps
it is not possible for him to exert himself
except to a very restricted extent. That
is to say, the lifting of a trifling weight
or the muscular effort of pulling a small
rope may nearly cause his undoing later
even though he may feel no distress at
the time. This happened with one of our
naval divers at a depth of 306 feet. lie
returned to the surface after a submergence
of something like half an hour, apparently
in good condition, but collapsed
shortly afterwards and needed three or
four days in which to recover his
strength—though he was a splendid
physical specimen.
The cause of this exhaustion is primarily
due to the excess of nitrogen
which permeates the blood and fluid substances
of the body, and which, if not
properly checked by means of the hospital
lock or recompression chamber,
leads to attacks of the "bends", more or
less general paralysis, and possibly to a
frothy condition of the blood which is
almost certain to produce death.
Not long ago, one of America's foremost
salvors said: "Make it practicable
to send a diver down to a depth of two
hundred feet and more so that he can
really work there, and millions of dollars
can be made." This is no idle boast, and
probably one of the immediate aftermaths
of the present war will be the
organizing of scores of wrecking enterprises
bent upon recovering some of the
enormous wealth carried to the bottom
of the seas by U boats, mines, and other
agencies during the period of conflict.
It is true, that a great many of the
stricken vessels have been sunk in waters
much deeper than 300 feet, but it is
equally certain that hundreds and hundreds
of these craft have gone to their
graves at lesser depths.
Estimates vary, but there is every
likelihood that the war's toll will reach a
total of 100,000,000 tons of shipping before
the dire struggle comes to a halt.
In the Adriatic, in the Mediterranean, in
the North Sea, and in other waters along
the coast of Europe and about the British
Isles vessels have been sunk that lie submerged
a good deal less than 300 feet,
and engineering enterprise will not halt
until a fair measure of these have been