Iron County register. [volume] (Ironton, Iron County, Mo.) 1867-1965, 1886-03-04
IN A C-AiSSON,
Sensations Experienced Under High-Air
Pressure sixty Feet Under Ground.

Sensations Experienced Under High-Air
Pressure sixty Feet Under Ground.
The exterior aspect of the caisson,
when the work has reached a depth of
sixty feet, resembles stone pyramid
about twenty feet high, out of the top of
which projects chimney-like funnel
about two feet in diameter, and a
smaller pipe from which constantly
pours stream of black and dirty wa
ter. The pyramid is the pier so far as
it has been completed; the chimney is
the shaft by which the caisson is
reached, and the dirty water is the
earth which the men are removing sixty
odd feet below-more of which anon.
The caisson itself is down in the earth
at the depth above quoted. In structure
it is much like a boat of strong and
heavy oak, and without deck. turned
upside down, with it's gunwales, or
edges, of strong iron. 1t is set in the
desired spot and excavation started in
the earth under it, while as it sinks men
above lay the masonry upon it. One
can imagine that at a depth of sixty
feet, with stone and concrete piled
upon it, the weight it sustains is
something enormous. This is true
enough, and the only thing that
holds the ponderous load from sinking
the caisson in a flash through the re-
manning dirt down to bedrock is the
tremendous air-pressure which ispumped
in to support the weight. The air-pres-
sure is putin for that purpose, as well as
to exclude the water which might drain
it, and is not the natural density of the
atmosphere at that depth, as many seem
to suppose
Doffing his own elegant apparel, the
reporter accepted the courtesy of a rub
Der coat, a SLOUGH hat and a pair of hip
boots from the hands of Mr.. P. II. Ayl-
ward, the principal foreman on the
bridge. and, committing himself to the
guidance of Maurice Connolly, as clever
a gentleman as ever breathed condensed
atmosphere in the bosom of the earth,
he started on his perilous journey. Up
the half-fnished pier he clambered and
down into the funnel he followed his
guide The descent is made for fifty
feet by an iron ladder, wet, slippery and
altogether treacherous. With a stout
heart the reporter swung from rung to
rung until the darkness enveloped him
and the hum of busy work above
was lost to the ear. At last the descent
was completed and the guide opened
q small iron door like furnace lid
and the two crept through into a
chamber lighted with an incandescent
lamp and of just sufficient size to hold
them both and no more. 1t was the
air lock, and here the trials of the trip
are concentrated. Another furnace
door like the one through which en-
trance had been made was on the other
side of the chamber, and through its
entrance into the caisson was about to
be made. Some little time must pass,
however, before leaving the chamber,
as the air must be brought to the pres
sure it holds in the caisson. The
guide reached up and turned faucet
like arrangement, and thereupon tribu-
lations began. The compressed air
from within rushed into the lock with |
a hiss and roar which challenges |
the tumult of Niagara and sensations |
strange and dreadful seized at once |
upon the reporter. An alarming popping
set up within his ears, sharp pains
taS through his head and his brain
reeled so that he staggered back and
leaned for support against the IRON
armor of the lock- Ten minutes OF
this varying torture were required ana
then the second door was swung open,
bright lights flashed up. a cool soft air
weiIed from below and relief came as
the rushing noise ceased. Through the
door TO another ladder and ten feet
down the reporter and his guide went,
and landed at last in the caisson. ,