Year: 1870

Sensations.


The following is from the st. Louis
Republican, of the 26th ult., and has
reference to the manner in which the
piers are built for the great bridge
now being constructed across the
Mississippi river at that city:
Nearly every day there are quite a
number of visitors to the piers, and
general curiosity seems to be felt to
visit the air chambers. In the east
pier the depths now so great that not
a few gentlemen change their minds
about going down, when they reach
the top of the winding stairs that leads
10 what seems the internal regions be-
low. The desrent, however, is very
easily accomplished piece of business,
and very rarely accompanied with
any unpleasant sensations or deleteri-
Gus effect. There is something in it,
however, calculated to somewhat dis
turb nervOusly constituted person.
First, a descent of nearly ninety feet
by a winding wooden stairway, the
gloom increasing as you go. Then
the bottom is reached, or rather the
end of a ladder, where there is damp
glOOminess, and you see, by dim can
die light, water Just below the strip
YOU stand on. 1t is, however, a tri-
fling pool, but magnified by the flick
ering candle light. Then comes the
air-lock. You step off the end of the
ladder and Chamber through what
seems an immense stove door; and
now the trial begins. The apartment
. cir oh inlt
high, with walls and ceilings of iron.
The iron door is closed, but there is no
fastening, it is Just swung to, for il,
too, is of massive iron.


The attendant turns little valve,
and the air begins to rush in with a
sound like steam. In few moments
the pressure has increased so that the
door has closed firmly. In few more
il would take many horsepower to
open it, and the atmospheric pressure
begins to make itself felt, by a feeling
of fullness in the ears; but this is
quickly relieved by theact of swallow
ing saliva, apple juice or anything of
the sort, or by stopping the nOstrils
and initiating the cheeks. In some in
stances q sharp pain is felt, but this Is
very rare, and never we believe, where
there is q considerate hand at the
valve to turn off the air the moment
any pain is felt. In any case the
pressure can be relieved in moment
by turning another valve which lets
the air off, when the pressure in the
lock is equal TO that in the chamber
under the pier. Another iron door
similar TO that through which the
lock is entered, opens of itself, and
stepping through il we enter the
famous air-ehamber. This has been
already fully described, and so we will
not 90 over details. 1t is indeed a
most curious and interesting place to
visit. On every side, so far as one can
see, is something novel, unique
whether it is the soft yielding sand
under foot, or the mouth of the sand
pump, like an immense serpent gOrg-
ing itself with sand and water. The
first thing perhaps which attracts the
visitors attention is the alteration in
the sound of his voice. He seems in
n moment to have acquired unusual
gift as a ventrilOquist. His voice, to
himself only, seems away from his
body, and with a decidedly nasal
twang.


1t is also suppressed in tone, sounds
like what we might suppose are the
accents of the ghost of deceased Yam
kee. To whistle is vain, and almost
equally so is an attempt to blow out
candle. With a strong swift blow
the flame disappears, but only in a
second to spring again into life. The
density OF The air Gan be realized by
moving the hand, when a sensation of
wind is felt, even by comparatively
slow movement. In fact, it would
seem almost as if one were walking
through and breathing thin, invisible
water. Over head, resting on the
iron roof, is more than twenty thous-
and tons of masonry, and this air, in
which the men in the chamber walk
about and breathe, supports itself
something over half of the enormous
weight. The chamber is divided into
three compartments, the divisions be-
ing mainly formed of the massive
iron supports to the pier. NOtwith-
standing the depth of the caisson, the
air is constantly escaping, and its loss
is eduaIized by the action of the air
pumps. Mr.. Thompson has charge of
the works in the air chamber, and re-
ports that no obstruction of any un-
usual kind has been encountered in
the sinking of the eaissOn, which in a
few days now, will have reached the
limestone rock on which the masonry
of the great pier is destined to rest.