The Charleston daily news. [volume] (Charleston, S.C.) 1865-1873, 1870-03-18
SQUEEZED AIR.
Going Down Stairs Under the Missis-
sippi iRivcr-strangeA Atmospheric Sem
sntions.

In the course of an article on the great bridge
across the Mississippi, now building, the St.
Louis Republican says:
Nearly every day there are quite number OF
visitors to the piers, and general curiosity seems
to be felt to visit tile air chambers. In the east
pier the depth Is now 80 great that not few gen.
tlcIncn change their minds about going down
when they reach the top or the winding stairs
that leads to What seem the Internal regions be.
low. The descent, hnwevcr, Is very easily &C.
complished piece OF business, nnd very rarely ac-
conpanlcri with any unpleasant sensations or de.
leterluus effect rnere Is something In 1t. how
ever calculated 10 somewhat disturb nerVously
constituted person. First, n descent OF nearly
ninety feet by n winding wooden stairway, tho
gloom increasing Us you go. Then tic bottom Is
reached, or 4uther The end of u ladder, where
there is damp Eoominess, ana you see: oy md a,nl
on. 1t Ia, however u trinilg pool, but magnited
by tile Pickering candlcght. Then comes ihe
air.lock. You step or the end OF the ladder and
Chamber through what seems an immense Stove.
door; and now the trial begins. The apartment
entered Is circular, about eight feet high, WIFI
walls and ceilings Of iron. The iron door Is closed
but there is no fastening, IL Is Just swung to, fot
it, 100, Is Of massive iron.
begins TO rush In with q sound like steam. In q
few moments the pressure has increased 30 that
the door has closed nrlnly. In leW more ,d y
would take many horsepower TO open it, and
the atmospheric pressure begins to make Itself
felt, by feeling OF fullness In the ears; but this Is
quickly relieved by the act OF swallowing saliva,
apple juice, or anything Of the sort, or by stop
ping the nostrlls ami innaiing the cheeks. In
some instances sharp pain Is felt, but tlls l.
very rare, and never we believe, where there Is
considcrate hand at the valve to turn OF the all
the moment any pain Is felt. In any case the
pressure can be relieved In moment, by turning
another valve which lets the air on, when INT
pressure In the lock Is equal to that In the cnam
Der under the pier.
the lock Is entercd opens OF ITSELF AMI stepping
| through II we enter the famous alr.chambcr. Th
| has been already fully described, and so we VIII
not go over details II Is ln,leed most curious
and interesting place to visit. On every side, 81
| far rs one can see, Is something novel, unique
whether 1t Is the soft yielding sand under fo0t o.
| the mouth OF the sand pump, like an immense ser
pent gorglng itself with sand aud water The nrs
| thing perhaps which attracts tile VlSlt"r5 atten
tion is the alteration in the sound OF m voice. III
seems in o moment TO have acquled unusun
gift as ventriloquist. His voice, to himsell only
seems away from his body, anu with decldeuii
nasal twang. 1t Is also suppressed In tone. souna
like what we might suppose are the accents oil ~
| ghost OF u deceased Yankee To whistle Is vain
and almost equally so Is an attempt to blow out
candle. With strong, swift blow the lame dls
appears, but only In Il second to spring again lnt
| lfe The density Of tue air can be reaiizet D.
| moving the hand when sensation o! Wlnd i
| felt, even by u comparatively slow movement. u
| fact. 1t woulll seem almost as II one were walk
| Ing through anu breathing thin, Invisible water
| over heali resting ON the iron roof, Is more thai
twenty thousand tons Of masonry, and thl' alr
| in which the men In the chamber walk about ant
breathe supports Itself something over half
| the enormous weight.
The chamber Is divided into three compart
ments, the divisions being mainly formed or th
massive iron supports to the pier. Notwithsfanu
Ing the depth OF the caissun. the air Is constantly
escaping, and Its loss Is equalzed by the ACTOR
of the air.pumpS. Mr. Thompson has charge o
| the works In the ;tir-chamb-r, and repuris tina
no obstruction Of any unusual kind has been en-
countercd I'm the sinking OF the calsSon which
| In few days now, will have reached The lime
stone rock on which the masonry OF the grea
pier Is destined TO rest.