The Middlebury register and Addison County journal. [volume] (Middlebury, Vt.) 1883-1885, 1885-11-27
AN UNDERGROUND EXPRESS
SENDING MES sAGES THROUGH
PNEUMATIC TUBES.
Novel Way OF Forwarding Commu.
niratious md Packages Long pis-
tances i'm the Metropolis.

Novel Way OF Forwarding COMMIT.
niratious nnd pnclkngcs Long pis-
tnnces i'm the Metropolis.
The system of dispatching messages 20
comparatively long distances through
pneumatic tubes has been operated by
the Western Union Telegraph company
for about four months, and its perfect
success is assured. 1t is intended to make
this system the centre of an intricate
pneumatic railway which shall connect
every Western Union Office in the city,
Specifications have already been made to
complete this ingenious purpose, which
will be carried through with all con-
venicnt speed. The general scheme of
transmitting messages through tube by
means of air pressure is not new, and has
been for years successfully practced be-
tween the Dey street office of the COM
pany and the newspaper offices. But the
particular methods embraced in this new
system have many original features
A trench from four to six feet beneath
the surface of the street connects the
Western Union Office at Broadway and
Dey street with their uptown office at
Fifth avenue and Twenty third street.
This site was formerly occupied by the
old brownstone mansion long known as
the Peckham homestead. 1t was bought
by the company little over two years
ago, and is intended for distribution
office for a large territory above Four
teenth street. Work began upon the
trench which runs through Broadway
about eighteen months ago, during the
strike of the telegraph employees. The
trench contains six tubes. -Four about
six inches in diameter The brass tubes
are designed for the pneumatic service.
Two run without interruption from the
| operators room in the top floor of the
Dey street building to the basement of
the Twenty-third street office. The
other two are used for conveying mes
sages to intermediate offices. The iron
tubes are filled with telegraph wires al.
ready laid but not connected, to be used
in cases of extraordinary business pres
sure. For transmission the messages are
! put into leather box, cylindrical in
shape, which fits the tube easily, capped
at each joint with flanges that make it
air tight. In the basement of each build
ing there are four engines of $50 horse
! power each. These engines work the
tubes, one in each building be-
ing connected with each tube.
When the box of messages is
slipped into the tube, one engine ex-
hausts the air in the pipe before it and
the other pumps air in the pipe behind
+ it, and the box whizzes through at the
rate of mile a minute About fifty
separate messages are sent with every
box, though it will hold one hundred.
The tube is laid in sections of twenty
feet, and elongations and contractions
of the metal by changes of temperature
are carefully provided for. In some
PAGES the closeness of the New York
Steam Heating company's pipes has
made this allowance especially necessary.
A small joint is inserted at points which
will admit of an expansion in every
eight hundred feet of pipe of two inches.
Some time ago one of the steam pipes
sprung leak and the brass tubes be-
came SO hot that they could not be
handled. This incident caused the
greatest expansion vet observed, which
was an inch and three quarters in the
eight hundred feet of tubing.
The tubes, if worked to their greatest
capacity, can transmit ten boxes or a
a thousand messages, each minute.
Packages may be sent as well as paper
lhCoSh9CS' VI uuy lHlHB clSc IHdU can DC
got into the box. The direct tubes will
not admit of any stoppagcs short of the
terminal stations, but if messages are de-
signed for way stations that are con-
nected with the other two tubes the
operator at the dispatching office informs
the operator at the receiving office by an
electric bell. The receiving operator
swings the section of the
tube above him to one side
thus breaking the connection. He re.
places it with glass face to stop the
suction, and wire screen to stop the
box at its end. His station is connected
by a curved tube that comes up out of
the street, and by the time he has COM
pleted these changes the box is before
him and he reopens the tube. This sys-
TEN of reversible stop-covers that catch
the boxes up Just at the right station is
something new in mechanical achieve
ments.
Alright collars protect the points
where the sections of the tubing Join.
At distances of about 400 feet a man.
hole is sunk into the trench and work
men may descend and make such repairs
as are needed from time to time. Iniu-
ries TO the pipe which impair its opera
ton may be placed by passing a box
through it connected with rope at each
end. In connecting the terminal sta
ton, which cost something more than
500, 600, 76, 400 feet of tubing is used.
The cost of the engines, air pumps and
compressors is about as much more The
pressure of air in the compressed tank is
thirty pounds to the square inch, and the
perfection of the machinery has been
shown by an experiment which proves
the exhaust TO be twenty-eieht and one
half inches, almost an actual vacuum
Neto York Tribune.