The Norfolk Virginian. [volume] (Norfolk, Va.) 186?-189?, 1896-07-22

tied. perhaps, but as proportionately ef-
| ficient, have been tn operation for years
in London, Paris, Berlin and Vienna. The
pneumatic tubes IN European cities are
none OF them very large as far as their
diameter is concerned. Their carrying
capacity Is thus somewhat limited, but
| only as to- the transmission OF packages.
Otherwise these systems are very COM
plete, and in London, Paris. Berlin and
Vienna our American method OF mes.
sage delivery would seem very slow In
deed
Tho London pneumatic tubes differ
very materially from those of Paris
not only in the mechanical method OF
transmission. but also in the ma nner in
which the circuits are arranged around
| the city. London uses what Is known as
the radial system. Paris uses the cir
cult system. In London the pipes or
tubes radiat= from the central station
which ;n this case Is the general post,
| office. Outgoing and return tubes are
laid 10 and from the outlying stations
In Paris, however. a single pipe starting
| from the central station makes a circuit
or outlying stations and then returns to
the starting point. The circuit arrange.
ment is also used in Vienna. but 1t may
be said IN favor OF She London system
that Berlin, which originally employed
the circuit system. replaced 1t in 1854 by
the rad!al system. Yet the Paris plant
Is In some parts a combination for the
reason that double lines of tubes have
been laid from the Place de la Bourse to
the Place du Theatre Francais and from
these to Halles and to the Rue de Gre.
Inelie. Also single lines of pipe have hesn
extended to the Place du Havre and to
the Avenue des Champs Elysees.
London operates forty-two stations
ana thirty-four miles of tubes. 1t is
estimated ta,at over fifty-seven thou
SAND messages are transmitted daily
Paris. on the other hand, operates less
than twenty stations and transmits
nearly as many messages rs London.
There is therefore something DO be said
III favor of the Paris system as opposed
10 that of London by reason of the
economy of ITS working force. Berlin
operates over twenty-eight miles OF
double tubing and has thirty eight sta
tons. me Vienna plant corresponds
In It's operation to that of Paris, only in
smaller proportion. There is greater
, simplicity In the Lonon arrangement
or the tubes which may be said to re-
semble a. double track railway. while
some confusion Is apt to result in che
operation OF the Partisan tubes. The
latter form succession of loops and
once carrier starts out from the CEN
t,al station, It Is compelled to make a
complete circuit of the city before It
can return to It's starting point II
might be supposed from this that much
time would be lost in the transmission
OF empty carriers, but this difficulty Is
overcome by the fact that the carriers
| themselves arc not acted upon by COM
pressed air or vacuum. The propelling
force in the pipes is exerted upon a
small piston which Is shot through the
pipes and drags after It long trains OF
carriers. Just as locomotive pulls n
train of cars. In London the carriers
themselves are acted upon by the p,o-
pelling force and are shot through the
/ a
the Philadelphia postomce.
Pneumatic tubes are operated on the
| principle which causes a vacuum to be
created in the tube in front of the car
i'ier. thus compelling the air behind tho
carrier to drive 1t through the tube, OF
in the protection Of compressed air into
| the tube behind the carrier or in q com
9 bination of both methods.
n The carriers used in the tubes of Paris
z are made OF iron covered with leather
q yet do not last nearly long as the Lon.
= don carrieds which are made of gutta-
q perclea, covered with felt. The London
carriers will stand two thousand miles
;, OF travel, but the Paris carriers usually
4 give out after having travelled twelve
: hundred miles. There is also less trou.
:, BILE in London with carriers sticking II
= the tubes than there is in Paris. where
1t Is claimed the annoyance is frequent
s AN ELECTRIC DEVICE FOR LOCAT
Il ING INSTRUCTIONS.
r This brings forward very curious in
$ strument which is used for locating OF
s obstruction In the underground Paris
Il The magnificent sewer system of TIL,
d French capital makes the inspection o
l. the tubes an easy matter. as they ar,
n all laid in the sewers. When pipe Il
n INSTRUCTED. however. other means OF in
lspection must be resorted to. 4 dia
phragm is attached to the end of the oh
structed tube and pistol is discharged
into the tube through an opening jus
C below where the diapragm Is placed
q The sound acting on the diaphragm
= causes an electric circuit to be closed
= which In turn causes n mark to be mad
h on n chronograph. The sound wav
n travelling through the tube finally meet
e the obstruction and is reflected causln,
Is another mark to be made on the chrome
e graph The interval of time between
i the two sounds can thus be easily deter
= mined and the position OF the obstruc
Y, ton located The rest Is easy. The pip
II being measured It is only necessary t
J. descend into the sewer, take out the re
o ouisite section of the pipe and remov
= the offending obstruction.
e A PROPOSED TUBE BETWEEN LON
:. DON AND PARIS.
e Ut has been proposed that pneumati
q tube be laid from London to Paris b
: way Of the English channel. This some
= what realizes that time-honored jok
t. about the possibility of a person gon
lie to Europe in a pneumatic tube with tina
IS other distinct possibility of "gettin
e stuck" in the middle. There will hav
u 10 be some better method devised. how
:. ever, before a tube can be laid unde
, lwater. However we'll Drotacted corrosio