The record-union., 1893-04-03
PNEUMATIC TUBES.
Their Extensive Use IN London. Paris,
Vienna and Berlin.

In an article on Progress in Pneu-
matte Transmission" in the current
number of the Engineering ldgdzine,
William Allen Smith gives the following
facts regarding the use OF pneumatic tubes
in Europe:
Pneumatic tubes for local transmission
of kilograms are now used in all the prin-
cpal cities OF Great Britain. AT present
about 80 miles of such tubes are in opera
ton, requiring an aggregate OF 400 horse
power, and transmitting daily average
of over l05, 600 messages Tor over 3O,OOU,-
900 annually, more than half OF these IN
London. The lengths of tubes vary
greatly; the average length is about $50
yards; the greatest single length in Lon
don is 1892 yards. The tubes are of lead,
laid in cast-iron pipes for protection, and
are usually of p inches, inner diameter;
some tubes are II and some of three
inches inner diameter are used. AS q
general rule, with the same air pressure
and diameter of tube, the speed carries m
UerSeLy as the length Of the tube. In tubes
not over d mile in length the usual aver
age speed is % to 30 miles an hour. The
carriers are of gutta-percha covered with
/ felt, with buffer at the front end, and
/ au elastic band at the back, or open end,
! to hold in the messages. An ordinary
carrier weighing u ounces holds dozen
messages.
The marked success of the British
pneumatic service led to the adoption OF
similar systems in Paris, Vienna and
Berlin. The pneumatic system of Paris
was put into operation in 1866, and has
grown steadily, so that to-day in Paris
tubes are used almost exclusively for
transmission of local kilograms and let
ters demanding quick delivery. A small
stamped envelope, the petit 6LeU, costing
81 centimes, or 10 cents is used for the
message, which, dropped into a special
postal box, is delivered anywhere in
Paris within an hour, often in twenty
| five minutes.
In Vienna the ''tube-post" was estab-
lished in March, 1875. The nine districts
of the city are connected with the central
station. The ''tube-mail' is dropped
into special post boxes, collected every
half hour, forwarded to the central sta
ton and distributed. Pneumatic en-
velopes cost Is kreuZers about cents
ordinary letters 3 kreuZers. Tube let
ters'' are delivered within one hour aftel
mailing. The Vienna system consists o
a main circuit of 5.34 miles, with three
branch lines; total length ID miles
In Berlin the Prussian postal authori-
ties began in 1862 discussion of measures
of relief for the oYer-crowded local tele
graph system, and a pneumatic line was
opened in 1865 between the Central Tele.
graph Station and the Exchange build
ing. The beginning of the present exten
sive tube post of Berlin dates from
1876, since which time it has been en-
larged, until there are now over twenty
eight miles of tube line in the city, will
thirty-eight stations. Tube letters" ar,
to-day delivered in Berlin more quickly
than kilograms at a cost equivalent to Z
cents, and tube postcards" at 81 cents
The tubes in Berlin are of wrought iron
and have an inner diameter of Is mn.
equal to 30 inches. The system is oper
ated by eight steam engines, aggregatinI
only l2S horse power.