Evening star. [volume] (Washington, D.C.) 1854-1972, 1903-04-11
IN PNEUMATIC TUBES
Letters and Parcels to Cross
the English Channel.
SOUNDS REASONABLE
lis II
NO GREAT DIFFICULTIES TO BE
OVERCOME.
Would Be a Financial Success - How
the System Would
Operate.
Special Correspondence of The Evening Star.


each something over a yard in diameter,
| and through these tubes will pass the mail
| and small parcels, at high speed driven by
pneumatic force.
Capitalists and engineers are now en-
gagged with the specifications of the great
| work. Who these gentlemen are remains a
| secret for the present, but from the same
source from which 1 have these exclusive
details-hitherto a guarded secret learn
that a certain all-powerful English politi-
clan, himself cOmmoner and OF an I'M
| mensely rich and active industrial family
having it's interests not hundred miles
from Birmingham, has accorded the project
| his benevolent attention. Hence 1t is
probable that a great part OF the iron tubes
will come from Birmingham. and that the
present English government will rather aid
| than hinder the great work.
Indeed, there is no reason why Eng1sh
patriotism should look askance at the pro-
posed tubes The preponderance OF the
British marine Is an accomplished 1act. II
contributes notably to the richness OF the
tight little island. Therefore English pa
triotism watches over 1t to guard 1t. This
is one of the reasons why the English are
| determined to prevent, at any price, the
construction of channel tunnel whose
railway would change their island to
part Of the continent
An Aid to England.
With the postal tubes England will also
cease to be an island: but only to the ex-
tent of aiding and not hinderins the march
of Englands maritime supremacy. Only
samples will travel by the tubes parcel
post!
Whether the tubes are to be laid along
the bottom of the channel or sustained by
pillars at certain height above the sur
face of the water Is not yet decided. A
third idea is to lay them in compare
lively small tunnel; but this is the tunnel
idea again, and might prove unpopular in
England. Whichever system is adopted 1t
must permit workmen to traverse the
tubes for the sake of repairs. 1t must also
be possible to lay new tubes, according to
the needs of the service.
Suspended in Air.
The suspended tube offers the least OBJ
jections. 1t can be made about yard In
diameter, of comparatively thin sheet iron;
and its lightness will permit the pillars
being placed a. considerable distance-say,
800 yards-apart. The pillars would be
made to project above the surface of the
water. like lighthouses, and they would
sustain the tubes at sufficient height IN
the air. At night they can alternate red
and green lights, and be an aid to naviga-
ton instead of a hindrance.
~ The building of the pillars on foundations,
the construction on the spot of suspension
cables and the posing Of the tube all belong
to a mode Of engineering and construction
already perfected by long practice. The
only serious difficulty anticipated settles
round the laying of the foundations in the
open sea part of the channel, where there
are depths as great as sixty yards at high
tide. AS will be seen, 1t is proposed to
surmount this difficulty with the aid of
floating foundation piles during the period
of their construction, which can be
grounded or foated at will. before their
completion.
Another consideration in favor of this
mode Of laying the tubes consists in the
calculated cost. which will not exceed 3d.
600, 900 francs ($5,OOO OOO. Hence it is fore
dividends-a point which Is said to have
chiefly interested the English statesman.
By Compressed Air.
A question that is taking still more study
IL that Of how the compressed air is to be
used. In every Paris sub post offlce-and
there are such in each ward, according to
the needs of the population-you can buy
pneumatic envelope for cents. Inclose
your letter in 1t and drop 1t into q special
box marked pneumatic letters Within a
few minutes you will see boy or girl take
be in the box. and hand them to the
operator Of a great machine that resembles
a printing press or cider mill.
"Chfffff! Fffff!'
n.
It is the compressed air. The operator of
the big machine has placed the pneumatic
letters in little leather cylinder, and the
leather cylinder in the machines receiver.
Then he has opened the throttle-and COM
pressed air sends the leather cylinder nv.
ing across Paris In an underground pneu-
matte tube. A hundred such tubes meet at
a common center, where the transfers are
effected. Then the letters are sent on the
second part of their quick journey, to the
sub post Office to which they may be d.
rected where boys in uniform are in wait
ing to deliver them like kilograms.
The Probable System.
The system works perfectly within the
limits of Paris and 1t is this system which
will probably be adopted for the channel
tubes. Inside the great tubes-one yard in
diameter, for workmen to pass through on
repairing trips-will be placed the smaller
pneumatic tubes.
Calais to Dover Is eighteen miles, or
course, it is much greater distance than
between any such pneumatic stations oper-
ated under the Partisan system. Should
the pneumatic pressure threaten to weaken
under it, relay pumping stations are sug-
gested. to be established at the lighthouse
suspension pillars. Such relay pumping
stations are completely effective in the
work of pumping Oil through the American
petroleum pipe lines. They force the thick
fluid over hills and dales.
Another system OF transmission is also
under careful study It has not SO brilliant
a look at first glance, but, as will be seen,
1t has great surprise idea connected with
it. p IL
By Means Of Small Cars.
Imagine that the two great tubes each
one yard in diameter have been establish
ed. Later on there will be four and six and
eight They VIII be painted. to preserve
them from the chemical action of the sea
water. Running through the interior of
each will be a horizontal wooden platform.
eleven inches below the center.
On this platform will be constructed q
miniature narrOw-gauge railway track, for
the circulation of little wagons
The traction of the miniature jsnAns-each
composed of from ten to fifteen wagons.
weighing, fully loaded, not more than 1000
pounds apiece-wiil be accomplished by the
aid of compressed and rarefed air in a
bronze tube six inches in diameter laid i'm
mediately beneath the wooden platform
that sustains the track.
This bronze tube is split throughout its
length and furnished with a double LID in
leather. The piston Is connected with the
wagon at the head of the train by a thin
blade slipping between the leather lips
In a word, it is a traction system that
was at one time In successful use for trans