The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1872-12-07

UNDERGROUND TRANSPORTATION IN WASH
lSGToN-As VERY INTERESTING GOVERNMENT
EyrEGlNEST.-Th Washington Star says {:
The pneumatic tube, about which so much
las been said within the past quarter of a
century, will soon be constructed and put to
Il practical test between the Capitol and Gov
crnnicnt Printing Office. Reference has
heretofore been made in the Star to the pro-
ject OF Mr.. Albert Brisbane; and brief de-
scription Of the tube made by him was given.
Congress, it will be remembered, at the last ses-
sion appropriated $l5 200 to construct tube
OF his patent between the Capitol and Gov
elnment Printing Office, and as the work of
laying it will soon be commenced there will
no doubt be much interest felt il its compile
ton aud practical working.
Pneumatic tubes are now successfully
working short distances In New York, Lon
don, Paris, and Berlin, but they are con-
structed on different plan from that of Mr..
Brisbane, the vehicle in those tubes being
run on wheels, while in that Of Mr.. Brs-
baue 1t is not, and consequently much loss
by friction Is avoided Mr.. Brisbane claims
that he can transmit packages through a
tube from New York to San Francisco by
hollow spheres in the tube and exl,allsting
the air from the other end from that in which
the sphere Is started, thus creating vacuum,
causing the atmospheric pressure of fifteen
pounds to the square inch to drive the
sphere through rapidly.
The tube is made of pine slaves three or
four inches wide, one inch thick, put to-
Sether in circular form, and securely fastened
with Heavy iron hoops placed at intervals of
four or five feet. Several coatings of thick
paper are then wrapped around it to make II
perfectly air-tisht, and the tube is placed in
Int nah, ,lx ~ I'D i,,,
it is put together, however, the wooden
slaves are subjected to steam exhaustion of
sixty pounds pressure TO the square inch,
which drives out the sap and congeals the
aibumen. They are then boiled in prepa-
ration Of rosin and linSeed oil to make them
perfectly waterproof. The inside diameter
will be thirty.one inches, and that of the
sphere, thirty inches. The entire length
OF it will be $500 feet. The machinery
to work it CONSISTS Of two small engines,
one in the capitol and one in the print
Ing office, with single telegraph wire be-
tween the two points, two air.pumps and
blowers, one Of each ut each end. Parcels to
be transmitted from one building TO the other
will be placed in the sphere. the signal given
10 the man 1t the other end by means of the
telegraph-wire TO start the engine there,
which eXha,tsts the wind from that end, and
the atmospheric pressure upon the ball soon
starts ii towards its destination. The ex-
hauSt Is kept up, and the natural pressure
behind the bali carries 1t along at, a rapid
rate, not more than two ard a bali or three
minutes being consumed from the Capitol to
the printing Office. TO send it the other
way will. however, require Que or two min
utes longer, as there Ii III. ascent OF about
for'y-fyc feet from the printing office to the
Capitol.
The esbausting machinery at the Capitol
viii need 10 be more powerful than at the
other cud on account Of this ascent and the
greater force requisite TO bring the sphere
up. The inventor claims that the attnos-
pherie pressure alone will drive the sphere
through the tube; but II necessary the ma.
ehinsfy can also DO used 10 force cir IN the