North Iowa times. [volume] (McGregor, Iowa) 1867-current, 1870-03-16
VOLUME XIV---NN %

tubes have been constructed in London
and are in operation. A little railway
with cars placed inside---the cars drawn
by piston fitting the tube. The attrac-
ton Of power is obtained by exhaustinc
the air in front The tubes which the in
vention employs will be trihe larger
than the spheres or globes. so that they
can roll freely without touching the sides
On the bottom, metallic plate or rail
will be laid slightly concave to adapt it to
the canvexity of the sphere. This plate
or rail will be its road bed. The proper
ties which the pneumatic tube poss esses,
fit it admirably for the. new vehicle OF
motion. 1t will furnish the sphere a
track that is, first, smooth, even and solid;
second, perfectly clean, free from dirt and
dust. and protected against the perturb-
ing action of the wind. rain or snow; third,
a passage way in which the spheres, NOV
ing with the current of air, will not be
impeded in their motion by the resistance
of the atmosphere. From these explana-
tons it will be seen that the invention
consists in employing hollow spheres or
globes, with the load to he transported in
side, operating in the pneumatic tubes.
We will not enter into details of con-
struction and management. Suffice it to
say that lines ef tubes can be easily and
rapidly constructed through all parts of
the country, even in the Rocky Noun
tains, where 10 railroad can go. The
tubes may be placed under or over ground,
but better over, raised some fifteen feet in
the air, and supported on framework or
piers. They would be best, made of wood
of narrow plank, tongued and groved,
the joints ccmented. A line of tubes of
eight feet in diameter could be built for
about $4,000 per mile, the right Of way
not included.
To form an idea Of the system in prac>
tical operation. we have but to imagine
tube six or eight feet in diameter, travers-
ing the country from New York to Phila-
delphia, supported on frame work or piers;
the spheres placed in the mouth at one
end, with the air exhausted at the other
by an air pump, worked by steam. AS
soon as air enough is drawn out of the
tube to destroy its equilibrium, current
sets in which, striking the sphere-and
with force proportional to its diameter
carries it rolling rapidly to its destina-
ton. The spheres will, SO to say, fly On
their smooth and even track, on which no
particle of dirt or dust exists to impede
their motion, and no resistance Of the at,
is to be overcome. The press
ure on a sphere six feet in diameter, up-
der complete exhaustion, is about 52,-
600 pounds. Now, when the spheres are
once in motion, less than 100 pounds will
propel them with all the velocity required.
When We consider this fact, we can
conceive the ease with which a current,
strong enough to drive them, can be es.
tablished. In the pneumatic tubes of
London ten tons are carried on the little
cars within them forty miles an hour,
with pressure of six ounces to the
square inch. I'm Il complete exhaustion,
the pressure is fifteen poundsl If this
pressure of six ounces is sufficient to over
come the friction of car wheels, and of an
air-tight fitting piston that drags the cars,
it is easy to understand that very trihing
pressure will suffice to propcl the spheres
(which are rolled, not slid on their clean
and smooth track.
To form an estimate of the velocity
with which the sphere will move, we may
safely calculate it ut double that attained
by the locomotive running at the highest
speed, which is from seventy>five to one
hundred miles an hour. This would give
velocity of from one hundred and fifty
to two hundred miles an hour for the
spheres-an estimate that is not exag GER
ated.
The spheres will be stopped by suc>
cession of brakes on springs, padded to
prevent abrasion of their surfaces, and ~
reversing the current of air, presenting
an air cushion against which the spheres
will be brought gently to stand.
II will be thought by some that the oh
jscts inside the spheres will be broken and
ground up. This is an error. The cen.
trifugal action will keep everything in
it's place; besides they will be packed
tiuht1v