Eastern times. [volume] (Bath, Me.) 1846-1857, 1852-12-02
A Successful Atmospheric
Railway.

halfway. .a.aa a..
To the French belongs the credit of bay
ing brought to successful issue the expert.
ment of an atmospheric railway on a large
scale. This mode of propelling cars has
been adopted at ST. Germain, city abou,
Is miles from Paris. The distance run is
five miles and half-the last half mile with
an ascent of 8 l-2 per cent. The ascent
was too great to be overcome by an engine
in all wea,hers. The following description
of the machinery employed is given by a
foreign correspondent of the Ohio State
Journal:
AN iron tube is laid down in the centre
Of the track, which is sunk about one-lhird
of Its diameter in the bed of the road. For
distance of about $500 yards the tube has
diameter of only 1-2 feet the ascent here
being SO slight as not to require the same
amount of force as is required OIL the steep
grade ascending to St. GERMAN, where the
pipe for distance Of $500 yards is 2 fee. l
inch in diameter.
The manner ofapplying the atmospheric
pressure to the propulsion of the train is ex-
the entire length Of the tube, so as 10 pro-
duce perfect vacuum Just before the arri.
val OF each train, which IS every half hour,
BY means of powerful and beautiful engines,
somewhat resembling those ut Fairmount.
These engines are placed, two Of two hun
dred horse power ut St. GERMAN, and one
each at the towns of Nauterre and Chat
ton, in the valley towards Paris.
To each engine are adapted two large cyl
inders which exhaust fourteen cubic feet of
air per second. The pressure in the air
cauldron (chauderes) attached TO the ex-
hausling machines is equal TO six absolute
atmospheres. 1t will be readily understood,
that when this long tube is completely ex-
hausted of air, if piston so nicely adjusted
10 the size of the tube as to render it air.
light, is allowed to 60 loose at one end, it
will rush through TO the other end TO fill up
the vacuum. To apply the motive power,
therefore, to the propulsion Of the train, it is
only necessary that this piston be attached
to The train of cars in such a way as to drag
them along after il.
This was The great difficutyto encounter :;
but so admirably and SO simply was this ov-
ercome that the engineer assured US that an
accident Of any kind seldom ever occurred
Throughout the entire length of the tube, a
section is made in the top, leaving an open
space of about five inches. In each Gu. edge
of the section there is an offset, 70 catch The
edges of a valve which fits down upon it,
This valve is made Of piece of sole leath-
er half an inch thick, having plates of iron
attached 10 il on both the upper and cores
ponding under side, to give il strength to re-
sist the suction Of the vacuum, which are
perhaps, one-iourih of an inei. in thickness.
They are not quite as wide as the leather,
but wide enough to touch the offset in the
section.
The plates are about nine inches long, and
their ends, above and below, are placed
three.quarlers of an inch apart, forming
joints, so as to give the leather piabiIitv
and at The same lime fnnness TO resist the
powerful atmospheric pressure which is
brought TO bear on il, when the air is ex.
haUsted. The entire length of the valve,
from one end of the tube TO The other, is at
tsched TO one side, like cellar door, for ex-
ample.
From the back side OF the piston, a strong
iron rod passes up through the aperture,
which is made by raising up the edge of the
valve, and is attached 10 the bottom OF the
foremost car. As fast as The piston passes
along, the valve is relieved from pressure be-
hind ii, the loose edge is liberated, and the
bar of iron which is attached 10 the car a
foot or more behind the piston meets with
no obstruction to its passage
The pressure of The atmosphere on the
valve in front of The piston, where the vacu-
uin still exists, is SO great that there is m
danger of the bar of iron exerling pressure
SO far forward as to loosen the pliabe valve !;
bnt to render the matter more certain, and
10 obvate all doubt, slide on the bottom of
The car slips along on the iron plate of the
valve over and in advance of The piston, and
presses it firmly down. Every part Of the
tube is kept well oiled. The rate at which
trims ascend varies from fifteen 10 twenty
miles the hour, according to the load. :.
When we went up, there were six cars
very we'll filed with passengers. After the
ascent commences two bridges across the
Seine, and one viaduct of twenty feet high
and wide arches are crossed, and one long
tunnel through the brow of the hill and un-
der The Kings terrace is passed, where the
road is periodically curved.
The road has now been in operation FIVE
years, and SO safely and so we'll has it worked
that The experiment is regarded as entirely
successful. The cost of the entire macIlin.
cry was eleven millions of francs. The cost
OF working it or the dividends which the
road pays, did not ascertain"