A NEW SYSTEM OF APPARATUS, TO BE CALLED ATMOSPHERIC POST,' FOR TRANSMITTING LETTERS AND MESSAGES, AND APPLICABLE TO RAILWAYS AND AS A SPEAKING TRUMPET
Year: 1854

page_text: by the Act.)
PROVISIONAL SPECIFICATION left by Auguste Edouard Loradoux Bell-
ford at the Office of the Commissioners of Patents, with his Petition,
on the 3rd February 1854.-A communication.
I, AUGUSTE EDOUARD LORADOUX BELLFORD, of 16, Castle Street, Holborn,
(City) London, Patent Agent, do hereby declare the nature of the said Inven-
tion for "A NEW SYSTEM OF APPARATUS, TO BE CALLED ATMOSPHERIC POST,' FOR
TRANSMITTING LETTERS AND MESSAGES, AND APPLICABLE TO RAILWAYS AND AS A
SPEAKING TRUMPET," to be as follows, viz. :-
This apparatus consists in a succession of cylindrical channels laid down
along and parallel to the lines of railway, and whose ends are at a suitable
distance from each other at every station, where one channel terminates and
the other begins. These carrying channels, which pass under ground at the
crossings, are open at one end and closed at the other by a hinged lid or
embolus.
They consist of cast-iron pipes with air-tight joints, the last of them having
a pipe branching off at a suitable distance from the orifice shut by the lid.'
On this branch pipe is fitted another pipe, which leaves the railway line
and establishes a communication between the channel & a vertical pipe

page_text: which is erected in the centre of a chimney belonging to a steam boiler.
Near the base and in the interior of the vertical pipe enters a blast pipe or
tuyer, from which the steam is shut off by a valve or cock. This valve being
opened, the steam rushes through the blast pipe into the vertical pipe which
communicates with the carrying channel, and at the same time the air con-
tained in the latter is sucked out by the jet of steam, which carries it away
into the atmosphere, thus also increasing the draught of the chimney. The
jet of steam which rushes out through the blast pipe may be regulated by
opening the valve more or less, so as to rarefy more or less the air contained
in the channel, the draught of the chimney and production of steam being
increased or diminished in the same proportion.
This apparatus may be applied in the following manner to the carriage of
letters:-
Let two equal lines of channels be laid down by the sides of the sleepers
on which the rails are fixed; one of the lines will be for the up and the other
for the down service.
In case of repairs becoming necessary in one of the lines the other may be
made to do for both; for this purpose it is sufficient to place one more boiler
at each end of the railway. :
The letters sent by the atmospheric post are contained in several spherical
boxes of about two millimetres less diameter than that of the piping they
have to pass through. Each box has engraved on it the name of the post
office where the letters have to be delivered which are locked up in it. Let
us now suppose that a certain number of boxes containing letters have been
introduced by the mouth piece into the carrying channel; the starting signal is
then given to the fireman at the next station, who has to attend to the boiler
there, whereupon he opens the steam regulator, and thus causes to be sucked
out and carried away the air contained in the carrying pipes; by these means
the column of letter boxes are set in motion, and pushed forward by the
atmospheric air, which follows it in the channel with a speed proportionate to
the rarefaction of air, as indicated by manometers.
When the travelling
boxes have past the branch pipe, their speed is gradually reduced by the
resistance of the column of air which they force back into the extremity of
the channel, and finally they get out by opening the hinged shutter. This
latter consists of an india-rubber buffer suspended by a balistic pendulum.
The deadened shock of the box pushes back the pendulum, which allows them
to get out and fall into a baskett at the end of the channel.
A bell, which is acted upon by the balastic pendulum, gives notice to the
attendant of the office to receive the boxes. Those which are arrived at or

page_text: near their destination are kept; the others are sent forward in the next channel,
which they pass through in a similar manner as the preceeding, and so on to
the last station.
For verbal communications this apparatus is used in the intervals which
elapse between the above-mentioned letter posts. For this purpose it is only
necessary to speak slowly at one end of the pipe, in order that the words thus
spoken reach distinctly the other end with a speed from 1050 to 1115 feet per
second, between the temperatures 16° and 68° Fahrenheit.