AN IMPROVED SYSTEM OF HYDRAULIC TELEGRAPH
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Comte Charles de Montblanc and
Lucien Gaulard at the Office of the Commissioners of Patents on the
27th May 1881.
Comte CHARLES DE MONTBLANC and LUCIEN GAULARD, both of Boulevard
Saint Denis, No. 1, at Paris, Chemists. "AN IMPROVED SYSTEM OF HYDRAULIC
TELEGRAPH."
Our hydraulic telegraph is based on the combined employment of the constant
pressure exerted by a column of water of determined height, and of the velocity of
flow in a pipe of the same liquid under a given pressure. If by an opening formed
in a pipe at a height of 33 feet, for example, below the level of the reservoir which
supplies it with water, we introduce a body of slightly smaller section than that of
the pipe, and of a weight less than that of the column of water which it supports,
it will be displaced with a speed which will be so much the greater in proportion
to its weight being so much the less. It is upon these principles that we construct
our hydraulic telegraph for the rapid transmission of letters or despatches, and
which is specially intended to connect two stations separated by a sea or
channel.
In carrying out the Invention we connect the two stations by a tube of a
diameter of 4 inches, for example. This tube is of lead of about ths of an inch
thick, and is covered with an armour formed of iron wire wound spirally round it,
and protected externally by a wrapping of tanned or tarred hemp. This arrange-
ment, while enabling the tube to resist the pressure of the column of water which
owing to its immersion it has to support, leaves it sufficient flexibility to allow
of its following the undulations of the ground. At each of the terminal stations
this tube is put into communication with a water pipe, whose section or bore is at
least equal to it, and whose source of supply, whether natural or artificial, is about
160 feet above the level of the sea or channel. The communicating tube is con-
Dected to the water pipe by an apparatus composed of a box, which is closed at
top and bottom by sluices or valves, and has at front a water tight door.
communicating tube and the water pipe are fitted to the bottom and top of the
box respectively. The internal section of the box is greater than the bore of the
communicating tube, and it is intended to receive a case or receptacle containing
The

page_text: the letters or dispatches to be transmitted. This case is of smaller diameter than
the communicating tube, and is formed of iron wire rolled into a close coil, and
covered with a tight india rubber casing. Its mouth is closed with a water tight
cover.
The working of the apparatus is as follows:-Both the sluices of the box being
closed the door is opened, and the case containing the letters or dispatches is intro-
duced into it. The door is then closed, and the two sluices are opened; the
pressure thus comes into action, and the case is caused to travel through the tube
to the other station with considerable speed. The tube at the receiving station
must be opened, and the case on reaching it may be allowed to fall into a vessel
formed with openings to allow the water to run off. When it is required to
dispatch another case the two sluices are again closed, the case introduced into the
box, and so on as before.