IMPROVEMENTS IN METHODS OF AND APPARATUS FOR TRANSMITTING SIGNALS BY MEANS OF ELECTRICITY
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Arthur French St. George and
Charles Ambrose McEvoy at the Office of the Commissioners of Patents on
the 1st September 1883.
"
ARTHUR FRENCH ST. GEORGE, of Bucklersbury, in the City of London, and
CHARLES AMBROSE MCEVOY, of Adam Street, Adelphi, in the County of Middlesex
IMPROVEMENTS IN METHODS OF AND APPARATUS FOR TRANSMITTING SIGNALS
BY MEANS OF ELECTRICITY
Our invention relates to novel methods of and apparatus for transmitting
electric telegraphic or telephonic signals or messages without the use of any
connecting wire between the two points between which it is desired that such
signals or messages shall be transmitted; and it is especially applicable for use in
the transmission of such messages between places which it may be impossible or
undesirable to connect by means of a conducting wire, as for instance between a
ship at sea and a lighthouse or other shore station.
We employ instead of a wire between the two places to be connected a
conducting medium such as water, moist air, fog, mist, or clouds, and the earth.
Assuming that telegraphic or telephonic connection is to be made between a ship
at sea and a lighthouse surrounded by water, we employ and arrange at each such
station a telegraphic or telephonic transmitting and receiving instrument of any
convenient kind the conducting wire of each such instrument being connected to a
plate or wire of metal or other suitable conducting material and of sufficient size
which is immersed in the water round the ship and round the lighthouse
respectively. The wire or plate at one of the two stations is composed of one
such metal or conducting material and that at the other station of a different
metal or material.
The dissimilar metals or materials are acted upon chemically by the water in
which they are immersed, in the same way as in a galvanic battery or pile, and
differences of electric potential between the distant stations are thus produced,
and we utilize these electric actions by means of suitable apparatus arranged at
each station in connection with the telegraphic or telephonic instrument.
We also arrange in connection with the instrument at each station an insulated
wire sunk in the water preferably to the bottom so as to touch the earth and

page_text: carrying at its lower extremity a piece of metal, and we prefer to insert in this
wire between the telegraph or telephone apparatus an adjustable resistance coil or
other equivalent resistance apparatus of the ordinary well-known kind capable of
considerable electrical resistance.
We sometimes also employ at each station an ordinary galvanic battery for the
purpose of increasing the electric potentials.
Where our invention is to be applied to the transmission of signals or messages
through the medium of moist air, fog, mist, or clouds, instead of through water, we
employ at each station arrangements of apparatus similar to that already described,
but we connect each station with the moist air, fog, mist, or clouds above it, by
means of a balloon or a high mast or pole above the station and connected with the
latter by a conducting wire. In this form of application of our invention we
prefer to use dissimilar metals for the metallic connections fitted to the balloons,
and sometimes we connect to the apparatus at each station a sufficiently powerful
galvanic battery. A connection to the earth of a kind similar to that already
described is provided at each station and connected to the telegraphic or telephonic
instrument.
The novel methods of and apparatus for transmitting signals, which form the
subject of our present invention, may be applied and used in many different
circumstances, as for instance, between ships afloat in the water, or between such
ships and a station on land, or a station surrounded with water such as a lighthouse,
or between distant points separated by water, or between the tops of mountains,
balloons in the air, or high towers or buildings on land.