IMPROVEMENTS IN ELECTRO-TELEGRAPHIC CONDUCTORS AND THE BATTERIES CONNECTED THEREWITH
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by William Alexander Lyttle at
the Office of the Commissioners of Patents, with his Petition, on
the 13th October 1868.
I, WILLIAM ALEXANDER LYTTLE, of the General Post Office, London,
in the County of Middlesex, Civil Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN ELECTRO-TELEGRAPHIC CONDUCTORS
AND THE BATTERIES CONNECTED THEREWITH," to be as follows:-
I use two voltaic batteries or other sources of electricity, one being
placed at each end of the wire or other conductor. The positive pole
of one voltaic or other battery is connected by means of the said con-
ductor with the negative pole of the battery at the opposite end of the
system, and the remaining poles of the respective batteries are connected
together either by means of a second "return" wire or by means of the
earth. At or near one or both ends of the conductors of this system I
attach a zinc or other like electro-positive element in such a way that it
shall form with the wire or other conductor to which it is for the time
attached a single voltaic pair, and I excite the voltaic action of such
electro-positive element either by direct exposure to the moisture of the
earth, or by any of the well known combinations of salts, acids, or other

page_text: oxidising agencies (with or without the intervention of a porous
diaphragm) by means of which the electro-motive energy of the zinc or
other like element in a battery is intensified. It may be found most
convenient to have an electro-positive element of this description at either
end of the system so that it may be attached and brought into play at
that end from which despatches are being sent. This arrangement for
assisting the transmitting power of the system will work with a single
wire, but I prefer, generally, to employ a second wire for the return
circuit. The point of the aforesaid auxiliary electro-positive element at
which connexion is made with the line conductor should be above or
otherwise insulated from water or earth, and connected solely with the line
conductor, the latter being from such point of junction to the adjacent
battery carefully insulated from the earth. The electro-positive auxiliary
element acts best when connected with the line at the despatching end
of the system. If magneto-electric batteries are employed to furnish
the signaling current, this current may by means of a proper "switch"
or "cut-off" arrangement be made to flow in one direction only.
When voltaic batteries with two or more exciting liquids, like Daniel's,
are used, I connect the poles of each by means of a fine wire with
or without the intervention of a resistance by means of a liquid con-
ductor or a resistance coil or both, the object being to allow a very feeble
current to pass when the battery is not in use. By this means the
elements of the battery are always preserved in proper electrical relation
to each other, and diffusion with its destructive consequences avoided.
To guard still further against diffusion I employ a battery with
rectangular cells, each cell being divided into two compartments for the
opposite solid elements by means of a peculiar compound porous
diaphragm formed as follows:-A thin plate of clay is formed, and whilst
still wet is made to adhere to another plate consisting of a mixture of
clay and oxide of zinc. The plate is then burnt in the usual way and
placed in the battery cell with its oxide of zinc side turned to the zinc
element. It will, however, answer the purpose equally well if two
common thin porous plates are placed parallel and a little distance apart,
and the space between them is filled with oxide of zinc wetted with
sulphate of zinc solution or water.