TUPROUDMENTS IN ELECTRIC TELEGRAPHS.
Year: 1874

page_text: LETTERS PATENT to Sir James Anderson, Knight, and William
Henry Ash, both of 66, Old Broad Street, in the City of London,
fou the Tuxention of " TUPROUDMENTS IN ELECTRIC TELEGRAPHS.
"
PROVISIONAL SPECIFICATION left by the said Sir James Anderson
and William Henry Ash at the Office of the Commissioners of
Patents, with their Petition, on the 27th November 1874.
We, Sir JAMES ANDERSON, Knight, and WILLIAM HENRY ASH, both
of 66, Old Broad Street, in the City of London, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS,"
to be as follows:-
-
Our improvements relate to the means by which telegraphic signals
are sent and received.
We improve the conditions in sending and receiving on the duplex
system of signalling, either on telegraph lines or submarine cables
without the use of a condenser, in the artificial line by placing an
electro-magnet or induction coil in circuit, in the actual line immediately
after the differential relay or Wheatstone bridge, or any other similar
instrument or arrangement for duplex working.

page_text: We are aware that electro-magnets have been placed in the balance
circuit or artificial line of duplex arrangements, but we arrange the
electro-magnet or induction coil in circuit in the actual line.
We improve. the speed of working the duplex system with the
Wheatstone automatic instruments or other automatic sender without 5
the use of a condenser by placing an electro-magnet or induction coil in
the actual line as described above.
We improve the ordinary or single working of a Morse or any other
telegraphic apparatus on a submarine cable or telegraph line by placing
an electro-magnet or induction coil immediately after the sending key, 1
and with or without resistance after the receiving instrument.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Sir James Anderson and William Henry Ash
in the Great Seal Patent Office on the 27th May 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, Sir JAMES
ANDERSON, Knight, and WILLIAM HENRY ASH, both of 66, Old Broad
Street, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of November, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Sir James Anderson and
William Henry Ash, Her special license, that we, the said Sir James
Anderson and William Henry Ash, our executors, administrators,
and assigns, or such others as ive, the said Sir James Anderson and
William Henry Ash, our executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS," upon the condition
(amongst others) that we, the said Sir James Anderson and William
Henry Ash, our executors or administrators, by an instrument in writing
under our, or their hands and seals, or under the hand and seal of one

page_text: said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that we, the said Sir James Anderson and
William Henry Ash, do hereby declare the nature of the said Inven-
tion, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement thereof,
that is to say :-
1
Our improvements relate to the means by which telegraphic signals
are sent and received.
We improve the conditions in sending and receiving on the duplex
system of signalling either on telegraph lines or submarine cables
without the use of a condenser, in the artificial line by placing an
electro-magnet or induction.coil in circuit, in the actual line immediately
after the differential relay or Wheatstone bridge, or any other similar
instrument or arrangement for duplex working.
We are aware that electro-magnets have been placed in the balance
circuit or artificial line of duplex arrangements, but we arrange the
electro-magnet or induction coil in circuit in the actual line.
We improve the speed of working the duplex system with the
Wheatstone automatic instruments or other automatic sender without
the use of a condenser by placing an electro-magnet or induction coil in
the actual line, as described above.
We improve the ordinary or single working of a Morse or any other
telegraphic apparatus on a submarine cable or telegraph line by placing
an electro-magnet or induction coil immediately after the sending key,
and with or without resistance after the receiving instrument.
In practically carrying out our Invention we proceed as follows:-
For working duplex we use an electro-magnet made of a bar of iron of
about one inch in diameter, more or less, wound in sections with No. 30
copper wire of about 100 ohms resistance, having a terminal at about,
every 30 ohms with a switch for increasing or decreasing the resistance
on the bar. A diagram view of such an electro-magnet inserted in the
telegraph line to work duplex is shewn at Figure 1.

page_text: On a cable the arrangement can be the same, or small electro-magnets
with separate cores of about 10 ohms resistance each.
We further make use of additional resistance in circuit without
traversing the electro-magnets in order to lengthen the time for the
induced current to discharge itself into the line, as shewn in the diagram
view, Figure 2.
When not working duplex on cables we use the same arrangements
for reducing the effect of the static charge in the cable, and thus
enabling signals to be transmitted quicker than by the
Diagram views illustrating this are shewn at Figures 3.
ordinary means.
Having thus described the nature of our Invention, and the manner
of performing the same, we would have it understood that we claim, the
use of an electro-magnet in the actual line of an electric telegraph as
herein described, by which we are enabled,-
First. To work duplex on land lines without the use of condensers
or anything else in the artificial line except the resistance for
compensation.
Second. To work duplex on cables with a greatly reduced condenser
capacity in the compensation circuit, and thus save expense and increase
the speed of transmission.
Third. To increase the speed of transmission when working duplex on
Wheatstone's automatic instruments.
Fourth. To increase the speed of transmission on cables when not
working duplex.
In witness whereof, we, the said Sir James Anderson and William.
Henry Ash, have hereunto set our hands and seals, this Twenty-
fifth day of May, in the year of our Lord One thousand-eight
hundred and seventy-five.