IMPROVEMENTS IN ELECTRIC TELEGRAPHS
Year: 1854

page_text: tion of "IMPROVEMENTS IN ELECTRIC TELEGRAPHS."-A communication.
PROVISIONAL SPECIFICATION left by the said Robert Stirling Newall at
the Office of the Commissioners of Patents, with his Petition, on the
30th October 1854.
I ROBERT STIRLING NEWALL of Gateshead do hereby declare the nature of
the Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS" to be as follows
This Invention has for its object the so constructing electric telegraphs
that a single line wire and the earth may be employed as a means of com-
municating simultaneously in opposite directions between two stations. The
Invention is applicable to the several systems of electric telegraphs now in use.
In constructing a telegraph between two places there is a battery at each
station an insulated line wire communicating between the two distant places
and an earth connection is made to each battery. There is at each station a
resistance coil for adjusting the currents of electricity and in all cases there is
to be a suitable instrument for transmitting and another for receiving commn-
nications at each station so that a message or communication may at the same
moment be received from the distant station by one instrument whilst another
20751-2.

page_text: communication is being transmitted to that distant station through the same
wire by the other instrument and thus both instruments at both stations may
.simultaneously be in use although there is only one line wire between the two
stations.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Stirling Newall in the Great Seal Patent Office on
the 30th April 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME I ROBERT
STIRLING NEWALL of Gateshead send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent bearing date the Thirtieth day of October in the year of our Lord
One thousand eight hundred and fifty-four in the eighteenth year of Her
reign did for Herself Her heirs and successors give and grant unto me
the said Robert Stirling Newall Her special licence that I the said Robert
Stirling Newall my executors administrators and assigns or such others as I
the said Robert Stirling Newall my 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 "IMPROVE-
MENTS IN ELECTRIC TELEGRAPHS" a communication upon the condition (amongst
others) that I the said Robert Stirling Newall by an instrument in writing
under my hand and seal should particularly describe and ascertain the nature
of the 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 I the said Robert Stirling Newall do hereby
declare the nature of the said Invention 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 ;).
This Invention has for its object the so constructing electric telegraphs that
a single line wire and the earth may be employed as a means of communi-
cating simultaneously in opposite directions between two stations. In its
application to Morse's apparatus the only alteration required is in the relay
in which the helices of the electro-magnets are formed of two separate fine
copper silk-covered wires of equal size and length and coiled the same

page_text: number of times round the electro-magnets but in opposite directions as
shewn by the black and red lines at No. 3 in the Drawing hereunto annexed.
In the Drawing examples No. 1 and No. 2 two stations are represented:
marked London and Liverpool. Each contains a similar set of instruments.
No. 1 is the galvanic battery.
No. 2 is the lever key of Morse's apparatus.
No. 3 is a relay in which a a represent the poles of the electro-magnet.
round which are coiled in opposite directions as shewn by the black and red?
lines two fine copper wires insulated in the usual manner they enter at 6 and
leave at c.and d.
No. 4 is a galvanometer having two silk-covered fine copper wires of equal
size and length coiled side by side. The black wire enters at . and leaves
at i thence it goes through the lightning conductor (if one is used). to the line.
wire. While the red wire enters at h and leaves at 7 and thence passes on to.
No. 5 which is a resistance coil for regulating the resistance through the red
wire and making it equal to the black or line wire.
No. 6 is an ordinary galvanometer.
The lever key No. 2 is connected in the usual way by a wire from ƒ to
the battery by another wire from g to earth and by another from e to b. The
connection between the relay and registering apparatus is effected as usual by
means of a local battery and wires.
The relative position of the poles of the batteries in the two stations is imma--
terial. If they be in the same position that is if copper pole of one station be
connected by earth to the zinc pole of the other then the black wire becomes
charged with the stronger current and affects the instruments. If the relative
position-be-reversed that is zinc pole connected with zinc pole then the red
wire becomes charged with the current while the black remains unaffected.
The following illustrations will shew the mode of working.
First example. When the poles of the two batteries correspond as shewn.
suppose the lever key No. 2 at Liverpool station to be at rest that is e in.
connection with 9 theu the direction of a current sent from London station
when e and fare connected would be by the black wire from copper pole
to through the key to e thence to 6 where the current divides. One half
goes through the black line round the poles of the electro-magnet to c then
to h through the galvanometer to i through lightning conductor to line
wire and thence to Liverpool station when it will pass through lightning
conductor to through the galvanometer No. 4 to ½ thence to c through
the helices of the relay to b then to e. g of the lever key and to earth back to
London to the zinc pole of the battery there thus completing the circuit.

page_text: The other half of the current proceeding from the London battery and
dividing at b in the relay No. 3 goes through the red wire (that is in the oppo-
site direction to that through the black wire) round the poles of the electro-
magnet to d from thence through the galvanometer No. 4 from k to 1 (being
also in the opposite direction to the current through the black wire) thence
through the resistance coil from m to n through the galvanometer No. 6 from
o to p and thence to earth and to the zinc pole of the battery thus completing
its circuit.
If now the resistance coil be adjusted so that the same strength of current
circulates in the wire colored red as in the wire coloured black then the relay
No. 3 and the galvanometer No. 4 in London station will not act for the
currents annul each other's effects. On the other hand the galvanometer No. 6
will act for it is affected only by the current through the red wires.
Then in Liverpool station the galvanometer No. 4 and the relay No. 3 act
because the current passes only in one direction namely by the black wire
through them through e. g in No. 2 and thence back through earth to the
zinc pole of the London battery to complete the circuit. The galvanometer
No. 6 remains unaffected because there is no current through the red wire.
But if a current be sent simultaneously from both London and Liverpool
stations by bringing f into contact with e in both the lever key instruments
No. 2 then the action of the instruments in London station is as follows.
The power of the batteries in both stations being united the current goes with
double the force through the black wire that it does when only one station is
at work or one battery is in the circuit while the current through the red
wire being derived only from the battery in one station the currents will not
annul each other's effects and therefore the relay No. 3 and the galvanometer
No. 4 in London station will act in correspondence with the key No. 2 at the
Liverpool station at the same time the galvanometer No. 4 and the relay
No. 3 in Liverpool station act in unison with the key No. 2 of the London
station; and thus communications are simultaneously made between the two
stations through a single line wire and the earth.
The above is the arrangement I prefer. But as second example suppose
the poles of the batteries in the two stations to be reversed that is the zinc
of one station connected with the zinc of the other by the earth. Then if the
lever key in London station be put down that is f in contact with e the
current proceeds as before producing no effect on the relay No. 3 and galvano-
meter No. 4 in London station because the currents are of equal strength
but acting on the galvanometer No. 6 the circuit through the red wire being
complete. The current goes on through the line wire to Liverpool where it

page_text: acts on No. 4 and No. 3 as before. If now the key in Liverpool be put
down simultaneously with that in London no effect is produced in the black
wire because the similar poles of both batteries are connected and therefore
the current passing through No. 4 No. 3 and No. 6 in London station by the
red wire only acts on these instruments in unison with the movements of
the key in Liverpool which annuls the current that would otherwise pass
through the black wire if it were not inoved. At the same moment by the
annulling of the current in the black wire the galvanometers No. 4 and No. G
and the relay No. 3 in Liverpool station are acted upon by the red. wire only
and they therefore act in unison with the key in London which annuls-the
current in the black wire while the key in Liverpool is down but if it be up
no current passes through the red wire while one comes through the black
wire as before; and so communications are made simultaneously in both
directions. At the intermediate stations I use the simple Morse apparatus.
By means of a cominutator. the lever of the writing apparatus at the station
receiving a message becomes a mechanical or automatic lever key (bringing
the line battery of that station into the circuit) and thus the receiving appa-
ratus immediately or simultaneously re-transmits the message to the sending
station; that is collates or repeats the message at the sending station as it has
been actually received affected by weather or other causes of error.
I will now describe the application of my Invention to the needle telegraph.
In order to telegraph simultaneously in opposite directions between two stations
connected by one line wire the existing needle telegraph instruments require
no change whatever but they must be used exclusively for sending messages.
For receiving messages simultaneously with the sending a second instrument is
required which consists of the usual needle and dial without the handle or key
but the helices are double coils of fine silk-covered copper wire of equal size
and length as above described in reference to the helices of the electro-magnet.
In the Drawing example No. 3 two stations are again represented each
containing similar instruments.
No. 1 is the battery.
No. 2 is the sending instrument of which e is the key or handle.
No. 3 is the receiving instrument with the double coil helices.
No. 4 is a resistance coil for regulating the resistance in the red wire.
Suppose now that the instruments are connected as shewn by the black
and red wires and that the resistance of the current through the red wire is
adjusted by the coil so as to be equal to that through the black or line wire ;
then on the keve in London station being connected with a the current

page_text: on it but one half of the current which divides at b passes through the red
wire and acts on No. 2 the other half goes on to Liverpool through the black
wire and acts on No. 3 instrument in that station then on to earth and back
to London and so complete the circuit. If the key in Liverpool be connected
in the same way and the resistance coil adjusted the needle of No. 3 in Liver-
pool does not move but No. 2 does and No. 3 in London acts in unison with
it. But if e and g are brought into contact at the same instant at both stations
then as the earth connects the zinc poles of both batteries no current will be
produced in the black wire but as the circuit through the red wire in each
station is complete in itself the instruments No. 2 will both act each in unison
with its own key, No. 3 in London will act in unison with the key in Liverpool
and No. 3 in Liverpool in unison with the key in London and so messages are
sent simultaneously in both directions. I have used the single needle instru-
ment to illustrate the application of the Invention but it is evident that it is
equally applicable to the double needle instrument.
What I claim as the, Invention is the arranging or combining electric
telegraph apparatus in such manner as to be enabled to telegraph simul-
taneously in opposite directions between two stations using one line wire and
the earth as the means of communication.
In witness whereof I the said Robert Stirling Newall have hereunto
set my hand and seal this Thirtieth day of April year of our Lord
One thousand eight hundred and fifty-five.
Witness
FRED HARRIS.
R. S. NEWALL. (L.S.)