Receiving Apparatus for Working Long Lines.
Year: 1885

page_text: Receiving Apparatus for Working Long Lines.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for IMPROVEMENTS IN
AND RECEIVING APPARATUS FOR
WORKING LONG LINES a communication to me from abroad by Louis Maiche of
3 Rue Louis le Grand, Paris, France Electrical Engineer, to be as follows:-
ELECTRIC TELEGRAPHY, AND IN TRANSMITTING
This Invention relates to improvements in electric telegraphy and in transmitting
and receiving instruments for working long cables.
The transmitting instruments employed on long lines and more especially sub-
marine and subterranean lines, present two great objections. These transmitting
instruments which are worked directly by the hand of the operator, send along the
line currents differing in direction, but of unequal duration, in consequence of
which the signals of the receiver are neither clear nor readily decipherable. If for
example there be first sent through the line a positive current which produces a
signal in one direction and that this current should continue rather a long time,
when a negative current is transmitted, a portion of it is absorbed by the positive
charge retained by the line before neutral condition is regained and consequently
the signal produced by the residue of the negative current has very little amplitude.
In order to obviate this objection, I employ a mechanically operated transmitter,
which after each emission of a current through the line during a given time,
automatically sends through the line a current in the opposite direction of proper
duration, in order to restore the neutral condition of the line before the passage of
another working current. In this manner the signals made at the receiving or
recording instrument employed in connection with the transmitter will be perfectly
clear and equal in both directions, positive and negative of the line currents.
improved transmitter may be employed in connection with any suitable receiver,
mirror galvanometer siphon recorder &c, but it is preferred to employ a special
This

page_text: arrangement of recorder giving direct graphic indications whereby to obviate the
other objection to long distance telegraphy viz the weakness of the signals at the
receiving stations and the complication and delicacy of the instruments required to
render these signals distinguishable.
The Invention is illustrated in the accompanying drawings which show by way
of example, one arrangement of the improved transmitting and receiving instruments
for long distance telegraphy.
Figure A is side elevation, figure B a plan and figure Ca front elevation of
the transmitter. Figure D is an underside view of the base plate to show the
several electrical connections. Figure E is a diagram showing the path of the
currents in either direction Figures 1 to 4 represent the receiver, figure 1 being an
end view, figure 2 a part plan and figure a front view of the instrument for
directly utilising the induction spark for writing the message. Figure 4 is a
diagram showing the electrical working of this apparatus.
The improved transmitter permits of accurately and automatically regulating
the duration of each current and consequently of obtaining a regularity in the
signals which facilitates the reading of ordinary messages and renders any error in
the translation of the Morse or ordinary code impossible.
The instrument is composed of a fixed disc 1 formed in three parts electrically
insulated. The smallest of these parts, on which is represented the brush contact 2
figure A is a sector which is neutral, that is to say not influenced by any current,
and corresponds to the neutral or median line formed on the paper strip upon
which the message is received in the instrument hereinafter described. The
remainder of the disc is divided into two other portions insulated and separated
by a volute; they receive first the positive and then the negative current, according
to the direction of the current sent through the line. The brush 2 is mounted on
an axis 3 which is operated by a wheel train 4 and is in electrical communication
with the latter, while disc 1 is insulated therefrom. by the ebonite block 5. The
two parts of the disc 1 which receive the current are connected to the conductors
by the strips b. An arm 7 is fixed on the brush axis 3 for stopping the same at
every turn by means of the mechanism hereinafter described In order to regulate
the duration of each of the currents transmitted, that is to say the more or less
prolonged passage of the brush 2 over each portion of the disc 1, the brush is
adjustable by sliding in a socket x carried by an arm which is also capable of
adjustment upon axis 3. The speed of the clock train is regulated by a fly 8 of
any suitable kind. A metallic cylinder divided into three differential helical
sections electrically insulated and with which a brush would be in frictional
contact, would answer the same purpose and render the regulation of the currents
still easier. In this case the cylinder would be actuated by the clockwork, while
the brush carried on an arm having a screw adjustment, could be readily brought
in contact with that section of the cylinder which corresponds to the return to
zero, according to the intensity of the line current.
The instrument is operated by means of two keys 9, pivoted at 10, the extent of
their oscillation being regulated by screws. Each key on being depressed produces
(1) the contact of one of two pairs of commutator springs 12 with their studs 13
and (2) the release of the brush axis. This stop motion is actuated as follows:-
:-
The depression of either key depresses also an arm 14 fixed on a rock shaft 15
carrying another arm to which is pivoted a pawl 16 which engages with a ratchet
wheel 17 and each depression of lever 15 advances it one tooth; in the teeth of
said wheel is caused by a spring 24 to engage an arm 18 on a vertical rock shaft 19
having at its upper end another arm 20 acting as stop to the arm 7 on the axis 3
at every revolution of the latter. After each step in advance of wheel 17, the
stop 20 is brought into the path of arm 7, thus momentarily arresting the axis 3
and consequently the brush 2, which during this interval is on the neutral part of
the disc as represented in the drawings. The same results would be obtained
when a fixed brush and rotating cylinder are employed, that is to say the motion
of the cylinder would always be arrested when the fixed brush was in contact with.

page_text: the neutral part of said cylinder 21 is a spring for returning arm 14 and keys 9 to
position when released.
The apparatus is arranged to work with two batteries 22 and 23 figure E,
although this is not absolutely necessary. The line wire is attached to the
terminal L and is in electrical connection with the axis 3 of the wheel train while
to the terminal T are connected the earthwire, the wire from the negative electrode
of one of the batteries and the wire from the positive electrode of the other battery.
To the terminals P and S are respectively connected the wires from the positive
electrode of the first battery and the negative electrode of the second battery.
The action will be easily understood by observing the manner in which the
contacts and conductors are connected in Figure D and following the direction of
the currents transmitted, see Figures A, B &c. By pressing key 9a for example,
the axis 3 is released and the brush 2 quitting the neutral portion of the disc 1,
enters on the portion b, at same time that a positive current from battery 23 passes
through part b and axis 3 to the line and the receiver; the negative pole of
battery 23 being to earth and the circuit closed. When key gb is depressed for
changing the direction of the current, the brush commencing to rotate as before,
a negative current passes from battery 22 through part of the disc to the line
and the receiver where the circuit is closed, the positive pole of the battery 22
being to earth. The positive pole of one of the two batteries, and the negative
pole of the other being to earth, the passage of the brush from one portion of the
disc 1 to the other, places alternatively each of the two other poles to earth
through the receiver, thus automatically changing the direction of the current
transmitted.
It will be evident that the mechanism or motor by which axis 3 is operated may
be varied, as also the arrangement of the accessory parts of the instrument, which
may work with any other combination or any other number of batteries. The
improved transmitter herein before described may evidently be applied to work in
connection with any suitable receiver, but it is preferred to employ it in connection
with the receiver which I will now proceed to describe with reference to Figures 1,
2, 3, 4. a is a magnetic needle, suspended so as to vibrate freely between the
poles of two electro-magnets b influenced by the line current. According to the
direction of the current sent by the transmitter and which is changed according to
the signals transmitted, so the needle oscillates towards one or other of the
magnets. In Figures 1 and 3 are shown permanent magnets which magnetise
the soft iron screws d between which the needle a plays, but any kind of coils
with or without cores, capable of acting on needle a may be used. Opposite
needle a and in line therewith, is placed a metallic point e which is connected to
one end of the secondary wire f of an induction coil A Figure 4 whose primary
wire is connected with the poles of a battery P, the other end of said wire f being
connected to the needle a, so that the induction spark plays between the point of
the needle a and the point e. g (Figures 1 2 and 3) are the terminals for the line
wire and those of coils b, h the support of needle a and i the terminal by which it
is connected with the secondary wire of the induction coil, these parts being
insulated from the rest of the apparatus. kis the second terminal by which the
secondary wire is connected with the body of the instrument and consequently
with the point e (represented in dotted lines in Figure 1) mounted in a socket
provided with a spring and adjusting screw, for regulating its distance from the
needle a.
The entire apparatus is carried on a table supported on a pillar resting
on screw feet m. Between the needle a and the point e is drawn a paper tape n
wound on a reel o and passing over a fixed support p, through a hole in which the
point e passes. The tape is drawn over a guide roller q by means of clockwork or
other motor and the tape in passing between the needle a and the point e, will be
perforated by the successive sparks emitted between a and e. So long as the
needle a remains perpendicular, the sparks will play vertically and trace upon the
tape a straight line parallel to its edges, but when the needle deviates to the right
or left, the sparks will play obliquely and pierce the paper to right or left of the

page_text: median line, the sparks in fact tracing on the tape a sinuous line whose deviations
to the right or left of the median line will correspond to the positive and negative
currents transmitted through the line and consequently to the dots and dashes of
the Morse code.
The needle a instead of being suspended vertically may be horizontal and
mounted on a centre like a compass needle, in which case it would be connected
with the secondary wire of the induction coil, either through it's pivot or by means
of a conductor terminating above the same, and the paper tape being drawn over
a small metallic cylinder near one or other point of the needle.
In the example described, the spark acts mechanically by perforating the paper,
but I may use any kind of prepared paper upon which the spark would inscribe
the message by electro-chemical action; the invention residing in the employment
of the induction spark as above described, whatever may be its mode of action on
the paper tape.
I may also use in lieu of the single point e, any number of fixed needles or
points in order to obtain distinct currents, according to the deviation of the
movable needle a in one direction or the other, and in certain cases I may use
several sets of vibrating and fixed needles in the same apparatus without departing
from the invention.

page_text: Receiving Apparatus for Working Long Lines.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of 53,
Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention (a communication to me
from abroad by Louis Maiche of 3 Rue Louis le Grand, Paris, France Electrical
Engineer and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This Invention relates to improvements in electric telegraphy and in transmitting
and receiving instruments for working long cables.
The transmitting instruments employed on long lines and more especially
submarine and subterranean lines present two great objections. These transmitting
instruments which are worked directly by the hand of the operator, send along the
line currents differing in direction, but of unequal duration, in consequence of which
the signals of the receiver are neither clear nor readily decipherable. If for example
there be first sent through the line a positive current which produces a signal in
one direction and that this current should continue rather a long time, when a
negative current is transmitted, a portion of it is absorbed by the positive charge
retained by the line before neutral condition is regained and consequently the
signal produced by the residue of the negative current has very little amplitude.
In order to obviate this objection, I employ a mechanically operated transmitter,
which after each emission of a current through the line during a given time,
automatically sends through the line a current in the opposite direction of proper
duration, in order to restore the neutral condition of the line before the passage of
another working current. In this manner the signals made at the receiving or
recording instrument employed in connection with the transmitter will be perfectly
clear and equal in both directions, positive and negative of the line.currents.
improved transmitter may be employed in connection with any suitable receiver,
mirror galvanometer siphon recorder &c, but it is preferred to employ a special
arrangement of recorder giving direct graphic indications whereby to obviate the
other objection to long distance telegraphy viz the weakness of the signals at the
receiving stations and the complication and delicacy of the instruments required to
render these signals distinguishable.
This
The Invention is illustrated in the accompanying drawings which show by way
of example, one arrangement of the improved transmitting and receiving instruments
for long distance telegraphy.
Figure A is a side elevation, figure B a plan and figure C a front elevation of the
transmitter. Figure D is an underside view of the base plate to show the several
electrical connections. Figure E is a diagram showing the path of the currents in
either direction Figures 1 to 4 represent the receiver, figure 1 being an end view,
figure 2 a part plan and figure 3 a front view of the instrument for directly utilising
the induction spark for writing the message. Figure 4 is a diagram showing the
electrical working of this apparatus,

page_text: The improved transmitter permits of accurately and automatically regulating the
duration of each current and consequently of obtaining a regularity in the signals
which facilitates the reading of ordinary messages and renders any error in the
translation of the Morse or ordinary code impossible.
The
The instrument is composed of a fixed disc 1 formed in three parts electrically
insulated. The smallest of these parts, on which is represented the brush contact 2
figure A is a sector which is neutral, that is to say not influenced by any current,
and corresponds to the neutral or median line formed on the paper strip upon
which the message is received in the instrument hereinafter described.
remainder of the disc is divided into two other portions mounted in the same plane
on a disc of insulating material and separated by a space in the form of a volute;
they receive first the positive and then the negative current, according to the
direction of the current sent through the line. The brush 2 is mounted on an
axis 3 which is operated by a wheel train 4 and is in electrical communication with
the latter, while disc 1 is insulated therefrom by the ebonite block 5. The two
parts of the disc 1 which receive the current are connected to the conductors by
the strips b. An arm 7 is fixed on the brush axis 3 for stopping the same at every
turn by means of the mechanism hereinafter described In order to regulate the
duration of each of the currents transmitted, that is to say the more or less
prolonged passage of the brush 2 over each portion of the disc 1, the brush is
adjustable by sliding in a socket a carried by an arm which is also capable of
adjustment upon axis 3. The speed of the clock train is regulated by a fly 8 of
any suitable kind. A metallic cylinder divided into three differential helical sections
electrically insulated and a brush, in frictional contact therewith would answer the
same purpose and render the regulation of the currents still easier. In this case
the cylinder would be actuated by the clockwork, while the brush carried on an
arm having a screw adjustment, could be readily brought in contact with that
section of the cylinder which corresponds to the return to zero, according to the
intensity of the line current.
The instrument is operated by means of two keys 9, pivoted at 10, the extent of
their oscillation being regulated by screws. Each key on being depressed produces
(1) the contact of one of two pairs of commutator springs 12 with their studs 13
and (2) the escapement of the brush axis. This escapement motion is actuated
as follows:-
The depression of either key depresses also an arm 14 fixed on a rock shaft 15
carrying another arm to which is pivoted a pawl 16 which engages with a ratchet
wheel 17 and each depression of lever 14 advances it one tooth; in the teeth of
said wheel is caused by a spring 24 to engage an arm 18 on a vertical rock shaft 19
having at its upper end another arm 20 acting as stop to the arm 7 on the axis 3
at every revolution of the latter. After each step in advance of wheel 17, the
stop 20 is brought into the path of arm 7, thus momentarily arresting the axis 3
and consequently the brush 2, which during this interval on the neutral part of
the disc as represented in the drawings. The same results would be obtained when
a fixed brush and rotating cylinder are employed, that is to say the motion of the
cylinder would always be arrested when the fixed brush was in contact with the
neutral part of said cylinder 21 is a spring for returning arm 14; and keys 9 to
position when released.
The apparatus is arranged to work with two batteries 22 and 23 figure E,
although this is not absolutely necessary. The line wire is attached to the terminal L
and is in electrical connection with the axis 3 of the wheel train while to the
terminal T are connected the earth-wire, the wire from the negative electrode of one
of the batteries and the wire from the positive electrode of the other battery. To
the terminals P and S are respectively connected the wires from the positive
electrode of the first battery and the negative electrode of the second battery.
The action will be easily understood by observing the manner in which the
contacts and conductors are connected. in Figure D and following the direction of
the currents transmitted, see Figures A, B &c. By pressing key 9ª for example,

page_text: the axis 3 is released and the brush 2 quitting the neutral portion of the disc 1,
enters on the portion b, at same time that a positive current from battery 23 passes
through part b and axis 3 to the line and the receiver; the negative pole of
battery 23 being to earth and the circuit closed. When key 9b is depressed for
changing the direction of the current, the brush commencing to rotate as before, a
negative current passes from battery 22 through part b of the disc to the line and
the receiver where the circuit is closed, the positive pole of the battery 22 being to
earth. The positive pole of one of the two batteries, and the negative pole of the
other being to earth, the passage of the brush from one portion of the disc 1 to the
other, places alternatively each of the two other poles to earth through the receiver,
thus automatically changing the direction of the current transmitted.
It will be evident that the mechanism or motor by which axis 3 is operated
may be varied, as also the arrangement of the accessory parts of the instru-
ment, which may work with any other combination or any other number of
batteries.
The improved transmitter herein before described may evidently be applied to
work in connection with any suitable receiver, but it is preferred to employ it in
connection with the receiver which I will now proceed to describe with reference to
Figures 1, 2, 3, 4. a is a magnetic needle, suspended so as to vibrate freely between
the poles of two electro-magnets b influenced by the line current. According to the
direction of the current sent by the transmitter and which is changed according to
the signals transmitted, so the needle oscillates towards one or other of the magnets.
In Figures 1 and 3 the cores of the bobbins are permanently magnetized and they
communicate their magnetism to the soft iron screws d between which the needle a
plays, but any kind of coils with or without cores, capable of acting on needle a
may be used.
Opposite needle a and in line therewith, is placed a metallic point e
which is connected to one end of the secondary wire f of an induction coil A
Figure 4 whose primary wire is connected with the poles of a battery P, the other
end of said wire f being connected to the needle a, so that the induction spark
plays between the point of the needle a and the point e. g (Figures 1 2 and 3) are
the terminals for the line wire and those of coils b, h the support of needle a and i
the terminal by which it is connected with the secondary wire of the induction coil,
these parts being insulated from the rest of the apparatus. k is the second terminal
by which the secondary wire is connected with the body of the instrument and
consequently with the point e (represented in dotted lines in Figure 1) mounted in
a socket provided with a spring and adjusting screw, for regulating its distance
from the needle a. The entire apparatus is carried on a table supported on a
pillar resting on screw feet m. Between the needle a.. and the point e is drawn a
paper tape n wound on a reel o and passing over a fixed support p, through a hole
in which the point e passes. The tape is drawn over a guide roller q by means of
clockwork or other motor and the tape in passing between the needle a and the
point e, will be perforated by the successive sparks emitted between a and e. So
long as the needle a remains perpendicular, the sparks will play, vertically and trace
upon the tape a straight line parallel to its edges, but when the needle deviates to
the right or left, the sparks will play obliquely and pierce the paper to right or left
of the median line, the sparks in fact tracing on the tape a sinuous line whose
deviations to the right or left of the median line will correspond to the positive
and negative currents transmitted through the line and consequently to the dots
and dashes of the Morse code.
The needle a instead of being suspended vertically may be horizontal and mounted
on a centre like a compass needle, in which case it would be connected with the
secondary wire of the induction coil, either through it's pivot or by means of a
conductor terminating above the same, and the paper tape being drawn over a
small metallic cylinder near one or other point of the needle.
In the example described, the spark acts mechanically by perforating the paper
but I may use any kind of prepared paper upon which the spark would inscribe
the message by electro chemical action; the invention residing in the employment

page_text: of the induction spark as above described whatever may be its mode of action on
the paper tape.
I may also use in lieu of the single point e any number of fixed needles or points
in order to obtain distinct currents according to the deviation of the movable
needle a in one direction or the other, and in certain cases I may use several sets
of vibrating and fixed needles in the same apparatus without departing from the
invention.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
1st The herein described system of transmitting telegraphic signals which is based
on the equality of the times of the emissions obtained by means of an invariable
mechanical escapement such as that herein described or its equivalent.
2nd The method of automatically neutralizing the excess current remaining in
the line after each emission as herein described.
3rd The combination of mechanism herein described for obtaining the results
above specified, or any other mechanical combination on the same principle and
employed for the same purpose.
4th The receiver or recorder herein described for obtaining a graphic record by
means of an induction spark playing between a fixed surface or series of fixed points
and a movable point influenced by the line current, whether said movable point or
needle be arranged vertically as shown in the annexed drawings or horizontally.