Year: 1887

page_text: Date of Application, 9th Mar., 1887
Complete Left, 18th Nov., 1887
Complete Accepted. 20th Jan., 1888
I, CHARLES SELDEN of Baltimore in the State of Maryland United States of
America, Electrician, do hereby declare the nature of this invention to be as
follows:-
My invention relates to simultaneous telegraphy and telephony, and has for its
object to improve the construction and arrangement of telegraphic and telephonic
systems whereby they are adapted for the simultaneous use of any of the ordinary
systems of telegraphy and induced current systems of telegraphy or telephony over
the same line wire.
"
Heretofore attempts have been made to make use of the same line wire for the
simultaneous transmission of various kinds of currents and it has been ascertained that
the induced current signals may be superposed upon a line wire over which Morse
signals are being sent by connecting the said induced current signal apparatus to
the main line by means of separators or inductors in the form of condensers or
inductoriums which allow the high tension currents of the induced current signals to
pass, but which are opaque to the passage of the lower tension Morse or other tele-
graphic signals.
Even when this kind of a separator has been used it has been found that the making
and breaking of the circuit in producing the Morse signals would cause such an abrupt
charge and discharge of the line that the effects thereof would be distinguished in the
receiving apparatus of the induced current apparatus and the reception of signals,
therein would be more or less interfered with.
This objection has been overcome by rendering gradual the omission and extinction
of the Morse signals currents so that the line would become charged and discharged
gradually, thereby lessening the disturbances in the induced current signal apparatus.
Various means have been suggested for rendering gradual these telegraphic signals,
and one of the means consisting in placing in the main telegraphic line, magnet coils
or helices with or without magnet cores. While such magnets have been found
effectual in graduating the currents, they are impracticable for various reasons and
principally for the reason that a large amount of resistance is thereby interpolated in
the line, requiring more battery power to transmit signals over a given length of line,
and by the increase of battery power necessary to be employed, the currents were not

page_text: graduated sufficiently, and furthermore the magnetic effects from the cores increased
the difficulties experienced in multiplex telegraph working by thus limiting their use
to comparatively short circuits or lines.
One of the principal features of my present invention relates to such an arrange-
ment of the graduators in the line circuit that the objections heretofore encountered
are overcome, and it consists in arranging a portion of the telegraphie circuit in
multiple are and interpolating the electro-magnetic or other resistances which act as
graduators in the various arc circuits. It is well known that an electric current
passing from a battery over a line, or series of lines arranged in multiple are, will
divide itself between those are circuits in accordance with well known laws depending
upon the amount of resistance in each circuit. I make use of this fact and so arrange
the number of are circuits and so distribute the resistance therein that when the current
from the battery reaches the point of juncture of the various are circuits the current
will be effectually graduated without such a loss of potential as will interfere with the
operation of long lines, and without the detrimental magnetic affects that exist where
electro-magnets are employed in the line direct and not in are.
Other features of my invention consist in the various arrangements and construc-
tions of the separator or inductorium by means of which the induced current telegraph
of telephone system is connected to the main telegraph line, while still other features
consist in the details of construction more particularly pointed out hereafter.
Referring now to the accompanying drawings forming part of this specification, the
various arrangements will be found to be illustrated diagrammatically.
In Fig. 1 A represents the main line of any ordinary simple of multiplex telegraph;
B, the main battery, and C the key or other circuit controller. The telegraph receiving
apparatus is omitted for convenience and clearness.
The main line A, is divided at some convenient point, as D, D', into a multiple are
circuit, shown in this instance as consisting of three divisions, though any convenient
number may be used, and in each of the are circuits is interpolated a current
graduator E. The graduators may be of any desired or usual construction, as
artificial resistances of carbon coils or a combination of any or all of these, as the
construction of the graduator forms no part of my present invention.
It will be seen that the current from the battery will divide at the point D where
the arc circuits begin and the amount of the current traversing each of the are circuits
will be directly proportional to the resistance that each one bears to the sum of all.
In the present instance there being three are circuits of equal resistance, the battery
power employed will divide one-third of it traversing each are circuit and meeting
again at the junction of said circuits with the main line at D', and passing on the main
line with slightly diminished potential while at the same time the current will be
effectually graduated.
Attached to the line beyond the point D', is a separator F. This separator may be
formed in various ways, that shown at F, consisting of an inductorium with a primary
and secondary wire, both of which may be of the same resistance and character or not
as may be desired. One of the terminals of one coil is connected to the line wire,
while the other coil" is insulated or connected to a condenser, and the other terminal
is connected with an induced current receiver, as the telephone G, and passing through
the secondary circuit of the induction coil H, goes to earth. The induction coil H,
has a primary circuit H', in which is placed any proper device T, for controlling or
varying the strength of the circuit in said primary.
Another form of separator is shown at F, in which a loop from the main line forms
one coil of the inductorium, the other coil being in the form of a closed circuit
including the receiver and one coil of another inductorium in the primary of which is
placed the transmitter T. At F2, is shown a condenser used as a separator, one plate
of the condenser being connected to the main line and the other to the ground and
including the receiver and one coil of the transmitter inductorium.
In order to avoid the induction from one telephonic circuit to another it is often
desirable to use a complete metallic circuit for the telephone or induced current
system and in Fig. 2 I have represented my improved system of graduating the

page_text: telegraphic currents in the lines 1 and 2, and several ways of connecting said circuits
so as to use a round or metallic circuit for the induced currents, the several arrange-
ments being shown at one station or end of the line only, it being understood that the
same or a similar arrangement is used at the other end.
The Morse or multiple telegraph circuits 1 and 2 are arranged for graduating the
currents as before described and at K, a portion of each line is used as one circuit of
an inductorium. The receiver of the induced current system is placed in one line
which also forms the secondary of the induction coil of the transmitter which is in the
primary of said coil. At K is shown another manner of connecting the telephone
by means of branches from the two lines forming an inductorium, the terminals of the
branches being free and at K2 is shown a similar manner in which the terminals of
the branches are connected to one side of the condenser, the other sides of which are
connected to ground. It will be seen that the induced current signals will pass over
one telegraph line in one direction and over the other in an opposite direction and by
this means disturbances from other adjacent lines will be overcome.
It has been common heretofore to connect the induced current telegraph circuit to
the main line by placing the separator at some point beyond the operating instruments.
In this way the induced current system is subject to the full effects of the disturbances
produced by the variations in the current in the Morse or other system and as a
consequence large graduators had to be used to properly control the emission and
extinction of the changing currents.
By my system of multiple are circuits this objection to the use of great resistances
as graduators may be further overcome by connecting the induced current system to
one of the arc branches of the circuit as shown in Fig. 3.
This arrangement will be readily understood and it will be seen that as only a
portion of the current from the transmitting battery passes through the branch or are
even if it were not graduated at all by artificial resistance, the effects upon the
induced current system would be only proportional to the whole current passing
through all the are circuits and therefore the deleterious effects would be much reduced.
But when the resistance or graduator is interpolated into this are circuit and the
comparatively small amount of current flowing through the same is effectually
graduated the effects upon the induction system are fully removed.
It will be readily seen that the amount of resistance of the graduators in each branch
may vary, and that the greater resistance may be used in connection with the are and
to which the induced current system is connected.
In Fig. 1 have shown the separator as consisting of a condenser, but it is
evident that any of the forms of separators heretofore described may be used in this
connection.
In further carrying out my improvement in dividing up the resistances or graduators
I have shown in Fig. 4 another feature consisting in interpolating in each are circuit
two separate resistances or graduators, and in attaching the separator connecting the
induction circuit hetween the resistances.
In this arrangement not only the outgoing currents will be graduated, but the
incoming currents will meet the resistance just before they reach the separator and
will be graduated at this point also. It is obvious that any of the various forms of
graduators and separators heretofore described may be used in this connection.
Various other arrangements of the devices shown will readily suggest themselves to
those skilled in the art and need not be specifically described herein, it being under-
stood that my invention is not limited to the specific arrangements shown, they being
illustrated to show the principles of my invention.
Datad sli. mil Jay Mad 1007
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Simultaneous Telegraphy and Telephony.
1, CHARLES SELDEN of Baltimore in the State of Maryland, United States of
America, Electrician, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention relates to simultaneous telegraphy and telephony, and has for its
object to improve the construction and arrangement of telegraphic and telephonic
systems whereby they are adapted for the simultaneous use of any of the ordinary
systems of telegraphy and induced current systems of telegraphy or telephony over
the sanie line wire.
Heretofore attempts have been made to make use of the same line wire for the
simultaneous transmission of various kinds of currents and it has been ascertained
that the induced current signals may be superposed upon a line wire over which
Morse signals are being sent by connecting the said induced current signal apparatus
to the main line by means of separators or inductors in the form of condensers or
inductoriums which allow the high tension currents of the induced current signals to
pass, but which are opaque to the passage of the lower tension Morse or other
telegraphic signals.
Even when this kind of a separator has been used it has been found that the making
and breaking of the circuit in producing the Morse signals would cause such an
abrupt charge and discharge of the line that the effects thereof would be distinguished
in the receiving apparatus of the induced current apparatus and the reception of
signals therein would be more or less interfered with.
This objection has been overcome by rendering gradual the omission and extinction
of the Morse signal currents so that the line would become charged and discharged
gradually thereby lessening the disturbances in the induced current signal apparatus.
Various means have been suggested for rendering gradual these telegraphic signals,
one of the means consisting in placing in the main telegraphic line magnet coils or
helices with or without magnet cores. While such magnets have been found effectual
in graduating the currents, they are impracticable for various reasons and principally
for the reason that a large amount of resistance is thereby interpolated in the line,
requiring more battery power to transmit signals over a given length of line, and by
the increase of battery power necessary to be employed, the currents were not
graduated sufficiently, and furthermore the magnetic effects from the cores increased
the difficulties experienced in multiplex telegraph working by thus limiting their use
to comparatively short circuits or lines.
One of the principal features of my present invention relates to such an arrange-
ment of the graduators in the line circuit that the objections heretofore encountered
are overcome, and it consists in arranging a portion of the telegraphic circuit in
multiple are and interpolating the electro-magnetic or other resistances which act as
graduators in the various are circuits. It is well known that an electric current

page_text: passing from a battery over a line or series of lines arranged in multiple are, will
divide itself between those arc circuits in accordance with well known laws depending
upon the amount of resistance in each circuit. I make use of this fact and so arrange
the number of arc circuits and so distribute the resistance therein that when the
current from the battery reaches the point of juncture of the various are circuits the
current will be effectually graduated without such a loss of potential as will interfere
with the operation of long lines, and without the detrimental magnetic effects that
exist where electro-magnets are employed in the line direct and not in arc.
Other features of my invention consist in the various arrangements and
constructions of the separator or inductorium by means of which the induced current
telegraph or telephone system is connected to the main telegraph line, while still
other features consist in the details of construction more particularly pointed out
hereinafter.
Referring now to the drawings filed with my Provisional Specification, the various
arrangements will be found to be illustrated diagrammatically.
In Fig. 1, A represents the main line of any ordinary simple or multiplex telegraph;
B the main battery, and Cthe key or other circuit controller. The telegraph receiving
apparatus is omitted for convenience and clearness.
The main line A is divided at some convenient point as D, D, into a multiple are
circuit, shown in this instance as consisting of three divisions, though any convenient
number may be used, and in each of the are circuits is interpolated a current
graduator E. The graduators may be of any desired or usual construction, as artificial
resistances of carbon, coils or a combination of any or all of these, as the construction
of the graduator forms no part of my present invention.
It will be seen that the current from the battery will divide at the point D, where
the are circuits begin and the amount of the current traversing each of the are
circuits will be directly proportional to the resistance that each one hears to the sum
of all thus if the resistance in one are circuit is one half the resistance in each of two
others, one half the current would, flow through said circuit and one quarter through
each of the others. In the present instance there being three are circuits of equal
resistance, the battery power employed will divide, one-third of it traversing each are
circuit and meeting again at the junction of said circuits with the main line at D', and
passing on the main line with slightly diminished potential while at the same time tho
current will he effectually graduated.
Attached to the line beyond the point D' is a separator F. This separator may be
formed in various ways, that shown at F consisting of an inductorium with a primary
and secondary wire, both of which may be of the same resistance and character or not
as may be desired. One of the terminals of one coil, is connected to the line wire,
while the other coil, is insulated or connected to a condenser, and the other terminal
is connected with an induced current receiver, as the telephone G, and passing through
the secondary circuit of the induction coil H, goes to earth. The induction coil H,
has a primary circuit H', in which is placed any proper device T, for controlling or
varying the strength of the circuit in said primary.
Another form of separator is shown at F, in which a loop from the main line
forms one coil of the inductorium, the other coil being in the form of a closed circuit
including the receiver, and one coil of another inductorium in the primary of
which is placed the transmitter T. At F2 is shown a condenser used as il
separator, one plate of the condenser being connected to the main line and the
other to the ground and including the receiver and one coil of the transmitter
inductorium.
In order to avoid the induction from one telephonic circuit to another it is often
desirable to use a complete metallic circuit for the telephone or induced current
system, and in Fig. 2 I have represented my improved system of graduating the
telegraphic currents in the lines 1 and 2, and several ways of connecting said
circuits so as to use a round or metallic circuit for the induced currents, the
several arrangements being shown at one station or end of the line only, it
being understood that the same or a similar arrangement is used at the other end.

page_text: The Morse or multiple telegraph circuits 1 and 2, are arranged for graduating the
currents as before described, and at K a portion of each line is used as one circuit of
an inductorium. The receiver of the induced current system is placed in one line
which also forins the secondary of the induction coil of the transmitter which is in the
primary of said coil. At K is shown another manner of connecting the telephone by
means of branches from the two lines forming an inductorium, the terminals of the
branches being free, and at K is shown a similar manner in which the terminals of
the branches are connected to one side of the condenser, the other sides of which are
connected to ground. It will be seen that the induced current signals will pass over
one telegraph line in one direction and over the other in an opposite direction and by
this means disturbances from other adjacent lines will be overcome.
It has been common heretofore to connect the induced current telegraph circuit to
the main line by placing the separator at some point beyond the operating instru-
ments. In this way the induced current system is subject to the full effects of the
disturbances produced by the variations in the current in the Morse or other system
and as a consequence large graduators had to be used to properly control the emission
and extinction of the changing currents.
By my system of multiple are circuits this objection to the use of great resistances
as graduators may be further overcome by connecting the induced current system to
one of the are branches of the circuit as shown in Fig. 3.
This arrangement will be readily understood and it will be seen that as only a
portion of the current from the transmitting battery passes through the branch or are even
if it were not graduated at all by artificial resistance, the effects upon the induced
current system would be only proportional to the whole current passing through all
the are circuits and therefore the deleterious effects would be much reduced. But
when the resistance or graduator is interpolated into this are circuit and the compara-
tively small amount of current flowing through the same is effectually graduated, the
effects upon the induction system are fully removed.
It will be readily seen that the amount of resistance of the graduators in each branch
may vary, and that the greater resistance may be used in connection with the are and
to which the induced current system is connected.
In Fig. 1 have shown the separator as consisting of a condenser, but it is
evident that any of the forms of separators heretofore described may be used in this
connection.
In further carrying out my improvement in dividing up the resistances or graduators
I have shown in Fig. 4 another feature consisting in interpolating in each are circuit two
separate resistances or graduators, and in attaching the separator, connecting the
induction circuit, between the resistances.
In this arrangement not only the outgoing currents will be graduated, but the
incoming currents will meet the resistance just before they reach the separator and
will be graduated at this point also. It is obvious that any of the various forms of
graduators and separators heretofore described may be used in this connection.
Various other arrangements of the devices shown will readily suggest themselves to
those skilled in the art and need not be specifically described herein, it being under-
stood that my invention is not limited to the specific arrangements shown, they being
illustrated to show the principles of my invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination with a telegraph line composed in part of multiple are circuits,
of current graduators arranged in said are circuits, substantially as described.
2. The combination with a telegraph line, of current graduators arranged in branch
or multiple arc circuits, substantially as described.
3. The combination with a telegraph line having branch or multiple are circuits and
current graduators arranged therein, of an induced current circuit connected therewith
by separators, substantially as described.

page_text: 4. The combination with a telegraphic line having branch or multiple are circuits
and current graduators arranged therein, of an induced current circuit connected
thereto by means of inductoriums acting as separators, substantially as described.
5. The combination of two telegraph circuits each having branch or multiple arc
circuits containing graduators, and portions or branches of said lines arranged in
inductive relations to each other, of induced current instruments connected to said
portions or branches, whereby the two lines form a complete metallic circuit for said
induced current instruments, substantially as described.
6. The combination with a telegraph line composed in part of branch or multiple
are circuits and having current graduators in said branch or are circuits, of an induced
current circuit connected to one of said branch or are circuits by means of separators,
substantially as described.
7. The combination with a telegraph line composed in part of branch or multiple
are circuits, of current graduators arranged in each of said branch circuits, the
said graduators consisting of two or more separate resistances, substantially as
described.
8. The combination with a telegraph line composed in part of branch or multiple
are circuits and having two separate current graduators in each branch, of an induced
current circuit connected to one of the branch circuits between the graduators
substantially as described.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Applicant's Agent.