IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS
Year: 1874

page_text: LETTERS PATENT to Joseph Barker Stearns, of Boston, Massachusetts,
United States of America, now of 8, Southampton Buildings,
London, Electrician, for the Invention of "IMPROVEMENTS IN ELECTRIC
TELEGRAPH APPARATUS."-Partly a communication from abroad by
James C. Upham, of Sydney, Cape Breton, Nova Scotia.
PROVISIONAL SPECIFICATION left by the said Joseph Barker Stearns
at the Office of the Commissioners of Patents, with his Petition,.
on the 21st January 1874.
I, JOSEPH BARKER STEARNS, of Boston, Massachusetts, United States
of America, now of No. 8, Southampton Buildings, London, Electrician,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN ELECTRIC TELEGRAPH APPARATUS," partly a communication, to be as
follows:-
This Invention relates to telegraphic apparatus whereby two different
messages may be transmitted at the same time in one direction upon a

page_text: single wire, and either one message or two different messages may be
transmitted in the opposite direction at the same time upon the said
wire, that is to say, two, three, or four messages may be sent at the
same time through a single wire or cable.
The manner in which my said Invention may be carried into practise
will be readily understood by reference to the accompanying Drawing
which shows the arrangement of my improved apparatus at two
terminal stations.
At station 1 I place three polarized relays R¹, R³, and R³; three
transmitters T', T, and T, similar in construction and action to those
shown and described in the Specification of former Letters Patent
granted to me dated November 11th, 1872, No. 3344; two finger keys K¹
and K; two sounders, ink writers, or other recording or indicating
instruments I and I²; three line batteries M³, M², and M³; two local
batterics Land L²; three local batteries N', Nº, and Nº. R¹, R², and R³,
are connected either consecutively or side by side in the bridge wire of a
"Wheatstone bridge" B¹, the line or cable forming the arm C and the
rheostat B whose resistance of which may be varied to suit that of
the line forming the arm D of the bridge, as described in the aforesaid
Letters Patent. Transmitter T¹ is operated by K' and local battery N¹;
Tis operated by K² and N2; T is placed in a small and separate "Wheat-
stone bridge" B², one arm of which is opened by the combined move-
ments of T and T%, so that T3 is not operated unless both K¹ and K²
are closed.
The instruments and connections at station 2 are precisely similar to
those of station 1. Instrument I is placed in another small Wheatstone
bridge Br 3, one arm of which is kept closed by the back or "rest
contact" points of the armatures of relays R¹ and R², and is opened by
the forward movement of either of these armatures.
The connections are so arranged that when K¹ only is closed at
station 1 it works transmitter T which sends a + or positive current
from battery M' from, say, thirty cells through arms A and C of the
bridge Br¹ to the line and also through arms B and D of the
bridge B¹ to the earth, and when the rheostat is properly adjusted no
portion of the current passes through R', R³, and R³, but upon arriving
at station 2 this positive current attracts the armature of R' opening one
arm of the bridgo B in which I' is placed, and allowing I³ to work.

page_text: -
The armatures of R' and R' are not attracted because the polarity of the
current is such as to repel them. If K² at station 1 is closed transmitter
T is worked and a or negative current from battery M* from, say,
30 cells is sent to line as before, to which current R° at station 2 responds,
closing the circuit of L' through I' in the ordinary manner.
In this
case the armature of R' is not attracted because the polarity of the
current is such as to repel it, and the armature of R³ is not attracted
because the current, though of the requisite polarity, is not strong
enough to overcome the retractile force tending to prevent its movement.
If K and K are both closed at station 1 transmitters T and T are both
closed and their combined movements operate transmitter T which
sends a
or negative current from batteries M³ and M³ from, say, sixty
cells to the line. This current is strong enough to attract the armature
of R at station 2, which in moving from its back or "rest contact
opens one arm of the bridge in which I³ is placed, allowing I' to work;
it attracts the armature of R also and works I'. Transmitters T and T
may be operated by hand if preferred, dispensing with keys K' and K²
and local batteries N¹ and N³, but I prefer to use them as described.
The aforesaid "Wheatstone bridge" may be in each instance replaced
if desired by the differential magnot, the balanced magnet, or the
divided magnet described in the said former Specification without in any
way effecting the result.
-
"
Condensers or induction coils are applied as shown and described in
the Letters Patent above referred to.
The key connections may be varied so that K¹ shall send a weak + or
positive current, K² a strong or negative current, and both together a
weak-
or negative current, or vice versa, but I prefer the connections
as described.
-
The transmitter T may be operated by an ordinary electro-magnet
and local battery, the circuit of which is closed by closing both keys K'
and K

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Barker Stearns in the Great Seal Patent
Office on the 21st July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
BARKER STEARNS, of Boston, Massachusetts, United States of America,
now of 8, Southampton Buildings, London, Electrician, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of January, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Joseph Barker Stearns, Her
special licence that I, the said Joseph Barker Stearns, my executors,
administrators, and assigns, or such others as I, the said Joseph Barker
Stearns, 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
"IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS," partly the result of a
communication to me from abroad by James C. Upham, of Sydney,
Cape Breton, Nova Scotia, and partly of Invention and discovery made
by me, upon the condition (amongst others) that I, the said Joseph
Barker Stearns, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, 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 Joseph Barker Stearns, 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, reference being had to the accompanying
Drawings forming a part of this Specification:-
This Invention relates to telegraphic apparatus whereby at the same
time two different messages may be transmitted in one direction upon a
.
,

page_text: single wire while either one message or two different messages are
being transmitted in the opposite direction also upon the same wire,
that is to say, two, three, or four separate and independent messages
may be sent at the same time through a single wire or cable.
single wire while either one message or two different messages are
being transmitted in the opposite direction also upon the same wire,
that is to say, two, three, or four separate and independent messages
may be sent at the same time through a single wire or cable.
The manner in which my said Invention may be carried into practice
will be readily understood by reference to the accompanying Drawings
which I will now proceed to describe.
Figure 1 shows the arrangement of my improved apparatus at two
terminal stations, wherein what I term the bridge method of working is
employed: At station No. 1 I place three polarized relays or other
receiving instruments R¹, R², and R³; three transmitters T³, T2, and T³;
similar in construction and action to those shown and described in the
Specification of former Letters Patent granted to me November 11th
A.D. 1872, No. 3344; two finger keys K' and K²; two sounders, ink
writers, or other recording or indicating instruments I¹ and I²; threo
line batteries M', M², and Ms; two local batteries L' and L*2; and three
local batteries N1, N2, and N³. . . . . The instruments R¹, R*, and R³ are
connected either consecutively or side by side in the bridge wire of a
Wheatstone bridge Br¹, the line or cable forming the arm C and the
rheostat R whose resistance may be varied to suit that of the line
forming the arm D of the bridge, as described in the Specification of the
aforesaid Letters Patent. The transmitter T is operated by the key K¹
and local battery N'. The transmitter T is operated by the key K³ and
battery No. The transmitter T³ is placed in the bridge wire of a
small and separate Wheatstone bridge BB, one arm of which is opened
by the combined movements of the transmitters T' and T, and the
transmitter T³ is not operated unless both keys K' and K² are closed at
the same time. The instruments and connections of station 2 are
precisely similar to those of station 1. Instrument I' is placed in
another small Wheatstone bridge B³, one arm of which is kept closed
by the back or "rest contact points of the armatures of relays R¹
and R and is opened by the forward movement of either of these
armatures. The connections are so arranged that when K¹ only is closed
at station 1 it works transmitter T", which sends a + or positive current
from battery M', say from thirty cells, through arms A and C of the
bridge B to the line and also through arm B and the rheostat or arm
"

page_text: -
2
-
or
or
D of the bridge Br¹ to the earth; and when this rheostat is properly
adjusted no portion of the current passes through R', R, and R. But
upon arriving at station 2 this positive current attracts the armature of
the relay R opening one arm of the bridge Br 6 in which the instru-
ment I³ is placed, thus allowing the instrument 1³ to be affected by the
current from the battery L³. The armatures of the relays R³ and RⓇ are
not attracted because the polarity of the current repels them. If the
key K at station 1 is closed transmitter T is worked, and a
negative current from battery M², from say 30 cells is sent to line as
before, to which current the relay R at station 2 responds closing the
circuit of battery L' through the instrument I* in the ordinary manner.
In this case the armature of R' is not attracted because the polarity of
the current repels it, and the armature of R³ is not attracted because the
current though of the requisito polarity is not strong enough to over-
come the retractile force tending to prevent its movement. If the keys
K and K are both closed at station 1 transmitters T and T2 are both
closed, and their combined movements open one arm of bridge Br² and
allow local battery N³ to operate transmitter T³, which sends a
negative current from batteries M² and M³ (from say sixty cells) to the
line. This current is strong enough to attract the armature of R' at
station 2, which armature in moving from its back or "rest contact "
opens one arm of the bridge wherein the instrument I³ is placed,
allowing the said instrument to work; it also attracts the armature
of R and thereby works the instrument I*. Transmitters T¹ and T
may be operated by hand, if preferred, dispensing with keys K¹ and K
and local batteries N¹ and N³, but I prefer to use them as described.
Thus two distinct messages may be sent from station No. 1 to station
No. 2 at the same instant, and as the several currents sent out from
station No. 1 do not in any case pass through or affect the receiving
instruments R', R³, R³, these instruments are always in condition to
receive any one of the three varieties of battery current sent from
station 2 and to be acted upon by these received currents in the same
manner as we have seen that R*, R, R, are acted upon by the three
currents sent from station 1, and therefore while these messages are
being sent in one direction, as aforesaid, one or two distinct messages
may be sent at the same instant in the opposite direction. To com-
pensate for the effect of the static charge and discharge of the line a
condenser C or other " compensator is applied, as described in the
"

page_text: Specification of my former Letters Patent, No. 3344, A.D. 1872;
No. 2870, A.D. 1873; and No. 3879; A.D. 1873. The Wheatstone
bridge may in each case be replaced by the differential electro-magnet,
the balanced magnet, or the divided magnet described in the Speci-
fication of my said former Letters Patent, without in any way affecting
the nature of this Invention.
Figure 2 shows how the said Invention may be carried into effect by
employing the differential method. In this Figure I omit the finger
keys K¹, K, and represent the transmitters T', T, as worked directly
by hand. The instruments and connections being precisely the same at
both stations only one station is represented. The transmitting
apparatus and connections are the same as in Figure 1 except that the
electro-magnet of the transmitter T is wound differentially, that is to
say, with two wires, and the current of battery N³ flows through these
two wires around the cores o in opposite directions producing no effect
upon these cores until the current flowing through one of these wires
is interrupted. The circuit of one of these wires is bifurcated and passes
to the two insulated screws 6, 7, of the transmitters T¹, T, thence from
anvils c¹, c, upon which screws 61, 6³, rest back to battery N³. The
opening of the contact points at a¹ only or at a³, only does not interrupt
this circuit, but the simultaneous opening of the points at a¹, a³,
interrupts this circuit and allows the current of battery Ns to operate the
magnet of the transmitter T3 through the remaining or uninterrupted
circuit of the differential magnet. In short the simultaneous closing of
transmitters T¹, T, opens one branch of the differential local circuit in
the same manner that the simultaneous closing of transmitters T', T*, in
the apparatus shown in Figure 1 opens one arm of the bridge B‚ª and
with the same result.

page_text: in connection with Figure 1. Instrument I' instead of being connected
in a bridge as in Figure 1, is also wound with two wires through which
the current of local battery L' flows in opposite directions producing no
effect upon I' until the current flowing through one of these wires is
interrupted. The circuit of one of these wires is made through the
tongues and back or rest contact points of R¹, R³, and the forward
movement of either of these tongues opens this circuit and allows the
current of battery L¹ to operate the instrument I'.
It will be observed that both in Figure 1 and Figure 2 the
instrument I' is represented as operated by the opening of the back
contact points of instruments R¹, R2, instead of by the closing of the
front contact points e. This arrangement is designed to obviate a
difficulty which occurs in the reception of the signals when the
instrument is operated from the front contact points e, and will be
best understood by reference to Figure 5 where the instrument I' is
represented as working from the front points e. If now transmitter T
at station No. 2 is closed and the current from battery M* is sent over
the line to station No. 1 it will attract the tongue of relay R' and close
the circuit of battery L at the front contact e thereby operating I'. If
now while transmitter T4 remains closed T5 also is closed sending the
current of the combined batteries M and M over the line. This
stronger current will attract the tongue of relay or receiving instru-
ment R² which through its front contact points e will also work I'.
But this latter current being of a contrary polarity from that of the
battery M* repels the tongue of R₁ at the same time that it attracts that
of R, and during the interval after the tongue of relay R' has left its
front contact, and before the tongue of relay R2 has reached its front
contact the circuit of local battery L' is open allowing I' also to open
and interrupt the signal. This difficulty is obviated by working from
the back contact points as shown in Figures 1 and 2, and may also be
obviated, though not so completely, by making either I' or R' and R
sluggish or "lagging" magnets which may be accomplished in several
ways, as for example in Figure 5 where a condenser C is shown con-
nected across the poles of the instrument I', that is to say, the two
terminals of the condenser C are connected to the two terminals h, i, of I¹,
or an induction or other coil D may be used instead of a condenser.
This coil is connected in the same manner as the condenser, as shown by

page_text: the dotted lines in the same Figure. The discharge from the condenser C
or the coil D tends to keep I' closed during the above specified interval
of time.
Figure 3 shows the method of connecting two sets of these instru-
ments to form a repeater or translator. This method consists in so
arranging the local connections that each of the relays or receiving
instruments on the east side operates the transmitter of the same polarity
or sign on the west side, and vice versa. Transmitters T¹, T³, on each
side are worked from the back contact points of the corresponding relays
on the opposite side, while the transmitter T2 on each side may be worked
from either the front or back contact points of the corresponding relay
on the opposite side.
Figure 4 shows another form of repeater designed for repeating from
one line operated according to my Invention through a central or dis-
tributing office to two "duplex lines." The tongues of relays R¹, R², on
the west side take the place of and act in precisely the same manner
as the two finger. keys K', K2, in Figure 1, separately or jointly
sending their appropriate currents from batteries M', M³, M³, through
relays R³, R, R³, on the east side, and thence to the line running east,
as fully explained in connection with Figures 1 and 2. Transmitter T
takes the place of I¹ in Figures 1 and 2, and on being closed by the
action of the relays R¹ or R on the east side sends the current of M*
through R¹ on the west side and thence to the line running west, while
transmitter T takes the place of I² in Figures 1 and 2, and on being
closed by R³ on the east side sends the current of M³ through relay R²
on the west side, and thence to the line running south.
Figure 6 illustrates another method of operating instrument I¹ from
the back contact points of relays R', R². L', L*, are two local batterics
of equal force joined in a single circuit, of which the tongues and back
contact points of R¹, R³, form a portion. The terminals 1, i, of I¹ are
connected to the poles of L'. While the circuit remains unbroken no
current flows through I¹, but when the circuit is broken by the forward
movement of either of the tongues the current of L³ finds a new circuit
through I and operates the same.
The same method of working, that is to say, with opposed batteries,
may be employed to operate the transmitter T³, as shown in Figure 7,

page_text: where the connections are so arranged that the combined movement of
both the transmitters T, T², opens the circuit in which batteries N³, N*,
are connected, and allows the current of N³ to act upon and operate
transmitter T³.
and
Figure 8 illustrates a simpler method of working transmitter Ts. The
battery N³ is joined up in a simple circuit with the transmitter T³,
when transmitters T, T³, are both closed at the same moment and the
insulated screws 61, 62, are in contact with the springs 81, 82, the circuit is
completed and transmitter T closes.
Figure 9 illustrates another method of working transmitter T³ by the
combined movements of keys K', K, and transmitters T', T. The three
local batteries N1, N2, N³, are joined up in a single circuit with trans-
mitters T, T, Ts. The poles of battery N³ are however contrary to
those of batteries N¹, N2, as shown, and its current is opposed to theirs so
that the combined effective force of the three batteries is only equal to
that of either one of them acting singly, and is not sufficient to operate
the three transmitters. If now the key K¹ is closed the current of
battery N¹ is closed in a short circuit through transmitter T and closes
it, while batteries N³, N³, being opposed to each other have no effect upon
transmitters T, Ts. If key K' is closed the battery N³ in like manner
works transmitter T, while batteries N¹, N³, oppose each other and do
not effect transmitters T¹, Ts. If however keys K¹, K³, are closed at the
same moment battery N¹ works transmitter T¹, battery N
mitter T, and battery N³ works transmitter T³.
-
works trans-
It is evident that the transmitters T¹, T, Ts, may be made to send the
several varieties of currents in any desired order, for example trans-
mitter T may be made to send a small or negative current, trans-
mitter T² a small + or positive current, and both together a large + or
positive current without in any way affecting the result, providing the
relay R is of such polarity as to be operated by a - or negative current,
while relay R³ is worked by a small + or positive current, and relay R
by a large or positive current. Or transmitter T may send a small +
or positive current, transmitter Tº a large or negative current, and
transmitter T³ a small or negative current; or transmitter T¹ may
send a small or negative current, transmitter T a large + or positive
current, and transmitter T3 a small + or positive current.
-
-
-

page_text: transmitting two messages or communications simultaneously in the
same direction when operated as herein described.
Seventh. The combination at one station of local batteries N¹, Nº, N³,
keys K, K², transmitters T, T³, T³, main batteries M¹, M³, and M³,
relays R¹, R, and R³, instruments I¹ and I, local batteries L', L, and
their connections with the line wire, and with similar apparatus at
another station, and with neutralizing, compensating, or balanced circuits
whereby the receiving apparatus is operated by received currents, and
not by transmitted currents, for the purpose of transmitting distinct or
separate communications simultaneously in the same direction or in
opposite directions over the same wire or conductor.
Eighth. The adaptation of my Invention to a translating or repeating
apparatus as herein described.
Ninth. The apparatus consisting of the receiving instruments R¹, R³, R³,
combined with the "Wheatstone bridge" B'1 as described in connection
with Figure 1 of the Drawings for the purpose specified.
Tenth. The combination of transmitters T¹, T2, T3, with the "Wheat-
stone bridge" B' 2 in such a manner that the combined movements of the
transmitters T and T2 are required to operate transmitter T as described
in connection with Figure 1 and for the purpose specified.
Eleventh. The combination of the recording or indicating instrument
with a condenser or induction or other coil, as illustrated in Figure 5,
and for the purpose specified.
Twelfth. The combination of the transmitter T with the local
batteries N³, N*, screws 61, 63, and anvils c¹, c², as illustrated in Figure 7 a
for the purpose specified.
Thirteenth. The combination of transmitter Ts, battery N³, insulated
screws 6, 6, and springs 81, 82, (or other contact points) as illustrated in
Figure 8, and for the purpose specified.
Fourteenth. The combination of transmitters T¹, T, T³, with bat- 3
teries N', N, N³, and keys K³, K², as illustrated in Figure 9, and for the
purpose specified.
Fifteenth. The adaptation to the purpose of my present Invention of
a condenser or an induction coil, or other compensating apparatus

page_text: In witness whereof, I, the said Joseph Barker Stearns, have here-
unto set my hand and seal, this Twentieth day of July, in the
year of our Lord One thousand eight hundred and seventy-
four
Witness,
H. J. NOONE,
8, Southampton Buildings,
London.
JOSEPH B. STEARNS. (L.S.)