IMPROVEMENTS IN TELEGRAP
Year: 1883

page_text: LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey, for an
"
Invention of "IMPROVEMENTS IN TELEGRAPHY communicated to him from
abroad by Patrick B. Delany of the City, County and State of New York
United States of America
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office
of the Commissioners of Patents on the 9th October 1883.
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN
TELEGRAPHY" [communicated to him from abroad by Patrick B. Delany of the
City, County and State of New York United States of America]
The various systems of duplex telegraphy in practical use, in which two
messages may be sent in the same direction as well as in opposite directions, depend
for successful operation upon a system of balanced circuits involving bridges and
resistances, as well as a necessary complication of circuits and apparatus. Such
organizations are liable to be thrown out of adjustment by variations in the static
condition of the line, and for other reasons, and the lines have to be repeatedly
rebalanced or readjusted.
The object of this invention is to produce a system of the greatest simplicity
which will not be open to the objections which are found to be incident to those
systems involving balanced circuits, bridges, etc.
Under the improved organization, the line is not liable to be disturbed by
ordinary static effects and the operation is not dependent upon any system of
balanced or artificial lines, upon any special division of the current, or upon any
delicate or even approximately delicate adjustment of apparatus. Messages may
be sent in opposite directions with perfect facility and accuracy; and where two
messages are simultaneously transmitted in the same direction the operation of the
system is as complete and perfect as if each operator were working upon an
independent line.
The operation of the apparatus depends in all the arrangements upon the same
general principle, which I will now describe.
A continuously, rapidly operated circuit-breaker, is used at each station which
circuit breakers may be actuated by means of a local circuit with a battery and

page_text: magnet included therein. But any manner of actuating the circuit-breakers at
the necessary speed may be employed.
A circuit-breaker of any character may be employed, tuned forks, however are
preferred because they possess definite normal rates of vibration and may be
adjusted with facility.
A tuned fork mounted in a suitable support is vibrated automatically and
continuously by a magnet included in a local battery circuit. This circuit is made
and broken between a platinum contact on the inside of one of the tines of the
fork, and a delicate spring contact finger.
The main line is electrically connected with the fork. The other tine of the
fork is provided on its opposite faces with platinum contact pieces, which alternately
make contact with delicate platinum contact springs carried on pivotted insulated
levers. A line in which telegraphic apparatus is placed runs from each lever to the
ground.
Each of the lines may be equipped with independent transmitting and receiving
apparatus; or one line may be provided with receiving apparatus only, and the
other line with transmitting apparatus.
Resistances may be placed in shunts around the contacts to prevent sparking,
but they are not necessary parts.
The forks at two connected stations are of different pitches and their normal rates
of vibration are preferably very unequal, the fork at one station may vibrato
200 times per second, and the fork at the other station 90 or 100 times per second;
or the difference in the rates of vibration may be greater than this, or less, without
affecting the perfection of the operation.
Suppose now there be at each station a relay in the line connecting one lever
with the ground, and a key and battery in the line from the other lever to the
ground.
If the two forks at the two stations are started into vibration say the fork at
station X at the rate of 200 per second and that at station Y at the rate of
90 per second-when the key at station X is put down, electrical impulses from the
battery Y will be sent into the line through the contact and fork at the rate of
200 per second. These impulses, which represent a practically continuous current,
arriving at station Y-where the fork is vibrating at the rate of 90 per second
pass into the line containing the receiving relay (the circuit through the line being
completed 90 times per second) and operate the relay and a sounder in connection
therewith.
As the currents received by the relays are made up of fine vibrations or impulses
it is desirable to employ some means of preventing chattering on the sounders.
There are several methods of accomplishing that result for example, the receiving
sounder at each station may be worked by a local battery which is shunted from
the sounder coil through the armature of the relay, when the armature is against
its back stop.
A relay and sounder and a key may be provided in each of the circuits at each
station. These lines at each station may therefore either be used for transmission
or reception as may be desired. Two main batteries are employed at each station
one connected with the transmission key of each of the lines. The batteries at
each station are arranged with unlike poles to the line;
Under this organization two messages may be transmitted simultaneously in
the same direction or two messages be sent in opposite directions.
For preventing chattering on the sounder the manner already described may be
resorted to or a supplementary relay may be introduced which controls the circuit
of the local battery of the sounder and is interposed between the sounder and the
primary relay
The circuit of the local battery of the sounder is completed when the armature.
of the primary relay is drawn against its front stop; the sounder therefore, gives
a reading stroke by the force of a spring when its local circuit is broken and is
not operated by the pull of the magnet as usual. The local circuit of the

page_text: supplemental relay is completed when the armature of the primary relay is
against its back stop. The sounder therefore gives a reading stroke whenever an
impulse of electricity is received from the line and the armature of the primary
relay attracted.
A sounder of the same character may be worked by a single relay without the
intervention of a supplemental relay, the sounder then gives its reading stroke by
the force of a spring when the armature of the relay leaves its back stop and breaks
the circuit of the local battery.
A sounder of this character possesses material advantages over an ordinary
sounder. Ordinarily the armature is attracted against the pull of the spring by
the sounder magnet in giving a reading stroke, and when the magnet is first
energized the armature is removed some distance from it and does not therefore
promptly respond to its attraction. In my improved instrument however the
moment the local circuit is broken the sounder armature is released and with the
full force of its spring is drawn down on the bridge to give the reading stroke.
The instrument therefore works with greater distinctness and accuracy. The
reading stroke of the sounder is given when the relay armature leaves its back
stop. This method of working is very advantageous as any vibration of the relay
armature on its front stop does not affect the sounder.
A relay sounder and key may be used in each of the lines together with a
switch by which either of the lines may be completed through the battery when
the operator in that line is to transmit or put to the ground, when he is to receive.
Sometimes for preventing chattering a polarized sounder is employed it is worked
by a split local battery. The line from the middle of the local battery passes
through the coil of the polarized sounder and thence to the relay armature, and
the line from one pole of the battery is connected with the front stop and that
from the opposite pole with the back stop of the relay armature. The sounder
therefore only responds when the polarity of the local battery current is reversed
by the relay armature passing from one stop to the other. Any mere vibration or
chattering of the relay armature on either of the stops will not affect the sounder.
Instead of employing a vibrating fork to alternately make and break the main
line circuit with each of the instrument lines an entirely different form of circuit
breaker can be employed consisting of a circular table of contacts on which a series
of insulated contact pieces is arranged. The instrument lines are connected with
the alternate contacts in the series.
The main line circuit is completed successively and alternately through the lines
by a trailing finger carried in a radial arm mounted on a vertical rotating shaft
placed in the centre of the stationary table. This shaft is in electrical connection
with the main line and is fast to an armature disc provided with a series of
armature teeth, actuated by a motor magnet, placed in the local circuit of a
battery. This motor circuit is automatically made and broken by a break wheel
also carried on the vertical shaft. Of course the motor may be set to run at any
desired speed and under this organization the apparatus at one station may be
rotated two or three times faster or more or less than at the other station.
As remarked at the beginning of this specification, any form of circuit-breaker
may be employed.
If the forks or circuit breakers were actuated synchronously in the proper
direction at each station, the apparatus would be in condition for the transmission
of messages. But my invention does not comprehend a synchronous system of
telegraphy; but on the contrary is based on the unequal action of circuit-breakers
at each of the stations.
To obtain a synchronous movement of independently vibrating forks would
require a remarkable delicacy of operation and refinement of adjustment. According
to my present invention however, there is a wide latitude of adjustment. It is not
necessary that the fork at one station should vibrate so many times relatively to
the fork at the other station; but on the contrary it is quite immaterial, within
wide limits, what relation the rates of vibration bear to each other. So when the

page_text: circuit breakers are started to interrupt the circuit at one station at what is known
approximately to be a certain number of interruptions per second say one hundred
and the circuit breaker at the other station is started into operation at a speed
approximately two, three, or four times faster, the apparatus is in proper working
condition; and as a matter of fact, substantially no adjustment at all is necessary.
As before remarked, there is no balancing of the lines, but on the contrary the
circuits momentarily and successively given to the operators at the two stations
are separate and distinct.
If desirable on long lines where the static effect might interfere with the working
of the 'lines, condensers may be employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Sydney Pitt in the Patent Office on the 8th April 1884.
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN
TELEGRAPHY" A communication to me from abroad by Patrick B. Delany of the
City County and State of New York United States of America
The various systems of duplex telegraphy in practical use in which two messages
may be sent in the same direction as well as in opposite directions depend for
successful operation upon a system of balanced circuits involving bridges and
resistances as well as a necessary complication of circuits and apparatus. Such
organizations are liable to be thrown out of adjustment by variations in the static
condition of the line and for other reasons and the lines have to be repeatedly
rebalanced or. readjusted.
The object of this invention is to produce a system of the greatest simplicity
which will not be open to the objections which are found to be incident to those
systems involving balanced circuits bridges &c.
Under the improved organization the line is not liable to be disturbed by ordinary
static effects and the operation is not dependent upon any 'system of balanced or
artificial lines upon any special division of the current or upon any delicate or even
approximately delicate adjustment of apparatus. Messages may be sent in opposite
directions with perfect facility and accuracy: and where two messages are
simultaneously transmitted in the same direction the operation of the system is as
complete and perfect as if each operator were working upon an independent line.
In the accompanying Drawing:-
Figures 1. 2 and 4 are diagramatic plan views each illustrating the organizations
at two stations connected by a main line.
Figure 3 is a detail view showing a sounder and its connections.
In all of the arrangements illustrated the operation of the apparatus depends
upon the same general principle which I will now describe.
I make use at each station of a continuously rapidly operated circuit breaker
which circuit breakers are shown in the various drawings as actuated by means of
a local circuit with a battery and magnet included therein. Obviously however
any manner of actuating the circuit breakers at the necessary speed may be
employed.
In Figures 1 and 2 I have shown vibratory circuit breakers and in Figure 4 a
rotary circuit breaker but as will appear hereafter a circuit breaker of any character
may be employed. I prefer tuned forks however because they possess definite
normal rates of vibration and may be adjusted with facility.
In Figures 1 and 2 at each station a tuned fork A mounted in a suitable support
is vibrated automatically and continuously by a magnet B included in a local
battery circuit indicated by the dotted lines. This cireuit is made and broken
between the platinum contact on the inside of one of the tines of the fork and a
delicate spring contact finger c on a pivoted insulated lever C which is adjusted by
means of a thumb screw against which it is normally drawn by a spring. The
magnet B is provided with adjustable or screw extension pole-pieces 6 which may
be approached to or withdrawn from the tines of the fork in a measure to regulate
its rate of vibration if necessary.
The main line is electrically connected with the vibrators or forks at each
station. The other tine of the fork is provided on its opposite faces with platinum
contact pieces d. e. which alternately make contact with delicate platinum contact
springs carried on pivoted insulated levers D. E. These levers may be adjusted in

page_text: the same manner as the lever first described. A line e in which telegraphio
apparatus is placed runs from the lever E to the ground and a similar line d¹ from
the lever D.
In Figures 2 and 4 I have shown each of the lines and e¹ equipped with
independent transmitting and receiving apparatus; while in Figure 1 the line e'
is provided with receiving apparatus only. and the line d with transmitting
apparatus..
Resistances R R¹ R³ placed in shunts around the contacts c. d. and e to prevent
sparking may be employed as shown in Figure 4 at Y but they are not necessary
parts and are omitted in the other figures.
The forks at two connected stations are of different pitches and their normal
rates of vibration are preferably very unequal the fork at one station may vibrate
200 times per second and the fork at the other station 90 or 100 times per second;
or the difference in the rates of vibration may be greater than this or less without
affecting the perfection of the operation. The rates of vibration may as above
mentioned be adjusted within limits if occasion requires by means of the adjustable
pole pieces on the vibrator magnet or other means.
The proper rates of vibration of the forks should however depend upon their
normal rates and not upon adjustment or modification of those rates; because it is
desirable that the vibrations should be wide and strong so that the completions of
the branch circuits may be entirely clear and independent of each other as
obviously the best results can be obtained in that way.
Referring now especially to Figure 1 which shows a relay in the line e¹ at each
station and a key and battery in the line d¹.
If the two forks at the two stations are started into vibration say the fork at
station X at the rate of 200 per second and that at station Y at the rate of 90 per
second. when the key at station X is put down, electrical impulses from the
battery Y will be sent into the line through the contact d and fork at the rate of
200 per second. These impulses which represent a practically continuous current,
arriving at station Y where the fork is vibrating at the rate of 90 per second-
pass into the line e¹ from the contact e (the circuit through the line e¹ being
completed 90 times per second) and operates the relay F and sounder G in a
manner herein after described. Of course if the key at station Y is open the
line d' will be broken and no impulses of electricity will pass over this line from
the contact d.
If a message is being simultaneously transmitted from stations Y and X the
operation is as follows:-
If at the moment when at station X the key is depressed and the transmitting
battery Y is put to line through the branch circuit and the contact d the line di
at station Y is also put in connection with the main line at the contact d the
operation is as follows-If the key at Y is open the line d is broken at that
station and of course no effect is produced. If the key is closed however the
transmitting battery at Y merely opposes the transmitting battery at ✗- these
batteries being arranged with like poles to the line--and of course no effect is
produced in the sounders G in the lines e¹ at both stations. If however while the
key at station Y is depressed and the line d connected with the main line through
the contact & the line e¹ is connected with the main line through the contact e at
station Y there will be a complete circuit from the key at X to the relay in the
line e¹ at station Y. So if the key at station Y is depressed and the line d¹ at that
station placed in communication with the main line and the line e¹ at station X
thrown into communication with the main line through the contact e there will be
a complete battery circuit from the key at station Y to the relay in the line e¹ at
station X. When the lines e¹ are momentarily simultaneously placed in communi-
cation with the main line through the contacts e at each station, no effect of course
is produced; and where the lines d' at each station are momentarily simultaneously
connected with the main line, the batteries at each station are opposed and no
effect is produced but as the circuit interrupters act very rapidly and at different

page_text: speeds as described there is always a sufficient number of communications per
second between the key at one station and the relay at the other to give practically
independent circuits from the transmitter at one station to the receiver at the
other. The current on these circuits is made up of impulses of electricity which
are thrown upon the line with such rapidity as to give for working purposes a
practically continuous current for each pair of operators.
In Figure 1 H is the sounder and is the local battery for the transmitting
operator.
The difference in the rates of vibration of the forks at the two stations is such
that no coincidence of vibration (which would unless the vibrations were in the same
direction, interrupt communication between the operators at the two stations) can
last long enough to disturb the circuits.
As the currents received from the relays are made up of fine vibrations or
impulses it is desirable to employ some means of preventing chattering on the
sounders. I have shown in this application three methods of accomplishing that
result.
In Figure 1 the receiving sounder at each station is worked by a local battery f
which is shunted from the sounder coil through the armature of the relay F when
the armature is against its back stop as clearly illustrated in the drawing. It will
be obvious that by such arrangement the moment the relay armature is drawn from
its back stop the local battery will operate the sounder and any vibration of the
relay armature on its front stop will not affect the sounder because the circuit
through the sounder can never be broken until the main line is opened sufficiently
long to permit the relay armature to go over against its back stop and shunt the
local battery J.
In Figure 2 I have shown a relay and sounder and a key in each of the
circuits e¹. d. at each station. These lines at each station may therefore either be
used for transmission or reception as may be desired. In this figure I have also
shown two main batteries at each station one connected with the transmission key
of each of the lines e'. d. The batteries at each station are arranged, with unlike
poles to the line; that is, at station X the battery Y in the line e¹ is arranged with
its negative pole to the line while the battery Y in the line e¹ at station Y is arranged
with its positive pole to the line. The two batteries in the lines d' are also arranged
with unlike poles to the line. Under this organization it will be obvious that two
messages may be transmitted simultaneously in the same direction or two messages
be sent in opposite directions. When two messages are sent in the same direction
the operator in the line e¹ at one station transmits to the operator in the same line.
at the other station and the operators in the line d work in the same way. When
the contacts are by the vibrating forks completed simultaneously over the main
line and through the lines e¹ at each station the batteries in these lines will work
together, whereas if while the battery in the line e¹ at the transmitting station is
on the main line the fork at the other station makes contact with the line d the
batteries in the two lines will be opposed and there will be no stroke on the sounder
in the line ď¹ at the receiving station. Therefore the keys at either station X or Y
may be simultaneously operated to transmit two messages in the same direction.
The sounder in either case in the lines e¹ or d' at the receiving station only act
when the circuit through the unopposed batteries is completed. These completions
of the circuit when the forks are vibrated at the speeds given or at greater or less
speed are always of sufficient number to give practically independent working
circuits to each pair of operatora. At station Y in this figure I have shown the
same arrangement for preventing chattering on the sounder as is illustrated in
Figure 1. At station ✗ however I have illustrated another means as follows:-
a supplementary relay G which controls the circuit of the local battery g of the
sounder H is interposed between the sounder and the primary relay F. Any
vibration of the armature of the relay F on its back stop will not be of sufficient
amplitude to permit the armature of the supplemental relay G to leave its front
stop and cause a stroke on the sounder.

page_text: It will be observed that the circuit of the local battery g of the sounder H is
completed when the armature of the relay G is drawn against its front stop: the
sounder therefore gives a reading stroke by the force of a spring when its local
circuit is broken and is not operated by the pull of the magnet as usual the local
circuit of the relay G is completed when the armature of the relay F is against its
back stop. The sounder H therefore gives a reading stroke whenever an impulse
of electricity is received from the line and the armature of the relay F attracted.
In Figure 3 I have shewn a sounder of the same character worked by a single
relay without the intervention of a supplemental relay. In this Figure the
sounder gives its reading stroke by the force of a spring when the armature of the
relay F leaves its back stop and breaks the circuit of local battery f. A sounder of
this character possesses material advantages over an ordinary sounder. Ordinarily
the armature is attracted against the pull of the spring by the sounder magnet in
giving a reading stroke and when the magnet is first energized the armature is
removed some distance from it and does not therefore promptly respond to its
attraction. In my improved instrument however the moment the local circuit is
broken the sounder armature is released and with the full force of its spring is
drawn down on the bridge to give the reading stroke. The instrument therefore
works with greater distinctness and accuracy. In both the arrangements illustrated
in Figure 1 and at both stations in Figure 2 the reading stroke of the sounder is
given when the relay armature leaves its back stop. This method of working is
very advantageous as any vibration of the relay armature on its front stop does not
affect the sounder.
In Figure 4 I have shown two connected stations X and Y with a different
arrangement at each station. In this figure I have adopted this plan of illustration
as well as in Figure 2 to avoid unnecessary multiplication of drawings. Obviously
both stations might be organized either as illustrated at Y or X.
At station Y I have shown a relay sounder and key in each of the lines e¹. d. so
that the lines may be used for transmission or reception. Either of the lines may
be completed through the battery Y when the operator in that line is to transmit
or put to ground when he is to receive by a switch L. At this station I have
illustrated another means for preventing chattering on the sounder. The polarized
sounder I is worked by a split local battery K. The line from the middle of the
local battery passes through the coil of the polarized sounder and thence to the
relay armature and the line from one pole of the battery is connected with the
front stop and that from the opposite pole with the back stop of the relay
armature. The sounder therefore only responds when the polarity of the local
battery current is reversed by the relay armature passing from one stop to the
other. Any mere vibration or chattering of the relay armature on either of the
stops will not affect the sounder.
The operation of a polarized sounder is so well understood that further
description is unnecessary. With two stations equipped as illustrated at Y two
messages can be sent in opposite directions only.
4
At station X in this figure I have shown an arrangement of instruments and
.batteries precisely similar to that illustrated at station Y Figure 2. Instead 4
however of employing a vibrating fork to alternately make and break the main
line circuit with each of the lines e. d. I use an entirely different form of circuit
breaker. This apparatus consists of a circular table of contacts on which a series
of insulated contact pieces n is arranged. The line d is connected with the
alternate contacts in the series and the line e with the remaining contacts. The 5
main line circuit is completed successively and alternately through the lines e. d. by
a trailing finger o carried in a radial arm O mounted on a vertical rotating shaft M
placed in the centre of the stationary table. This shaft is in electrical connection
with the main line and is fast to an armature disc M provided with a series of
armature teeth m actuated by a motor magnet L placed in the local circuit of a 5
battery. This motor circuit is automatically made and broken by a break wheel P
also carried on the vertical shaft M the circuit being completed through the spring

page_text: arm the break wheel and the spring arm R. Of course the motor may be set to
run at any desired speed and under this organization the apparatus at one station
may be rotated two or three times faster or more or less than at the other station.
The operation is the same as that of the apparatus shown in the other figures and
further description is deemed unnecessary.
As remarked at the beginning of this specification any form of circuit breaker
may be employed, as will be obvious. Of course if the apparatus shown in
Figure 4 as well as the forks shown in the other figures were actuated synchronously
in the proper direction at each station the apparatus would be in condition for the
transmission of messages. But the invention does not comprehend a synchronous
system of telegraphy but on the contrary is based on the unequal action of circuit
breakers at each of the stations.
To obtain a synchronous movement of independently vibrating forks would
require a remarkable delicacy of operation and refinement of adjustment. According
to the present invention however there is a wide latitude of adjustment. It is not
necessary that the fork at one station should vibrate so many times relatively to
the fork at the other station; but on the contrary it is quite immaterial within
wide limits what relation the rates of vibration bear to each other. So when the
circuit breakers are started to interrupt the circuit at one station at what is known
approximately to be a certain number of interruptions per second-say 100--and
the circuit breaker at the other station is started into operation at a speed
approximately two, three or four times faster the apparatus is in proper working
condition and as a matter of fact substantially no adjustment at all is necessary.
As before remarked there is no balancing of the lines but on the contrary the
circuits momentarily and successively given to the operators at the two stations are
separate and distinct.
If desirable on long lines where the static effect might interfere with the working
of the lines condensers C may be employed as illustrated in Fig: 2.
I claim as the Invention:-
:-
First. The improvement in the art of multiple transmission which consists in
rapidly and independently making and breaking connection between the main line
and the lines containing transmitting and receiving apparatus at the stations at
unequal speeds and then transmitting messages as set forth over such interrupted
circuit.
Second-The combination of a main line, the branch or transmitting and
receiving lines at each station, and a circuit breaker at each station which auto-
matically and successively makes and breaks the main line circuit through each of
the branch circuits the circuit breaker at one station acting to make and break the
circuit more rapidly than at the other station for the purpose set forth.
Third The combination of a main line, the branch or transmitting and
receiving lines at each end of the main line, telegraphic apparatus in said branch
lines, and a circuit breaker at each station interposed between the main line and
branch lines so as to successively and rapidly make and break the circuit with said
lines, the circuit breaker at one station acting to make and break the circuit more
rapidly than that at the other station for the purpose set forth.
Fourth-The combination of a main line, branch or transmitting and receiving
lines at each station, a circuit breaker at each station interposed between the main
lines and the branch lines, the circuit breaker at one station being actuated more
rapidly than that at the other station and telegraphic receiving apparatus, trans-
mitting apparatus and a battery in each of the branch lines, the two batteries at
each station being arranged with opposite poles to the line for the purpose set
forth.
Fifth The combination of a main line, branch or transmitting and receiving
lines at each end of the main line, a vibratory circuit breaker at each station
interposed between the main line and the branch lines and means of vibrating the
circuit breakers at different speeds for the purpose set forth.
Sixth The combination of a main line, branch or transmitting and receiving

page_text: lines at each station, a vibrating fork at each station with a local battery circuit
and magnet for automatically vibrating it which fork rapidly makes and breaks
the circuit through each of the branch lines, the fork at one station being vibrated
more rapidly than that at the other station.
Seventh The combination of a main line, branch lines at each station, a circuit
breaker at each station which makes and breaks the main line circuit with each of
the branch lines and a battery in each branch line, the two batteries at each end of
the line being arranged with opposite poles to the line.
Eighth The combination of a main line, branch lines at each end of the main
line, circuit breakers at each station which rapidly make and break the main line
circuit with each of the branch lines, the circuit breaker at one station acting more
rapidly than that at the other station, a relay or relays at each station in one or both
of the branch lines and means for preventing chattering on the sounder liable to be
caused by the vibratory current.
Ninth The combination of a main line, branch or transmitting and receiving
lines at each end of the main line, a circuit breaker interposed between the main
and branch lines at each station, that at one station being actuated more rapidly
than that at the other, in one or both of the branch lines at each station, and
a relay having a polarized sounder and split battery in its local circuit and a
transmitting key or keys at each station.
Tenth. The combination substantially as set forth of a main line, branch or
transmitting and receiving lines at each station, circuit-breakers actuated at
different speeds interposed between the ends of the main line and the branch lines,
a transmitting key battery and relay in each of the branch lines and a polarized
sounder, local circuit and split battery for each relay.
Eleventh The combination of the main line the branch or transmitting and
receiving lines at each end of the main line, telegraphic apparatus in said branch
lines, a circuit breaker at each station interposed between the main line and
branch lines so as to successively and rapidly make and break the circuit with said
lines the circuit breakers at one station acting to make and break the circuit more
rapidly than that at the other station, and condensers connected in the branch lines
for the purpose set forth.
Twelfth The combination with a system of telegraphy in which each signal or
impulse is made up of fine vibrations or impulses of an arrangement of relays and
sounders in which the stroke on the sounder is given when the relay armature
leaves its back stop
Thirteenth-A sounder, the armature of which is normally attracted and which
gives its reading stroke by the force of a spring when its local circuit is open.
Fourteenth. The method of working sounders by shunting the local circuit from
the sounder coil substantially as illustrated.
In witness whereof I the said Sydney Pitt have hereunto set my hand and
seal this twentieth day of February in the year of our Lord One thousand eight
hundred and eighty four.