IMPROVEMENTS IN ELECTRIC TELEGRAPHS, AND IN APPARATUS CONNECTED THEREWITH
Year: 1855

page_text: LETTERS PATENT to Charles Tilston Bright, of Liverpool, in the County
of Lancaster, Engineer, and Edward Brailsford Bright, of the same
Place, Secretary to the English and Irish Magnetic Telegraph Company,
for the Invention of "IMPROVEMENTS IN ELECTRIC TELEGRAPHS, AND IN
APPARATUS CONNECTED THEREWITH."
Sealed the 29th February 1856, and dated the 17th September 1855.
PROVISIONAL SPECIFICATION left by the said Charles Tilston Bright and
Edward Brailsford Bright at the Office of the Commissioners of Patents,
with their Petition, on the 17th September 1855.
We, CHARLES TILSTON BRIGHT, of Liverpool, in the County of Lancaster,
Engineer, and EDWARD BRAILSFORD BRIGHT, of the same Place, Secretary to
the English and Irish Magnetic Telegraph Company, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS, AND
IN APPARATUS CONNECTED THEREWITH," to be as follows:-
Our Invention consists, firstly, in a method of electro-telegraphic signalling
by sound instead of by sight, that is to say, in a method of communicating the
signals transmitted by electricity by means of sounds instead of by the deflec-
tions or movements of pointers, whereby the signals may be audible to and
noted by the ear instead of by the eye, and in apparatus connected therewith.

page_text: Secondly, in a method of connecting the sending apparatus intended to be
used in conjunction with the first part of our Invention; and this may be
applied to telegraphic instruments now in use.
The first part of our Invention is intended to remedy the disadvantages
arising from the employment of the needle telegraphs now in use, in which
signals are indicated by the deflections or movements of pointers, and in which
it is necessary, where speedy working is an object, to employ two clerks to each
instrument at the receiving station, one to read off the signals from the dial by
sight, and the other to write down the words as they are called out by the
reading clerk. Independently of the expense of the employment of writing
clerks, errors occur through words of similar sound, but different orthography,
being mistaken by the writers, or from omissions being made when the reader
is in advance of the writer, or when two words of like sound occur near each
other, or at night, or when the clerks are working long stages of duty, from
the eyes of the reader being tired by constantly watching the motions of the
needles, or through the noise of many messages being called out in one instru-
ment room.
In carrying our Invention into effect, we either construct an electro-
telegraphic apparatus complete in itself, or we apply a certain part or certain
parts of such apparatus to telegraphs now in use. In order to produce sounds,
we employ secondary currents applied at the receiving end by the motion of
magnetic needles, coils, or the armatures of electro-magnets acted upon by the
main line circuit, or where the line circuit is very long, we employ relays of
intermediate currents. The instrument may be either used with one line wire,
or as a double-signal telegraph with two wires. A complete electro-phonetic
telegraphic instrument constructed according to our Invention consists of three
parts-First, the sending key; second, the receiving relay; and, third, the
acoustic, or phonetic, or sounding apparatus.
:
The first part, or sending key, is a lever key or axle with a handle, by which
the alternations of connections producing the signals are transmitted; or in
operations with long circuits, we employ the sending arrangement, which con-
stitutes the second part of our Invention, and which is as follows:-At one
end of the conducting wires a battery or series of batteries is connected to
earth in such manner as to send a positive current of electricity, and at the
other end a battery or batteries so connected as to send a negative current.
The batteries should be as nearly equal in force as possible. A coil and needle
at each end are in circuit with the batteries, and the deflection which is main-
tained by the batteries (according to the amount of imperfect insulation or
charge of electricity received by the conducting wires) is neutralized by a regu-

page_text: lating magnet or spring, capable of nice adjustment, whereby the needles at
each end are kept up to their place of rest; or, an electro-magnet and arma-
ture, or any other means of producing electrical motion, may be used in place
of the coil and needle. To produce a signal at the distant end, the battery at the
sending end for the time being is reversed, or taken off, or put on short circuit,
and the current at the distant end being then unrestrained by the opposing
influence of the current from the sending end, is developed to a much greater
extent through its signalling apparatus, and a movement of the needle or
armature (&c.) is produced. By this the time occupied by the transmission of
a current from end to end of a long circuit, and the effects of imperfect insula-
tion, are very considerably lessened; or, in shorter circuits, the batteries may
be out of connection with the conducting wire, and put in circuit by a movement
of the sending key, or it may be always in communication with the line when
the key is at rest, and its movement at any station, by opening the circuit, may
produce a signal throughout the circuit; or the arrangement of the key may
be such as to send magneto-electric or induced currents; or any other suitable
method of transmitting the alternations of connections for producing the signal
may be adopted.
The second part is an electro-magnetic relay coil, wound with fine wire, the
armature of which being attached to a lever, lightly hung upon pivots and
regulated by a spring or counterpoise, makes or breaks the current from a
secondary battery by its movement, when the electro-magnet is influenced by
the currents and alternations of the key at the sending end for the time being;
or, in very long circuits, it may be desirable to make the relay more sensitive
by the moveable part being influenced in one direction by one current, and
brought back to its place of rest by another, (thus developing the whole force
of the currents used, instead of the difference between the power of the current
and the regulating spring or weight); and we then prefer to use a magnetic
needle, delicately and equally balanced upon its axis, to which an arm is
attached, to make or break the secondary currents. The needle is suspended
within deflecting coils, which differ from the coils hitherto used, by being
wound upon soft iron pins, whereby great increase of power is gained, and the
needle lies firmly over against the side to which it is deflected, without, how-
ever, retaining the magnetism induced by a current, in such a manner as to be
prejudicial to rapid motion, as is the case with electro-magnetic coils wound
upon iron cores.
Both the relays are adapted to reading from by the eye,
in case of the phonetic apparatus being out of order, and they may be used
with advantage as "indicating" or "visual" telegraphs, independently of any
acoustic arrangements.

page_text: The third part of which the instrument is composed is the acoustic appa-
ratus, which consists of a hammer or hammers directly actuated by an electro-
magnet, with an armature lever or deflecting coils, or by other means of
obtaining motion from electric currents; the hammers, are made to strike
against a sounding stud, or bell or bells, or other similar means of producing
and emitting sound. A convenient construction of this acoustic part in single
wire instruments consists of an electro-magnet, with an armature lever, with
hammer attached, striking against a stud connected to a sounding board; a
spring, capable of nice adjustment, recovers the lever, and the distance of its
iron armature from the poles of the coils is regulated by a screw against the
end of which it lies when at rest. The code of signals used with a single wire
may be expressed by long or short blows, more or less sustained, of a hammer,
the different notes of which are easily distinguished, and may be rapidly pro-
duced. In single wire instruments the acoustic apparatus may be placed in
front of the clerk; in double wire instruments, the apparatus belonging to each
wire may be fixed on a different side of the clerk, who may be seated between
them, when bells differing in tone would be struck by the hammers on either
side. The vibration or ring of the bells is regulated by pads or mufflers
attached to screw regulators, or by other suitable arrangements. The double
wire signals are expressed by notes to the right or to the left, and by both
combined.
The phonetic part may be readily applied to instruments in present use, by
causing the needles which are employed in such instrument to give visual
signals, to make or break the secondary currents actuating the coils of the
sounding apparatus, or by removing the dials altogether and substituting relays
to suit the alphabet employed. Thus, in the ordinary magnetic needle tele-
graph, it can be easily done by insulating the needles and their bearings, and
connecting them to the poles of the secondary battery, and the pins, against
which they are stopped, to the coils of the sounding apparatus; or the coils
and needles may be removed from the dial and planted on the base of the
instrument, so that the needles lie horizontally on vertical axes, and contact
can be improved by placing a small drop of mercury in the under pivot holes.
An increased number of permutations of signals may be obtained from one
wire by having a double needle dial and sending apparatus, so connected that
the deflection of the left hand is occasioned by the movement of the correspond-
ing magneto-electric coil lever at the sending end, and the deflection of the
right-hand needle by the movement of the right-hand lever, (the needles
recovering their position by gravity, or by the local current they send through
the sending coils, passing likewise through their own coils in a reverse direc-

page_text: tion to the first deflective current,) while on the movement of both levers a
battery current is sent instead of a magneto-electric current, and brings into
play an electro-magnetic coil at the receiving end, always in circuit, but unaf-
fected by the magneto-electric currents; the armature of this coil carries with
it a lever which moves both needles together, so that a double wire code of
signals may be obtained from a single wire. The phonetic principle can be
applied to right and left movement electric telegraphs, by making the needles
when single wire instruments are used into relays, by insulating them and con-
necting them and their stop pins with the local battery and sounding coils, as
described above, and the same applies to double needle instruments of the
same class; but rack needle will then have a double phonetic apparatus in con-
nection with it, in which the movement to the right or left will be expressed by
different notes, and it is best for the movements to the right on both sides
to be expressed by high notes, and to the left by lower notes, and that they
should all differ, though the rights and lefts of the two sides are respectively
of a similar character to each other. Thus the notes may be chords.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Tilston Bright and Edward Brailsford Bright in the
Great Seal Patent Office on the 17th March 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, CHARLES
TILSTON BRIGHT, of Liverpool, in the County of Lancaster, Engineer, and
EDWARD BRAILSFORD BRIGHT, of the same Place, Secretary to the English and
Irish Magnetic Telegraph Company, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of September, in the year of our
Lord One thousand eight hundred and fifty-five, in the nineteenth year of
Her reign, did, for Herself. Her heirs and successors, give and grant unto us,
the said Charles Tilston Bright, and Edward Brailsford Bright, Her special
licence that we, the said Charles Tilston Bright and Edward Brailsford
Bright, our executors, administrators, and assigns, or such others as we, the
said Charles Tilston Bright and Edward Brailsford Bright, our 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 ex-
pressed, 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 TELEGRAPHS, AND IN
APPARATUS CONNECTED THEREWITH," upon the condition (amongst others) that
we, the said Charles Tilston Bright and Edward Brailsford Bright, or one of
us, or our executors or administrators, by an instrument in writing under our,
or their, or one of our or 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 we, the said Charles Tilston Bright and Edward
Brailsford Bright, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement thereof, reference being had to
the Drawings hereunto annexed, that is to say :--
Our Invention consists of improvements in the electric telegraph complete,
that is to say, in communicating the power and connecting the conductors as a
medium, and in means whereby the power transmitted is made to.manifest
improved results. It comprises the employment of a system of telegraphing in
which the signals are demonstrated by sound instead of by visual indications;
of arrangements for connecting telegraphic apparatus, whereby increased effects
may be obtained from the sending part of the instruments, and from the con-
ductors; and in means of increasing the sensitiveness of the receiving apparatus
or relays, and protecting them from the effect of return currents. The prin-
ciple upon which our apparatus for producing sound is constructed, consists in
causing a secondary current to operate upon a magnet or armature directly
actuating the hammer of a bell or other means of producing sound by the
movement of an indicator or relay in the primary or line circuit.

page_text: The form we prefer to employ for communicating phonetic signals in this
manner is shewn at Figures 1, 2, top and side views of the instrument. u, in
Figure 1, is the bell, which is removed in Figure 2, but shewn by dotted
lines; b, b, are electro-magnetic coils; and e, a magnet on axle d, bearing
double aru e, e, at one end of which is a metallic hanuner head f, and at the
other end a muffler 9, or pad made of leather or other suitable material;
h is a pin projecting from the axle & passing between the fork of the reversing
connector i.
Figure 3 is a Drawing of the reversing connector, shewing the manner
in which it may be connected to the relay. a is an iron or steel fork
attached by an axle or spring to a fixed bearing which is connected to
one end of B, the electro-magnetic coils of the phonetic apparatus, the other
end of which is connected to c, the arm of receiving relay; d, e, are two
magnetic bars between which the fork plays, being slightly attracted by
one or the other of them, as it may be moved on one or the other side
of the central point, by the projecting pin f of the magnet influenced by
the acoustic coil; d is a stop, against which the relay arm clies when at
rest and e, a stop against which it lies when deflected; is connected
to one pole of the local battery g, and also to bar d, against which the
connecting fork is attracted, when the phonetic apparatus is at rest or silent;
e, e¹, are connected to the other pole. Thus, when the relay instrument is at
rest, both ends of the phonetic coil are in connexion with one pole of the battery,
the other pole being entirely disconnected, and therefore no current from the
local battery is in motion; but on the relay being deflected, it follows that
while d, one end of the phonetic coil, is left in contact with d, one pole of the
battery c, the other end comes into contact with e', and the circuit is com-
pleted through B. The current in its passage polarizes the coil, acts upon the
magnet, and the required sound is emitted. The pin f, being attached to the
same axis as the magnet, moves with it, and upon coming in contact with
the other leg of the connector, detaches the connector from e, and moving it
beyond the central point of attraction, the connector is drawn into close contact
with c.
By this both ends of the coil B are connected to the other pole of the
battery, and the current ceases; but as soon as the arm of the relay returns to
d, the current passes in the opposite direction, and by the cousequent reverse
movement of the magnet, the connector is brought back by pin f to d, which
may be termed its zero position. A slide, such as has been used in electric
clocks, with like connexions to those described above, and other modes of
reversing the current, can be used in place of the connector; or two batteries
may be employed for each sounding apparatus, the current being passed first

page_text: from one battery to produce an effect in one direction, and from the other in an
opposite direction; but we prefer the plan we have described. The relay may
put on a current in one direction only through the phonetic coil, the magnet
or armature of which may be brought back to zero by a spring; but we do not
find this so efficient a means of recovering the hammer as reversing the current,
the reacting effects of a spring or of gravity being sluggish compared with the
prompt effect of a reversed current; and besides requiring the signals to be sent
more slowly, such a mode of bringing back the striker calls for the use of a
much stronger local battery to overcome the restraining force of the spring or
weight. In making contact with the relay, we employ a flexible arm moving
against fixed stops, by which an increased effect is produced by the greater
duration of the current, which is of considerable importance in very quick
signalling and while better contact is made during the transmission of the
current, on its cessation or reversion, the spring assists in bringing it back to
zero or the same principle may be applied by using flexible stops. The
phonetic apparatus admits of being applied to the indicating telegraphs now in
use, as we have mentioned in our Provisional Specification, where we state that
in single wire instruments of which the indicators move in one direction only,
the acoustic instrument may be placed in front of the operator, the signals
being expressed by blows of the hammer, more or less sustained, corresponding
to the short and long strokes of the recording alphabets in common use; and
in this case it is better, instead of having a hammer on one end of the striking
arm and a muffler on the other, to have hammers of different sizes or material,
whereby different notes are produced, or one hammer moving between two belts
of different notes, as the spaces and greater or less duration of sound are thus
more clearly distinguished. In single wire instruments, the indicators of which
move to both sides, we employ two bells or other sounding apparatus of different
tones, and prefer to place them upon bearings on each side of the operator;
and where more than one instrument of this kind is used in a room, to enclose
them within screens, varying the pitch of each sounding apparatus from another.
In double wire apparatus we express the signals by sounds on one side of the
operator by one wire, on the other side by the other wire, and by both com-
bined. The system may also be applied to a right and left movement of each
wire, as described in our Provisional Specification. The plan of connecting
the transmitting apparatus is shewn at Figures 4, 5, and 6.
In Figure 4, a, a', are coils at the two ends of a circuit; and b, b, batteries
oppositely connected; c, c¹, being keys for disconnecting, reversing, or placing
on short circuit the batteries; d, d, are magnetic regulators adjusted by micro-
meter screws e, e¹, whereby any deflection by charge and defective insulation

page_text: can be neutralized; or springs capable of being nicely set can be used to restrain
the needles in place of the magnets. On depressing key c, the opposing
influence of its battery b being withdrawn, the current generated by battery b¹,
being developed in much greater force, overcomes the resistance of its mag-
netic regulator (or spring), and the indicator or relay worked by coil a¹ is
moved by its own battery, and by this, in addition to the advantage by reason
of lessened interference by defective insulation, and greater velocity of effect,
there is no inconvenience from the return current, as its reaction is in the same
direction as the influence of the magnetic regulator.
Figure 5 shews a similar arrangement, wherein electro-magnetic coils and
soft iron armatures with delicate restraining springs are employed in place
of deflecting coils, the letters being the same for corresponding parts of the
apparatus.
Figure 6 shews a similar arrangement to the last, with reciprocating con-
nections, whereby cross communication may be maintained. The batteries,
keys, and coils are designated by the same letters as before; a, a, being per-
manently in circuit in opposite directions to each other, when the apparatus is
ready for operation in either direction simultaneously; b, b, have at one end
armature f, restrained by spring or magnet delicately adjusted, so attracted by
the current from the other end when its own current is off, as well as by the
stronger force of the latter, and at the other end armature g, which is restrained
by a spring with greater pressure, or magnet with greater attraction, and is only
acted upon when the current from the other end is withdrawn, and the current
of its own battery passes to earth at the other end without interference; f, g,
are in communication with one end of phonetic apparatus h (or other means of
manifesting signals), the other end of which is in connexion with a local
battery i, and thence to stop ; f is kept away from by the permanent
attraction of d, when either current is on; g is kept away from k by its spring
when both currents are on. Thus, the ordinary action of the batteries, when
the instruments are at rest, is to retain at each end the armature f against d,
g being held back from a. When, as described before, the current excited in
the line wire by the battery at either end is withdrawn by means of keys c, c',
it will be seen that the relay at the other end is worked by the increased effect
of current from 6 or b', on armature g or g'; and if the current is withdrawn
from both ends, both of the instruments are brought into action by the cessa-
tion of the current allowing the weaker springs at each end to act. By a
switch attached to the instrument, the batteries may be thrown off when the
instrument is not working, and when signalling alternately the batteries may
be brought into play at each signal instead of being kept permanently on.

page_text: On circuits where it is desirable to use magneto-electric or induced currents,
we employ induction coils with an arrangement for alternating the connexions
of the secondary coils, simultaneously with changing the battery connexions
with the primary coils, so that a permanent current is maintained of great
intensity, analogous to that derived from a very powerful magneto-electric
machine.
Figure 7 shews an instrument of this kind; the poles of induced coils a, a,
b, b, are placed opposite to each other, and the connexions so made, that on a
current being passed through the coils, their opposite poles are of different
names; c is the frame of an ordinary train of clock-work by which the axle d
is caused to rotate; d is divided into four parts, as shewn at X, of which e, f,
are in communication with the two poles of a quantity battery (by means of
springs resting on the projecting rims of e, f), and g, h, are in communication
with the line and earth of the circuit by the same means. Two springs i
j, from the two ends of the secondary or intensity coils of the series a, a,
b, b, rest on g, h, and two springs 1, k, of sufficient breadth and substance to
convey well the current from the battery, rest upon c,f. It will be seen that
on axle'd being rotated by the action of the clock-work train, the ends of
the intensity coils will be changed exactly when the battery current is
reversed through the primary coils. By this a current, which is for all
practical purposes permanent, is derived from the induction coils. Or the
alternation of currents may be made by an armature rapidly alternating
between two electro-magnets, or by other suitable means; or, instead of
reversing the currents through the primary coils of one series, a separate
series may be excited, and their intensity ends synchronously brought into
communication with the line and earth.
We do not confine our claim for the use of this apparatus solely to such
a mode of connecting to the line as we have described, for it may be generally
used for telegraphic purposes with advantage, where a continual supply of
magneto-electricity is desired, analogous to the flow from a voltaic scries.
At Figure 8 is shewn a method by which temporary currents may be excited
by induction coils arranged in a similar manner. By the key c the currents
from a quantity battery are reversed through the primary coils of a, a, b, b,
and the currents thereby induced in the secondary coils are passed along the
line without going through their own receiving coils e, in accordance with
the principle embodied in the finger key, claimed in our Patent of October,
One thousand eight hundred and fifty-two.
At Figure 9 is shewn, in section, a method of winding coils of this kind,
which is very powerful. The thick wire, part of which only is shewn, is

page_text: sur-
wound upon a rod of iron, and is surrounded by an iron tube in metallic con-
tact with the rod by means of the flanges of the coil, which are likewise of
iron. The secondary coils may also be surrounded by another iron tube, and
an additional serving of the primary coil, if the circuit is of unusual resis-
tance, or they may be enclosed within the tube; and where it is necessary to
increase the quantitative or electro-magnetic effects, we find the shape drawn
at Figures 10 and 11, which may be varied upon the same principle, to be very
effective. The centre core a being wound with thick primary' wire, the s
rounding rods b, which fit into the large iron flanges c of the centre core (and
are therefore component parts of an electro-magnet, composed of the interior
and exterior bars, together with the flanges,) are wound with fine or secondary
wire; and additional primary or secondary coils may be combined together in
a suitable manner outside, and in circuit with the first, to produce still greater
determination of polarity and prolongation of induced effect, if still greater
results are required. The key may only send one current, that produced by
the break, if desired, the weaker current 'emitted on making contact with the
primary coils being cut off by a slide piece from the line. In using very
powerful currents of this sort it is necessary to adopt very effectual means
for protecting the receiving coils from the effects of the return current, and
for this we have contrived an arrangement, which is represented in Figure 8,
as in circuit at f.
:
Figure 12 is a front view of this instrument, and the Diagram, Figure 13,
shews its principle. A is a coil, having one end 6 in connexion with the send-
ing apparatus, and the other end d in connection with the earth; b is likewise
connected to a stop e.
The coil A works an arm or slide f, which is in con-
nexion with the line, and plays between e and another stop g, which is in
connexion with one end of the receiving coil H, the other end of which is
in connection with earth. A is so connected that the first current of the
sending coils does not move it, being in the direction to move it towards g,
against which it is already lying. The second or reversing current deflects it,
and the arm f is now in contact with e, and the line discharges its return
current through coil A, and this being in the opposite direction to the last cur-
rent, the arm is recovered to its place of rest against g; thus the receiving
coils cannot be in connexion with the line after any current has been sent,
until the line has discharged itself by passing through the supplementary coil;
and as the application of this principle to single current apparatus and other
descriptions of coils and magnets is simple and obvious, it is not necessary to
describe further variations in form of the instrument.
The part of our Invention by which the sensitiveness of the receiving

page_text: apparatus is increased is as follows:--Figures 14 to 18 shew the improve-
ment as adapted to double current alphabets, where the indicator or arm of
relay is deflected by one current, and brought back to zero by another.
Figure 14 shews a pair of deflecting coils wound upon iron pins a, a, a, a;
and at Figure 15 is shewn a side view, at Figure 16 a top view, and at
Figure 17 an internal side view (the outer pair of coils being removed), of a
compound arrangement of great effect on the same principle.
The pins
a, a, a, a, on which the coils are wound are made of soft iron, and are united
laterally by thin plates of the same metal b, b, b, b, and at their outer ends by
stouter iron plates c, c, c, c, whereby the pair of coils on each side are electro-
magnetic as well as deflective in their effects. The magnets inside, which are
drawn as bar magnets, may be horse-shoe magnets, as shewn in side and front
view at D, F. g, Figure 15, is a pair of magnetic regulators, which can be
adjusted in case of atmospheric deflections, or residual magnetism from other
causes existing in the coils.
Figure 18 shews this principle applied to double movement coils, with a
means of obtaining a dead beat, which is applicable to all methods of moving
indicating magnets, by the increased force of temporary polarity induced in
soft iron, which has not hitherto been rendered capable of being used with a
double movement without the use of comparatively heavy weights, springs, or
magnets to bring the needle back to the centre. a, a, are coils, arranged as
above described. To the axle of the magnets is attached an arm with a pin b,
which is restrained in the centre by a cup or locking piece c fixed to the end
of a lever d, to the lower part of which is attached a soft iron armature e,
attracted by electro-magnet f, when a current is sent through the coils, and
kept in its position when at rest by spring g. A section of the cup is shewn
at H. On a current being sent in either direction, the electro-magnet with-
drawing the cup at the same time that the electro-magnetic deflecting coils
above are influencing the inner needles, the indicator moves to one or the other
side as the current may influence it; and on the current ceasing, the armature
being drawn back by its spring, the cup moves the pin back to the centre,
being stronger than the residual magnetism left in the coils, and the indicator
assumes its position again at zero.
And having now described the nature of our said Invention, and in what
manner the same is to be performed, we declare that we claim,—
First, the herein-before described method of and apparatus for communi-
cating signals transmitted by electricity by means of sound, which may be
either used separately as a complete instrument, or applied in part to other
telegraph instruments now in use.

page_text: Second, the apparatus for transmitting electric currents, herein-before
described, and the means for connecting such arrangements in conjunction
with our phonetic telegraph, or with other instruments.
Third, the means herein-before described of increasing the sensitiveness and
distinctness of the receiving apparatus or relays, and protecting them from the
effects of return currents.
In witness whereof, we, the said Charles Tilston Bright and Edward
Brailsford Bright, have hereunto set our hands and seals, this
Thirteenth day of March, in the year of our Lord One thousand eight
hundred and fifty-six.
CHARLES T. BRIGHT. (L.S.)
EDWARD B. BRIGHT. (L.S.)