IMPROVEMENTS IN TELEPHONES AND IN APPARATUS CONNECTED THEREWITH
Year: 1878

page_text: LETTERS PATENT to Joshua Franklin Bailey, of New York City, in the
United States of America, at present residing at Charing Cross, in the County
of Middlesex, for the Invention of "IMPROVEMENTS IN TELEPHONES AND IN
APPARATUS CONNECTED THEREWITH." A. communication from abroad by
Elisha Gray, of Chicago, in the State of Illinois, United States of America,
COMPLETE SPECIFICATION filed by the said Joshua Franklin Bailey at the
Office of the Commissioners of Patents on the 10th May 1878.
JOSHUA FRANKLIN BAILEY, of New York City, in the United States of America,
at present residing at Charing Cross, in the County of Middlesex. 'IMPROVEMENTS
IN TELEPHONES AND IN APPARATUS CONNECTED THEREWITH." A communication
from abroad by Elisha Gray, of Chicago, in the State of Illinois, United States of
America.
This Invention has for its object improvements in telephones and in apparatus
connected therewith.
Figure 1 of the Drawings annexed represents a plan or top view of a telephone
constructed according to this Invention. Portions are broken away to show the
parts beneath.
Figure 2 represents the apparatus, partly in section, on the line 2, 2, of
Figure 1.
Figure 3 is an end view of the apparatus, showing a mode of connecting the
wires.
And Figure 4 is a diagram illustrating the arrangement on circuit.
The instrument is shown as consisting of a base plate or handle A made of iron
or steel. An ordinary electro-magnet B wound with a low resistance and adapted
to a local battery of, say, 3 cells is secured to one end of this handle.
A supplementary electro-magnet C, with a resistance of one hundred Ohms, more
or less, according to the length of the line that is used, having a tubular core

page_text: radially slotted for the greater portion of its length, of about 3/ths of an inch in
length, is mounted upon the magnet B, substantially in the same axial plane, but
separated from it, and kept froin contact therewith by a plate or washer c of some
non-metallic substance, such as thin paper for instance, the two magnets being
bound together by a non-magnetic metal screw, such as brass for instance. Under
this construction the supplementary magnet C, which has no electrical connection
with any other part of the apparatus, is acted upon inductively by the magnet B,
as herein-after more fully explained. A stiff spring plate D of iron or steel is
secured by one end to the handle A, its other end being perforated, so as to form an
eye through which the magnet B passes.
A cup or casing E of hard rubber or other suitable material is mounted upon the
loop or eye of the spring plate D, being secured thereto by means of a ring F
provided with internal spurs f, through which iron or steel screws
spring plate D, thus securing magnetic connection between the plate D and
ring F.
pass into the
A thin sheet metal diaphragm G, preferably made of iron and nickel, plated to
prevent corrosion, rests upon the ring F, and is clamped thereon by the mouth-
piece E, which screws into the cap E, an annular washer g of soft paper or other
analogous material being interposed between the diaphragm and mouth-piece or
screw cap, which allows increased freedom of movement to the diaphragm and
prevents the introduction of vibrations foreign to those produced by the voice. By
this mode of construction it will be observed that the two poles of the magnet are
brought in close proximity to each other. The construction is such that the spring
of the plate tends to hold the end of the supplementary magnet C in contact with
the diaphragm G. To adjust it at the proper distance for the perfect transmission
and reception of articulate sounds I interpose an adjusting screw H between the
frame A and the spring plate D, and as the diaphragm is secured to the spring plate
while the magnet is secured to the handle, it is obvious that the turning of the
screw in one direction will tend to force the diaphragm and magnet apart, while
its turning in the other will cause them to approximate, thus affording the nicest
adjustment required.
The arrangement upon circuit is shown in Figure 4, which represents two
instruments, such as that above described, adapted for the reception and trans-
mission of messages either way upon the line.
It will be observed that the line starts from the ground, passes through one
supplementary magnet C, then to the other magnet, and thence to the ground,
without any battery, while each magnet B has its own independent local circuit
and battery.
In the Drawings, 1 and 4 represent the local wires, and 2 and 3 the line
wires.
The operation of the apparatus is as follows:-The batteries keep the magnets B
always charged, and these charge the supplementary magnets C inductively, while
the line normally remains quiescent. When either diaphragm is thrown into
vibration, corresponding magneto-currents are induced upon a line in a well-known
way.
Experience has demonstrated that a telephone constructed as above described
possesses great practical advantages over any heretofore known; first, in eliminating
sounds foreign to the articulate sounds being transmitted; and, secondly, in its
capacity for taking up and reproducing the finer shades of vibrations, which are
important elements in determining quality. It copies accurately all the over-tones
without introducing any foreign ones, thus preserving accurately all the peculiar
characteristics of the particular voice of the person who is speaking.
These advantagesare due,-
First. To the introduction of the supplementary magnet.
Secondly. Its peculiar construction and connection with the magnet B, whereby
it is rendered responsive in the highest degree to the inductive effects of any
movements in the dienbraam

page_text: And, Thirdly. To the employment of the ring F, which contributes to the mass
of the inductor without in any way trammelling its motion by its weight.
In order to receive more efficiently telephonic communications, two telephones in
the same circuit are mounted upon a common support in such manner that they
may be applied simultaneously one to each ear of the person receiving the
message.
Figure 5 is a side elevation, partly in section, the handle portion of the apparatus
being broken to occupy a less space, and one of the telephones being represented in
vertical central longitudinal section to show its construction more clearly.
G
Figure 6 represents a plan or top view of one of the telephones.
And Figure 7, a perspective view of the core of the magnet detached.
The instruments are shown as mounted upon the ends of a U shaped or
bifurcated spring handle or support, for convenience of construction made in three
pieces; a yoke-shaped portion A, upon the upper ends of which are screwed
corrugated handles A¹, in the other ends of which handles are screwed the upper
portions A² of the support.
Forked brackets B secured upon the ends of the support are provided with
pivots b, upon which the telephones oscillate in a vertical plane.
In their general construction the telephones proper are substantially similar to
those already described. Certain modifications of construction are however
required to adapt them to the present purpose, and also to secure certain other
advantages, which modifications will be herein-after described.
The telephones in this instance are shown as mounted upon a frame consisting of
a ring C, a cross bar C', and connecting bar c, into which the pivots b above
mentioned are inserted.
An ordinary electro-magnet D, wound with a low resistance, and adapted to a
local battery of, say, three cells, is provided with a stem d working endwise, piston
fashion, through a tubular projection C on the frame. A sot nut d' fits on a screw
on the end of this stem to adjust the magnet backwards and forwards relatively to
the diaphragmn, the magnet being normally thrust forward by a coiled spring d
inside the tubular extension.
Set screws d³ pass through the tubular extension into longitudinal grooves in
the stem to prevent it from turning, and hold it securely while permitting of its
longitudinal adjustment.
A supplementary electro-magnet E, with a resistance of 100 Ohms, more or less,
according to the length of the line that is used, and having a tubular core e rudially
slotted for the greater portion of its length of about 3/ths of an inch in length, is
mounted upon the magnet D substantially in the same axial plane but separated
from it, and kept from contact therewith by a plate or washer e¹ of some non-
magnetic substance, such as thin paper, for instance; the two magnets being bound
together by a non-magnetic screw, such as brass for instance. Under this con-
struction the supplementary magnet E, which has no electrical connection with any
other part of the apparatus, is acted upon inductively by the magnet D.
A cup or casing F of hard rubber or other suitable material is mounted upon
the ring C of the frame, being secured thereto by means of a secondary or induction
ring G provided with internal spurs g, through which iron or steel screws g' pass
into the ring, thus securing magnetic connection between the rings C and G.
The usual thin sheet-metal diaphragm H rests upon the ring G, and is clamped
thereon by means of a mouth-piece F' provided with a deep flange f, with a female
screw formed thereon, which screws upon the cup F, an annular washer of soft
paper or other analogous material being interposed between the diaphragm and
mouth-piece or screw cap, which allows increased freedom of movement to the
diaphragm, and prevents the introduction of vibrations foreign to those produced
by the voice.
By mounting the telephones upon rocking bearings, as herein-before described,
they adapt themselves readily to the cars of the person receiving the messages, the
intention being to apply one to each ear. The handle upon which they are mounted

page_text: is preferably made of such length and form that the two sides come near together
under the chin, while the arins project some distance farther down. The handles
are thus brought near enough together to be grasped with one hand, leaving the
other free to hold an ordinary single telephone or transmitting instrument to the
mouth for talking or sending a message, by which arrangement the necessity of
shifting the instruments from the mouth to the ear, as is the case where a single
telephone is used, is avoided; and the application of the telephones close to the ear
excludes extraneous noises, and the sound being transmitted to both ears at once
is rendered much more distinct.
Another advantage of the improvement is that the instruments when applied to
the ears do not need to be removed until the conversation is completed.
I have described one form of telephone, but it is obvious that any of the ordinary
forms of speaking telephones may be adapted to the apparatus.
In order to secure an increased volume and clearness of sound two diaphragms
are employed, each provided with an electro-magnet secured to the poles of the
permanent shaped magnet common to both, at such an angle with reference to
each other as to admit of the use of a common mouth-piece, so shaped as to allow
the lips of the speaker to approximate as closely as possible to both diaphragms.
Figure 8 represents a plan or top view of the improved apparatus; and Figure 9,
a view in elevation thereof, one side bieng shewn in vertical section through the
centre of the magnet.
Figure 10 shews the arrangement in circuit.
A permanent U shaped or horse-shoe steel magnet A constitutes the handle of
the instrument, and may be highly finished and ornamented if desired. A rubber
disc B, B', of about one half an inch in thickness, and of a diameter slightly larger
than the diaphragm, is secured to each pole of the magnet by screws d. A small
helix C wound upon a hard rubber spool about an inch in diameter, and about
equal in length to the thickness of the disc B, B', is firmly inserted in each disk
and provided with the ordinary connecting wires. A soft iron core D screws into
each pole of the permanent magnet A, and is firmly secured therein by a check
nut d. The soft iron core slides loosely through the helix, and is held permanently
charged by the pole of its respective magnet. This core is adjustable relatively
to the diaphragm by unscrewing the check nut and turning the core back or forth
with a screwdriver until properly adjusted, when the check nut is screwed up again,
thus holding the core securely in position.
A diaphragm E is firmly secured in place between the disc B and the screw
cap F; rings e of paper or other suitable material are interposed between the
diaphragm and dise and cap respectively, and these parts are all securely clamped
together by a brass ring G provided with a flange g` overlapping the disc, and an
internal screw thread in which the cap F screws.
The mouth-piece H of metal or other suitable material terminates in a bifurcated
tube, each branch being secured to its respective cap F by screws f, so as to bring
the mouth of each tube over the centre of its respective diaphragm.
The diaphragms, it will be observed, are arranged at an angle of about 40 degrees
with reference to each other, by which means the lips of the speaker are brought
very near both diaphragms, so that practically each diaphragm is actuated with the
saine energy as a single one constructed in the ordinary way, by which means
almost double the electro-motive force of a single diaphragm is generated. In con-
sequence of this organization, articulate words are transmitted with greater force
and clearness than they are with a single diaphragm under the same circum-
stances..
Each telephone is a counterpart of the other, and the apparatus thus constitutes
what I term a bipolar telephone.
An improvement upon the "bipolar" telephone, securing an increased volume and
clearness of sound, consists,-
First. In combining four diaphragms with a common mouth-piece.

page_text: And, Secondly. In duplicating each diaphragm so as to secure double the vibrating
surface.
Figure 11 represents a plan or top view of an instrument composed of two single
bipolar telephones, and having four diaphragms arranged around a common mouth-
piece, each diaphragm having its own magnet.
Figure 12, a side elevation thereof, partly in central longitudinal section through
one of the magnets, on the line 2, 2, of Figure 11.
Figure 13, a plan or top view of a bipolar telephone with its diaphragms dupli-
cated or arranged on each side of the pole of its magnets.
Figure 14 is a side elevation, partly in section therethrough, on the line 4, 4, of
Figure 13, showing the method of connecting each pair of diaphragms.
Figure 15, a plan or top view of a multi-polar duplex telephone, having eight
diaphragms connected with a common mouth-piece.
Figure 16, a side elevation thereof, partly in section on the line 6, 6, of Figure 15.
Figure 17, a side elevation, partly in section, showing the bipolar duplex tele-
phone as provided with separate handles, or permanent magnets for each pair of
diaphragms.
And Figure 18, a similar view showing a duplex multi-polar telephone similarly
constructed.
The improved apparatus embodies all that is shewn in the bipolar telephone
having a permanent U shaped or horse-shoe steel magnet A, which constitutes the
handles of the instrument, rubber disks B, helices C, soft iron cores D, dia-
phragms E, screw cap F, clamping rings G, and mouth-piece H.
In the apparatus shown in Figures 13, 14, 15, & 16 a tubular soft-iron core E
passes through the pole of the magnet, and extends therethrough far enough to
receive a supplementary helix C'. In front of this magnet is mounted a secondary
diaphragm E, in precisely the same manner as the corresponding one E. The
secondary cap F¹ is made solid with no opening for the mouth-piece. The core D
has a small hole drilled through it from end to end, about one-eighth of an inch in
diameter. In this hole is suspended a light rod d of wood or some non-magnetic
metal (such as brass, for instance), each end of which rod is attached to its respective
diaphragms E, E³, so that the movement of one, from any cause whatever, produces
a corresponding movement in the other.
The advantage of the improvement is that two diaphragms are made to vibrate
in front of two electro-magnets, both of which are charged from the same pole of a
permanent magnet without making any changes in any respect in the mouth-piece.
Experience has demonstrated that this method will generate greater electrical forces
than a single diaphragm, and consequently produce a louder sound. A similar
apparatus is attached to the other pole of the inagnet, and thus four diaphragms
are made to vibrate instead of two, as in the bipolar telephone, and still the same
relations between the diaphragm and the mouth-piece are maintained as in the
aforesaid instrument.
Another mode of producing substantially the same effect, at least in kind, if not
in degree, is to leave out the connecting rod, in which case the secondary diaphragm
will be actuated by the vibrations of the columns of air contained in the hollow
cove D.
It should be observed that this hollow cove in connection with the space under
the diaphragm forms an air-tight chamber.
.
It is obvious that this form can be extended by adding another permanent
magnet with all the attachments heretofore described, and eight or more dia-
phragms can be actuated instead of four, by attaching two or more branches like
those already described to the mouth-piece placed at right angles with them, as
fully shown by Figures 15 and 16; in other words, the Invention is not confined to
any number of diaphragms, but as many as can conveniently be attached to a single
mouth-piece may be used.
The several electro-magnets in the system are connected to line, either "tandem"
or "joint," as the resistance of the line upon which the instrument is used requires,

page_text: Instead of mounting a secondary magnet upon the same pole of the permanent
magnet as the primary one, as shown in Figures 13, 14, 15, and 16, the two poles
of the permanent magnet are brought into the position shown in Figures 17 and 18,
so that the secondary magnet is mounted on the other pole of the permanent
magnet. It follows, as a consequence of this arrangement however, that twice as
many permanent magnets are needed to operate a given number of diaphragms as
would be required in the instrument shown in Figure 16.
The space between the two poles of the permanent magnet, shown in Figures 17
and 18, is bridged over with a tubular piece I, of brass or some non-magnetic
substance. This is to confine the column of air contained in the casing and core of
the magnet. In other respects the apparatus is exactly the same as that herein-
before described.
The operation of the improved telephone will readily be understood from the
foregoing description.
There has been difficulty heretofore in arranging on one line wire a number
of telephone stations provided with call bells, because the coils of the electro-
magnets of the call bells of the intermediate stations stop the electric waves or
impulses originated by the speaking telephone.
The fact is well known that when an electro-magnet is included in a circuit,
through which vibrations are transmitted (whether the magnet be of high or low
resistance), it greatly impedes the passage of such vibrations, and the more rapid
or highly attenuated they are, the more difficult it is to transmit them through the
coils of such magnet. This difficulty is so prominent under the systems heretofore
practised that the insertion of even 2 or 3 extra magnets in a circuit practically
prevents the transmission of articulate sounds or spoken words over a line, however
short. To obviate this objection and at the same time leave the bell or call
magnet in circuit, this improvement is devised.
Figure 10 represents my improved arrangement upon circuit of instruments and
apparatus on a line consisting of two terminal and two intermediate stations.
Figure 20 represents two terminal stations and an intermediate station shewing
my improvements as more especially adapted for operation in connection with a
line equipped under the Morse system.
The construction and operation of the instruments represented in the diagrams
being well known, it is deemed unnecessary to represent or describe them in detail,
except so far as is necessary to illustrate my new organization of apparatus.
In Figure 10 of the accompanying Drawings, 4 stations, A, B, C, D, are repre-
sented as arranged in a speaking telephone circuit. Each station is provided with
one or more speaking telephones E, E, E², Es, and also with an ordinary electric
call bell, F, F, F, F³, having either an ordinary magneto-electric generator or a
battery as the case requires. In this instance station A is shown as provided with
a generator G, while station D is represented as provided with a battery L, B, and
an ordinary Morse key K. for throwing it on and off the line.
The batteries and generators are omitted from the intermediate stations for
convenience of representation.
The battery is employed for calling on such lines only as use what is known as
the "battery telephone."
The magneto-electric generator is used on such lines as use the permanent
magnet telephone, no battery being required in such cases.
Each station is provided with a switch I, I, I, I, which in one position directs
the circuit through its respective telephone magnet, and in the other position
through its respective bell magnet, leaving out the telephone as will be readily
understood by reference to the Drawings, which shew the method of running the
circuits, and which represent the telephone connection wires as running around the
bell magnet. A similar switch J throws the generator on or off the line as required.
When the line is not in use the switches are all left standing, so that the circuit
passes through the bell magnets, shunting the telephones, thus enabling any one

page_text: station to call any other by means of its alarm or call bell and battery, or bell and
magneto-generator as the case may be.
In Figure 19 the switches I, I³, on the terminal stations A and D are respectively
shown in position for conversing between those two stations. The intermediate
stations B and C are necessarily left in position for calling, therefore the circuit is
directed through the bell magnets of those stations, as it would be impracticable to
have them all switches out of circuit whenever any two stations wished to converse.
My improvement allows these magnets to remain in circuit, and therefore be in
position to receive calls without in the least interfering with the transmission of the
voice vibrations over the lines from one terminal station to the other.
The condenser may be made a part of the apparatus; that is, for instance, it may
be placed in the bottom of signal boxes as ordinarily constructed, or it may be
made separate as in the ordinary form, and connected through the box by incans of
wires of such length as may be inost convenient.
In the Drawings the condensers, H, H', H, H³, are shown as shunting the aların
or call apparatus, or in other words as arranged in branch circuit.
It is frequently desirable to use the speaking telephone on ordinary Morse
circuits, which this improvement renders it practicable to do very advantageously
by means of the arrangement represented in Figure 20, which shows 3 stations
X, Y, Z.
Having thus described the nature of the said Invention, and the manner of
performing the same, I would have it understood that I claim in respect to the
parts of the Invention illustrated by Figures 1, 2, 3, and 4 of the Drawings,-
First. The combination, substantially as herein-before set forth, in a speaking
telephone of a primary magnet, a supplementary magnet mounted thereon, and
intermediate connections which isolate them both magnetically and electrically,
so that the supplementary magnet is charged by induction only and not by
contact.
Second. The combination, substantially as herein-before set forth, in a speaking
telephone of an electro-magnet, a diaphragm, and an isolated supplementary magnet
interposed between the primary maguet and the diaphragm.
Third. The combination, substantially as herein-before set forth, of a handle
with a magnet mounted thereon, a plate united to the handle and encircling the
magnet without contact therewith, and a diaphragm mounted upon the encircling
plate, whereby the two poles of the magnet are brought near together.
Fourth. The combination, substantially as herein-before set forth, of the handle,
the magnet mounted thereon, the encircling plate carrying the diaphragın, and
the adjusting screw interposed between the handle and plate to adjust the dia-
phragin relatively to the magnet.
Fifth. The combination, substantially as hercin-before set forth, of the plate, the
box. or casing mounted thereon, the ring supporting the diaphragm, and the screws
connecting the ring and supporting plate.
Sixth. The combination, substantially as herein-before set forth, in a speaking
telephone of a diaphragm with a soft iron ring, upon which it rests, whereby a
greater inductive capacity is given to the diaphragm by increasing the mass of
metal without encumbering its motions with additional weight.
Seventh. The speaking telephone herein-before described, consisting of the com-
bination of a handle, a primary and a supplementary magnet mounted thereon, a
diaphragın mounted independently of the magnets on a supporting plate, and an
adjusting screw for regulating the relation of the diaphragm to the magnet.
Eighth. In a speaking telephone the arrangement on circuit, substantially as
herein-before set forth, consisting of the combination of a local battery at each end
charging a magnet, supplementary magnets isolated magnetically and electrically
from the primary magnets, so as to act by induction only, and earth connection
with each supplementary magnet, and a line wire connecting the supplementary
magnets, whereby the line remains quiescent until thrown into action by the
vibrations of the inductor.

page_text: I also claim, as respects the parts of the Invention illustrated by Figures 5, 6,
and 7 of the Drawings,―
First. The combination, substantially as herein-before set forth, of a pair of
telephones with a common support, whereby they may be applied simultaneously,
one to each ear of the person receiving the message.
Second. A yoke-shaped yielding support adapted to fit under the chin and
having a telephone mounted upon each branch thereof, whereby the instrument
may be grasped by one hand while a telephone is applied to cach car of the
person receiving the message, and leaving the other hand free to hold a trans-
mitting instrument.
Third. The combination, substantially as herein-before set forth, of a bifurcated
support, a supporting bracket on each arm of the support, and a telephone pivotted
to rock upon said brackets to facilitate their adjustment to the ears of the person
receiving the message.
Fourth. The combination, substantially as herein-before set forth, of a supporting
frame, a magnet having a projecting stem movable endwise through a tubular
extension of the supporting frame, an adjusting screw and a spring which normally
presses the magnet towards the diaphragm to regulate its relation thereto.
I also clain as respects the parts of the Invention illustrated by Figures 8 and 9
of the Drawings,—
First. A bipolar telephone constructed, substantially as herein-before set forth),
with its two diaphragms approximating each other at one edge, and arranged at
an acute angle, and having a common mouth-piece, whereby the lip may be brought
close to each diaphragm to increase the electro-motive force.
Second. The combination, substantially as herein-before set forth, of two tele-
phones mounted upon a common support at an acute angle to each other, with
an interposed bifurcated mouth-piece secured to said support.
Third. The combination, substantially as herein-before set forth, of a permanent
magnet, two diaphragms mounted thereon at an acute angle to each other, and
approximating at one edge with an interposed bifurcated mouth-piece, each branch
of which comes opposite the centre of its respective diaphragm.
Fourth. The combination, substantially as herein-before set forth, of the disk,
the cap, the interposed diaphragm, and the flanged ring overlapping the disk and
screwing over the cap to clamp the diaphragm firmly at its edge.
Fifth. The combination, substantially as herein-before set forth, of the permanent
magnet, a screwed sof iron core passing therethrough, and a check nut on the core,
whereby the core may be adjusted relatively to the diaphragm.
I also claim as respects the part of the Invention illustrated by Figures 11, 12,
13, 14, 15, 16, 17, and 18 of the Drawings,-
First. The combination, substantially as herein-before set forth, of four telephones
with a common mouth-piece, around which they are arranged at an angle, whereby
they may be brought close together so as to produce the best result.
Second. A secondary magnet in combination with a secondary diaphragm,
actuated by a primary diaphragm, substantially as herein-before set forth, to
increase the electro-motive force of the vibrations.
Third. In combination, a magnet, two diaphragms, and an interposed tight air
chamber, whereby the movement of one diaphragm by the magnet is transmitted
through the enclosed column of air to the other.
Fourth. In combination, a permanent magnet, diaphragms mounted thereon, and
electro-magnets interposed between the diaphragms, so that the diaphragms are
actuated by two magnets of similar polarity.
Fifth. The combination, substantially as herein-before set forth, of a mouth-piece,
a primary diaphragm, a secondary diaphragm actuated thereby, and a solid cap or
cover enclosing the secondary diaphragm.
Sixth. The combination, substantially as herein-before set forth, of a permanent
horse-shoe magnet, electro-magnets mounted on each pole thereof, a diaphragın for

page_text: each magnet, and a mouth-piece for one diaphragm, so as to operate one diaphragm
from or by the other.
Seventh. The combination, substantially as herein-before set forth, of a permanent
horse-shoe magnet with an electro-magnet mounted on cach pole, a tubular core for
cach magnet, and an interposed connecting piece constituting with the core and
diaphragms a closed chamber, through which one diaphragm operates upon the
other.
Eighth. The combination, substantially as herein-before set forth, of a series of
diaphragms nounted in pairs upon each pole of their respective horse-shoe magnets,
and connected with a common mouth-piece.
Ninth. A series of secondary magnets combined with a series of secondary
diaphragins actuated by the movements of a series of primary diaphragms from a
common mouth-piece, substantially as herein-before set forth.
I also claim as respects the part of the Invention illustrated by Figures 19 and 20
of the Drawings,―
First. The hercin-before described art of transmitting sounds through a bell
magnet or other signal magnet and condenser, arranged in branch circuits in a
main line.
Second. The herein-before described art of transmitting sounds through a series
of bell magnets or other signal magnets and condensers arranged in branch circuits
in a main line.
Third. The combination, substantially as herein-before set forth, in a telephone
of a bell magnet or other signal inagnet and its actuating apparatus, a condenser
shunting said magnet and actuating apparatus, and a telephone magnet shunting
said bell magnet, actuating apparatus and condenser, and a switch controlling the
shunts.
Fourth. The combination, substantially as herein-before set forth, in a Morse
circuit of a series of condensers shunting the relays at each station, telephone
magnets at two or more stations, and switches which simultaneously shunt the
telephone magnets into line and throw off the batteries.
Fifth. The combination, substantially as herein-before set forth, in a single
electric circuit of a series of stations, each provided with a bell magnet or other
signal magnet and its actuating apparatus, a condenser shunting them, a telephone
magnet shunting the bell magnet, actuating apparatus and condenser, and switches
controlling the shunts, whereby the signal magnet actuating mechanism and
condenser at the transmitting stations are cut out of circuit, which passes through
the corresponding apparatus at the intermediate stations shunting the telephones.
In witness whereof, I, the said Joshua Franklin Bailey, have hereunto set my
hand and seal, this Twenty-fifth day of April, in the year of our Lord
One thousand eight hundred and seventy-eight.
TOSHIITA T DATTE