Improvements in Mechanical Telephone Apparatus.
Year: 1886

page_text: Date of Application, 29th Dec., 1886
Complete Left, 12th Sept., 1887
Complete Accepted, 14th Oct., 1887
[Communicated from abroad by GEORGE WASHINGTON LORD and HENRY ELMER
TOWNSEND, both of Boston, Massachusetts, United States of America.]
Improvements in Mechanical Telephone Apparatus.
1, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature of
this invention to be as follows:-
The first part of my invention relates to the combination with the conducting wire
of a mechanical telephone, of a tubular case having supports extending within the
same for supporting the conducting wire at angles and other points, its object being
to prevent the interference with the transmission of sound waves by angles in the
wire, to give protection for the supports, to permit the free movement of the wire on
the supports, and to obtain a compact support occupying but little space which can
be conveniently and easily attached at any desired point.
The second part of my invention relates to a case made in two parts connected
together, containing the diaphragm of the telephone and having resonating cavities
on each side of the same, formed as hereinafter more fully set forth, its object being
to give increased power to the telephone.
The third part of my invention relates to the combination with the said case of a
band of lead or some other non-resonant material, which surrounds the case, its object
being to prevent indistinctness in the transmission of sounds caused by resonance
The fourth part of my invention relates to the combination with the case of flexible
connections attached to the sides of the case for attaching the telephone, its object
being to obtain a mechanical telephone from which the line can always be extended
for such a distance in a direction at right angles to the plane of the diaphragm as will
be sufficient to ensure the satisfactory transmission of vibrations no matter in what
direction the line may extend from the points which are connected, thus enabling the
use of mechanical telephones to be largely increased. It has also for its object the
inore perfect insulation of the telephone, and also to enable the telephone to be placed
outside of the wall of a building.

page_text: The fifth part of my invention relates to the combination with the diaphragm of a
means for insulating the same from the case, its object being to prevent the dissipation
of vibration and the taking up of extraneous vibrations.
The sixth part of my invention relates to the combination with the case of the
telephone of a mouth piece in the sides of the case at right angles to the plane of the
diaphragm, its object being to enable the telephone to be used in any position.
The seventh part of my invention relates to the combination with the telephone case
of a hearing tube connected with the same as hereinafter more fully set forth, its
object being to concentrate the sound waves within the hearing tube.
The eighth part of my invention relates to the combination with the case of a plug
of india rubber or other suitable material, through which the conducting wire passes,
its object being to prevent the wire from coming into contact with the wood of
the case.
The ninth part of my invention relates to the combination with the conducting
wire of a wire passing through the diaphragm and provided with a screw thread and
nut, its object being to afford convenient means for giving the desired tension
to the wire.
The tenth part of my invention relates to the combination with the conducting wire
located within the walls and floors of a building of supporting devices as hereinafter
more fully set forth, its object being to enable mechanical telephones to be used in
buildings in place of speaking tubes.
The eleventh part of my invention relates to the combination with the conducting
wire of a mechanical telephone of a suspended weighted telephone from which the
conducting wire extends vertically, and the angle or other supporters, hereinafter
more fully described, which permit the free movement of the wire on the same, its
object being to obtain a mechanical telephone line in which the desired tension will
be automatically and constantly maintained.
The twelfth part of my invention relates to the combination with the telephone of
a calling device as hereinafter more fully set forth.
The tubular cases for supporting the wire at angles are of such construction that
they can be conveniently attached close to the wall or ceiling of the building, thus
enabling the wire to be carried up out of the way before leaving the building.
In the use of mechanical telephones it has been found that angles or turns,
especially right angles, seriously interfere with the transmission of vibrations, and
therefore mechanical telephones have found but little use except when the line could
extend straight away from the telephone but when the angle hanger which I have
invented is used there is no perceptible interference with the transmission of vibration,
and consequently by its use I am able to largely extend the use of mechanical
telephones especially in cities and towns where it is difficult to obtain straight lines
and where mechanical telephones would be exceedingly useful for the transmission of
speech for short distances.
This angle hangor consists of a tube of tin or other suitable metal about one inch
in diameter and either straight or bent to conform to the angle or turn made by the
wire. Within this tube are suitably secured two or more supports which may either
be loops, rings or perforated dises which support the wire in the centre of the tube
and are placed at such an angle to one another that the wire will conform to the
angle made by the tube and in passing through a right or other angle will make two
or more larger angles.
These loops or rings are formed of tarred hemp, or of wire covered with cotton or
other fibrous material preferably coated or saturated with parafine or other suitable
insulatory material, and are opened in such a manner that the wire rests upon the
same without being embraced thereby, so that the minimum of contact is afforded
between the wire and the supports.
The supports when made of covered wire can be inserted through perforations in
the walls of the tubular case distant from each other about one-third of the circumference
of the same, so that opened loops are formed within the case and twisted together or
the outside of the case. The loops when formed of tarred rope can be similarly

page_text: inserted through perforations in the walls of the case and secured by knots on the
rope. Loops of tarred rope are formed of two rings of iron or other suitable material
each of which bears against a flange in the tube which rings are prevented from
coming together by means of blocks placed on the inside of the tube or by any other
suitable device. A Cord of tarred hemp or other suitable material is wrapped around
each of these rings and part of this cord is then made into a loop which extends
toward the centre of the tube and is maintained in an open form by means of the
guys or traces.
The open form of the loops enables the wire to move freely upon the
same when it is desired to stretch the wire while at the same time no amount of strain
upon the wire will bring it into contact with the walls of the tube.
The covered wire loop has a curved form which permits a certain vibratory motion
which tends to prevent any dampening of the vibrations on the wire.
This curved form cannot be destroyed by any strain upon the conducting wire.
In some cases I may use a perforated dise suitably secured within the tubular case
for supporting the wire. This disc may be made of thin metal parchment or leather
and to each side of the centre of the disc is attached a plate of wood in which is a
perforation through which the wire passes. When this disc is used it may be desirable
in some cases to fix the wire in position by set screws. The case may be made in two
parts centrally hinged and fastened together in any suitable manner.
The tubular case may also be made in two parts sliding within each other. By the
use of this tubular case the supports are protected from injury or disturbance while
at the same time a compact and easily attached line support is obtained.
My improved telephone consists of a hollow case of wood made in two parts
opposed to one another face to face so that two cavities are formed on each side of
the diaphragm which extends across the case. These cavities are preferably bell
shaped while the case is preferably cylindrical with rounded ends.
A band of some
non-resonant metal such as lead, and which material I prefer to use extends around
the case and acts to prevent any resonance in the case.
The band also serves to
secure the two parts of the caso together, but they may be otherwise secured through
the band of nonresonant material must be placed around the case.
The diaphragm which may be of any material suitable for use in an acoustic
telephone, may be stretched over the end of one of the sections of the case, or may be
secured to a ring, which is fitted within a shoulder in one section of the case. A wire
passes through the diaphragm and is secured to a wooden hutton on the opposite side
of the diaphragm. A convenient means of doing this is by means of a nut which
moves upon a screw-thread upon the wire, thus enabling the wire to be drawn
through the diaphragm for the purpose of increasing the tension of the conducting
wire. This wire passes through a plug of india-rubber leather or other suitable
material in one section of the case and is provided with an eye to which the conducting
wire is attached. The object of the india rubber plug is to prevent the wire from
coming into contact with the wood of the case.
The case is provided with an opening in its side in which may be inserted a suitable
mouth-piece for talking into the telephone or for hearing the sound produced in the
same, and it may also have attached thereto a flexible tube inserted into an opening
in the case. This tube has attached to it an ear or mouth-piece such as is used in
instruments for the use of the deaf or in stethoscopes. Both the mouthpiece and the
flexible tube with mouth or ear piece may be used or only one of these, as may be
found desirable.
The flexible tube enables the telephone to be placed outside a building, which in
sonic cases will be a desirable location, the tube extending into the building.
The tube may have a branch tube attached thereto which can be used for hearing
purposes, while the other branch is used for speaking purposes.
When the flexible
tube is attached to the case opposite the diaphragm and I prefer to attach to the tube
a trumpet shaped piece which extends within the case about half way to the diaphragm.
The cavity in this piece is preferably formed like that of a stethoscope, so that the
sound waves are concentrated within the tube and thus the transmission of speech is
rendered more perfect.

page_text: The transmission of sound waves mechanically by a conducting wire is facilitated
when the wire extends straight away for a considerable distance at right angles to
the plane of the diaphragm, and it is also advantageous that the case should make
as little contact as possible with the wall to which it is attached.
I effect both these results by the attachment of rings to the side of the case. A
flexible wire or cord is attached on each side of the telephone to one of the rings and
passes through the other rings.
When the telephone is used outside of a building, these cords or wires are attached
to the same, and when the telephone is used inside a building, they may be attached
to any suitable point.
This method of attachment by the use of flexible cords permits the telephone to be
turned at any angle to the wall of the building, so that the conducting wire can be
extended straight away in a line at right angles to the plane of the diaphragm no
matter what may be the direction of the point which is connected.
An
A device which I sometimes employ to produce a sound in the telephone for the
purpose of calling attention when it is desired to carry on a conversation consists of a
plate of metal moving in a slot in the side of the case and pivotted to the same.
arm extends outside the case and another arm extends within the case under the
diaphragm and carries a metallic knob.
The weight of this arm in its normal position keeps it away from the diaphragm,
but when the first arm is depressed the knob slides against the end of a wire, and
causes a loud sound to be produced in the connected telephone.
in this way a succession of taps can be produced which will be heard at a
considerable distance from the telephone.
The
I also use in some instances some insulating substance such as tarred hempen cord
for separating the ring to which the diaphragm is attached, from the case.
object of this device is to prevent the communication to the diaphragm of vibrations
in the case.
It is desirable in a mechanical telephone system, that the conducting wire should
have a certain tension, but owing to the effect of changes of temperature upon the
wire this tension cannot always be maintained constant. I am able to accomplish
this by the use of my angle hangers, the supports in which are of such form that
the free movement of the wire upon them is permitted.
This telephone is weighted in any suitable manner as by the attachment of a weight
and thus produces a constant tension in the conducting wire. Either both, or only
one of the telephones may be weighted. The telephone may bear in a curved bracket
fixed upon the wall and thus be prevented from swinging.
Mechanical telephones are very useful in buildings in place of speaking tubes and
have been used for that purpose. By the use of my angle hangers, I am enabled
to place the conducting wire within the floors and walls of the building thus
concealing it.
The wire may be enclosed in a tube and supported therein by the supports made
of wire covered with cotton, coated with paraffine or otherwise suitably insulated.
Dated this 29th day of December 1886.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: Improvements in Mechanical Telephone Apparatus.
1. HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :—
This invention relates to mechanical telephone apparatus.
One part of my said invention comprises the combination with the conducting wire
of a mechanical telephone of a tubular case having supports extending within the
same for supporting the conducting wire at angles and other points; its object being
to prevent the interference with the transmission of sound waves by angles in the
wire, to give protection for the supports, to permit the free movement of the wire on
the supports, and to obtain a compact support occupying but little space, which can
be conveniently and easily attached at any desired point.
Another part of my invention comprises a case made in two parts connected
together, containing the diaphragm of the telephone and having resonating cavities
on each side of the same, formed as hereinafter set forth, its object being to give
power to the telephone.
Another part of my invention comprises the combination with the said case of a
band of lead or some other non-resonant material, which surrounds the case, its
object being to prevent indistinctness in the transmission of sounds caused by
resonance.
Another part of my invention comprises the combination with the case of flexible
connections attached to the sides of the case for attaching the telephone, its object
being to obtain a mechanical telephone from which the line can always be extended
for such a distance in a direction at right angles to the plane of the diaphragm as will
be sufficient to ensure the satisfactory transmission of vibrations, no matter in what
direction the line may extend from the points which are connected, thus enabling the
use of mechanical telephones to be largely increased. It also has for its object the
more perfect insulation of the telephone, and also to enable the telephone to be placed
outside the wall of a building.
Another part of my invention comprises the combination with the diaphragm, of
means for insulating the same from the case, its object being to prevent the dissipation
of vibration and the taking up of extraneous vibrations.
Another part of my invention comprises the combination with the case of the tele-
phone of a mouth piece, in the sides of the case at right angles to the plane of the
diaphragun, its object being to enable the telephone to be used in any position.
Another part of my invention comprises the combination with the telephone case,
of a hearing tube connected with the same as hereinafter set forth, its object being to
concentrate the sound waves within the hearing tube.
Another part of my invention comprises the combination with the case of a plug of
india rubber or other suitable material, through which the conducting wire passes,

page_text: its object being to prevent the wire from coming into contact with the wood of'
the case.
Another part of my invention comprises the combination with the conducting wire,
of a wire passing through the diaphragm and provided with a screw thread and nut,
its object being to afford convenient means for giving the desired tension to the wire.
Another part of my invention relates to the combination with the conducting wire
located within the walls and floors of a building, of supporting devices as hereinafter
set forth, its object being to enable mechanical telephones to be used in buildings in
place of speaking tubes.
Another part of my invention comprises the combination with the conducting wire
of a mechanical telephone, of a suspended weighted telephone from which the con-
ducting wire extends vertically, and the angle or other supporters, hereinafter
described, which permit the free movement of the wire on the same, its object being
to obtain a mechanical telephone line in which the desired tension will be automatically
and constantly maintained."
Another part of my invention comprises the combination with the telephone of a
calling device as hereinafter set forth."
In the accompanying drawings,
Figure 1 shows a telephone line provided with my improved angle-hangers.
Figure 2 is a sectional view of a form of my improved angle hanger.
Figures 3, 4 and 5 are sectional views of other forms of the same.
Figures 6, 7, 8 and 9 are sectional views of different forms of devices for supporting
the conducting wire within the tubular case.
Figure 10 is a longitudinal sectional view of my improved telephone.
Figure 11 is a view in elevation of my improved telephone, showing the manner of
attaching the same to the outside of the wall of a building.
Figure 12 is another view, in elevation, of the same.
Figure 13 is a sectional view showing the calling device.
Figure 14 is a view of a weighted telephone line.
Figure 15 is a sectional view of a building and a telephone line within the walls
and floors of the same.
Figure 16 is a view of the device used for supporting the wire in the building, and
Figure 17 is a view of the device used for giving tension to the line.
Similar letters of reference indicate the same parts throughout the drawings.
A Figure 1 is a conducting wire stretched between two buildings. B, B are the
telephones, and C, C are the tubular cases for supporting the wire at angles. These
supports or angle hangers are of such construction that they can be conveniently
attached close to the wall or ceiling of the building, thus enabling the wire to be
carried up out of the way before leaving the building.
In the use of mechanical telephones it has been found that angles or turns,
especially right angles, seriously interfere with the transmission of vibrations and
therefore mechanical telephones have found but little use except when the line could
extend straight away from the telephone. When however the angle hanger con-
structed according to this invention is used there is no perceptible interference with
the transmission of vibration, and consequently by its use it will be possible to
largely extend the use of mechanical telephones, especially in cities and towns where
it is difficult to obtain straight lines and where mechanical telephones would be
exceedingly useful for the transmission of speech for short distances.
This angle hanger consists of a tube 1 of tin or other suitable metal about one
inch in diameter and either straight or bent to conform to the angle or turn made
by the wire. Within this tube are suitably secured two or more supports E which
may either be loops, rings or perforated discs which support the wire in the centre of
the tube and are placed at such an angle to one another that the wire will con-
form to the angle inade by the tube and in passing through a right or other angle
will make two or more larger angles.
These loops
or rings are formed of tarred hemp or of wire covered with cotton
or other fibrous material, preferably coated or saturated with paraffin or other

page_text: suitable insulating material, and are opened in such a manner that the wire rests
upon the same without being embraced thereby, so that the minimum of contact is
afforded between the wire and the supports.
In Figures 2 and 3 the supports are shown as inserted through perforations in the
walls of the tubular case, distant from each other about one third of the circumference
of the same, so that opened loops are formed within the case and twisted together on.
the outside of the case.
In Figure 8 the loops are formed of tarred rope similarly inserted through per-
forations in the walls of the case and secured by knots a on the rope; and in Figure 7
they are represented as formed by eyes within the case. These eyes are formed of
two rings of iron or other suitable material, each of which bears against a flange c
in the tube, which rings are prevented from coming together by means of blocks d,
similar to those shown in Figure 5, placed on the inside of the tube, or by any other
suitable device.
The
A cord of tarred hemp or other suitable material is wrapped around each of these
rings, and part of this cord is then made into a loop which extends toward the centre
of the tube and is maintained in an open form by means of the guys or laces e.
open form of the loops enables the wire to move freely upon the same when it is
desired to stretch the wire, while at the same time no amount of strain upon the wire
will bring it into contact with the walls of the tube.
The covered wire loop, shown in Figure 6, has a curved form which permits a
certain vibratory motion, which tends to prevent any dampening of the vibrations on
the wire.
This curved form cannot be destroyed by any strain upon the conducting wire.
In some cases I may use a perforated disc suitably secured within the tubular case,
as shown in Figure 4, for supporting the wire. This disc may be made of thin metal,
parchment or leather, and to each side of the centre of the disc is attached a plate of
wood, in which is a perforation through which the wire passes. When this disc is
used, it may be desirable, in some cases, to fix the wire in position by set screws f.
The case may be made in two parts centrally hinged and fastened together in any
suitable manner.
The tubular case may also be made in two parts sliding within each other, as shown
in Figures 3 and 5. By the use of this tubular case the supports are protected from
injury or disturbance, while at the same time a compact and easily attached line
support is obtained.
My improved telephone is shown in Figures :0 and 11. It consists of a hollow
case of wood made in two parts a¹ all opposed to one another face to face, so that two
cavities are formed on each side of the diaphragm G which extends across the case.
These cavities are preferably bell shaped, while the case is preferably cylindrical with
rounded ends. H is a band of some non-resonant metal such as lead, which I prefer
to use, which band extends around the case and acts to prevent any resonance in the
The band also serves to secure the two parts of the case together, but they
may be otherwise secured though the band of non-resonant material must be placed
around the case.
case.
The diaphragm G which may be of any material suitable for use in an acoustic
telephone, may be stretched over the end of one of the sections of the case, or may be
secured to a ring I which is fitted within a shoulder in the section B of the case.
The inner face of this ring may be bevelled off so that it will form a continuation of
the section of the case. K is a wire which passes through the diaphragm and is
secured to the wooden button h on the opposite side of the diaphragm. A convenient
means of doing this is by a nut i which moves upon a screw-thread upon the wire,
thus enabling the wire to be drawn through the diaphragm for the purpose of
increasing the tension of the conducting wire. This wire passes through a plug L of
india rubber, leather or other suitable material in the section a' of the case B, and is
provided with an eye to which the conducting wire A is attached. The object of
the india-rubber plug is to prevent the wire from coming into contact with the wood
of the case.

page_text: The section a¹ of the case is provided with an opening in its side in which may bo
inserted a suitable mouth-piece for talking into the telephone or for hearing the sound
produced in the same; and it may also have attached thereto a flexible tube N inserted
into an opening in the case. This tube has attached to it an ear or mouth-piece O
such as is used in instruments for the use of the deaf or in stethoscopes. Both the
mouth piece M and the flexible tube with mouth or ear piece may be used, or only one
of these, as may be found desirable.
As shown in Figure 12 the flexible tube enables the telephone to be placed outside
of a building, which in some cases will be a desirable location, the tube extending into
the building. As shown in the same figure the tube may have a branch tube attached
thereto, which can be used for hearing purposes, while the other branch is used for
speaking purposes. When the flexible tube is attached to the case opposite the
diaphragni, as shown in Figures 10 and 11, I prefer to attach to the tube the trumpet
shaped piece P which extends within the case about half way to the diaphragm.
The cavity in this piece is preferably formed like that of a stethoscope, so that the
sound waves are concentrated within the tube and thus render the transmission of
speech more perfect.
The transmission of sound waves mechanically by a conducting wire is facilitated
when the wire extends straight away for a considerable distance at right angles to the
plane of the diaphragm, and it is also advantageous that the case should make as little
contact as possible with the wall to which it is attached.
I effect both these results by the method of attachment shown in Figures 1, 11
and 12. To the sides of the case, are attached rings R R¹, upon the section a¹ all
respectively. A flexible wire or cord S is attached on each side of the telephone to
one of the rings R and passes through the rings R¹.
When the telephone is used outside of the building, these cords or wires are
attached to the same, as shown in Figures 11 and 12, and when the telephone is used
inside a building, they may be attached to any suitable point.
As shown in Figure 12 this method of attachment by the use of flexible cords
permits the telephone to be turned at any angle to the wall of the building, so that
the conducting wire can be extended straight away in a line at right angles to the
plane of the diaphragm, no matter what may be the direction of the point, which is
connected.
Figure 13 represents a device which I sometimes employ to produce a sound in
the telephone for the purpose of calling attention when it is desired to carry on a
conversation. It consists of a plate of metal m moving in a slot in the side of the
case and pivotted to the same. An arm n extends outside the case, and another arm o
extends within the case under the diaphragm and carries a metallic knob p.
The weight of this arm in its normal position keeps it away from the diaphragm,
but when the arm n is depressed, the knob p strikes against the end of the wire K
and causes a loud sound to be produced in the connected telephone.
In this way a succession of taps can be produced which will be heard at a con-
siderable distance from the telephone.
Figure 13 also shows the use of some insulating substance such as tarred hempen
cord, for separating the ring I, to which the diaphragm is attached, from the case.
The object of this device is to prevent the communication to the diaphragm, of
vibrations in the case.
It is desirable in a mechanical telephone system, that the conducting wire should
have a certain tension, but owing to the effect of changes of temperature upon the wire
this tension cannot always be maintained constant.
Figure 14 represents the device which I use for overcoming this difficulty and
automatically maintaining the conducting wire at a constant tension and which device
I am enabled to use owing to the form of my angle hangers C, and the supports in
which are of such form that the free movement of the wire upon them is permitted.
B is the telephone, from which the conducting wire extends vertically and to which
wire the telephone is suspended.
This telephone is weighted in any suitable manner as by the attachment of a

page_text: weight T, and thus produces a constant tension in the conducting wire. Either, both
or only one of the telephones may be weighted. The telephone may bear in a curved
bracket fixed upon the wall and thus be prevented from swinging.
Mechanical telephones are very useful in buildings in place of speaking tubes and
have been used for that purpose. By the use of my angle hangers, I am enabled to
place the conducting wire within the floors and walls of the building thus concealing it.
Figure 15 represents such an arrangement in which A is the conducting wire,
B the telephone and C, C the angle hangers. The wire may be enclosed in a tube v and
supported therein by the supports s¹ shown in Figure 16 made of wire covered with
cotton, coated with paraffine or otherwise suitably insulated.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, as communicated to me by my
foreign correspondent, 1 declare that what I claim is :—
First.—The combination with the conducting wire of a mechanical telephone, of a
tubular case supported substantially as described, and two or more supports secured
within such case and placed at an angle to each other, through which supports the
conductor passes, substantially as, and for the purpose, set forth.
Second. The combination with the conducting wire of a mechanical telephone, of
the tubular case D conforming to the direction of the wire, and the opened supports E
extending within the case and supporting the line, substantially as, and for the
purpose, set forth.
Third. A supporting tube or tubular case, consisting of two parts, one sliding
within the other, in combination with the conducting wire supports extending within
the case, substantially as, and for the purpose, set forth.
Fourth. The combination with the tubular case D made in two parts, and provided
with the conducting wire supports E, extending within the case, of the central hinge,
substantially as, and for the purpose, set forth.
Fifth. The combination of the tubular case D, the flanges c, c, the rings b, b, the
loops E formed as described, the conducting wire A supported on the said loops and
the braces e, e substantially as, and for the purpose, set forth.
Sixth. A telephone case in combination with the flexible cords or wires attached
to each side of said case and to a suitable support substantially as, and for the purpose,
set forth.
Seventh. The elongated telephone case B in combination with the cords or wires
attached to each side of said case, extending along the same, and attached to a support,
substantially as, and for the purpose, set forth.
Eighth. The combination of the case B, the diaphragm G within said case, the
conducting wire A, the flexible connections s, s attached to each side of the case, and
each attached to the outside of a building, and a tube connecting the interior of the
case to the interior of the building, substantially as, and for the purpose, set forth.
Ninth. A telephone case consisting of the wooden sections, in combination with a
diaphragm held between said sections, a cup shaped cavity or space being formed in
the case on each side of the said diaphragm, and a wire connected to said diaphragm,
substantially as, and for the purpose, set forth.
Tenth. The combination of a telephone case consisting of two sections, with a band
or envelope of non-resonant material surrounding said sections at the joint and
extending along the surface of said soctions, substantially as, and for the purpose,
set forth.
Eleventh. In combination with the telephone case, the diaphragm, the conducting
wire and the elongated india-rubber plug L inserted in one end of said case and
surrounding said wire, substantially as, and for the purpose, set forth.
Twelfth. In combination with the diaphragm of a mechanical telephone, a case
comprising two sections having said diaphragm between them, said sections being
constructed with bell-shaped cavities which flare at their outer edges from their interior
surface to their exterior to allow the diaphragm to occupy the entire area in cross
section of the case, substantially as, and for the purpose, set forth.

page_text: Thirteenth. In combination with a diaphragın, a case comprising two sections
having the diaphragm between them and having also elongated cavities and a mouth-
piece which is inserted in the side of one of said sections above the bottom of the
cavity, substantially as, and for the purpose, set forth.
Fourteenth. The bevelled ring I and the diaphragin attached thereto, in
combination with the two sections of the telephone case, the inner face of said ring
forming a continuation of the inner face of one of said sections and comploting the
outward flare thereof, substantially as, and for the purpose, set forth.
Fifteenth. A mechanical telephone line in which the conducting wire is
maintained at a constant tension by the weight of the telephone, substantially as, and
for the purpose, set forth.
Sixteenth. The combination of a conducting wire extending vertically to a
telephone from a suitable support, and a weighted telephone suspended from said wire,
substantially as, and for the purpose, set forth.
Seventeenth. The combination with a mechanical telephone line, of the angle
hanger C as described, the conducting wire A extending vertically from the same, and
the weighted telephone.
Eighteenth. The combination substantially, as, and for the purpose set forth, of the
conducting wire of a mechanical telephone arranged within the walls and floors of a
building, and devices Cas described for supporting the conducting wire at angles.
Nineteenth. The combination substantially as, and for the purpose, set forth, of
the tube, conducting wire C, and supports s¹ within the tube, substantially as, and
for the purpose, set forth.
Twentieth. The combination with the conducting wire, of a mechanical telephone,
of the tube D made in two sections at an angle to one another and connected by a
shorter section, perforations e, e, in each of the larger sections arranged as described,
near the short section, a wire F covered with an insulating and sound deadening material,
as described, passing through these perforations and having its ends connected, as
described on the outside of the tube and curved loops forined by the wire F for
supporting the conducting wire within the tube.
Dated this 25th day of August 1887.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.