Improvements in Nautical Signals or Sea Telephones.
Year: 1891

page_text: Date of Application, 22nd Dec., 1891-Accepted, 7th May, 1892
COMPLETE SPECIFICATION.
Improvements in Nautical Signals or Sea Telephones.
We, ERNEST HUBER, Philosophiæ Doctor, FREDERICK JACOB KNEUPER,
Medicine Doctor, and JAMES ROBERT DAVIES, Agent, all of 13 Park Row,
New York, United States of America, 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 :-
Our invention relates to apparatus employed for the detection of sounds pro-
ceeding from any object in contact with water, whether the said sounds originate
from such objects or, by the use of our apparatus, are originated at the place of
observation and reception and are there received when reflected from such object.
Our apparatus is intended to receive sound-waves pulsating in a body of water,
and to so transform and intensify, transmit and indicate the impression, or its
effect so produced, that the position, distance and orbit of the object from which
such sound-waves proceed, may be determined.
Our invention, therefore, consists in apparatus adapted to be placed upon vessels
afloat at sea or at fortresses; to be located at entrances to harbors and other
places and by means of which may be ascertained the location, distance and
movements of objects in the water; and also in apparatus by means of which
persons at a distance from each other may employ systems of signalling and com-
munication by the transmission of sound through the water.
This apparatus involves the following well known principles:
1. Sound-waves of any number may interfere with and cross each other without
losing their distinguishing and individual character.
2. Liquids. principally water, are better conductors of sound than air, and the
metals are better conductors of sound than either water or air.
3. Sound is either intercepted, absorbed, reflected or refracted by screens
properly placed intermediate the vibratory center and the receiver.
4. Metal bars, strips and wires will transmit or conduct sound to distant places
without difficulty and with great rapidity.
In constructing this apparatus the above principles are utilized in the following
manner:
Sound-waves produced in a body of water and passing therethrough, will contact
with metal strips immersed in such body of water and suitably arranged in what
we term an "interceptor." The metal strips will thereby be caused to vibrate.
The vibrations, not being of the desired intensity, are transmitted by wires to
microphones, or microphonic resounders, which greatly magnify and intensify such
sound vibrations. The microphones are inserted into telephonic circuits and are
connected with telephones of a character which will multiply and magnify the
vibrations. Having been received, magnified, multiplied and transmitted, the
intensity of the sound vibrations is caused to be indicated by a suitable device
termed an "indicator." Certain other devices are also employed to give notice of
disturbances in the apparatus and to indicate the direction and distance of the
author of such disturbances.
The details of construction are shown in the accompanying drawings, in which
Figure 1 is a vertical sectional view of the casing for supporting certain of the
parts of the apparatus, and showing the primary and secondary telephones, part of
the director, a series of groups of resounders and certain other co-operating parts;
Figure 2 is a top plan of the same showing the means for suspending ;
Figure 3 is a side elevation of the interceptor-block, showing one portion in
section to disclose the construction of interceptor-tubes;
Figure 4 is a top plan of the interceptor-block, showing a part in section to
indicate location and structure of interceptor-tubes;

page_text: igure o is a cross section or the casing, showing the director i plan;
Figure 7 is a detail view showing in side elevation the elongated tubular
portion of the casing and a single group of resounding plates, also the supporting
casing in section ;
Figure 8 a top plan of Figure 7;
Figure 9 a top plan of the indicator;
Figure 10 a side elevation of the indicator;
Figure 11 a plan of the circuits showing the different parts of the apparatus
arranged therein for operation ;
Figure 12 is a vertical section of one of the interceptor-tubes;
Figure 13 is a horizontal section of one of the interceptor-tubes ;
Figure 14 is a side elevation of the interceptor-block showing the protecting
wire-screens and also the auxiliary interceptor-block, secured to the bottom of the
primary block, and its protecting wire screen; also showing the signalling-bell;
Figure 15 is an end elevation of the parts shown in Figure 14;
Figure 16 is a horizontal section of one of the interceptor-tubes, showing the
sound-absorbing section; and
Figure 17 shows a vessel with the interceptor-block and its attachments lashed
to the side thereof in operative position;
Figure 18 is a top plan of a portion of the interceptor-block_showing a modifi-
cation, in which the intercepting tubes and microphonic resounders are combined,
the diaphragm being shown in section, and
Figure 19 is a side elevation of Figure 18, a section being broken away to show
certain interior parts.
The sound, or sound-wave, interceptor consists of a block A of proper dimensions
and of a form and shape suitable to accommodate the sound-wave receiving tubes.
The block is preferably diamond shape in outline and has formed in the sides
thereof, at each angle, a deep. vertical recess 1 rounded out at its inner end and
being open toward the side of the block, thus allowing the passage of the water
to the extreme inner or closed end of the recess. The block is composed of non-
metallic material, such as wood, paper, hard-rubber, etc., and is preferably composed
of lamellas of such different non-conducting materials secured together in any
suitable way, this construction making the block, as nearly as possible, a non-
conductor of sound. At the extreme inner end of each recess 1 is secured a
metallic tube 2 closed at the bottom and divided longitudinally by a non-conducting
or absorbing diaphragm 3 and each of the two chambers in each tube 2 thus
made, is filled with water or a watery solution of any suitable salt, such as
chlorides or sulphates, thus producing a conductor of sound homogeneous in
nature to the surrounding conducting medium (sea water) in which the sound
interceptor is placed when in operation. This diaphragm 3, may be constructed in
any desirable and convenient shape, either in lamellæ or in one piece; as to the
material a non-conductor for electricity, which at the same time absorbs sound,
as for instance wood, rubber and the like, must be used. On each side of each
diaphragm 3 is located a metallic strip 4 and to cach strip 4 is attached a wire 5
of silver, copper, or other suitable conducting material, covered with a tube of
rubber 6. Each metallic-tube 2 has the end of a rubber-tube 7 stretched over its
neck 8, which rubber-tube 7 encloses the pair of rubber-tube enclosed wires 5
extending from the respective conducting strips 4. The conducting-wires 5 are
covered in the manner above described to prevent contact with each other. The
metallic tubes 2 are protected top and bottom by plates a and b of any material
which will resist water and violence and are made to conform in size and shape to
the upper and lower surfaces of the block A to which they are securely fastened.
The metallic receiving tubes are placed in the recesses of the block so that a flat
side of each diaphragm will be presented to the open end of each recess.
In the
rear chamber of each receiving tube 2 is located, and secured in any suitable
manner, a section of a tube s', composed of non-conducting or absorbing material

page_text: such as wood, gutta-percha, electrical insulating material, etc. This section of tube
is for the purpose of intercepting and absorbing all sounds coming from the opposite
side of the block and thus preventing such sounds from striking the conducting
strip on the rear side of the diaphragm. See Figure 16. It is manifest that
sound vibrations passing through the water and entering the recesses in the inter-
ceptor-block will strike the exposed curved surface of the interceptor tube 2 and
will pass therethrough and, passing through it, will be communicated to the metal
conducting strips through the watery conducting medium in said tube. From the
conducting strips the sound vibrations will be conducted through the wires 5 to
the microphones.
A block of the shape shown in the drawings and above described is conceived to
be the best adapted to cut water, but it may be of any other shape suitable
for the purpose.
The block will be submerged in the water to a depth
sufficient to avoid the majority of, or all sounds, emanating from the surface;
and may be protected against animal and vegetable deposits by removable wire
screens, as shown at B in Figures 14 and 15. When used upon a vessel afloat it
may be placed beneath the keel amidships and when so placed will be securely, but
adjustably, and removably fastened thereto. It may be attached to any suitable
suspending apparatus and passed over the bows and allowed to run astern and be
lashed to the deck on each side at the desired place of adjustment, as in Figure 17.
For observation from shore it may be placed in the water at a suitable depth and
at any distance from shore and connected with the accessory receiving, trans-
forming, etc., devices located on shore at a proper observatory.
In order to intercept sound emanating or reflected from the bottom of the sea, a
secondary block C may be attached to the bottom of the sound-wave interceptor or
block and supplied with the same arrangement of tubes and wires above described.
See Figures 14 and 15. This secondary block may be a semi-circular and
vertically disposed segment as shown in said figures.
An ordinary electric bell submerged in the water, and to be rung by the
observer is a part of the apparatus, as shown at C2 in Figures 14 and 15.
Each pair of wires 5 is conducted from its interceptor to a microphone or
microphonic resounder, comprising a case D. This case is composed of any
suitable material which is a non-conductor of sound. Each resounder consists
of two pairs of resounding plates 9, 10 and 9, 10 perforated for the passage of
the insulated bearing pin 11 having its end screw-threaded. The plates of each
pair are in microphonic contact with carbon 12 and the two pairs of plates are
separated from each other and also from the casing by the washers, 13 which
are composed of any insulating substance, the carbons and washers being also
perforated for the passage of the insulated pin 11 and the pairs of plates, the
carbons and the washers being firmly held together and to the casing by the
clamping nuts 14 on the screw-threaded ends of the insulated pin, 11.
There is a microphonic resounder for each tube of the interceptor and each tube
is connected with its respective resounder by the pair of conducting wires 5; one
plate in one of the two pairs of resounding plates being connected to one of
the pair of wires and one plate of the other pair being connected to the other of
the pair of wires.
Bells, hollow plates or other mechanical devices for transmitting sound may
be employed for the resounders, flat metal plates being shown in the drawings.
The devices thus far described constitute in effect a mechanical telephone and
are of a form which is thought to be best adapted to receive, transmit and
magnify sound-vibrations or the effect produced thereby. After the sound
vibrations have been transmitted to the microphones, they, at such device, cause
the well known changes in the carbon contacts, which, on their part, cause
undulations in the current passing through the carbons and through the other parts
of the apparatus, by suitable electrical connections or circuits as hereinafter fully
explained.
The casing E to which the several parts of the apparatus are secured and by

page_text: which they are enclosed and supported, is circular in shape and composed of any
suitable material. The casing is provided with a large chamber e for the reception
of the multiplex telephone, such chamber being closed near the top of the casing
by a partition e' which supports the parts of the director. Above the partition
and seated on the shoulder e is the dial F and above the dial is the transparent
covering e. From the bottom of the chamber e extends the elongated tubular
portion et ending in another, but smaller, chamber e in which is located the steno-
resounder. The microphonic resounders are arranged in the casing D which is
placed just beneath the large chamber e and surrounding the elongated, tubular
portion of the casing.
While we have described and shown the microphonic resounders as combined
with the main apparatus, that is, arranged adjacent that portion of the apparatus
which will be located on shipboard, it is manifest that the same result would be
attained by combining such microphonic resounders, or equivalent microphones or
resounding-plates, with the interceptor-block, arranging the same in the inter-
cepting tubes. By this construction it is apparent that a compact and simplified
arrangement of intercepting tubes and microphones will be secured, the whole to be
submerged as above described. See Figures 18 and 19. In these figures A indicates
the interceptor-block, 1 recesses therein, 50 metallic receiving tube, 51, the
diaphragm to which are secured microphonic carbon-plates 52, 53 being contact-
springs between the plates 52 and the tube 50, and 54 the connecting wires or
electrodes. In operation the microphonic-carbons 52 are counter-balanced by the
differential coils of the telephone. P, indicates the center of sound vibrations.
This modified construction, manifestly, results in bringing the microphones, or
equivalents, into such close relationship to the interceptor tubes, and makes the sound
wave connections between the interceptor tubes and microphones so short, as to
render the reception of the sound waves, their transmission to the microphones,
their transformation and intensification practically simultaneous, thus avoiding
either the loss of power or time.
The director is composed of concentric ring-segments, 18 and 19 in groups of
four each, circularly arranged and secured to the partition e¹. A vertical rotary
shaft or pin 15 having a bearing in the partition and extending through and
supported by the dial F, carries an arm 16 below the dial provided with a pair of
spring friction-pads or brushes, 17 each of which bears upon two successive
segments of the groups of four-ring-segments 18 and 19 of the director.
The pin
or shaft 15 also carries a belt-pulley 20 located below the dial F¹ and a compass
needle 21 and indicating hand 22 both located and revolving above the dial F
This construction enables the indicating hand and compass needle to be observed
at the same time. The shaft or pin 15 is made to revolve by any suitable means,
such as clock-work, small dynanio, etc., not shown. As shown in the drawings
such actuating means will cause a belt-pulley 23 to be rotated, a strap or belt 24
extending from said pulley 23 through the casing E and around the pulley 20 on
the shaft or pin 15 which carries the brush-carrying arm 16. There are as many
groups of directors as there are interceptor-tubes and resounders.
The indicating hand will be caused to have between 100 and 150 revolutions per
minute.
While we have shown the compass ncedle 21 as carred by the revolving shaft 15
it will be manifest that we may locate the same above the glass cover, the main
object being to have the relation of the compass needle and indicating hand such as
to enable them both to be observed at the same instant.
Now by mounting the compass needle on the revolving shaft as shown in the
drawings, manifestly, the revolution of such shaft will tend to cause the revolution
of such needle. The friction between the point of the shaft 12 and the cup of the
compass-needle, however, will be of such an immaterial degree as to cause but a
slight movement or variation of such needle in opposition to the force of the
magnetic pole" which will tend to hold it stationary. The variation or movement
caused by this opposition of mechanical power to natural force will not exceed 5°.
66

page_text: The multiplex and differential telephone or receiver consists of a magnetized
steel core H, extending through the longitudinal, tubular portion of the casing E
and into the chamber e, and surrounding this core and located within the chamber is
a small casing I. Within the small casing I and upon the core H are placed as
many bobbins 25 as there are resounders and interceptors. Each bobbin is
provided with two coils, wound in opposite directions. The differential coiling of
these bobbins is for the purpose of eliminating all sounds produced by the vessel
proper.
The object of having several bobbins upon the magnetized steel or core is to
provide a complemental bobbin for each group of director segments, each group of
microphonic resounders, and each tube of the indicator.
The differential winding of such bobbins is for the purpose of providing two
direct circuits or connections, respectively, from the two conducting strips located
in each interceptor tube, through the respective complemental microphones and
groups of ring segments to the respective complemental bobbins. Thus the
apparatus is made to receive simultaneously two differential sound waves counter-
balancing each other, either partly or entirely as will be described and brought out
theoretically hereafter.
Above the core H is a diaphragm 26 suitable for telephonic transmission. A
microphonic carbon pin 27, supported vertically on an arm 28 rests normally on the
diaphragm 26. The arm which supports the carbon pin 27 is pivoted to the
casing as shown at 29 and a counter-balance 30 is secured to the pivoted end
thereof beyond the pivotal point. The other end of the arm is provided with a
screw-threaded pin 31 and spring 32, a thumb-nut 33 regulating the pressure of
the carbon pin 27 on the diaphragm 26. The carbon più 27 is adjustable on the
arm 28.
A steno-resounder, or secondary telephone, is located at the bottom of the
casing E in the small chamber ed, and consists of the bobbin 34 wound with a
simple coil of insulated copper-wire, and secured to the lower end of the core H.
Below the bobbin 34 is the diaphragm 36 supported by the casing E. To the casing
is also secured a bracket arm 37 to which is pivoted an arm 38 provided at its rear
end with a counter-balance 39 and at its forward end with a socket in which is
adjustably secured a steel pin 40 which rests normally against the diaphragm 36.
The bracket-arm also supports a capillary tube 41 filled with mercury.
bottom of this tube is closed by a stopper 42 which is transfixed by a steel
needle 43. When the telephone is inactive the pin 40 is withdrawn from the
mercury and rests against the diaphragın 36.
The
The sound waves, or sound vibrations, transmitted from the wave interceptor to
the differential coils of the multiplex telephone, by means of the wires running
from the wave interceptor to and from the microphonic resounder, being very
feeble their effect must be magnified. Therefore, by arranging the primary and
secondary telephones upon the same magnetized steel core, as shown in the
drawings, they are made to strengthen each other reciprocally and by their
dependent and co-operative action to magnify aud multiply the vibrations caused
primarily by sound vibrations; for a minute change of the contact between the
microphonic carbon-pin 27 and the diaphragın 26 will cause an energetic play of the
diaphragm of the secondary telephone; this on its part will increase the vibration
of the diaphragm 26 and so on until action and reaction between both the diaphragms
have reached a maximum corresponding in intensity to the original exciting power
of the wave interceptor.
The alarm J is an ordinary electric bell.
The intensity indicator consists of an electro-magnet K of ordinary construction
and an armature 44 supplied with a hand 45 moving with respect to a scale 46.
The armature is controlled by a spring 47 the tensions of which may be regulated
in any suitable manner.
If a current, resulting primarily from the sound vibrations, passes through the
electros, the armature will, according to the intensity of the interrupted current

page_text: and the time of influence, be attracted by the cores of the magnet, and the hand,
therefore, will have a certain deflection, which will be shown by the scale over
which such hand moves.
The intensity indicator, as well as the alarm, are set to work by the vibrations
of the diaphragm of the secondary telephone. The vibrations of the diaphragm
of the secondary telephone force pin 40 into the mercury of the tube 41 thus
establishing the circuit between the alarm and indicator and the other devices of
the apparatus.
Each microphonic resounder is connected with its respective director by two
wires s,s, connecting respectively with the upper ones of the two pairs of resounding
plates 9, 10, and extending thence to, and connecting respectively with, two
alternating segments 18, 19 of the corresponding group of director segments. To
the other alternating two of such groups of director-segments are respectively con-
nected two wires, 3, 3, which extend thence to, and are connected respectively
with, the oppositely coiled wires of a single and corresponding bobbin 25 of the
multiplex telephone. It follows, therefore, that each of the brushes 17 is always
in contact with a segment having connection with the multiplex telephone and also
with a segment having connection with a microphonic resounder.
Any suitable battery S or electricity generator is employed, the circuits from
which extend as follows: The opposite poles are represented at S', S2, Figure 11,
and from the positive pole S1 extends a circuits to the carbon pin 27, and by the
contact of said pin 27 with diaphragm 26, to the telephone receiver by circuit s
from thence by circuit to the bobbin 34, and from thence, by circuit 4, to the
negative pole S2 of the battery S. From the circuit S", extending from the
positive pole of the battery, extends another circuit 1 to the lower plate of
the lower pair of microphonic resounders through the carbon to the upper plate of
such lower pair and from thence by connections to the outer one of the pair
of director segments 18. At this point the circuit is continued, by the revolution
of arm-and contact of one of the spring-pads or brushes with the pair 18 of ring
segments, through the second ring-segments of pair 18, and by connection s² to the
bobbin 25 from thence by circuit s', st, to the negative pole of battery.
Another circuit 13x, complemental to the one last above described, extends from
circuit to the lower plate of the upper pair of microphonic resounders, through
the carbon to the upper plate of such pair, and from thence by connections to the
first ring segment of pair 19, of the director. At this point the circuit is continued,
by the revolution of arm-and contact of the second one of the pair of spring pads
or brushes, with the pair 19 of ring segments, through the second ring segment of
pair 19, and by connections to the bobbin 25; from thence by circuit sx, 54 to
the negative pole of battery. From the circuit s", extends another circuit $12
connecting with pin 43 projecting into the tube 41. At this point the circuit is
continued by the dipping of pin 40 into the mercury of tube 41 (caused by
vibrations of diaphragm 36), from pin 40 through circuit so to the indicator K;
through the electro-magnet of such indicator to the alarm J by connections and
from thence by circuits 8, 4, to the negative pole of battery.
It will thus be seen that the different parts of the apparatus are electrically
connected in multiple arc and that there are three definite branches as follows:
1. Positive pole of battery, carbon pin 27,-telephone receiver T, secondary
telephone, negative pole of battery.
2. Positive pole of battery,-two pairs of resounder plates,-director segments,—
multiplex telephone with differential coils,-negative pole of battery.
3. Positive pole of battery,-capillary mercurial tube,-intensity indicator,-
alarm, negative pole of battery.
It is manifest that the intensity of the current pervading each of these three
branches may be suitably regulated by inserted resistances.
The connection between the tubes of the interceptor and the microphones is by
wires 5, which are two for each receiving tube and its complemental microphone.
Such wires are connected respectively with the two conducting strips located in the

page_text: receiving tubes, and from thence extend to, and are connected respectively with the
upper one of the two pairs of microphonic resounding plates.
It will be manifest that, though single wire connections are shown in the drawings,
Figure 11, as extending throughont, and connecting the different parts of, the
apparatus, as many wires as are deemed necessary and expedient for the different
purposes, may be employed.
The casing E is suitably arranged for a "Cardanian suspension," as shown in
Figures 1 and 2.
The operation is as follows:
When the interceptor has been arranged and placed in the desired position,
sound-waves proceeding from any moving object in the water or reflected from some
object in the water and entering the recesses of the block A are received by the
metallic conducting tubes, conveyed across the watery conducting contents of said
tubes to the conducting strips of the diaphragm 3, and transmitted by the wires to
the microphones where they cause vibrations of the plates 9 thereof. At this point
of their passage the sound vibrations are increased in volume or made stronger and
transformed into electrical vibrations. From the microphones the sound vibrations
are transmitted to the director.
The brushes 17, having been set in motion pass over the ring-segments, and, upon
each revolution, successively open and close the different circuits between the
primary, or multiplex telephone, and the microphones. The primary telephone being
influenced, the diaphragm thereof vibrates, thus causing a change of contact between
the carbon pin 27 and the diaphragm. This contact of pin 27 with its diaphragm
causes an energetic play or vibration of the diaphragm 36 of the secondary telephone
or steno-resounder. By the vibrations of the diaphragm 36 of the secondary telephone
the pin 40 is immersed in the mercury in the tube 41 to a greater or less degree thus
establishing the several circuits and actuating the alarm J which directs attention on
telephonic disturbances, while the hand of the intensity indicator K is caused to be
deflected over the scale 46 and thus show the nature and extent of such disturbances.
The theory of these parts is as follows: Any medium, placed in the way of
translatory undulations, absorbs them partly or entirely according to the individual
character of the vibratory movement and to the physical qualities of the medium.
Light and sound vibrations are subjected to the same laws.
A diaphragm composed of n layers or films, being struck on its face by a quantity
of sound V, lets pass a quantity VX" and, therefore, absorbs a quantity V
(1-X"), being a fractional co-efficient, which changes with the character of the
absorbing medium and the character of the sound vibrations absorbed. Therefore,
we will have for two different characters or categories of sound vibrations the
following expressions :
Sound waves striking upon a system composed of two metallic plates, separated
by a diaphragm of so-called insulating material, will be divided up in the different
parts of said system in the following way: Let the initial quantity be V₁ then :
(1) A partial reflection takes place on the face of the front plate = V..
(2) A partial absorption takes place in front plate = Vo
(3) A partial absorption takes place in diaphragm V₁ (1 − X‚³).
(4) A partial absorption takes place in rear plate = V2.
The rest passing through the system
Evidently V-V+V₁+ V₁ (1−X₁") + V₂+ V3 (1). For simplifying the expression
let Vr o and V.
0. (2). Then the quantity of sound absorbed by the metallic
plates is obviously for one category of sound waves: V₁ = V₁+V2 (3.) and for
another we get: V V₁'+ V. (4).
3
1
0
= V3 3"
1
It is evident also, that we may create conditions under which either V, or V,
may turn out = 0; but either of them being zero excludes the other expression from

page_text: Suppose
P
v. (5). then
AV 1
P
V2. (6). and consequently
V₁₁₂ (7).
12.
The quantities V₁, V2, V3, V2, are those parts of the sound waves which will be
transmitted from the "wave interceptor" to a "microphonic resounder." In order
to eliminate a certain category of sound waves and to transmit another, equations 6.
and 7. show that a differential bobbin is used, each coil of which is supplied by its
respective metallic wave interceptor plate. The number of wave interceptors
correspond with the number of differentially wound bobbins, which constitute the
primary telephone.
The same results will be obtained if equation 5. be represented under this form:
(8) AV, = m (Vo-V2) m representing the number of wave interceptors.
m increasing, it is obvious that the limit of equation 8 will be: (9) Am V,=
constant, an expression which represents the general form of equation 6.
-
If instead of an impractically high m and a slow speed of the director the speed
of the director is raised eg. to 120 revolutions per minute and the number m kept
within very restricted limits, equation 9 will hold strong. Supposing the number of
wave interceptors to be e.g. 16; the number of circuits inserted within one second's
time will be 32; thereby the constancy of the "indicator level" is easily kept up.
Equation 6 may be fulfilled by inserting proper resistances into one of the
differential coils of the bobbins of the primary telephone.
It will be manifest that the theory above given remains the same if the resounder
plates or microphones are placed in the block with the interceptor tubes as shown
in Figures 18 and 19; because it is immaterial where the parts of the apparatus are
placed so long as they, theoretically and practically, perform the same functions.
Resuming, from the results obtained, we find that an apparatus which shall
indicate a certain character, or as we may call it, a certain "color" of sound and
eliminate or reduce to constancy any other sound "color" which is not wanted, will
be composed principally of the following parts:
(1) Sound-wave interceptors.
(2) Differential bobbins (primary telephone).
(3) A multiplier of those differential actions exerted upon the differential
bobbins, riz.: a steno-sounder" (secondary telephone).
(4) A director for connecting the interceptors successively with the circuits.
(5) Accessory parts by which the observer may detect those multiplied
differences both by the eye and ear.
Any number of receiving tubes may be employed, depending upon the horizontal
scope and range it is desired to command, the drawings, Figure 4, showing four of
these tubes corresponding to the main points of the compass. Each tube governs
a certain point of the horizon and sound-waves emanating from an eastern center
of vibration will not enter the northern recess, or if they do, will not strike the
flat face of the diaphragn vertically, but entering the recess diagonally, will be
either absorbed or have their mechanical power and effect weakened by repeated
contacts with, and reflection from, the walls of the recess and, therefore, partially
if not entirely lost.
Sounds made by superficial agitation of the water, and sounds proceeding from
the structure to which the apparatus is attached will enter both compartments and
will influence both strips of the diaphragm alike.
The latter class of sounds, manifestly, will be constant in their nature and will,
therefore, constantly influence the apparatus in an easily recognizable manner.
While on the other hand, sounds which are within the intended scope of reception
will influence the apparatus to an extent plus the amount which such constant
sounds do, and will, consequently, be easily detected. Sounds emanating from the
structure to which the apparatus is attached and sounds caused by superficial

page_text: agitation of the water will influence both the conducting strips within the inter-
ceptor tubes to the same degree and, therefore, will actuate equally both pairs of
resounder-plates and the microphonic action thereby produced may be rendered
equal by the insertion of suitable resistances if it is not already equal, and, con-
sequently, no telephonic action will be apparent. Both coils working equally the
diaphragm 26 is at rest as both influences are acting upon it oppositely. Thus will
be eliminated all sounds not within the intended scope of reception.
The sound-waves originating from another center of vibration distant from the
vessel, will be received by that interceptor-tube only facing the same directly.
The rear strip of the diaphragm cannot be influenced to the same extent as the
front one, as explained, on account of its location. If one coil only is at work the
diaphragm 26 is in operation. It is evident that the interceptors and the ring
segments of the director must cover the same relative scope of the horizon, so that
for instance castern segments must correspond in position with the eastern inter-
ceptor, northern segments with the northern interceptor, etc., so that the locality of
sound can be at once detected.
The mechanical power developed by the coils of the secondary telephone, or
steno-resounder, depends upon the intensity of the vibrations of the diaphragm of
the primary, or multiplex telephone. The telephones being upon the same core and
in the same circuits, afford mutual reinforcement and magnify and intensify in each
other the telephonic demonstration.
In their revolution each of the brushes 17 bears upon a pair of ring-segments of
the director, one of each pair being connected with the multiplex telephone and
the other with a microphonic resounder, thus successively establishing the different
circuits between the microphonic resounders and the multiplex telephone.
The needle 43 and the pin 40 are in the circuit indicated by the wires s¹¹1, 510
which is closed by the contact of the pin 40 with the mercury in the tube 41. The
time during which the pin 40 remains in the mercury controls the extent of move-
ment of the armature and, consequently, the extent of deflection of the hand carried
by the armature. The time during which the pin 40 remains in the mercury depends
upon the intensity of vibration of the diaphragm 36 causing vibrations of the
said pin.
The energy of the sound-waves produced and the duration and intensity of their
telephonic equivalents, as shown by the hand 45, will be a measure of the
character, distance, approach, or recession of the object from which the sound-
waves proceed.
The time during which the steel pin is immersed in the mercury depends upon
the vigour of the diaphragm of the secondary telephone which forces the said pin
more or less deeply into the mercury. Let the number of oscillations or vibrations
of said diaphragm be u and the time of immersion due to the unit of force exerted
upon the needle during one oscillation = t; then the integral time for all the
oscillations in the unit of time will be; T₁ up to For any other amount of
forcing-in power we therefore have T₁
=
-
uj ty.
The action of the current, passing the electro-magnets of the intensity indicator,
upon the armature being dependent upon the time during which the cores of the
magnet are influenced, it is obvious that the deflection of the needle will be a
function of that time and proportioned to it, or:
Angular deflection = (u, t₁) = c u₁ t₁ where c is constant.
"
This equation formally corresponds with equation 6., whereby it is provided that
the wave interceptor and intensity indicator, i.e. originally the "steno-sounder' are
homogeneous in their action and correlating.
As to the "alarm," it may be regulated so that it is set to motion when T,
i.e. when the intensity of approaching danger reaches a certain pitch.
= ug tg
The telephone-receiver T held to the ear of the observer, affords prompt
information of the activity of the telephones and of its character and extent.
The alarm-bell calls attention to the activity of the apparatus.
The electric-bell submerged may be used to obtain from any object, in contact
R

page_text: WICH Water, a refection of the sound produced by the bell from which exact calcula-
tions of the distance of the object may be made.
Two persons using the apparatus may, by means of the submerged bell,-to be
rung according to conventional systems, such as the "Morse" alphabet, or flag
signalling, communicate to any desired extent.
The term or phrase "sound-wave connections" is employed in contradistinction
to electrical connections.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:
1. The combination in an apparatus for receiving, transmitting and indicating
sound the sound-wave interceptor, the resounder, the receiver, the director, the
indicator, sound-wave connections between the several parts above named, an
electric battery and an electric circuit extending from the battery to and through
the resounder, receiver, director and to the indicator.
2. The combination in an apparatus for receiving, transmitting and indicating
sound the sound-wave interceptor, the resounder, the director, the multiplex
telephone, the steno-resounder, the indicator, sound-wave connections between the
several parts above named, an electric battery, and an electric circuit in which the
several parts above named are located.
3. The combination in an apparatus for receiving, transmitting and indicating
sound the sound-wave interceptor, the auxiliary interceptor secured thereto, the
resounder, the receiver, the director, the indicator, sound-wave connections between
several parts above named, an electric battery and an electric circuit in which the
several parts above named are located.
4. The combination in an apparatus for receiving, transmitting and indicating
sound the sound-wave interceptor, a protector therefor, the resounder, the
receiver, the director, the indicator, sound-wave connections between the several
parts above named, an electric battery and an electric circuit within which the
several parts above named are located.
5. The combination in an apparatus for receiving, transmitting and indicating
sound-the sound-wave interceptor, the resounder, the receiver, the director, the
indicator, the alarm, and telephone-receiver, sound-wave connections between the
several parts above named, an electric battery and an electric circuit, the resounder,
receiver, director, indicator, alarm and telephone-receiver being located within such
electric circuit.
:
6. The combination in an apparatus for receiving, transmitting and indicating
sound the sound-wave interceptor, an electric bell, the resounder, the receiver,
the director, the indicator, sound-wave connections between the several parts above
named, an electric battery and an electric circuit extending from the battery to and
through the resounder, receiver, director and the indicator.
7. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor consisting of a block provided with a series of
recesses, a sound-wave intercepting-tube located within each recess, a resounder,
receiver, director and indicator, sound-wave connections extending from the
interceptor-tubes to and through the resounder, receiver, director and to the
indicator.
8. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor consisting of a block provided with a series of
recesses, a sound-wave intercepting tube located within each recess, such tubes
being filled with a conducting medium and containing a dividing, conducting
diaphragm, a sound-wave absorber located within one of the chambers of each
tube, a resounder, receiver, director, and indicator, sound-wave connections
extending from the interceptor-tubes to and through the resounder, receiver,
director and to the indicator.
9. The combination in an apparatus for receiving, transmitting and indicatin

page_text: ound a sound-wave interceptor consisting of a block provided with a series of
ecesses, a sound-wave intercepting tube located within each recess, such tubes
eing filled with a conducting medium and containing a dividing, conducting
liaphragm, sound-wave absorber arranged within one of the divisions of the tubes,
consisting of a section of a tube of non-conducting material, a resounder, receiver,
lirector and indicator, sound-wave connections extending from the interceptor-tubes,
o and through the resounder, receiver, director and to the indicator.
10. The combination in an apparatus for receiving, transmitting and indicating
ound a sound-wave interceptor consisting of a block provided with a series of
recesses, a sound-wave intercepting-tube located within each recess, such tubes
being filled with a conducting medium, and containing a dividing diaphragm,
conducting strips located on each side of said diaphragm, a resounder, receiver,
director and indicator, sound-wave connections extending from the intercepting-tubes
to and through the resounder, receiver, director and to the indicator.
11. The combination in an apparatus for receiving, transmitting and indicating
sound-a sound-wave interceptor consisting of a block provided with a series of
recesses, a sound-wave intercepting-tube located within each recess, such tubes being
filled with a medium homogeneous to the conducting medium in which the block is
to be submerged, and containing a dividing diaphragm, conducting strips
side of said diaphragm, a resounder, receiver, director and indicator, sound-wave
connections extending from the interceptor-tubes to and through the resounder,
receiver, director and to the indicator.
on each
12. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor consisting of a block provided with a series of
recesses circularly arranged, a sound-wave intercepting-tube located within each
recess at its extreme inner end, such tubes being filled with a conducting medium and
containing a dividing, conducting diaphragm arranged transversely to the horizontal
depth of the recesses, a resounder, receiver, director and indicator, sound-wave
connections extending from the interceptor-tubes to and through the resounder,
receiver, director and to the indicator.
13. The combination in an apparatus for receiving, transmitting and indicating
sound-a sound-wave interceptor consisting of a diamond-shaped block having at
each angle thereof a recess, the extreme inner end of which is rounded out, a
sound-wave intercepting tube located within each recess at the extreme inner end,
such tubes being filled with a conducting medium and containing a dividing,
conducting diaphragm, a resounder, receiver, director, and indicator, sound-wave
connections extending from the interceptor-tubes to and through the resounder,
receiver, director, and to the indicator.
14. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor consisting of a block provided with a series of
recesses, a sound-wave intercepting-tube located within each recess, such tubes
being filled with a conducting medium and containing a dividing, conducting
diaphragm, a resounder, rubber-covered wires connecting the intercepting tubes
with the resounder, a receiver, director and indicator, sound-wave connections
extending from the resounder to and through the receiver and director and to the
indicator.
15. The combination in an apparatus for receiving, transmitting and indicating
sound-a sound-wave interceptor consisting of a block provided with a series of
recesses, a sound-wave intercepting-tube located within each recess, such tubes being
filled with a conducting medium and containing a dividing conducting diaphragm,
a resounder, connecting wires extending from each interceptor-tube to the
resounder, such wires being covered and separated from each other by rubber-tubes
and the rubber-tube-covered wires of the respective interceptor-tubes being enclosed
by a protecting rubber tube, which latter is connected with the said interceptor
tube, a receiver, director, and indicator, sound-wave connections extending
from the resounder to and through the receiver and director and to the indicator.

page_text: 16. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor consisting of a block provided with a series of
recesses, each recess having located therein a sound-wave intercepting-tube, such
tubes being filled with a conducting medium and containing a conducting dividing
diaphragm, non-conducting, protecting plates secured top and bottom to said block,
a resounder, receiver, director, and indicator, sound-wave connections extending
from the interceptor tubes to and through the resounder, receiver, and director and
to the indicator.
17. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder and connections between the two,
the resounder consisting of a series of groups of resounding plates, each group
comprising four plates centrally perforated, microphonic carbons separating certain
of the plates of cach group, a screw-threaded insulated-pin passing through the
plates and carbons, and clamping nuts on the ends of said pin for securely holding
said plates and carbons together, a receiver, director and indicator, and sound-wave
connections extending from the resounder to and through the receiver and director
and to the indicator.
18. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder and connections between the two,
the resounder consisting of a series of groups of resounding plates, each plate of
each group being perforated, perforated microphonic carbons separating certain of
the plates of each group, an insulated screw-threaded pin passing through the
plates and carbons, and clamping-nuts on the ends of said pin for securely holding
said plates and carbons together, a receiver, director, and indicator, and sound-wave
connections extending from the resounder to and through the receiver and director
and to the indicator.
19. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder and connections between the two,
the resounder consisting of a series of groups of resounding plates, each group
comprising four centrally perforated plates arranged in pairs divided from each
other by a washer, centrally perforated microphonic carbons separating the plates
of each pair, a screw-threaded insulated-pin passing through said plates, carbons
and washer, and clamping nuts on the ends of said pin for securely holding the
parts together, a receiver, director and indicator, and sound-wave connections
extending from the resounder to and through the receiver and director and to the
indicator.
20. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor comprising a series of intercepting tubes, a
resounder consisting of a series of groups of resounding plates, each group com-
prising four plates arranged in pairs divided from each other, by a washer,
microphonic carbons separating the plates of each pair, means for holding the
plates, carbons and washers together, connections between the interceptor and
resounder consisting of two wires extending from each tube of the interceptor to
and connected respectively with one plate of a complemental pair of a corresponding
group of resounder plates, a receiver, director and indicator, and sound-wave
connections extending from the resounder to and through the receiver and director
and to the indicator.
:
21. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor comprising a series of intercepting tubes, a
resounder consisting of a series of groups of resounding plates, each group com-
prising four plates arranged in pairs divided from each other by a washer,
microphonic carbons separating the plates of each pair, means for holding the
plates, carbons and washers together, connections between the interceptor and
resounder consisting of two wires, covered and separated from each other by rubber
tubes and arranged within a common protecting tube, such wires extending from
each tube of the interceptor to and connected respectively with one plate of a

page_text: complemental pair of a corresponding group of resounder plates, a receiver, director
and indicator, and sound-wave connections extending from the resounder to and
through the receiver and director and to the indicator.
sound:
22. The combination in an apparatus for receiving, transmitting and indicating
a casing having a large chamber and below the same a small, elongated
portion, a sound-wave interceptor, a resounder consisting of a series of groups of
resounding plates, a casing in which the groups are circularly arranged, said casing
of plates being secured to and encircling the elongated portion of the first named
casing and being located immediately below the large chamber of the latter, sound-
wave connections extending from the interceptor to and through the resounder,
receiver, director and to the indicator.
23. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder, a multiplex telephone or receiver
consisting of a centrally perforated casing having a chamber into which extends a
sound-conducting core, a series of bobbins seated in said chamber and upon said
cure, a diaphragm seated in said casing above the bobbins, an arm pivoted to said
casing above the diaphragm and carrying an adjustable carbon-pin and a counter-
balance at one end and adjusting device at the other, a director, and an indicator,
sound-wave connections extending from the interceptor to and through the resounder,
receiver, director and to the indicator.
24. The combination in an apparatus for receiving, transmitting and indicating
sound- a sound-wave interceptor, a resounder, a multiplex telephone or receiver
consisting of a centrally perforated casing having a chamber into which extends a
sound-conducting core, a series of bobbins located within said casing and upon said
core, a diaphragm seated in said casing above the bobbins, an arm pivoted to said
casing above the diaphragm and carrying a carbon-pin and a counter-balance at one
end and adjusting device at the other, a director, and an indicator, sound-wave
connections extending from the interceptor to and through the resounder, receiver,
director and to the indicator.
25. The combination in an apparatus for receiving, transmitting and indicating
sound-a sound-wave interceptor, a resounder, a multiplex telephone or receiver
consisting of a centrally perforated casing having a chamber into which extends a
sound-conducting core, a series of bobbins located within said chamber and upon
said core one above the other, a diaphragni seated in said casing above the bobbins,
an arm pivoted to said casing above the diaphragm and carrying an adjustable
carbon-pin, and a counter-balance at one end and a spring ander tension at the
other end, and a screw for regulating the expansion of the spring, a director and an
indicator, sound-wave connections extending from the interceptor to and through
the resounder, receiver, director and to the indicator.
26. The combination in an apparatus for receiving, transmitting and indicating
sound-a sound-wave interceptor, a resounder, a multiplex telephone or receiver
consisting of a centrally perforated casing having a chamber into which extends a
sound conducting core, a series of bobbins located within said chamber and upon
said core one above the other, each bobbin consisting of two coils of wire wound
oppositely, a diaphragm seated in said casing above the bobbins, a pivoted arm
above the diaphragmn carrying a carbon-pin, a counter-balance, spring and adjusting
screw, a director and an indicator, sound-wave connections extending from the
interceptor to and through the resounder, receiver, director and to the indicator.
27. The combination in an apparatus for receiving, transmitting and indicating
sound-a main casing having a large chamber and below the same a small, tubular,
elongated portion, a sound-wave interceptor, a resounder, a multiplex telephone or
receiver comprising a small casing having a chamber, a diaphragm seated in the
upper end of said small casing, and a pivoted arm carrying a carbon-pin located
above said diaphragın, all located within the chamber of said main casing, a sound-
conducting core extending through the elongated portion of the main casing and
into the chamber of the small casing, a series of bobbins carried on said core below
said diaphragın, a director and an indicator, sound-wave connections extending

page_text: from the interceptor to and through the resounder, receiver and director and to the
indicator.
28. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder, a multiplex telephone or receiver
comprising a sound-conducting core, a series of bobbins, a diaphragm and carbon-
pin, a secondary telephone or steno-sounder consisting of a bobbin secured to the
lower end of the said sound-conducting core and composed of a coil of copper wire,
a diaphragm, a pivoted arm carrying a counter-balance at one end and an adjustable
steel-pin at its other end, a tube filled with mercury suitably supported directly
under said pin, said tube having a stopper in its lower end transfixed by a needle, a
director and an indicator, sound-wave connections extending from the interceptor
to and through the resounder, receiver, director and to the indicator.
29. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder, a primary telephone or receiver
comprising a sound-conducting core, a series of bobbins, a diaphragm and carbon-
pin, a secondary telephone or steno-sounder consisting of a bobbin secured upon the
lower end of said core, a diaphragm, a pivoted arm carrying a counter-balance and
a steel pin, a tube filled with mercury suitably supported directly under said pin,
said tube having a stopper in its lower end transfixed by a needle, a director and an
indicator, sound-wave connections extending from the interceptor to and through
the resounder, primary and secondary telephones, director and to the indicator.
30. The combination in an apparatus for receiving, transmitting and indicating
sound-a casing comprising a large chamber and a small chamber and an elongated
tubular portion connecting the two chambers, a sound-wave interceptor, a resounder,
a primary telephone or receiver comprising a sound-conducting core, a series of
bobbins, a diaphragm and carbon-pin, a secondary telephone or steno-sounder
consisting of a bobbin secured upon the lower end of said core, a diaphragm seated
in the small chamber of the casing, a bracket arm secured to said casing and
supporting a tube filled with mercury having a stopper in its lower end transfixed
by a needle, an arm pivoted to said bracket arm and carrying at one end a counter-
balance and at the other an adjustable steel-pin located directly over the said tube
and under the last named diaphragm, a director and an indicator, sound-wave
connections extending from the interceptor to and through the resounder, primary
and secondary telephones, director and to the indicator.
31. The combination in an apparatus for receiving, transmitting and indicating
sound-a casing comprising a large chamber and a small chamber and an
elongated tubular portion connecting the two chambers, a sound-wave interceptor,
a resounder, a primary telephone or receiver comprising a sound-conducting core,
a series of bobbins, a diaphragm and carbon-pin, a secondary telephone or steno-
sounder consisting of a bobbin secured upon the lower end of said core composed
of a coil of insulated copper wire, a diaphragm seated in the small chamber of the
casing, a bracket-arm secured to said casing and supporting a tube filled with
mercury having a stopper in its lower end transfixed by a needle, an arm pivoted
to said bracket arm and carrying at one end a counter-balance and a socket at the
other in which is adjustably secured a steel-pin, said pin being located directly
over the tube and between the same and the last named diaphragm, a director and
an indicator, sound-wave connections extending from the interceptor to and
through the resounder, primary and secondary telephones, director and to the
indicator.
32. The combination in an apparatus for receiving, transmitting and indicating
sound-a sound-wave interceptor, a resounder, primary and secondary telephones,
a director, consisting of a series of groups of ring-segments circularly arranged, a
vertical shaft carrying an arm provided with brushes, said shaft also carrying a
band pulley, an indicating hand and a compass-needle, means for rotating said
shaft, a dial arranged relatively to said hand and needle, sound-wave connec-
tion extending from the interceptor to and through the resounder, telephones,
director and to the indicator.

page_text: :
33. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder, primary and secondary telephones,
a director, a casing for supporting the resounder telephones and indicator, the
director consisting of a series of groups of ring-segments circularly arranged, a
vertical shaft carrying an arm provided with brushes said shaft also carrying a
band-pulley an indicating hand and a compass-needle, a dial seated in said casing
between said arm and the hand, an indicator, sound-wave connections extending
from the interceptor to and through the resounder, telephones, director, and to the
indicator.
34. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, resounder, primary and secondary telephones,
a director, a casing for supporting the resounder, telephones and director, said
director consisting of a series of groups of ring-segments circularly arranged, cach
group consisting of four segments, a vertical shaft carrying an arm provided with
two brushes each bearing upon two successive segments, said shaft also carrying a
band-pulley above said arm and an indicating hand and compass-needle above said
pulley, a dial seated in said casing between said pulley and hand, an indicator,
sound-wave connections extending from the interceptor to and through the
resounder, telephones, director and to the indicator.
35. The combination in an apparatus for receiving, transmitting and indicating
sound :- a sound-wave interceptor, a resounder, primary and secondary telephones,
a director, a casing having a large and a small chamber in which the primary and
secondary telephones are respectively located, and also having an elongated
portion connecting the two chambers and to which the resounder is secured, and
also having a partition by which the parts of the director are supported, said
director consisting of a series of groups of ring-segments circularly arranged, a
shaft carrying an arm to the free end of which latter is secured a pair of brushes
which bear upon the segments, a band-pulley, indicating hand and compass-needle
also carried by said shaft, a dial scated in the casing below the hand and compass-
needle, an indicator, sound-wave connections extending from the interceptor to and
through the resounder, telephones, director and to the indicator.
36. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder consisting of a series of groups of
resounding plates, cach group arranged in pairs, a primary telephone comprising
a series of oppositely wound bobbins, a secondary telephone, a director comprising
a series of groups of ring-segments, an indicator, sound-wave connections extending
from the interceptor to the resounder, and a sound-wave connection extending from
each group of resounding plates to the corresponding group of ring-segments of the
director and each connection consisting of two wires connected respectively with
one of a pair of resounding plates and with one of a corresponding group of ring-
segments, connections between the director and primary telephone consisting of
two wires connected respectively with another of the ring-segments in the same
group and with an end of one of the oppositely wound coils of a corresponding
bobbin of the primary telephone, connections between the primary and secondary
telephones and between the latter and the indicator.
37. The combination in an apparatus for receiving, transmitting and indicating
sound a sound-wave interceptor, a resounder, a receiver, a director and an
indicator, the latter consisting of an electro-magnet having the pivoted armature
carrying an indicating hand, a scale suitably supported adjacent the hand, sound-
wave connections extending from the interceptor to and through the resounder,
receiver, director and to the indicator.
38. The combination in an apparatus for receiving, transmitting and indicating
sound-a sound-wave interceptor, a resounder, a receiver, a director, and an
indicator, the latter consisting of an electro-magnet having a spring-controlled
armature carrying an indicating hand, an adjusting device for controlling the
tension of said spring, a scale suitably supported adjacent the hand, sound-wave

page_text: connections extending from the interceptor to and through the resounder, receiver,
director and to the indicator.
39. A casing for holding an apparatus for receiving, transmitting and indicating
sound, the same consisting of a body portion having a large chamber for the
primary telephone, a smaller chamber for the secondary telephone and an elongated
tubular portion connecting the two chambers, a chamber for the microphonic
resounder between the said large and small chambers and a chamber for the
director and dial.
40. A casing for an apparatus for receiving, transmitting and indicating sound,
comprising a large chamber e, a small chamber e, separated from each other by a
tubular portion the bottom of the large chamber and the top of the small
chamber being perforated and the bottom of the small chamber being open.
41. A casing for an apparatus for receiving, transmitting and indicating sound,
comprising a body portion having chambers for the primary and secondary
telephones, a chamber for the microphonic resounder, a chamber for the director,
dial and hands, and means for suspending the said casing.
Dated the 22nd day of December 1891.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicants.