Improvements in Means of Telegraphing or Telephoning without Wires.
Year: 1896

page_text: Date of Application, 17th Dec., 1896
Complete Specification Left, 17th Sept., 1897-Accepted, 17th Dec., 1897
PROVISIONAL SPECIFICATION.
Improvements in Means of Telegraphing or Telephoning without
Wires.
ALFRED CHARLES BROWN of 129 Algernon Road Lewisham in the County of
London, Electrician, and GEORGE RICHARD NEILSON of 112 Tulse Hill Lambeth,
in the County of London Secretary to Public Company do hereby declare the
nature of this invention to be as follows:-
It has been known for some time past that waves of Electric energy of certain
periodicities or numbers of vibrations per second, known usually as Hertzian waves,
are capable of being radiated or projected so as to act on other Electric circuits
placed at a distance, and produce certain effects therein, such as sparking between
disconnected conductors, and the alteration in resistance of loose contacts or
"Coherers" etc. It has been known too that these effects are manifested through
considerable distance in space and through various media which are in some cases,
opaque to ordinary light.
The purpose of the present invention is to render the above mentioned phen-
omena more practicably applicable to certain purposes of signalling, and for
Telephoning or carrying on ordinary conversation across considerable distances
without wires.
We find that the above mentioned kinds of radiation are eminently adapted for
transmitting signals to a distance when such suitable means are provided.
For this purpose when a signalling Telegraph only is required we provide at or
in connection with the Transmitting Station a set of Apparatus for producing the
rays, such as a current generator and induction coil, or a high tension Electric
Machine and a Hertzian Oscillator, and a projector consisting preferably of a
metallic box or screen containing the pair of balls or electrodes of the oscillator,
between which the Hertzian or similar oscillating electric waves are generated,
the back of the box being preferably mirror shaped or carrying a separate mirror,
and the front part-being wholly or partially open or having optionally a lens of
ebonite pitch or other suitable material to assist in rendering the rays approxi-
mately parallel, or of concentrating them into a beam.
The wires of the generating circuit or Oscillator may pass through suitably
insulated holes in the back or other part of the metallic screen or projector box.
This projector we place in such position as to project or concentrate as much as
possible, the rays on to the Receiving Station, and in the battery, current
generator, or primary circuit (where an induction coil is used) we place a Morse
Key convenient for signalling, so as to produce the rays intermittently in the form
of dots and dashes. Or we may cause the signalling key, by means of a long range
arm or similar discharger, to open and close a short circuit across the secondary
circuit of the induction coil, or of the poles or electrodes of the high tension
machine where such is employed for producing the rays, or to make and break

page_text: the direct secondary circuit itself. Or the key may operate a metallic or other
opaque screen capable of covering part or all of the opening in front, of the poles
of the Oscillator, thereby alternately shielding and exposing the beam or penci
of rays from or on to the distant station.
At the Receiving station we then provide a second circuit or metallic loop, open
or closed, and preferably syntonised as nearly as possible to the generating circuit
and having in its path a "Lodge" Coherer, or set of loose contacts through which
a battery current is tending, the path of said Battery current continuing on
through a differential relay or other similar instrument capable of operating a
local circuit in response to variations of resistance in the coherer or set of loose
contacts produced by the varying impact of the Hertzian or Electric waves.
rapid vibrator, operated mechanically or electrically, may also be applied to the
coherer to continually restore its normal equilibrium or resistance after its having
been changed by the impact of electric waves.
A
For certain purposes of signalling we also find it useful to produce the electric
waves at the Transmitting Station in certain rated beats or series of impulses, so
that, on the local circuit at the receiving stallion being affected harmonically, in this
rate certain definite signals may be picked out and given from a series of possible
signals operated by the same local circuit.
For this purpose we prefer to use the apparatus described in the previous letters
patent No. 7773 of 1884.
The transmitting pendulums or reeds therein described taking the place of the
Morse Keys in the above description of apparatus to be used at the Transmitting
Station, and the electro-magnetic receiving recds or pendulums being included in
the local circuit at the Receiving Station, so as by their respective accumulation
or interference to successively pick out and make the proper, desired signals out
of the possible series. This method of signalling is especially adapted and advan-
tageous for Fire and Police Alarms and other Municipal Telegraphs.
For Telephoning we may place a Telephone Transmitter in the primary, or
battery, or generator circuit at the Transmitting Station, or may employ a shield
connected to a diaphragm, to alternately expose more and less of the radiation
emerging from a slit in the metallic shield of the projector otherwise then com-
pletely, or nearly completely, covering the electrodes of the electric wave generating
circuit or set,) in response to sound waves thrown upon the diaphragm, or, we
may use a disc of any substance capable of reflecting or refranging the radiation,
or of other material coated with such substance, as a diaphragm to reflect or refract
the rays on to the Receiving Station and so alternately concentrate the rays on
und scatter them from the apparatus at the Receiving Station in response to sound
waves thrown on to the reflecting or refranging diaphragm, or on to another
diaphragm accoustically, mechanically, or electrically connected therewith.
At the Receiving Station for reproducing or rendering the varying rays re-
apparent as sound waves we may use a disc of material capable of absorbing the
energy of the radiation mounted as a diaphragm over an air chamber or listening
tube, which applied to the ear renders the varying stream of radiation directly
apparent again as sound. Or the absorbing disc may form, or be connected to the
diaphragm of an ordinary Telephone Transmitter arranged to re-produce into a
Telephone Receiver for applying to the ear in an ordinary way.
or set of loose contacts which will vary its or their electrical resistance or resistances
Or any substance
in response to the impact of such radiation, may be exposed in the path of the
waves either in a tube or in the form of, or as a coating for, a long, thin, zig-
zagged or scrolled wire, or as a plain sheet, placed in the circuit of a battery and
suitable Telephone Receiver. Or arrangements capable of being acted upon by
the changes in magnetic polarity may be utilised to reproduce the transmitted
vibrations, or to vary an electrical current and thus reproduce them in any ordinary
well understood ways, and a current varied by such variable resistance or variable
magnetic polarity produced by the impact of a varying quantity or quality of
the transmitted rays, may also be utilised to give a visible, or a conventional

page_text: sound signal when the Apparatus is used for Telegraphing, instead of Telephoning
as described in the first portion of this Specification.
141
1
L 1000
A. C. BROWN.
GEO. R. NEILSON.
COMPLETE SPECIFICATION.
Improvements in Means of Telegraphing or Telephoning without
Wires.
ALFRED CHARLES BROWN, Electrician, and GEORGE RICHARD NEILSON, Secretary
to Public Company, both of 50 Old Broad Street in the County of London 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:-
It has been known for some time past that waves of Electric energy of certain
periodicities or numbers of vibrations per second, known usually as Hertzian
waves, are capable of being radiated or projected so as to act on other Electric cir-
cuits placed at a distance, and produce certain effects therein, such as sparking
between disconnected conductors, and the alteration in resistance of loose contacts
or "Coherers" etc. It has been known too that these effects are manifested
through considerable distances in space and through various media which are in:
some cases opaque to ordinary light.
The purpose of the present invention is to render the above-mentioned
phenomena more practicably applicable to certain purposes of signalling, and for
Telephoning without wires.
For this purpose when a signalling Telegraph only is required. we provide at,
or in connection with, the Transmitting Station a set of Apparatus for producing
the rays, such as a current generator and induction coil, or a high tension Electric
Machine, and a Hertzian Oscillator or Radiator, that is a pair of Electrodes, having
an inductive action on one another, and designed to suddenly equilibriate opposite
electric charges, impressed on them by an outside source (the induction coil or
electric machine) by violent electric surgings preferably across a spark gap, or
number of gaps thereby radiating energy into space. Any existing form of such
Oscillator or Radiator may be used for the present purpose, as the three ball
variety, consisting of one large central and two smaller charging balls, one on each
side; but we prefer to use a modification of the form, designed by Professor Righi,
wherein the spark is taken between a pair of balls, or electrodes, immersed in an
insulating liquid, such as oil. In place of using balls for the Electrodes, however,
we prefer to use more elongated rods with convex rounded, or half ball ends, as wo
find that the radiation from these is stronger than from balls & this form of elec-
trode is useful whether immersed in liquid or not. We prefer however to incline.
these rods upwards or else to curve them upwards somewhat crescent-shaped, so
that they may stand on insulating supports in a vessel of the insulating liquid,
and their outer ends (that is those most distant from the pair of ends which oppose
one another) project up out of the liquid, so that the charging sparks from the
machine, or induction coil may more conveniently be impressed upon them. Our
improved Radiator, constructed on this principle, is shewn in Fig. 1, wherein A A

page_text: are the elongated Electrodes, (the dotted lines indicating the optional straight form)
B the vessel made of insulating material and containing the oil or other insulating
liquid and C C the two small charging balls or Electrodes connected to the poles of
the machine or induction coil secondary. It will be seen that this construction
gives great facility for adjusting the spark gaps and is simple and the vessel not
requiring any special shaping is not liable to leak and so release the liquid.
Similar letters are used to indicate all similar parts throughout the drawings.
We prefer to enclose the Radiator bodily in a metallic box, closed on all sides,
but having an opening in front, the back of the box being preferably mirror-
shaped or carrying a separate metallic mirror, and the front hole being either left
open or preferably closed with a plate or lens of ebonite, pitch, or other suitable
material to assist in rendering the rays approximately parallel, or of concentrating
them into a beam.
To further render the beam parallel and cut off more of the diverging rays, so
as to prevent them from operating other receivers out of their direct line, we may
surround the front hole with a metallic pipe or tube, extending forward for any
desired distance, and preferably having its front end closed with an insulating
plate, or another lens, and having optionally other lenses in the course of its length.
Fig. 2 is a side view of the exterior of the entire projector, shewing the focussing
tube at E. The receiving instrument may also be enclosed in a similar box with
tube.
The wires of the generating circuit or Oscillator may pass through suitably
insulated holes in the back or other part of the metallic screen or projector box.
The projector we place in such position as to project or concentrate as much as
possible the beam or bundle of rays on to the Receiving Station. Or the Radiator
may, in some cases, be used alone without any metallic projector-box and its outer
charging knobs may be connected through condensers or otherwise to pipe systems
or to earth, or one connected directly to earth and the other to an insulated surface,
preferably elevated in the atmosphere. Or, and preferably, another separate pair
of balls or knobs may be placed near the ends of the Electrodes A A as shewn
at F F in Fig. 7, and these, instead of the charging knobs themselves, be connected
via condensers or otherwise to pipe systems, to earth, or one directly to earth and
the other to the elevated insulated surface. The second pair of balls are then prefer-
ably placed at such distance that they are not sparked into, together with each charg-
ing spark, passing from the charging knobs into the Electrodes A A, but a spark is
precipitated into them by the more violent disruption occuring every time a spark
passes across beween the Electrodes A A. This method has a great advantage in
reducing leakage, but they may also be placed closer if preferred and charged
together with the main electrodes.
In the battery, current generator, or primary circuit (where an induction coil is
used) at the Transmitting Station we place a Morse or other Key convenient for
signalling, so as to produce the waves intermittently in the form of dots and dashes.
Or we may cause the signalling key, by means of a light long range arm or similar
discharger, to open and close a short circuit across the secondary circuit of the
induction coil, or of the poles or Electrodes of the high tension machine where
such is employed for producing the charge, or to make and break the direct high
tension circuit itself. A suitable construction for the key when used in this way
is shewn in Fig. 3, wherein K is the Key, and L L Knobs communicating with the
high tension electrodes. Or the key may operate a metallic screen, capable of
covering part or all of the opening in front of the poles of the Oscillator, thereby
alternately shielding and exposing the beam or pencil of rays from or on to the
distant station, as shewn in Fig. 4, wherein M is the Key or operating handle, and
N the screen.
At the Receiving Station for detecting the radiant energy we then provide a
second oscillating circuit connecting inductive surfaces, or a road along which
electric surgings can take place, or a metallic loop, open or closed,, and in either
case preferably syntonised as nearly as possible to the generating oscillating

page_text: circuit or radiator, and having in its path a "Lodge" Coherer, or set of loose con-
tacts, or other light loose contact, through which a battery current is tending, the
path of said battery current continuing on, either directly through the electric
signalling instruments desired to be worked, or else through a relay or other
5 similar instrument, capable of operating a local circuit in response to variations
of resistance in the Coherer or set of loose contacts, produced by the varying impact
of the Hertzian or Electric waves. A vibrator, operated mechanically or electric-
ally, is also applied to the Coherer to continually restore its normal equilibrium or
resistance after the latter has been changed by the impact of Electric waves.
We do not limit ourselves to any particular form of light contact for the Coherer
but we prefer to employ a tube, made of glass, ebonite or other insulating material,
shewn in Fig 5 at 00, with stout conducting Electrodes, PP, sealed or otherwise
fixed in, which Electrodes may terminate inside as either stout rods or tubes
(shewn in the latter form at R Ř) extending near together, the remaining space in
the tube being loosely filled with the conducting granules, or cohering contacts S
and the air preferably exhausted to a very low tension, say through a small tubu-
lure as T, the tube being then hermetically sealed.
The outwardly extending rods from the tube may have tubular conductors U U
sliding on them and terminating in balls or other collecting or inductive surfaces.
The object of the telescopic slides is to tune the receiver or adjust its rate to that
of the Transmitting Oscillator when used for short distance work, or for longer
distances the conductors may be connected to other extensions or circuit arrange-
ments, or to pipe-systems, or to earth, or to insulated systems of collecting points
placed at an adjustable distance apart, or one pole to such system and the other to
oarth, and for these connections, both from the Transmitting Radiator (or
additional sparking knobs near same) and Receiving Coherer, we find broad strips
far better than ordinary round wires, as possessing less self-induction and there-
fore offering far less impedance to the passage of the rapid electric surgings, or
oscillating currents. The strips should be well insulated except when connected
to earth.
Any metallic granules will answer, but we find the most effective consist of
very fusible metals or alloys, the effect of cohering appearing to consist of a
minute fusing together of the contact points or surfaces. For most signalling
purposes, therefore, we prefer to use granules of soft solder, lead or tin, or alloys
of lead and tin, with or without Bismuth or Cadmium or all together. For other
purposes, however, we find Carbon granules very effective, especially when tho
Telephone is used as the receiving instrument as herein-after described.
V Fig. 5 shews the restoring vibrator consisting of an electro-magnet W and
ordinary make and break contact X all enclosed in a tight metal box, Y, which
may have extending tubes to enclose the battery wires. The armature pivot c
extends through the box and carries the rod of a light tapper D, arranged to
vibrate against the Coherer tube O. Or any other form of vibrator may he used
and it may shake the Coherer in other ways without directly tapping it.
Another form of Receiver, which we sometimes use, is shewn at Fig. 6 and con-
sists of the proper collectors and conductors E E formed of metallic strips or rods
terminating in balls, or other suitable Electrodes, (the system being tunable for
short distance working by bending the extremities more or less near
together) or which strips or rods may be connected for longer distance
working as above described with reference to the alternative granule
tube, and the approaching ends being fixed to an insulating block G and bridged
across by a very thin piece of wire H, preferably platinum or aluminium, bent
tripod fashion, so as to rest lightly on three points, two being preferably on one
Electrode and one on the other. The cohoring contact surfaces and wire may also
be covered by a suitably packed glass or other bell cover J, from which the air
may be exhausted, as by a closable tube through the block G underneath, or other-
wise. A vibrator V is also mounted preferably on the same base to restore the
equilibrium. Fig. 7 is a diagram of connections of the complete set of Trans-

page_text: mitting and Receiving Apparatus, the electrical connections shewn in full lines
being arranged for ordinary signalling and working, say, on a Morse Sounder or
Printer. The connections shewn in dotted lines relate to another requirement to
be described further on and should be ignored when considering plain Morse
signalling only. In this figure the spirals lettered I represent the generating
induction coil and g its make and break contact with preferably a condenser h.
a represents the signalling Key at the Transmitting Station. A A, B and C C
represent respectively the same parts as indicated by similar letters and described
in reference to Fig. 1. F. F. are the pair of additional knobs for connecting respec-
tively to elevated surfaces and to earth or to other arrangements as already
described, and 00, P P, U U represent the receiving Coherer and V the vibrator
as described in detail with reference to Fig. 5. represents the relay and c the
Morse Instrument, both of which may be of any ordinary form, and the latter
either a Sounder or Printer. The shunt roads lettered r shewn across the Electro-
magnets of the Morse Instrument and relay in Fig. 7 and of the Vibrator in
Fig. 5 represent ordinary spark shunts or condensers which it is desirable to place
across the Electro-magnets of all Instruments required in the vicinity of the
receiving Coherer.
For certain purposes of signalling we also find it useful to produce the electric
waves at the Transmitting Station in certain rated beats or series of impulses, so
that, on the local circuit at the Receiving Station, being affected harmonically,
in this rate, certain definite signals may be picked out and given from a series of
possible signals operated by the same local circuit.
For this purpose we prefer to use the apparatus described in Patent Specifica-
tion, No. 7773 of 1884, or other similar arrangements.
The Transmitting Pendulums or Reeds then take the place of or are used in con-
junction with the Signalling Keys described above, at the Transmitting Station
(operating as the Keys, but isochronously, to either open and close the electric
circuit or to oscillate a screening shield) and the electro-magnetic Receiving Reeds
or Pendulums being included in the local circuit at the Reediving Station, so as
by their respective accumulation or interference to pick out and make the proper
desired signals. A method of applying such synchronised vibrators, for both
Transmitting and Receiving, is indicated by the dotted lines in Fig. 7, wherein on
the transmitting side of the diagram i represents the transmitting pendulum or
reed or its equivalent, the full line connection between the points d and e being now
considered as broken, and the Key a being optional may be replaced by the direct
connection f.
On the receiving side of the diagram k k represents in a typical form two of any
number of the synchronised receiving pendulums or reeds (but of which any
ordinary kind may be-used) with their proper connections and m an electric bell
or other signalling device arranged to be put into action locally by the synchronised
vibrators.
As will be seen from the dotted connections the electro-magnetic coils of the
synchronised vibrators now replace those of the Morse or other Telegraph Instru-
ment which are now considered as absent, and a local current is applied to the bell
or signal on the accumulation or effective operation of any of the synchronised
vibrators, or the vibration of the latter alone (or of their equivalents) may also of
course for some purposes suffice to make the signals.
This method of signalling is especially adapted and advantageous for Fire and
Police Alarms and other Municipal Telegraphs, and is also useful for many other
purposes.
For Telephoning we may place a Telephone Transmitter in the primary, or
battery, or generator circuit at the Transmitting Station, either in place of or as a
shunt for or in series with, the ordinary make and break g of the induction coil
indicated at I Fig. 7, which make and break should then be rapid. Or (as shewn
in Fig. 8) we may employ a moving shield n connected to a diaphragm and having
a slit or slits to alternately expose more or less of the radiation emerging from a

page_text: similar slit or slits in a fixed metallic shield otherwise then completely, or nearly
completely covering the front of the projector box p, containing the electrodes of
the electric wave generating apparatus, so as to successively vary the intensity of
the radiation in response and in proportion to sound waves thrown upon the
diaphragm.
In both these cases it is desirable for the vibrating make and break in the
primary circuit of the generating induction coil to be of high rate, and the trans-
initting oscillator circuit designed to give a considerable number of oscillations for
each break, as, for instance, by connecting across by a loop of wire of some length
the Electrodes A A of the transmitting radiator shewn in Fig. 1 or its equivalent,
whereby it it less damped, although rendered less powerful, so that the received
stream of energy shall be as continuous as possible, subject to the varying
mechanism described above.
At the Receiving Station for reproducing or rendering the varying rays re-
apparent as sound waves we may use any substance, or set of loose contacts, which
will vary its, or their, electrical resistance, or resistances, in response to the
impact of such radiation, (when properly collected and concentrated thereon, as
herein-before described with reference to the Receiving arrangements for Tele-
graph Signalling) placed in the circuit of a Battery and suitable Telephone
Receiver. This arrangement is shewn in Fig. 9 wherein s is the Coherer or tube
containing loose contacts of the desired substance, and which Coherer may be con-
structed similarly to Fig. 5. This arrangement can also be used for receiving con-
ventional signals, as produced by the operations of the Morse Key, depicted in
Fig. 7 in the transmitting part of the apparatus. We find that a Telephone
Receiver used in this way, in conjunction with a Coherer, having preferably but
not necessarily, carbon granules, forms a very sensitive receiving set for detecting
very weak radiant energy as when coming from a long distance etc., because the
Telephone is able to appreciate far more minute and temporary (but sudden)
changes in the resistance of the Coherer than are required to vary a battery current
sufficiently to operate any other telegraphic instrument. Used in this way also
no restoring vibrator is required for the coherer, or at most only an arrangement to
give a few momentary taps at long intervals, but this can be conveniently done by
hand. Or instead of the Receiving Telephone being in direct circuit with the
Coherer it may be connected across the secondary of an induction coil, whose
primary is included in the battery and coherer circuit.
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. A transmitting radiator of Electric energy, consisting of a pair of elongated
rods, having their ends opposed to one another, and either inclined upwards at an
angle, or else curved in a somewhat crescent shape, so that in either case the bulk
of their surface, and especially their opposed ends, may be and are immersed in oil
or other insulating liquids, contained in an electrically insulating vessel, while
their opposite ends project out of said liquid conveniently for being charged by
sparks sent across from knobs or Electrodes opposed thereto and connected to a
source of high potential electricity, as and for the purposes above described.
2. A receiving Coherer, arranged as above described, advantageously for detect-
ing electric radiation and consisting of a-tube or vessel containing between or in
contact with the Electrodes of the collecting conductors granules of very fusible
metals or alloys as above enumerated and to accomplish the above-mentioned
objects.
3. The use and employment for the purpose of confining a stream of electric
radiation within narrow limits and so preventing it from operating other receivers
not intended to be operated thereby, or for the purpose of picking out more closely
and responding to the radiation coming from one better defined point only, a
metallic tube extending out from the front and surrounding a hole in an otherwise

page_text: closed metallic box containing the radiation producing device or the radiation
receiving device respectively, as and for the purposes above described.
4. Where an electro-magnetic vibrator is used to tap back or restore the normal
equilibrium of resistance of a Coherer after its having been changed by electric
radiation; the use and employment of a metallic box or case to cover in and enclose
the said vibrator entirely with the exception of the projecting tapping hammer,
or an axle on which this may be mounted, for the purpose of screening the radia-
tion generated by the vibrator away from the receiving Coherer.
5. An electro-magnetic vibrator fulfilling the conditions mentioned in claim 3.
above, and constructed as above described and illustrated in Fig. 5.
6. The use and employment in conjunction with an oscillator or radiator of
electric energy of a second pair of knobs opposed to the main pair of Electrodes or
surfaces, between which the oscillating currents or electric surgings are set up,
and connected to pipe-systems, or earth, either with or without the interposition of
condensers, or one to earth and the other to a radiating surface, preferably elevated
in the atmosphere. Or the use of one separate knob, so connected, in conjunction
with an earth connection or a connection to another of the above-mentioned.
systems, applied to the opposite charging knob.
7. The use and employment for the purpose of connecting the charging knobs or
the surface of an Electric Radiator, or other knobs inductively opposed to them,
to earth, or to other systems for increasing the radiation, of a conductor composed
of a broad strip instead of a round wire, as heretofore used, as and for the purposes
above described.
8. The combination with an induction coil or other high tension electric
generator and an oscillator or radiator of electric energy, of Reeds or Pendulums
for opening and closing the circuits of the induction coil or generator isochronously,
or otherwise producing the rays intermittently, or of alternately exposing and
shielding a beam of them, in an isochronous rate, for the purpose of actuating
tuned or synchronous electro-magnetic Reeds or l'endulum, placed in the
receiving circuit.
9. The combination with a Cohorer, granule tube or loose contact system used
for the purpose of detecting electric radiation of one or more synchronised electro-
magnetic Reeds or Pendulums for the purpose of picking out a signal or one of a
set of signals made by one transmitter without responding to others which may be
acting simultaneously or successively, as and for the purposes above described.
10. The use and employment of a Telephonic Transmitter or Microphone in
place of the ordinary make and break, or as a shunt for or in series with a rapidly
vibrating make and break of the primary circuit of an induction coil used for pro-
ducing Hertzian waves or high rate electric radiation capable of operating a
receiver at a distance, as and for the purposes above described.
11. The means above described of varying the intensity of a very rapidly pro-
duced set, or nearly continuous stream of electric waves by means of a slotted
screen covering and uncovering similar slots in a fixed screen in front of the
electric projector, proportionately to sound waves thrown upon a diaphragm actuat-
ing such screen as and for the purposes above described.
12. The combination with a Coherer or set of loose contacts used for detecting
electric radiation of a battery and telephone placed in the same circuit, whether
the said telephone is used to re-produce speech or other sounds, or only conven-
tional signals, as and for the purposes above described.
13. In a receiving set used for the purpose of reproducing signals or sounds from
a varying stream of electric radiation, the combination of a Telephone, Induction
coil, battery and Coherer, or set of loose contacts, the Telephone being connected
to one coil, say the secondary, of the Induction coil and the other coil, say the
primary, being connected in circuit with the Battery and Coherer or set of loose
contacts.
14. Where a Telephone is used in conjunction with a Colerer or set of loose con-
acts and Battery as a receiving set for detecting and responding to variations of

page_text: electric radiation, the use and employment for the purpose of such Coherer or set
of loose contacts of granules or subdivided particles composed of carbon.
15. The use and employment of a pointed conductor, or of a system of points
projecting into the atmosphere and connecting to an apparatus for either trans-
mitting or receiving electric waves.