improved Methou апа Apparatus for Recording and Reproducing Sounds and Electric Currents.
Year: 1888

page_text: Date of Application, 13th Jan., 1888
Complete Specification Left, 28th Sept., 1888
Complete Specification Accepted, 2nd Nov., 1888
improved Methou апа Apparatus for Recording and Reproducing
Sounds and Electric Currents.
I, WILHELM HEDICK, of 69, Catharina Street, Breda, in the Kingdom of the
Netherlands, Director of the Hoogere Burgerschool do hereby declare the nature of
this invention to be as follows:-
The invention consists in recording electric currents and sound waves by means
of gas jets which impinge upon a moving ribbon; and in reproducing electric
currents and sound waves by means of the signs, recorded on the ribbon.
The gas jets may be set in vibrations by ordinary manometric capsules of König in
the usual manner, or by some special electro-magnetic apparatus. For gas jets may
be used air and gaseous substances of all kinds, pure or mixed with smoke, dust, fine
spray of liquid, or other fine particles. The signs of the record may be obtained by
chemical action (decomposition of salts, oxidation, reduction), or by mechanical
fixation (adhesion to paper, to stearine, glue, wax etc.). The signs may be marked
instantaneously by the impact of the vibrating jet upon the ribbon, or developed
after the impact by some special treatment, such as is employed in photography,
lithography, or other graphic or printing arts.
Reproduction of currents and waves is obtained by the signs of the record in
different manners, according to the character of the record:
1° by the mechanic properties of the record.
20 by the magnetic properties of the record.
3° by the galvanic resistance of the record.
4° by the thermic properties of the record.
1°. When the signs form upon the ribbon thick and thin parts, or rough and
smooth parts, then the ribbon may be used like the tin-foil of a phonograph. The
ribbon, passing before a sound diaphragm, a telephone, or some similar apparatus, and
pressing against the diaphragm, will cause the diaphragm to vibrate in consequence of
the varying thickness, or the unequal friction of the signs. These vibrations of the
diaphragm generate sound waves, or electric currents.

page_text: The unequal signs will also reproduce.sound waves, when used like the holes of the
well-known acoustic siren of Cagniard de Latour. When a gas jet, issuing from a
capsule of König, plays against the unequal signs of the moving ribbon, then the gas
jet will be set in vibration, and the vibrations may be perceived by the ear, when
held against the capsule.
20. When the signs have magnetic properties, when for instance the signs are
charged with dust of iron, dust of nickel, or cobalt, then reproduction will be obtained
by passing the ribbon along the pole of a magnet which is surrounded by a wire coil.
The magnetic ingredients of the signs (iron, nickel, or cobalt) will, when passing the
pole, generate induced currents in the wire coil.
manner.
3. When the signs of the record possess galvanic properties, i.e. when those parts
of the ribbon, where signs are marked, offer either more or less resistance to a voltaic
current, than the other parts of the ribbon, where signs are not marked, then the
varying resistance of the ribbon may be used for reproduction in the following
Let the ribbon be drawn along the two poles of a voltaic battery which are
formed by two parallel wires or by two parallel knife-edges, placed at a short distance
from each other; the ribbon lying either upon the poles, or between the poles. In
both cases, whether the poles be on the same side, or on different sides, the ribbon
forms the connection between the two poles and conveys the voltaic current from
one pole to the other. The current will therefore pass different parts of the moving
ribbon and meet with varying degrees of resistance. The current itself will therefore
change in strength. These variations of strength form the reproduction, and are
perceptible by means of a telephone, by a galvanometer or otherwise.
4°. When the different parts of the record act differently with respect to heat, for
instance when the absorption, the radiation, or the conduction of heat varies
in the different parts of the ribbon, then these varying thermic qualities may
be used for reproduction as follows. Take the ribbon, pass it along a thermopile, a
photophone, a tasimeter, a bolometer, or some other instrument which is sensitive to
small variations of heat, and which generates electric currents, or sound waves by
varying heat. The ribbon, when heated to a temperature, differing from the
temperature of the sensitive instrument, will act upon the instrument with varying
force, because the different parts of the ribbon possess different thermic qualities.
Thus the sensitive instrument will generate varying electric currents or varying sound
waves which form the reproduction of the recorded currents or sound waves.
The apparatus, by which the record, or the reproduction of electric currents, or
sound waves is obtained according to the foresaid principles, may be constructed in
very various forms.
The apparatus represented on sheet 1 and on sheet 2, records electric currents and
sound waves by means of gas jets which, vibrating longitudinally like the well-known
manometric flames of König, impinge upon a moving ribbon; and reproduces electric
currents and sound waves by the signs, recorded upon the ribbon. This apparatus is
constructed and used as follows.
The tube, emitting the gas jet, is on sheet 1 denoted by S. The gas jet impinges
upon the ribbon B which slides over the edge K, where it is kept in the right position
by a moveable guide D. The ribbon is drawn off the lower drum, and wound round
the upper drum by turning the handle of the driving pulley R, an endless cord being
laid over the pulloy R and the upper drum. The ribbon may also be drawn off the
upper drum and wound round the lower one. The two drums are fixed to the
support T; they are provided with cushions or pads G which by friction will give to
the ribbon the necessary tension. The gas jet, issuing from the tube S, and impinging
against the ribbon, is set in vibration in two manners:
1st by sound waves, when the tube S is connected-by means of the tube F
with the well-known capsule of König, denoted by M, and when the diaphragm of
this capsule M is acted upon by sound waves.
2ndly by electric currents, when the tube S is connected with the capsule H, the
diaphragm of the capsule H being acted upon by the vibrating armature of an electro-
maguet.

page_text: On the same sheet 1 there is a vessel for distillation which is denoted by A and a
flask for sublimation, denoted by P, both serving for the dovelopment of gaseous sub-
stances which may be mixed with the vibrating jet that impinges upon the ribbon.
The flask P may be heated by a gas burner, fixed to the support T.
By this arrangement it is possible to make vibrating gas jets of hydrochloric acid,
sulphur dioxide, sulphur, zodine, chlorochromic acid, etc. etc.
The capsule H of sheet may be replaced by a telephonical apparatus, represented
on sheet 2 by Fig. 2, with a small air chamber behind the diaphragm, into which
the gas enters through the opening A and from which the vibrating gas jet issues
either through an opening O, bored in the vibrating diaphragm E, or through an
opening J, made in some other part of the chamber. In order to mix gaseous and
other fine substances with the escaping gas jet, different forms may be given to the
tube by which the gas jet escapes, as are represented by the tubes hand d. The
air chamber of this telephonical apparatus may be made as small as desired by
paraffin, wax or other material, wherein the wire coils with the soft iron cores are
bedded, and by which all unnecessary holes and superfluous cavities are filled. The
air chamber may also be closed by an inflexible plate C with two holes through which
pass the two iron cores of the bobbins, mounted upon the magnetic poles P. The
vibrating iron diaphragm E may be laid on gold-beater's-skin X or some other elastic
sheet, in order to make the diaphragm more moveable. Great mobility of the
diaphragm may also be obtained by cutting in a circular iron diaphragm H, sheet 2,
Fig. 3, a rectangular tongue, as is shown by F, the rectangular slits being closed
afterwards by india rubber, gold-beater's-skin, parchment, or some other elastic
sheet R. The iron bar D is placed across the horse-shoe magnet, and may be
fixed at the right distance from the poles P in order to regulate their magnetic
power.
Sheet 2 shows an arrangement, by which dry dust may be mixed with the
vibrating gas jet. V denotes a sort of sandbox or hour glass, consisting of two
vessels, one vessel upon the other. When sand, or sand mixed with dust, when
powder of silica, carbon, iron, nickel, copper or other substances run from the upper
compartment into the lower, the fine particles of the running stream are blown by
a pair of bellows or otherwise into the tube S, Fig. 1. The tube S is held by
holder Z and connected with the nanometric capsule of König, denoted by M.
Instead of dry dust we are allowed to mix with the gas jet a spray of liquid, divad
into fine particles by an ordinary atomizer, such as is used for medical purposes. The
fine particles may be brought into the gas jet before or after its issuing from the
tube S. In such a manner it is possible to mix with the gas jet all liquids, acids,
dissolved salts, in liquid finely divided substances etc. etc.
When an ordinary smoking flame is brought between the tube S and the edge K,
it will be driven by the vibrating jet against the ribbon, and the vibrations will be
marked upon the ribbon by smoke.
Two or more tubes S with the same gas or with different gases may be connected,
and directed simultaneously against the ribbon, which is drawn along the edge K.
The action of the gas jet may be either of a mechanical nature, such as is adhesion
of dust upon glue, paraffin, resin etc.,-or of chemical nature, such as is decomposition
of salts, oxidation, reduction, or of a physical nature,--such as is the decomposition
by heat, the making of gelatine, of albumin etc. insoluble by chromic salts or by
chlorochromic acid etc.
The apparatus also records electric currents without the aid of a vibrating diaphragm.
Let instead of a vibrating jet a steady jet of magnetic dust continually flow against
a ribbon which slides over the pole of an electro-magnet, while vibrating or inter-
mittent electric currents circulate in the bobbin of the electro-magnet. The dust
will stick upon the travelling ribbon by the intermittent magnetism of the pole, and
distinct figures, for instance dashes and dots, will be formed, corresponding to the
electric currents. By suitable means these figures or signs may be fixed upon the
travelling ribbon immediatly after their formation. They may be fixed for instance
by passing the ribbon over a hot cilinder, when the ribbon is prepared with paraffin,

page_text: or when resin is mixed with the dust, and they may be fixed by a spray of dissolved
varnish from an atomizer in other cases.
The apparatus represented on sheet 1 and sheet 2, reproduces the recorded electric
currents and sound waves by different instruments U and N, shewn on sheet 2, or
by E and L shown on sheet 1, according to the different character of the recorded
signs.
1. When the record has mechanical qualities, when for instance the record is made
by signs of varying thickness, then the instrument U, sheet 2; may be used for
reproduction. This instrument U consists chiefly of a diaphragm, an electro-magnet,
and a spring, mounted between the diaphragm and the electro-magnet. When a
record with signs of varying thickness is sliding along the spring which is connected
with the diaphragm by means of a thread, a hair, cork, rubber or otherwise, then the
diaphragm will vibrate and sound will be produced. The diaphragm of the instru-
ment U may be replaced by the smaller diaphragm N which is more sensitive, because
it is provided with an ear tube. The diaphragm may also be replaced by an ordinary
telephone, by a microphone or some similar apparatus; the varying thickness of
the recorded signs will act upon them mechanically, and currents or sound waves will
be reproduced
The varying thickness of the signs may be used for reproduction by the instrument U
without the aid of the diaphragm of the instrument U, when the spring, mounted in
front of the electro-magnet, is made of iron or steel. The spring may be set in
vibration by the varying thickness of the signs, and by the vibrations of the iron
spring electric currents may be induced in the bobbin of the magnet. These currents
are perceptible in a telephone, connected with the bobbin.
The induction of electric currents by the vibrations of such a spring will be especially
strong, when the spring is mounted between the poles of a double magnet, as is
shown by E on sheet 1.
I should not omit to say, that the construction of the spring, used in apparatus U,
sheet 2, and in apparatus E sheet 1, is of great importance. For certain records it
will be advantageous to use a spring, composed of parallel needles, forming a brush,
instead of only one flat spring which forms a strip. The motion of a spring, consisting
of parallel needles, depends not only on the thickness and the length of the signs, but
it depends on their breadth also. A small number of needles will be set in vibration
by small signs, a great number by large signs.
Hence it is obvious, that such a spring, composed of parallel needles, may also be
employed for the reproduction of waves, which are recorded by other means than by
longitudinally vibrating jets. Such a iron spring may also be employed for records,
made by transversally vibrating jets, either jets of gas or jets of liquid. The record
for instance, made by a siphon recorder, will be suitable for the reproduction by such
a spring, when the spring is mounted in front of a magnetic pole, as is shown in
apparatus E, sheet 1, and in apparatus U, sheet 2, and when the record is drawn along
the pole, while the record also slides along the spring and passes between the pole and
the spring or when the record is drawn along an other edge, and does not touch the
pole, but touches the spring only.
2. Magnetic properties of the record may be used for reproduction by means of the
apparatus U, sheet 2, in two manners.
First, when the signs are marked with dust of iron, nickel or cobalt, the signs will
induce electric currents in the bobbin of the apparatus, when sliding over the pole.
The induction will be reinforced by the assistance of the spring, when the spring is
made of iron or steel, magnetic or not magnetic.
Secondly, when the signs are marked with dust of iron nickel or cobalt, the iron
spring of the apparatus U may be set in vibration by the magnetism of the signs,
and act upon the diaphragm of the apparatus U, producing sound.
The first of these methods may also be used in apparatus E, sheet 1.
3. When the record offers varying galvanic resistance, when for instance the signs
are made by good conducting substances upon a non-conducting ribbon, or inversely by
bad conductors upon good conductors, by reducing substances upon reducible material

page_text: etc. etc., then for reproduction the plate L, shown on sheet 1, may be used. The small
rectangular plate L is surrounded by two parallel, insolated wires, forming a double
spiral round the plate. The plate may be mounted on the edge K, the two wires
being connected with the poles of a voltaic battery. When now the record is drawn
over the plate L, touching the wires, then the voltaic current will vary in strength.
These variations in strength form the reproduction of the record and are perceptible in
a telephone etc.
4. For reproduction by means of the thermic properties of the record it is necessary,
that the diaphragm of the apparatus U, sheet 2, be replaced by a thermopile, a
bolometer, a tasimeter, a radiophone or some similar instrument. The varying heat,
radiating from the different parts of the record, will act upon such an instrument with
varying force. Varying electric currents or varying sound waves will therefore be
reproduced, when the ribbon is drawn over or along the sensitive part of such an
instrument, and differs from its temperature.
Hitherto electric currents and sound waves have been recorded by scratching points,
by vibrating pens of very different forms, by electrolytic contact, by photographical
means, by transversally vibrating jets. But hitherto they have not been recorded by
the impact of longitudinally vibrating gas jets, impinging directly upon a moving
ribbon, nor by steady flowing jets, charged with magnetic dust.
A fortiori the reproduction of electric currents and sound waves by such record
constitutes an invention.
Dated this Ninth day of January 1888.

page_text: Improved Method and Apparatus for Recording and Reproducing
Sounds and Electric Currents.
1, WILHELM HEDICK, of 69, Catharina Street, Breda, in the Kingdom of the
Netherlands, Director of the Hoogere Burgerschool at Breda 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
The invention consists in recording sounds and electric currents by means of gas
jets which impinge upon a moving ribbon; and in reproducing sounds and electric
currents by means of the signs, recorded on the ribbon.
The gas jets may be set in vibration by ordinary manometric capsules of König in
the usual manner, or by some special electromagnetic apparatus. For gas jets may be
used air and gaseous substances of all kinds, pure, or mixed with smoke, dust, fine
spray of liquid, or other fine particles. The signs of the record may be obtained by
chemical action (decomposition of salts, oxidation, reduction etc.), or by mechanical
fixation (adhesion to paper, to stearine, glue, wax ete). The signs may be marked
instantaneously by the impact of the vibrating jet upon the ribbon, or developed after
the impact by some special treatment, such as is employed in photography, lithography,
or other graphic, or printing arts.
Reproduction of sounds and electric currents is obtained by the signs of the record
in different manners, according to the character of the record:
1° by the mechanic properties of the record.
2° by the magnetic properties of the record.
3° by the galvanic resistance of the record.
4° by the thermic properties of the record.
1°. When the signs form upon the ribbon thick and thin parts, or rough and smooth
parts, then the ribbon may be used like the tin-foil of a phonograph. The ribbon,
passing before a sound diaphragm, a telephone, or some similar apparatas, and pressing
against the diaphragm, will cause the diaphragm to vibrate in consequence of the
varying thickness, or the unequal friction of the signs. These vibrations of the
diaphragm generate sounds, or electric currents.
The unequal signs will also reproduce sounds, when used like the holes of the well-
known acoustic siren of Cagniard de Latour. When a gas jet, issuing from a capsule
of König, plays against the unequal signs of the moving ribbon, then the gas jet will
be set in vibration, and the vibrations may be perceived by the ear, when held against
the capsule.
2°. When the signs have magnetic properties, when for instance the signs are
charged with dust of iron, dust of nickel or cobalt, then reproduction will be obtained
by passing the ribbon along the pole of a magnet which is surrounded by a wire coil.
The magnetic ingredients of the signs (iron, nickel or cobalt) will, when passing the
pole, generate induced currents in the wire coil.
30. When the signs of the record possess galvanic properties, i.e. when those parts
of the ribbon, whero signs are marked, offer either more or less resistance to a voltaic

page_text: current, than the other parts of the ribbon, where signs are not marked, then the
varying resistance of the ribbon may be used for reproduction in the following manner.
Let the ribbon be drawn along the two poles of a voltaic battery which are formed
by two parallel wires, or by two parallel knife-edges, placed at a short distance from
each other; the ribbon lying either upon the poles, or between the poles. In both
cases, whether the poles be on the same side, or on different sides, the ribbon
forms the connection between the two poles and conveys the voltaic current from
one pole to the other. The current will therefore pass different parts of the moving
ribbon and meet with varying degrees of resistance. The current itself will therefore
change in strength. These variations of strength form the reproduction and are
perceptible by means of a telephone, by a galvanometer, or otherwise.
4°. When the different parts of the record act differently with respect to heat, for
instance when the absorption, the radiation, or the conduction of heat varies in the
different parts of the ribbon, then these varying thermic qualities may be used for
reproduction as follows. Take the ribbon, pass it along a thermopile, a photophone,
a tasimeter, a bolometer, or some other instrument which is sensitive to small variations
of heat and which generates sounds, or electric currents by varying heat. The ribbon,
when heated to a temperature, differing from the temperature of the sensitive instru-
ment, will act upon the instrument with varying force, because the different parts of
the ribbon possess different thermic qualities. Thus the sensitive instrument. will.
generate varying sounds, or varying electric currents which form the reproduction of
the recorded sounds, or recorded currents.
The apparatus, by which the record, or the reproduction of sounds, or electric
currents is obtained according to the foresaid principles, may be constructed in very
various forms.
The apparatus, represented by the drawings on sheet 1 and sheet 2, which aro
left with the provisional specification, records sounds and electric currents by means
of gas jets, which vibrating longitudinally like the well-known manometric flames
of König impinge upon a moving ribbon; and reproduces sounds and electric
currents by the signs, recorded upon the ribbon. This apparatus is constructed and
used as follows.
The tube, emitting the gas jet, is on sheet 1 denoted by S. The gas jet impinges
upon the ribbon B which slides over the edge K, where it is kept in the right
position by a moveable guide D. The ribbon is drawn off the lower drum and
wound round the upper drum by turning the handle of the driving pulley R, an
endless cord being laid over the pulley and the upper drum. The ribbon may
also be drawn off the upper drum and wound round the lower one. The two
drums are fixed to the support. T; they are provided with cushions or pads G
which by friction will give to the ribbon the necessary tension.
The gas jet,
issuing from the tube S, and impinging against the ribbon, is set in vibration in two
manners:
1st by sounds, when the tube S is connected-by means of the tube F-with the
well-known capsule of König, denoted by M, and when the diaphragm of this
capsule M is acted upon by sounds.
2ndly by electric currents, when the tube S is connected with the capsule H, the
diaphragm of the capsule H being acted upon by the vibrating armature of an electro
magnet.
On the same sheet 1 there is a vessel for distillation, which is denoted by A, and a
flask for sublimation, denoted by P; both serving for the development of gaseous
substances which may be mixed with the vibrating jet that impinges upon the ribbon.
The flask P may be heated by a gas burner, fixed to the support T. By this arrange-
ment it is possible to make vibrating gas jets of hydrochloric acid, sulphur-dioxide,
sulphur, zodine, chlorochromic acid etc. etc.
The capsule H of sheet 1 may be replaced by a telephonical apparatus, represented
on sheet 2 by Fig. 2, with a small air chamber behind the diaphragm, into which the
gas enters through the opening A and from which the vibrating gas jet issues either
through an opening O, bored in the vibrating diaphragm E, or through an opening J,

page_text: made in some other part of the chamber. In order to mix gaseous and other fine
substances with the escaping gas jet, different forms may be given to the tube by
which the gas jet escapes, as are represented by the tubes h and d. The air chamber
of this telephonical apparatus may be made as small as desired by paraffin, wax, or
other material, wherein the wire coils with the soft iron cores are bedded and by which
all unnecessary holes and superfluous cavities are filled. The air chamber may also be
closed by an inflexible plate C with two holes through which pass the two iron cores
of the bobbins, mounted upon the magnetic poles P. The vibrating iron diaphragm E
may be laid on gold-beater's-skin X or some other elastic sheet, in order to make
the diaphragm more moveable. Great mobility of the diaphragm may also be
obtained by cutting in a circular iron diaphragm H, sheet 2, Fig. 3, a rectangular
tongue, as is shown by F, the rectangular slits being closed afterwards by india
rubber, gold-beater's-skin, parchment, or some other clastic sheet R₁. The iron bar D
is placed across tho horse-shoe magnet and may be fixed at the right distance from the
poles P in order to regulate their magnetic power.
Sheet 2 shows an arrangement, by which dry dust may be mixed with the vibrating
gas jet. V denotes a sort of sandbox or hourglass, consisting of two vessels, one
vessel upon the other. When sand, or sand mixed with dust, with powder of silica,
carbon, iron, nickel, copper or other substances, runs from the upper compartment
into the lower, the fine particles of the running stream are blown by a pair of bellows
or otherwise into the tube S, Fig. 1. The tube S is held by a holder Z and connected
with the manometric capsule of König, denoted by M.
Instead of dry dust we are allowed to mix with the gas jet a spray of liquid, divided
into fine particles by an ordinary atomizer, such as is used for medical purposes. The
fine particles may be brought into the gas jet before or after its issuing from the
tube S. In such a manner it is possible to mix with the gas jet all liquids, acids,
dissolved salts, or in liquid finely divided substances etc.
When an ordinary smoking flame is brought between the tube S and the edge K, it
will be driven by the vibrating jet against the ribbon, and the vibrations will be
marked upon the ribbon by smoke.
Two or more tubes S with the same gas, or different gases may be connected, and
directed simultaneously against the ribbon, which is drawn along the edge K.
By suitable pressure of the gases a special sensitiveness for special sounds and for
special vibrating currents may be given to the gas jets, similar to the well-known
sensitive flames, used for acoustic experiments.
The voltaic are between the carbon poles of a galvanic battery, and the electric are
between the poles of a Holtz's or Wimshurst's Influence-machine may also be brought
in front of the ribbon, and be driven against the ribbon by a vibrating gas jet.
The heat and the electrification of the elements, constituting the arc, may act upon
the ribbon, and signs may be marked, when the ribbon by suitable means is
prepared.
The action of the gas jets may be either of a mechanical nature, such as is adhesion
of dust upon glue, paraffin, resin etc.-or of a chemical nature, such as is decom-
position of salts, oxidation, reduction, or of a physical nature, such as is the
decomposition by heat, the making of gelatine, of albumin etc. insoluble by chromic
salts, by alum, chlorochromic acid, tannic acid, etc.
The records may be positive, or negative. A positive record will be obtained, when
the writing substance, e.g. smoke, is fixed upon the ribbon by a vibrating jet which
contains the writing substance. A negative record will be obtained, when the writing
substance, e.g. smoke, is not contained in the vibrating jet, but in a second jet which
flows steadily against the ribbon and which makes a uniform continuous dash or line
upon the ribbon, as long as the first jet does not vibrate; but which make an
interrupted or broken line, i.e. negative signs, as soon as the first jet vibrates and
interrupts or breaks by these vibrations the steady flow of the second jet.
The apparatus also records electric currents without the aid of a vibrating diaphragm.
Let instead of a vibrating jet flow a steady jet of magnetic dust against a ribbon which
slides over the pole of an electromagnet, while vibrating, or intermittent electric

page_text: currents circulate in the bobbin of the electromagnet. The dust will stick upon the
travelling ribbon by the intermittent magnetism of the pole, and distinct figures, for
instance dashes and dots, will be formed, corresponding to the electric currents. By
suitable means these figures may be fixed upon the travelling ribbon immediately after
their formation. They may be fixed for instance by passing the ribbon over a hot
cilinder, when the ribbon is prepared with paraffin, or when resin is mixed with
the dust; and they may be fixed by a spray of dissolved varnish from an atomizer
in other cases.
The apparatus, represented on the sheets 1 and 2, left with the provisional specifi-
cation, reproduces sounds and electric currents by different instruments U and N,
shown on sheet 2, or by E and L, shown on sheet 1, according to the different
character of the signs.
1. When the record has mechanical qualities, when for instance the record is
made by signs of varying thickness, then the instrument U, sheet 2, may be used
for reproduction.
This instrument U consists chiefly of a diaphragm, an electromagnet, and a spring,
mounted between the diaphragm and the electromagnet. When a reord with signs of
varying thickness is sliding along the spring, which is connected with the diaphragm o
by means of a thread, a hair, cork, rubber, or otherwise, then the diaphragm will
vibrate and sound will be produced. The diaphragmn of the instrument U may be
replaced by the smaller diaphragm N which is more sensitive, because it is provided
with an ear tube. The diaphragm nay also be replaced by an ordinary telephone by
a microphone or by some similar apparatus; the varying thickness of the recorded
signs will act upon them mechanically and sounds or currents will be reproduced.
The varying thickness of the signs may be used for reproduction by the instrument U
in another manner, when the spring, mounted in front of the electromagnet, is made
of iron or steel. The spring may be set in vibration by the varying thickness of the
signs and by the vibrations of the iron spring electric currents may be induced
in the bobbin of the magnet. These currents are perceptible in a telephone, connected
with the bobbin.
The induction of electric currents by the vibrations of such a spring will be
especially strong, when the spring is mounted between the poles of a double magnet,
as is shown by E on sheet 1.
I should not omit to say, that the construction of the spring, used in apparatus U,
sheet 2, and in apparatus E, shect 1, is of great importance. For certain records it
will be advantageous to use a spring, composed of parallel needles, forming a brush,
instead of only one flat spring, which forms a strip. The motion of a spring, consisting
of parallel needles depends not only on the thickness and the length of the signs, but
it depends on their breadth also. A small number of needles will be set in vibration
by small signs, a great number by large signs. Hence it is obvious, that such a spring,
composed of parallel needles, may also be employed for the reproduction of sounds and
electric currents which are recorded by other means than by longitudinally vibrating
jets. Such a iron spring may also be employed for records, made by transversally
vibrating jets, either jets of gas, or jets of liquid. The record for instance, made by L
siphon recorder with thick ink, will be suitable for the reproduction by such a spring
when the spring is mounted in front of a magnetic pole, as is shown in apparatus E,
sheet 1, and in apparatus U, sheet 2; and when the record is drawn along the pole,
while the record also slides along the spring and passes between the pole and the
spring or when the record is drawn along another edge, and does not touch the
pole, but touches the spring only.
It is obvious also, that the form of the pole, whereupon the spring vibrates, will be
of importance. For certain records-the records for instance made by a siphon
recorder it will be advantageous to make the pole asymmetrical, to make the pole
for instance thicker at one corner than at the other corner; or to draw the ribbon not
along the front of the magnet, but to draw it along the side of the magnet, etc.
other cases it will be preferable to use an asymmetrical spring, consisting of parallel
needles which have a different length or have different thickness.
In

page_text: 2. Magnetic properties of the record may be used for reproduction by means of the
apparatus U, sheet 2, in two manners. First, when the signs are marked with dust
of iron, nickel or cobalt, the signs will induce electric currents in the bobbin of the
apparatus, when sliding over the pole. The induction will be reinforced by the
assistance of the spring, when the spring is made of iron or steel, magnetic or not
magnetic. Secondly when the signs are marked with dust of iron, nickel or cobalt,
the iron spring of the apparatus U may be set in vibration by the magnetism of the
signs and act upon the diaphragm of the apparatus U, producing sound. The first
of these methods may also be used in apparatus E, sheet 1.
3. When the record offers varying galvanic resistance, when for instance the
signs are made by good conducting substances upon a non-conducting ribbon, or
inversely by bad conductors upon good conductors, by reducing substances upon
reducible material, then for reproduction the plate L, shown on sheet 1, may be used.
The small rectangular plate L is surrounded by two parallel insolated wires, forming
a double spiral round the plate. The plate may be mounted on the edge K, the
two wires being connected with the poles of a voltaic battery. When now the
record is drawn over the plate L, touching the wires, then the voltaic current will
vary in strength. These variations in strength form the reproduction of the record
and are perceptible in a telephone etc.
4. For reproduction by means of the thermic properties of the record it is necessary,
that the diaphragm of the apparatus U, sheet 2, be replaced by a thermopile, a
bolometer, a tasimeter, a radiophone, a photophone, or some similar instrument. The
varying heat, radiating from the different parts of the record, or absorbed by the
different parts of the record, will act upon such an instrument with varying force.
Varying sounds, or varying electric currents will therefore be reproduced, when the
ribbon is drawn over or along the sensitive part of such an instrument.
Hitherto sounds and electric currents have been recorded by scratching points,
by vibrating pens of very different forms, by electrolytic contact, by photographical
means, by transversally vibrating jets. But hitherto they have not been recorded
by the impact of longitudinally vibrating gas jets, which directly impinge upon a
moving ribbon.
This new method of recording is useful as well for phonography as for telegraphy;
for intermittent currents and for vibrating currents; for telegraphs, for micro-
phones etc.
This method is superior to other methods of recording on account of its greater
sensitiveness and its rapidity.
Morcover sounds and electric currents, recorded by such method, are reproducible
by such record.
Having now particularly described and ascertained the nature of my said Invention,
and in what manner the same is to be performed, I declare that what I claim is:
1. Method and apparatus which substantially as described records sounds, or
electric currents by the impact of longitudinally vibrating gas jets which impinge
upon a moving ribbon; the gases being either pure, or mixed with dust, drops,
powder, or other fine particles; the record being made either instantaneously, or
developed, or itensified afterwards.
2. Method and apparatus which substantially as described reproduces sounds, or
electric currents by means either of the mechanic, or the magnetic, or the galvanic,
or the thermic properties of such a record, as is obtained by the foresaid method
of recording.
Dated this Twenty-seventh day of September 1888.