Improvements in Apparatus for Automatically Transmitting and Receiving Despatches, Messages, and the like in Facsimile.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Automatically Transmitting and
Receiving Despatches, Messages, and the like in Facsimile.
We, DR. FRIEDRICH SILBERSTEIN, of 5, Vorlaufstrasse, Vienna, in the Empire
of Austria, Lawyer, ANTON POLLAK, of 1/x, No. 342, Szentes, in the Kingdom of
Hungary, Merchant, and JozSEFU VIRÁG, of 82, Dob-utcza, Budapest, in the
Kingdom of Hungary, Engineer, do hereby declare the nature of this invention
to be as follows:-
The object of this invention is the forwarding of despatches in a form corre-
sponding exactly with the original, and at a speed which is at least equal to and
even exceeds that of the present electric telegraphs.
The idea of delivering the despatches given in, in a form corresponding to that
of the original, is not new. The subject in itself is so important that it would
be a matter of astonishment if the carrying out of this idea had not already formed
the subject of research.
The apparatus heretofore constructed for this purpose have however not been
approved in practice. The so-called copying telegraphs (Caselli, Mayer, etc.).
actually give a copy of the despatch given-in corresponding with the original, the
construction of these apparatus is however complicated, and at the same time,
they work so slowly that they do not comply with the requirements of practical
life. Moreover the telegram to be transmitted must be written on paper of a
particular kind and with a special kind of ink, which, apart from other circum-
stances, prevents the general use of these apparatus.
In contradistinction to these, the apparatus which forms the object of the present
invention attacks and solves the problem from quite a different standpoint. In
the apparatus heretofore employed, the picture of the despatch was formed by
decomposing chemically-prepared paper by the electric current at the receiving
station.
In the present improved apparatus on the contrary, a real, accurate light picture
of the telegram sent out from the transmitting station, appears at the receiving
station, where it is fixed and, in a fixed condition, can be immediately delivered
to the addressee.
Coupled to this the construction of the apparatus is very simple and the method
of operation is quite automatic, so that only a small working staff is necessary.
The principle of the apparatus is, shortly stated, as follows;-viz.;-The
picture of the despatch is projected in a suitable manner onto a series of selenium
cells.
As is known, the electrical resistance of selenium cells rises and falls in accord-
ance with the illumination thereof. An electric current from a suitable source
of current is continuously passed through the cells. This current, according to
the greater or less illumination of the selenium cells, experiences a less or greater
resistance; it therefore leaves the cell as a current of greater or less strength and
is conducted to the receiving station. Here the current passes through the winding

page_text: of one or more telephone-like apparatus, the diaphragms or membranes of which
are set in vibration in accordance with the strength of the current supplied, which
vibrations can be used in various ways so that a strip of paper, which is sensitive
to light and is continuously fed forward in a dark or closed chamber, can be
correspondingly lighted or exposed thereby in exact accordance with the varying
illumination of the selenium cells and in this manner a photograph of the telegram
projected on the selenium cells is produced. One has merely to take care that,
at the transmitting station, the separate points of the despatch successively act
upon the selenium cells at a suitable speed and that the vibrations of the telephone
diaphragms are transmitted in a suitable manner to paper which is sensitive to
light by the aid of a source of light, in order to obtain an exact copy of each
single point of the despatch and therefore a copy of the whole despatch.
Several forms or modifications of apparatus constructed on this principle are
hereinafter described, which are also shown diagrammatically in the drawings.
One the rotary wheel or disc K, Figure 1, at the transmitting station 1 are
arranged the manuscripts a, b, c, d of the despatches. The source of light L is
in the interior of the wheel if the despatches are written on a transparent mem-
brane, whilst the illumination is effected from the exterior if they are written
on non-transparent (plain) paper.
In the box B is arranged a series of selenium cells 1, 2, 3- The light
issuing from the wheel K passes through a convex lens C¹ to the selenium cells.
The number and size of the selenium cells is varied according to circumstances.
Their size must be such that they possess sufficient sensitiveness and that their
resistance shall be of suitable amount. Assuming the despatch to be transmitted
be written on paper 70 millimetres broad, and each point 3 millimetre in size
of the despatch should fall on one cell, the magnifying power of the lens C¹ must
be such that the image of each point of the despatch of 3 millimetre diameter
shall cover one selenium cell. In the present instance, therefore, the number of
cells to be employed must be the number of times, millimetre is contained in
70 millimetres, i.e. 210 cells. The unit of 3 millimetre is chosen on the basis, since
the clearness of the photograph to be produced requires it, that the separate
points thereof shall not exceed a maximum size of 3 millimetre diameter.
The several series of points of the photograph must likewise be at a maximum
distance of millimetre apart. In consequence of this, the wheel K must turn
through millimetre during the time one series of points comes into position.
It is obvious that the apparatus can also be adjusted for instance to %, millimetre,
in which case a correspondingly larger number of cells is required.
It has moreover been proved that the trustworthy operation of selenium cells
depends essentially on their size, and it is therefore necessary to effect the illumina-
tion thereof in such a manner that as large a cell surface as possible of each
be illuminated without detracting from the compendiousness of the apparatus.
This is perfectly attained by introducing behind the convex lens C, a second
lens C, which is preferably a cylinder-lens. In this manner, the breadth of the
selenium cells can be maintained at 3 millimetres diameter for each point of
the despatch, whilst the cylinder lens C expands the image, already enlarged to the
breadth of the cell, to the length of the selenium cell. By reason of the larger
dimensions of the cell, its resistance is reduced and the sensitiveness increased,
thus rendering the working of the whole apparatus more trustworthy.
The same object may be attained if the use of the lens C¹ be entirely dispensed
with and the despatch be caused to pass behind a shield having a slot of a
millimetre in width. The source of light is placed in front of this shield and the
rays of light pass through the slot. The selenium cells are arranged at such a
distance that the width of the ray of light passing through the slot covers the
length of the cells, whilst the cylinder-lens contracts the picture of each point
of millimetre in size to the width of the cells.
The wheel K is in connection, through gearing and shaft rt, with one end
of an arm k, which is made of conducting material, and with the driving-gear s.

page_text: At the other end of the arm k is a brush G. This brush moves in a circle along
the contact-pieces 1, 2, 31- of a commutator. Each of the contact-pieces is
electrically connected to one of the selenium cells.
The commutator is preferably constructed in such a manner that a series of
contact-pieces 11, 2, 3 corresponding in number with the selenium cells, is
arranged on the inner edge or surface of a circular ring made of insulating material,
each of these contact-pieces being electrically connected to a cell, whilst a
current is passed through the shaft t and arm k to the brush G from a source of
current X.
The arm with the brush G is moved, by means of the driving-gear s, on the
inner circular surface of the ring A, whereby the current is conducted in turn to
each of the selenium cells. By this arrangement of the commutator, the centri-
fugal force of the rapidly-rotating brush promotes an intimate contact thereof
with the contact pieces.
The gear-wheels r, r, are so arranged that the wheel K turns through 1 milli-
metre, whilst the arm k and brush G in its circular path, touches the whole of the
contact-pieces.
'
Each of the conducting wires extending from the contact pieces 11, 21, 31,
leads to the corresponding selenium cell 1, 2, 3—, from which conducting wires
again extend which unite together at i to form the conductor v. This conductor v
leads to the receiving station II.
The receiving station can be arranged in various ways. Two approved forms
thereof are hereinafter described.
I.
The combined conductor extending from the selenium cells leads to the arm k¹
or to the brush gl of a commutator, Figure 24, which is constructed exactly the
same as that at the transmitting station. At the inner circular surface of the
annular plate A¹ are arranged contact-pieces 111, 211, 31
over which the
arm and brush grotates synchronously with the arm k and brush G at
the transmitting station.
The rotation of the said brush is effected by means of the gearings. The
current coming from the transmitting station I passes from the conductor v
through the shaft to the arm and the brush g' and to the contacts 1, 2, 311 in
turn.
The current. in the contacts 11, 2, 3 passes from each contact to the coils
of an electromagnet m. In front of each electromagnet is mounted a thin iron
diaphragm 7, to which is secured a wedge by means of a light rod, which wedge,
in its position of rest, covers over the openings I, II, III of a box P. In the
box P is arranged a source of light L'.
Since now a stronger or weaker current from the selenium cells 1, 2, 3-
, passes
through the contact-pieces 111, 211, 31 to the electromagnets m, and the strength
of these currents depends upon the illumination of the selenium cells, the dia-
phragms and the wedges are correspondingly more or less strongly attracted by
the electromagnets m, and the openings I, II, II.
are more or less
covered. Through these openings therefore, rays of light issue corresponding in
strength to the illumination of the selenium cells.
The image of these apertures must now be reduced to the size of the original
despatch in such a manner that, in the case taken, the images of the several
apertures are reduced to 3 millimetre.
For this purpose, the rays of light issuing from the box P are received in a
dark chamber R by means of the objective Q.
The correspondingly reduced points of light fall on sensitized paper (which is
sensitive to light) and which is arranged in the form of an endless band in the
dark chamber, this band being moved by means of gearing from the shaft t',
in such a manner that is feeds forward a length of 3 millimetre for one revolution
of k¹ g.
In this manner there is produced on the sensitized plate H, the photograph

page_text: of the despatches a, b, c, d in their original size, which can be immediatel
developed, fixed and washed in the trays H¹ H3 and removed from the apparatu
ready for delivery.
II.
This second form of receiving-station, which is shown diagrammatically i
Figure 2, is based on the same principle as the one described under the heading I
but is considerably simplified in that the commutator which is similarly con
structed to, and works synchronously with the commutator at the transmitting
station, is done away with, and instead of the numerous telephone-lik
apparatuses l, m, x, merely a single peculiarly-arranged telephone apparatus i
required.
The current from the selenium cells 1, 2, 3-is passed to the telephone a
by means of the conductor v, Figure 2, and the diaphragm 6' of the said telephone
is set in vibrations corresponding to the strengths of the current. To the dia
phragm of the telephone is secured one end of a rod c¹ whilst to the other end
thereof is arranged a mirror d¹ in such a manner that it can swing in the direc
tion indicated by arrows. A support el is secured at one end to the mirror, and at
the other end to the shell of the telephone and both axes of rotation are parallel
to the axis of oscillation of the mirror. By reason of the vibrations of the dia-
phragm of the telephone, the rod el alternately rises and falls, the motion of
this rod setting the mirror into vibrations from its position of rest. On the mirror
is now projected, by means of a source of light L and a lens f¹, the image of a
point or preferably of a three-cornered aperture, which is reflected from the
mirror in a direction corresponding to the position thereof for the time being.
The lens fis unnecessary if a concave mirror be arranged at the telephone
instead of a flat one.
The reflected pencil of light rays falls on a dark chamber R in such a manner
that the point thereof, which has a three-cornered transverse section enters into
the millimetre broad slit Z in the dark chamber, either not at all, or only
partially, or entirely, according to the oscillations of the mirror, and produces in
this manner an image of the point or of the three-cornered aperture g¹ on the
sensitized sheet moving behind the slit of the dark chamber, this image corre-
sponding in size and intensity to the strength of the current passing through the
telephone; in this manner an image of the corresponding point of the despatch
arranged on the wheel K at the transmitting station is produced.
Instead of one telephone, if desired, two or more can be combined together as
shown in Figure 3, with a number of reflections from the mirrors d³, d³ in order
to increase the reflections of the pencil of rays.
As the telephone diaphragm makes also its own vibrations between the separate
current impulses it is necessary to bring these vibrations into unison with the
number of current impulses and to weaken or diminish same in such a way that
the separate impulses can unimpededly follow one another. The vibrations of
the telephone may be brought into unison with the number of the impulses either
by employing a diaphragm of suitable strength and size or by making the telephone
apparatus synchronizing.
A synchronizing telephone may be made as follows:
Two wires o, Figures 4 and 5, are stretched over the magnet poles of the tele-
phone on which above the two magnet poles a small iron plate o' is soldered which
represents the telephone diaphragm. The wires are connected with a screw o³
by means of which they may be slackened or tightened so that the number of
vibrations of same and of the diaphragm may be regulated.
The prevention of the vibrations of the telephone may also be effected by
mechanical means by a contact 03, Figure 4, preventing the vibrations of the
diaphragm in an opposite direction to the impulses. These vibrations in opposite
directions may however also be prevented by electrical means by means of fresh
current impulses which reach the telephone when its diaphragm approaches its
position of repose after its vibration. For this object double contacts as shown

page_text: in Figure 1 are arranged on the commutator, which double contacts are succes-
sively encountered by the brushes G, or two brushes are arranged on the arms /
which successively encounter each contact 11, 21, 31, whereby after each current
impulses a second impulse immediately reaches the telephone which prevents the
vibration of the diaphragm in the opposite direction.
In addition to the source of current X a second one may also be employed which
constantly sends into the telephone a current of constant strength but from an
opposite direction. This current is as strong as the one which has passed the
selenium cells when the latter are not lighted; the two current impulses com-
pensate one another in such a way that only those current impulses come into
action which correspond to the current strengthened by the lighting of the cells.
These vibrations of the diaphragm corresponding to the differences of current
impulses are of course proportionate to the lighting of the cells.
In order that in spite of the extremely small vibrations of the telephone dia-
phragm the movements of the mirror d¹ may be sufficiently great, the points of
rotation of the same must lie very close together which in the form of construc-
tion shown in Figures 2 and 3, causes difficulties; the result is more easily
attained by making use of the arrangement shown in Figures 6-8. On one pole
of a suitably bent magnet NS arranged above the telephone diaphragm, two small
sharp edges d³ are formed which form the axis of rotation of the mirror d', a small
iron plate d' is fixed below on the mirror which plate in consequence of magustic
attraction holds the mirror firmly on the sharp edges d³, and also rests on the upturned
end of a steel spring d5 fixed on the other pole of the magnet which spring is
connected with the telephone diaphragm d8 by means of bars d. By this arrange-
ment the points of rotation of the mirror may be shifted suitably close together
without fear of the mirror falling down.
In order that the pencil of rays reflected from the mirror & may be brought
along the whole length of the slit in the dark chamber, it is subjected, before it
reaches the dark chamber, to a further reflection by means of a polygonal rotary
prism h¹.
This prismatic mirror moves synchronously with the brush g of the commutator
in Figure 1 in such a manner that, whilst the prism makes one revolution on its
axis, the brush of the commutator makes as many revolutions as the prismatic
mirror has sides. The image of the variations in the current strength during
one revolution of the commutator brush, that is to say, the combined points of a
section of the original picture or of the despatch, are therefore each reflected by
one side of the prism in such a manner that, by reason of the rotation of the prism,
the pencil of rays reflected on the slit of the dark chamber is led along the whole
length thereof, whilst the arm K of the commutator makes one revolution; at the
beginning of the next revolution of the commutator-arm however, the next follow-
ing side of the prism begins to reflect and again throws the image of the point or
series of points next following on the commencing end of the slit, and then leads
the pencil of rays along the slit. In this manner therefore there is produced the
image of a row of points of the despatch on the sensitized paper, whilst the said
paper moves forward 13 millimetre.
In place of the polygonal reflecting prism the arrangement shown in Figures 9
and 10 may be adopted. Shaft h², Figure 9, which has an equal number of rota-
tions to the shaft of the commutator of the transmitting station, carries a disc h³,
the face of which is provided with an entire cam or screw surface. A lever h³
pivoted on a shaft he bears under the action of a spring against this cam surface.
The mirror h is mounted on this lever. If then the lever he turns in the direc-
tion indicated by the arrow, the mirror, in consequence of the cam or screw surface
moves during the whole rotation evenly in one direction, as soon, however, as the
end of the cam or screw surface comes under lever h³ it springs together with its
mirror suddenly back into its initial position, and re-commences its course afresh.
In place of a screw or cam surface, a spiral or snail cam, Figure 10, may be
arranged on the periphery of the disc h³, in which case of course the position of

page_text: the shaft h³ must be displaced to 90°. Figures 9 and 10 make this arrangement
evident without further explanation.
It is also of advantage to arrange a shield 8 on the shaft h2, Figure 11, which
shield revolves with the shaft in such a way that at the moment of the springing
back of the mirror h' it comes in front of same and prevents reflected light from
penetrating the dark chamber at this moment.
In this manner there is produced a complete picture of the despatch sent-in, the
development, fixing, washing, etcetera, whereof is effected in the manner described
under the heading I.
Doted this 2nd day of August 1898
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Agents for the Applicants.
Improvements in Apparatus for Automatically Transmitting and
Receiving Despatches, Messages and the like in Facsimile.
We, DR. FRIEDRICH SILBERSTEIN, of Vorlaufstrasse 5, Vienna, in the Empire
of Austria, Lawyer, ANTON POLLAK, of 1/x, No. 342, Szentes, in the Kingdom of
Hungary, Merchant, and JozSEFU VIRÁG, of 82, Dob-utcza, Budapest, in the
Kingdom of Hungary, Engineer, 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 object of this invention is the forwarding of despatches in a form corre-
sponding exactly with the original, and at a speed which is at least equal to and
even exceeds that of the present electric telegraphs.
The idea of delivering the despatches given in, in a form corresponding to that
of the original, is not new. The subject in itself is so important that it would
be a matter of astonishment if the carrying out of this idea had not already formed.
the subject of research.
The apparatus heretofore constructed for this purpose have however not been
approved in practice. The so-called copying telegraphs (Caselli, Mayer, etc.)
actually give a copy of the despatch given-in corresponding with the original, the
construction of these apparatus is however complicated, and at the same time,
they work so slowly that they do not comply with the requirements of practical
life. Moreover the telegram to be transmitted must be written on paper of a
particular kind and with a special kind of ink, which, apart from other circum-
stances, prevents the general use of these apparatus.
In contradistinction to these, the apparatus which forms the object of the present
invention attacks and solves the problem from quite a different standpoint. In
the apparatus heretofore employed, the picture of the despatch was formed by
decomposing chemically-prepared paper by the electric current at the receiving
station.
In the present improved apparatus on the contrary, a real, accurate light picture
of the telegram sent out from the transmitting station, appears at the receiving
station, where it is fixed and, in a fixed condition, can be immediately delivered
to the addressee.
.
Coupled to this the construction of the apparatus is very simple and the method,
of operation is quite automatic, so that only a small working staff is necessary.
The principle of the apparatus is, shortly stated, as follows: viz.;-The

page_text: picture of the despatch is projected in a suitable manner onto a series of selenium
cells.
As is known, the electrical resistance of selenium cells rises and falls in accord-
ance with the illumination thereof. An electric current from a suitable source
of current is continuously passed through the cells. This current, according to
the greater or less illumination of the selenium cells, experiences a less or greater
resistance; it therefore leaves the cell as a current of greater or less strength and
is conducted to the receiving station. Here the current passes through the winding
of one or more telephone-like apparatus, the diaphragms or membranes of which
are set in vibration in accordance with the strength of the current supplied, which
vibrations can be used in various ways so that a strip of paper, which is sensitive
to light and is continuously fed forward in a dark or closed chamber, can be
correspondingly lighted or exposed thereby in exact accordance with the varying
illumination of the selenium cells and in this manner a photograph of the telegram
projected on the selenium cells is produced. One has merely to take care that,
at the transmitting station, the separate points of the despatch successively act
upon the selenium cells at a suitable speed and that the vibrations of the telephone
diaphragms are transmitted in a suitable manner to paper which is sensitive to
light by the aid of a source of light, in order to obtain an exact copy of each
single point of the despatch and therefore a copy of the whole despatch.
Several forms or modifications of apparatus constructed on this principle are
hereinafter described, which are also shown diagrammatically in the drawings
accompanying the Provisional Specification.
On the rotary wheel or disc K, Figure 1, at the transmitting station I are
arranged the manuscripts a, b, c, d of the despatches. The source of light L is
in the interior of the wheel if the despatches are written on a transparent mem-
brane, whilst the illumination is effected from the exterior if they are written
on non-transparent (plain) paper.
- The light
In the box B is arranged a series of selenium cells 1, 2, 3-
issuing from the wheel K passes through a convex lens C¹ to the, selenium cells.
The number and size of the selenium cells is varied according to circumstances.
Their size must be such that they possess sufficient sensitiveness and that their
resistance shall be of suitable amount. Assuming the despatch to be transmitted
be written on paper 70 millimetres broad, and each point 1, millimetre in size
of the despatch should fall on one cell, the magnifying power of the lens C¹ must
be such that the image of each point of the despatch of 3 millimetre diameter
shall cover one selenium cell. In the present instance, therefore, the number of
cells to be employed must be the number of times 3 millimetre is contained in
70 millimetres, i.e. 210 cells. The unit of 3 millimetre is chosen on the basis, since
the clearness of the photograph to be produced requires it, that the separate
points thereof shall not exceed a maximum size of 3 millimetre diameter.
The several series of points of the photograph must likewise be at a maximuni
distance of 3 millimetre apart. In consequence of this, the wheel K must turn
through millimetre during the time one series of points comes into position.
It is obvious that the apparatus can also be adjusted for instance to 1 millimetre,
in which case a correspondingly larger number of cells is required.
It has moreover been proved that the trustworthy operation of selenium cells
depends essentially on their size, and it is therefore necessary to effect the illumina-
tion thereof in such a manner that as large a cell surface as possible of each
be illuminated without detracting from the compendiousness of the apparatus.
This is perfectly attained by introducing behind the convex lens C, a second
lens C, which is preferably a cylinder-lens. In this manner, the breadth of the
selenium cells can be maintained at 3 millimetres diameter for each point of
the despatch, whilst the cylinder lens C expands the image, already enlarged to the
breadth of the cell, to the length of the selenium cell. By reason of the larger
dimensions of the cell, its resistance is reduced and the sensitiveness increased,
thus rendering the working of the whole apparatus more trustworthy.

page_text: The same object may be attained if the use of the lens U be entirely dispensed
with and the despatch be caused to pass behind a shield having a slot of a
millimetre in width. The source of light is placed in front of this shield and the
rays of light pass through the slot. The selenium cells are arranged at such a
distance that the width of the ray of light passing through the slot covers the
length of the cells, whilst the cylinder-lens C contracts the picture of each point
of millimetre in size to the width of the cells.
The wheel is in connection, through gearing and shaft r t, with one end
of an arm k, which is made of conducting material, and with the driving-gear s.
At the other end of the arm k is a brush G. This brush moves in a circle along
the contact-pieces 11, 21, 31- of a commutator. Each of the contact-pieces is
electrically connected to one of the selenium cells.
The commutator is preferably constructed in such a manner that a series of
contact-pieces 11, 21, 31, corresponding in number with the selenium cells, is
arranged on the inner edge or surface of a circular ring made of insulating material,
each of these contact-pieces being electrically connected to a cell, whilst a
current is passed through the shaft and arm to the brush G from a source of
current X.
The arm with the brush G is moved, by means of the driving-gear s, on the
inner circular surface of the ring A, whereby the current is conducted in turn to
each of the selenium cells. By this arrangement of the commutator, the centri-
fugal force of the rapidly-rotating brush promotes an intimate contact thereof
with the contact pieces.
The gear-wheels rr, are so arranged that the wheel K turns through 3 milli-
metre, whilst the arm k and brush Gin its circular path, touches the whole of the
contact-pieces.
Each of the conducting wires extending from the contact pieces 11, 21, 31,-
leads to the corresponding selenium cell 1, 2, 3-, from which conducting wires
again extend which unite together at i to form the conductor v. This conductor v
leads to the receiving station. II.
The receiving station can be arranged in various ways. Two approved forms
thereof are hereinafter described.
I.
The combined conductor extending from the selenium cells leads to the arm
or to the brush g¹ of a commutator, Figure 2, which is constructed exactly the
same as that at the transmitting station. At the inner circular surface of the
annular plate A¹ are arranged contact-pieces 111, 21, 31, over which the
arm, and brush grotate synchronously with the arm and brush G at
the transmitting station.
The rotation of the said brush is effected by means of the gearing s¹. The
current coming from the transmitting station I passes from the conductor v
through the shaft t¹ to the arm k¹ and the brush g' and to the contact 11, 211 311 in
¡turn.
The current in the contacts 111, 211, 311 passes from each contact to the coils
of an electromagnet m. In front of each electromagnet is mounted a thin iron
diaphragm 7, to which is secured a shield or wedge by means of a light rod,
which shield or wedge, in its position of rest, covers over the openings I, II, III of
a box P. In the box l' is arranged a source of light L.
passes
Since now a stronger or weaker current from the selenium cells 1, 2, 3-
through the contact-pieces 111, 21, 31 to the electromagnets m, and the strength
of these currents depends upon the illumination of the selenium cells, the dia-
phragms and the wedges are correspondingly more or less strongly attracted by
the electromagnets m, and the openings I, II, III
are more or less
uncovered. Through these openings therefore, rays of light issue corresponding in
strength to the illumination of the selenium cells.
The image of these apertures must now be reduced to the size of the original

page_text: despatch in such a manner that, in the case taken, the images of the several
apertures are reduced to /, millimetre.
For this purpose, the rays of light issuing from the box P are received in a
dark chamber R by means of the objective Q.
The correspondingly reduced points of light fall on sensitized paper (which is
sensitive to light) and which is arranged in the form of an endless band in the
dark chamber, this band being moved by means of gearing r¹ from the shaft t¹,
in such a manner that it feeds forward a length of 3 millimetre for one revolution
of k¹ g¹.
In this manner there is produced on the sensitized plate H, the photograph
of the despatches a, b, c d in their original size, which can be immediately
developed, fixed and washed in the trays H¹ H2 and removed from the apparatus
ready for delivery.
II.
This second form of receiving-station, which is shown diagrammatically in
Figure 2, is based on the same principle as the one described under the heading I,
but is considerably simplified in that the commutator which is similarly con-
structed to, and works synchronously with the commutator at the transmitting
station, is done away with, and instead of the numerous telephone-like
apparatuses 1, m, t, merely a single peculiarly-arranged telephone apparatus is
required.
The current from the selenium cells 1, 2, 3– is passed to the telephone at
by means of the conductor v, Figure 2, and the diaphragm 6¹ of the said telephone
is set in vibrations corresponding to the strengths of the current. To the dia-
phragm 6 of the telephone is secured one end of a rod c¹ whilst to the other end
thereof is arranged a mirror d¹ in such a manner that it can swing in the direc-
tion indicated by arrows. A support el is secured at one end to the mirror, and at
the other end to the shell of the telephone and both axes of rotation are parallel
to the axis of oscillation of the mirror. By reason of the vibrations of the dia-
phragm 6 of the telephone, the rod e alternately rises and falls, the motion of
This rod setting the mirror into vibrations from its position of rest. On the mirror
is now projected, by means of a source of light L³ and a lens f', the image of a
point or preferably of a three-cornered aperture, which is reflected from the
mirror in a direction corresponding to the position thereof for the time being.
The lens fi is unnecessary if, a concave mirror be arranged at the telephone.
instead of a flat one.
The reflected pencil of light rays falls on a dark chamber R in such a manner
that the point thereof, which has a three-cornered transverse section enters into
the millimetre broad slit Z in the dark chamber, either not at all, or only
partially, or entirely, according to the oscillations of the mirror, and produces in
this manner an image of the point or of the three-cornered aperture g¹ on the
sensitized sheet moving behind the slit of the dark chamber, this image corre-
sponding in size and intensity to the strength of the current passing through the
telephone; in this manner an image of the corresponding point of the despatch
arranged on the wheel K at the transmitting station is produced.
Instead of one telephone, if desired, two or more can be combined together as
shown in Figure 3, with a number of reflections from the mirrors d², d³, in order
to increase the deflections of the pencil of rays.
As the telephone diaphragm makes its own vibrations between the separate
current impulses, it is necessary to bring these vibrations into unison with the
number of current impulses and to weaken or diminish same in such a way that
the separate impulses can unimpededly follow one another. The vibrations of
the telephone may be brought into unison with the number of the impulses either
by employing a diaphragm of suitable strength and size or by making the telephone
apparatus synchronizing.
A synchronizing telephone may be made as follows:
Two wires o, Figures 4 and 5, are stretched over the magnet poles of the tele-

page_text: phone on which above the two magnet poles a small iron plate o¹ is soldered which
represents the telephone diaphragm. The wires o are connected with a screw o²
by means of which they may be slackened or tightened so that the number of
vibrations of same and of the diaphragm may be regulated.
The prevention of the vibrations of the telephone may also be effected by
mechanical means by a contact o³, Figure 4, preventing the vibrations of the
diaphragm in an opposite direction to the impulses. These vibrations in opposite
directions may however also be prevented by electrical means by means of fresh
current impulses which reach the telephone when its diaphragm approaches its
position of repose after its vibration. For this object double contacts as shown
in Figure 1 are arranged on the commutator, which double contacts are succes-
sively encountered by the brushes G, or two brushes are arranged on the arms k
which successively encounter each contact 11, 21, 31, whereby after each current
impulse a second impulse immediately reaches the telephone which prevents the
vibration of the diaphragm in the opposite direction.
In addition to the source of current X a second one may also be employed which
constantly sends into the telephone a current of constant strength but from an
opposite direction. This current is as strong as the one which has passed the
selenium cells when the latter are not lighted; the two current impulses com-
pensate one another in such a way that only those current impulses come into
action which correspond to the current strengthened by the lighting of the cells.
These vibrations of the diaphragm corresponding to the differences of current
impulses are of course proportionate to the lighting of the cells.
In order that in spite of the extremely small vibrations of the telephone dia-
phragm the movements of the mirror d may be sufficiently great, the points of
rotation of the same must lie very close together which in the form of construc-
tion shown in Figures 2 and 3, causes difficulties; the result is more easily
attained by making use of the arrangement shown in Figures 6-8. On one pole
of a suitably bent magnet N S arranged above the telephone diaphragm, two small
sharp edges are formed which form the axis of rotation of the mirror d', a small
iron plate d is fixed below on the mirror, which plate in consequence of magnetic
attraction holds the mirror firmly on the sharp edges d³, and also rests on the upturned
end d of a steel spring d fixed on the other pole of the magnet which spring is
connected with the telephone diaphragm ds by means of bars d'. By this arrange-
ment the points of rotation of the mirror may be shifted suitably close together
without fear of the mirror falling down.
In order that the pencil of rays reflected from the mirror d' may be brought
along the whole length of the slit in the dark chamber, it is subjected, before it
reaches the dark chamber, to a further reflection by means of a polygonal rotary
prism h¹.
This prismatic mirror moves synchronously with the brush G of the commutator
in Figure 1 in such a manner that, whilst the prism makes one revolution on its
axis, the brush of the commutator makes as many revolutions as the prismatic
mirror has sides. The image of the variations in the current strength during
one revolution of the commutator brush, that is to say, the combined points of a
section of the original picture or of the despatch, are therefore each reflected by
one side of the prism in such a manner that, by reason of the rotation of the prism,
the pencil of rays reflected on the slit of the dark chamber is led along the whole
length thereof, whilst the arm K of the commutator makes one revolution; at the
beginning of the next revolution of the commutator-arm however, the next follow-
ing side of the prism begins to reflect and again throws the image of the point or
series of points next following on the commencing end of the slit, and then leads
the pencil of rays along the slit. In this manner therefore there is produced the
image of a row of points of the despatch on the sensitized paper, whilst the said
paper moves forward 3 millimetre.
In place of the polygonal reflecting prism the arrangement shown in Figures 9

page_text: and 10 may be adopted. Shaft h2, Figure 9, which has an equal number of rota-
tions to the shaft of the commutator of the transmitting station, carries a disc h³,
the face of which is provided with an entire cam. A lever pivoted on a shaft h
bears under the action of a spring against this cam surface.
The mirror his mounted on this lever. If then the lever he turns in the direc-
tion indicated by the arrow, the mirror, in consequence of the cam moves during
the whole rotation evenly in one direction, as soon, however, as the end of the cam
comes under lever hit springs together with its mirror suddenly back into its
initial position, and re-commences its course afresh. In place of a cam, a spiral
or snail cam, Figure 10, may be arranged on the periphery of the disc h³, in which
case of course the position of the shaft 2 must be displaced to 90°. Figures 9
and 10 make this arrangement evident without further explanation.
It is also of advantage to arrange a shield 8 on the shaft 3, Figure 11, which
shield revolves with the shaft in such a way that at the moment of the springing
back of the mirror h' it comes in front of same and prevents reflected light from
penetrating the dark chamber at this moment.
In this manner there is produced a complete picture of the despatch sent-in, the
development, fixing, washing, etcetera, whereof is effected in the manner described
under the heading I.
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. An apparatus for automatically transmitting and receiving despatches,
messages and the like in the form of a facsimile photograph of the original,
characterized by the picture of the despatch being suitably projected on to a
series of selenium cells, the electric resistance of which varies as is well known
according to the extent of the illumination, whereby a current reaches the receiving
station in the form of a current of greater or less strength and excites electro-
magnets there arranged to a greater or less extent, accordingly causing said
magnets to attract with varying force iron diaphragms arranged in front of them,
so that shields attached to these diaphragms which each cover an opening of a
box illuminated from the inside more or less uncover the said openings according
to the extent of the attraction, whereby a picture of this point of light is pro-
jected on a sensitive sheet, substantially as described.
2. An apparatus for transmitting and receiving despatches in the form of a
photograph entirely corresponding to the original, characterized by the separate
parts of the despatch (a b c d) being projected through a lens (C) at the trans-
mitting station on an enlarged scale in succession on to a series of selenium
cells (1, 2, 3) into which current is conveyed from a source of electric current (X)
by means of a rotating conductor (G) through successive contact pieces (1¹, 21, 31),
which current finds a resistance in the selenium cells corresponding to their
illumination, after which the current which has passed through the cells is con-
veyed by means of a single wire or conductor (v) to receiving conductors (k g¹)
synchronously rotating with the transmitting conductors (G) and through contact
pieces (1, 2, 3) into the coils of electro-magnets (m) which are arranged in
front of the openings (I II III) in a box (1) illuminated from the inside, and
attract diaphragms (1) according to the strength of the current, by which means
the openings (I II III) are more or less uncovered by shutters (r) attached to
the diaphragms (7) and the diminished picture of these openings is projected on
to a sensitive sheet moving synchronously with the wheel or disc (K) carrying the
despatch, on which sensitive sheet a true picture of the telegram thereby appears,
which picture is developed, fixed, washed and thus finished for delivery, sub-
stantially as described.
3. A form of construction of the apparatus for transmitting and receiving
telegraphic despatches herein before described, characterized by the separate parts
of the despatch (a, b, c, d) at the despatching station being projected in succes-

page_text: less
sion on an enlarged scale by a lens (C¹) on to a series of selenium cells (1, 2, 3)
in which a current is conveyed in succession from a source (X) of electric current
by means of a rotating conductor (k G) through contact pieces (11, 21, 3¹) which
current finds in the selenium cells a smaller or greater or resistance corresponding
to the illumination of the said cells, after which the current which has passed
the cells is conveyed in the form of a current of greater Or
strength by means of a single conductor (v) into a telephone apparatus (a)
arranged at the receiving station, on the diaphragm (6) of which telephone
apparatus a mirror (d) is oscillatingly mounted by means of a bar (c)
and support (el), which mirror in consequence of the vibrations of the diaphragm (b)
is set in oscillation and consequently reflects the picture of a point illuminated
from a source of light (L2) or rather through a triangular opening (g¹) in such
a way that the said point of light, according to the illumination of the selenium
cells and thus to the vibrations of the telephone diaphragm, enters either not at
all or only partially or entirely into an opening (Z) in a dark chamber (R) and
in this manner produces a true picture of the despatch on a sensitive sheet con-
stantly moved forward behind the opening in the dark chamber, which sensitive
sheet is then developed, fixed, washed and finished, substantially as described.
4. In apparatus for transmitting and receiving telegrams such as herein before
described, a regulatable telephone, characterized by the arrangement of two
wires (o) over the two magnetic poles of the telephone, the tension of which wires
is capable of being regulated and on which a small iron plate replacing the
telephone diaphragm is mounted substantially as described with reference to
Figures 4 and 5 of the drawings.
5. In apparatus for transmitting and receiving telegrams such as hereinbefore
described, the prevention of the subsidiary oscillations of the telephone diaphragm
by:
(a) Mechanical means by the use of a stop (o³).
(b) By electrical means by the introduction of fresh current impulses into
the telephone at the moment when the diaphragm (after the oscillation)
approaches its position of repose; substantially as described.
6. A form of construction of telephone for use in automatic apparatus for trans-
mitting and receiving telegrams such as described, with the object of enabling
the mirror (d) to indicate great deviations in spite of the minimum oscillations
of the telephone diaphragm, characterized by two small sharp edges (3) being
arranged on the one pole of the magnet (NS) and by a spring (d) being fixed on
the other pole and connected with the telephone diaphragm (8), the bent-up
end (d) of which spring forms three points of support for the mirror, on which
three points the mirror (1) provided on the under side with an iron plate (d)
rests and is constantly held by reason of magnetic attraction in spite of the com-
paratively small distance of the points from one another, substantially as described
with reference to Figures 6-8 of the drawings.
7. In apparatus for automatically transmitting and receiving telegrams such
as described, a polygonal rotating reflecting prism (h¹) arranged between the
mirror (d) and the dark chamber (R), the number of rotations of which prism
in proportion to that of the brush (G) of the commutator is as many times smaller
as the prism has sides and each side of which reflects the picture of the variations
of the strength of the current, that is to say various points of a section of the
original picture or rather of the despatch successively in such a way that the
group of rays reflected on the aperture (Z) of the dark chamber is conveyed along
the whole breadth of the same substantially as described.
8. In apparatus for automatically transmitting and receiving telegrams such
as described, the provision of a rotating or pivoting, mirror (h) in place of and
for the purpose of the polygonal rotating reflecting prism described, which mirror
is operated by means of a disc (3) on a shaft (2) which has the same number of
revolutions as the spindle of the commutator at the transmitting station, a cam

page_text: being formed on the face of the disc or a spiral surface or snail cam on its
periphery, on which surface there bears a pivoted lever (6) under the action of
a spring (h) on which lever the said mirror (h) is mounted, whereby in conse-
quence of the rotation of the shaft (2) the mirror (h) is evenly diverted, until the
lever reaches the end of the cam or spiral surface whereupon the mirror (h) springs
suddenly back under the influence of the spring (+) and commences its course
afresh substantially as described with reference to Figures 9 and 10 of the
drawings.
9. In apparatus for automatically transmitting and reproducing telegrams such
as described, the insertion of a cylindrical lens (C2) between the lens (C¹) and
the selenium cells (S), which cylindrical lens causes the point of the despatch
which has been enlarged through the first lens (C) to the width of the selenium
cells, to extend over the, in this case, increased length, substantially as described.
10. In the apparatus for automatically transmitting and receiving telegraphic
despatches such as described, the application and use of two or more compressed
telephones having multiple reflection by means of mirrors (2 d³) for the purpose
of increasing the deflections of the pencil of rays, substantially as described with
reference to Figure 3 of the drawings.
1 1000
W. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.