Improved Method and Apparatus for Rapidly Transmitting and Recording Telegrams.
Year: 1899

page_text: Date of Application, 18th Mar., 1899-Accepted, 2nd June, 1899
COMPLETE SPECIFICATION.
Improved Method and Apparatus for Rapidly Transmitting and
Recording Telegrams.
We, ANTON POLLAK, of Ilotel Royal, 45, Elisabethring, JozsEFU VIRAG, of
19, Elisabethring, JULIUS EGGER, of 7, Huszár utca, all of Budapesth, in the
Kingdom of Hungary, and Dr. FRIEDRICH SILBERSTEIN, of 5, Vorlaufstrasse,
Vienna, in the Empire of Austria, Electrician, Mechanical Engineer, Company
Director and Lawyer, respectively, 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:-
In the apparatuses hitherto known in which the despatch or transmission of a
telegram is automatically effected by means of a perforated strip of paper, the
recording of the marks or signs at the receiving station is effected either
mechanically by imprinting colour or ink on the strips of paper, or electrically,
except where Crehore & Squier's apparatus is used; as regards speed in record-
ing the signs, the greatest perfection is to be found with Wheatstone's telegraph.
It is hardly to be expected that a greater speed can be obtained by a further
improvement of the Wheatstone telegraph as the mechanism of the same is now so
fine and delicate that the handling of the same requires care and a certain skill,
in spite of which in certain cases as is known, for instance in telephony, the wire
is capable of forwarding signs following one another much more rapidly.
For these reasons Crehore & Squier in their telegraphic method have suggested
in place of the mechanical recording of the signs, a photographic recording, but
up to the present the apparatus employed by these inventors, in consequence of its
dimensions and high cost of working, by reason of the use of high tension and
powerful currents, has hindered a wider extension of this method.
We have found that the telephone described in Patent No. 168148 or a rapidly
oscillating un-restrained or un-restricted oscillations meter is very applicable for
photographically recording telegraphic signs when certain conditions are observed.
Our improvements differ, as regards their effect, from the improved arrangement
of Crehore & Squier mainly because we are no longer compelled to employ machines
for generating undulating or alternating currents, but may employ simple constant-
current sources, (electric batteries), and because the tension and intensity of the
currents are in most cases very considerably less than those of the currents employed
in other apparatuses. It may also be further noted that the electro-magnetic light-
polarising apparatus employed at the receiving station by Crehore & Squier cannot
be regarded as a suitable one, as apart from its operation requiring a considerable
amount of electrical energy the alternating current employed does not produce
sufficiently definite indicated marks on the photographic paper, as in consequence
of the gradual strengthening and weakening of the current, the dashes and dots
disappear precisely at their ends, and by reason of the great absorption of the
chemical rays the action of the light itself on the sensitive paper must be
insufficient.
It must further be noted that in the telegraphic process of Crehore & Squier,

page_text: the frequency of the alternating current employed must be a somewhat considerable
one in order that the reproduction of the signs may take place with sufficient
speed, as two entire periods are necessary for producing one mark, corresponding to
the dashes of the Morse code including the dots or intervals belonging thereto.
Finally we wish to point out that in Crehore & Squier's process, the signs
recorded are not sufficiently condensed, so that the recording of the said signs
involves a great consumption of paper, whilst the production and fixing of the
photographs necessitates a large and expensive apparatus and instruments.
Another method of photographic reproduction of the signs has been proposed
ly Ader for submarine cable telegraphy, namely in place of the lever transcribing
apparatus (syphon recorder) he registers movements of a conducting wire travel-
ling in a strong magnetic field and provided in the centre with a small diaphragm,
and traversed by electric currents, by registering or recording the digressions or
displacements of a point of light produced by a source of light being arranged in
front of the diaphragm to throw a point of light through a small aperture in the
said diaphragm onto the sensitive paper, which is constantly moved forward. This
method has however not been widely adopted, as photography in an apparatus of
such slight effectiveness as a cable telegraph offers no particular advantages.
The present invention enables telegrams to be transmitted at a speed far exceed-
ing that of the system now employed without large or expensive apparatuses being
necessary for this object. The peculiar or special construction of the apparatus
here plays only a subordinate part, and the essential peculiarity of the invention
consists actually in the method and way in which the apparatuses are employed
for telegraphic purposes.
The first part of the invention consists in a source or ray of light being employed
for the object of photographic reproduction of the signs, the intensity of which
ray remains constant, but its direction changes under the action of the current
producing the signs, this ray of light which is of constant intensity but varying
direction being received on a constantly moving sensitive sheet, which latter
reproduces and fixes in the ordinary manner the marks or signs in a writing similar
to that of the syphon recorders.
This part of our invention is therefore entirely different from the photographic
registration employed by Crehore & Squier and also the one employed by Ader, as
the ray of light in Crehore & Squier's apparatus undergoes variations of intensity
and in Ader's apparatus neither the intensity nor the direction of the ray of light
is changed, but other parts of the group. of rays on the movement or divergence
of the small diaphragm fall on the sensitive paper than was the case when it was
at rest.
In order to facilitate the comprehension of the invention, reference will now
be made to the accompanying drawings, in which
Figure 1 is a plan view, and Figure 2 a front view of a combination by means
of which this method of rapidly transmitting and recording telegrams may be
carried out.
A is a telephone provided with a mirror, said telephone being of the form of
construction described in Patent 16814 of 1898. F is a source of light from which
a group of rays falls through a diaphragm C on to a concave mirror a of the
telephone A. By means of this mirror a sharp picture is produced on the stip
of sensitive paper D which is constantly moving forward. The current trans-
mitted from the despatching station reaches the coil of the telephone A. It may
be pointed out that in order to attain the object sought for we need not exclusively
employ the mirror telephone herein before described, but that any rapidly oscillat-
ing mirror galvanometer or a so-called oscillations meter" may be employed
even if the same be not restricted or checked in fact for rapid work for the clear-
ness of the signs, and for the sensitiveness of the apparatus, it is preferable to
only slightly check or restrict the oscillating part.
66
Such oscillatographs or oscillations meters are already well known, and there-
fore it is not necessary to more particularly describe them. Blondel in the

page_text: "Electrician" Vol. 30, page 571 describes the most important types of these
apparatuses.
When a current impulse from the despatching station reaches the coil of the
telephone, the telephone diaphragm is moved and also the mirror a connected
therewith to an extent corresponding to this impulse. The oscillating mirror
produces an alteration in the direction of the reflected ray of light which change of
direction is expressed by an extraordinarily large displacement of the point of light
on the sensitive strip in proportion to the movement of the telephone diaphragm.
In consequence of the rapid vibrations of the telephone diaphragm and the
light weight of the mirror a the oscillations or vibrations of the latter are pro-
duced rapidly and the displacements are considerable even with a weak current.
In spite of this, the apparatus in this form is not yet complete, and it must
conform to certain conditions in order that the delivery of signs may be rapid and
the signs be sharp, and clearly legible. The telephone diaphragm or the oscillations
meter is in fact not in a position to reproduce with accuracy the character of the
current conveyed to it, as its own oscillations or vibrations are not checked or
restricted.
The second part of our method has therefore for its object, whilst maintaining
the clearness of the signs in spite of a moderate checking or restriction of the
vibrations, to enable the current impulses, corresponding to the separate sigus,
to be sent off from the transmitting station with great rapidity.
In order to allow of the method being better understood,, Figure 3 shows
diagrammatically the vibration or oscillation of such an apparatus where a current
of long duration is supplied. The line b indicates the position of repose of the
apparatus when it is not traversed by the current, the line c, on the other hand
shows the position of the apparatus during the passage of a current of a given
strength. If the circuit be closed at 1, the apparatus shifts at 2. over the line c
and then in consequence of its own vibration almost returns to the line b and then
cscillates or vibrates with always decreasing amplitude until the apparatus finally
comes to rest on the line c. If the apparatus were fully restricted or checked
(aperiodic) it would then describe a course, up to the line e indicated in this
diagram by the strong black curve. If however the current be interrupted at 3
where the apparatus has conveyed no noteworthy potential, or kinetic energy, as
it is in close proximity to its original position of repose, the eventual subsequent
vibration or oscillation is so small, that it can be entirely disregarded, and it does
not affect the correct reproduction of the sigus. A limitation of the duration of
the current impulse in the above direction may be produced by a selection or
arrangement of the perforations of the perforated strip of paper employed for trans-
mitting the signs at the transmitting station, and also its speed of travel in such
a way that the current impulse obtained by means of the contact produced by the
brushes only endures until the telephone diaphragm, or the vibrating part of the
oscillations meter at the receiving station has returned, in consequence of its own
vibrations, into the nearest position, to the position it assumed before the current
impulse.
The same object may be attained by suiting the direction of the current impulsc
not to the number of vibrations of the telephone, or of the vibrations or oscillations-
meter, but by modifying the number of oscillatious or vibrations of the said
apparatus to correspond with the duration of the current impulse, so that the
vibrating part stands nearest to the position it assumed before the commencement
of the vibrations, at the moment when the current impulse ceases.
The maintenance of this condition renders it necessary that the, paper
strip at the despatching station shall move forward at a given constant speed
which in practice would necessitate the use of exactly running operating machines
or mechanisms.
The said object may therefore be more easily attained by moving the paper strip
forward at a somewhat greater speed than was indicated hereinbefore, whereby
the duration of the impulse at the point of interruption is a less one whilst the

page_text: duration of time corresponding to the transmitting apparatus is obtained by intro-
ducing or inserting a condenser parallel to the transmitting apparatus whilst a
resistance may also be introduced in front of the condenser.
In consequence of this insertion a portion of the current accumulates in the
condenser when the circuit is closed, which discharges itself, after the circuit is
broken, through the coil of the telephone or the oscillation-meter.
For the object of keeping the mirror of the telephone or of the oscillation-
meter as small and consequently as light as possible, and also to allow of a weak
source of light being employed; instead of a diaphragm with a small aperture
being employed in front of the source of light, a diaphragm with an elongated
narrow slit may be employed, and the broad group of rays resulting from this,
may be condensed to one point by means of a cylindrical lens of the smallest
possible focal distance arranged in front of the sensitive sheet in closest possible
proximity to the same. The mirror may be made considerably narrower and
lighter if a cylindrical lens of small focal distance be also arranged in front of
same, the generatrix of which lens is parallel to the plane of oscillation of the ray
of light, and which is situated at such a distance from the mirror that the picture
produced by the lens results evenly on the mirror.
The ray of light reflected by the mirror again passes through the cylindrical
lens.
Fig. 4 is an elevation, and Fig. 5 a plan view of an arrangement which has been
found to be extremely advantageous.
In these figures, 4 and 5* indicate the transmitting station and 4 and 5 the
receiving station.
A pair of revoluble rollers is arranged at the transmitting station which rollers
draw under the brushes & m a perforated strip of paper corresponding to the signs
in the ordinary manner, whilst a positive or negative current passes into the con-
ducting under plates from the battery X either through the brush or the
brush m according as the brush or the brush m comes in contact with the plate
through the perforations.
A form of perforated paper strip particularly suitable for this object is shown in
Fig. 6, in which it is evident that the perforations are not circular but elongated
in form, causing the closing of the circuit and the interruption of the circuit to
proceed more precisely by reason of the more certain contacts of the brushes with
the plate 7.
The arrangement of the perforations is such that the openings serving for pro-
ducing the positive and negative impulses are arranged in separate lines. In
Fig. 6 the first four letters of the alphabet are represented by Morse signs.
The openings situated in the upper line represent the dashes, those in the under
line the dots of the Morse alphabet.
In case the current impulses used for giving the signs are not only positive
and negative, but alw of varying intensity the number of the brushes and open-
ings must be suitably arranged accordingly.
By the simultaneous utilization of current impulses of different direction and
intensity, the number of the signs may be considerably diminished, for instance,
by the weak positive impulse, forming the dots of the Morse code, whilst the
stronger impulses for the dashes, and weaker negative impulses correspond to
double dots, and the stronger negative impulses to double dashes of the Morse
code or alphabet.
These impulses reach the coil of the telephone or oscillations-meter arranged
at the receiving station 4b 5b and produce oscillations of the movable part of the
same which part is provided with a mirror. The direction and extent of these
oscillations correspond to the current impulses supplied. The group of rays falling
from the source of light F upon the mirror of the oscillating part, undergoes a
diversion proportionate to the vibrations of the mirror and describes marks running
in a spiral or zig-zag line on the sensitive sheet H fixed on the rotating and
simultaneously axially moving drum G₁ which marks after suitable developing and

page_text: fixing will correctly reproduce the text of the telegram sent from the transmitting
station. This arrangement is preferably applicable in non-continuous working
as during the changing of the already mentioned sensitive paper the second station
can send telegrams to the first, or to a third station. It may however also be
employed for continuous working if care be taken that the moment the sensitive
paper is filled with writings a second receiving apparatus entirely similar to the
one described, is switched on, whilst a fresh sheet of sensitive paper may be
inserted in the meantime in the first apparatus whilst the second is in action.
The arrangement described is merely intended to serve as an example of the
manner in which a ray of light moving to and fro in consequence of the vibrations
of a telephone or oscillations-meter may be registered photographically.
The arrangement may also be modified by the separate lines being recorded on
an endless band instead of on a sheet arranged on a drum, either in the manner
shown in Figure 1, or by the lines being arranged vertically to the direction of
movement of the band.
In this latter case, the developing and fixing of the signs may take place merely
by drawing the band through vessels containing suitable liquids.
Figure 7 shows the marks or signs made on the sensitive paper which correspond
to the letters perforated on the bands shown in Figure 6.
In order to render it possible to have a rapid succession of current impulses in
long telegraph lines in spite of the capacity and self induction of the wire it has
been found of advantage to introduce one or more self induction conductors parallel
to the line, the action of which devices is that after each current impulse a second
current impulse reaches the line wire from the opposite direction.
Condensers may also be preferably inserted in the line as is usual in cable
telegraphy.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. An improved method of rapid telegraphy in which the transmission of the
telegram proceeda automatically, characterised by the current impulses proceeding
from the transmitting station being conveyed into the coil of an electro-magnetic
apparatus, which rapidly re-acts under the influence of the current, and influences
the direction of a ray of light, and by the ray of light deficcted by means of this
apparatus in its direction corresponding to the current impulses being recorded
by photographic means, and also characterised by the correct reproduction of the
marks or signs produced by the electro-magnetic apparatus hereinbefore described
and the checking or restriction of the rapidly vibrating parts of the same being
obtained by the duration of the current impulse despatched from the transmitting
station, or the number of vibrations of the vibrating part of the electro-magnetic
apparatus, being so chosen or selected that the impulse ceases as soon as the rapidly
reaching part of the electro-magnetic apparatus by reason of its own vibrations
is nearest to the position in which it was before the commencement of the impulse,
substantially as herein before set forth.
2. A form of construction of an apparatus for carrying out the herein before
described method of rapid telegraphy consisting of a telephone or oscillations-
meter (A) provided with a mirror (a) and receiving the current impulse proceeding
from the transmitting station, and of a photographic recording apparatus, which
latter records on a strip, or sheet (DH) which is constantly moved forward, the
deviations of the ray of light reflected from the mirror, and corresponding to the
current impulses, substantially as described.
the
3. A modification of the hereinbefore described method of rapid telegraphy for
purpose of correct reproduction of the marks or signs by a checking or diminish-
ing method being employed, characterised by the current impulses being inter-
rupted at the transmitting station for the purpose of obtaining the described
necessary duration of the impulse as soon as the part of the electro-magnetic

page_text: apparatus which rapidly reacts under the influence of the current, has assumed
a position nearest to its initial position before the commencement of the impulse
substantially as described with reference to Figure 3 of the accompanying drawings.
4. A modification of the hereinbefore described method of checking or diminish-
ing the vibrations in the described method of rapid telegraphy characterised by
the current impulse at the transmitting station being earlier interrupted, and the
duration of the current impulse being extended for the necessary period by the inser-
tion or switching on of a condenser inserted in parallel with the electro-magnetic
apparatus, a resistance being also capable of being inserted before the condenser
substantially as described.
5. In the method of rapid telegraphy hereinbefore described the insertion of one
or more self-induction wires parallel to the line wire, substantially as herein before
described.
Dated this 17th day of March 1899.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.