Improvements in Signalling by Light Flashes or Optical Tele- graphy, together with the Method of Marking the Messages thus Sent.
Year: 1887

page_text: Date of Application, 26th Jan., 1887.
Specification Accepted, 22nd July, 1887
COMPLETE SPECIFICATION.
Improvements in Signalling by Light Flashes or Optical Tele-
graphy, together with the Method of Marking the Messages
thus Sent.
We EUGENE DUCRETET and EUGENE PINEL of the Firm of E. Ducretet & Cie.,
Mathematical instrument Makers of the city of Paris in the Republic of France do
hereby declare the nature of the said invention for IMPROVEMENTS IN SIGNALLING
BY LIGHT FLASHES, OR OPTICAL TELEGRAPHY, TOGETHER WITH THE METHOD OF MARKING
THE MESSAGES THUS SENT and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :—
The features of novelty of the invention consist in an automatic method of marking
telegraphic messages communicated by luminous rays so that the messages sent can
be preserved for future reference or for correction when necessary.
In apparatus generally employed a pedal or lever acting on a small movable screen
is used which masks and unmasks the pencil of light.
By a more or less prolonged action of this pedal or lever a corresponding move-
ment of the screen is effected, thus lengthening or shortening the duration of
the light or flashes, which correspond to the dots, and dashes, of the alphabetical
code used in this kind of telegraphic communication, such for example as the Morse
system. But the messages thus sent are not marked or impressed in any way, so that
they cannot be corrected or retained, as is the case with the system forming the
subject of this invention. The importance of the advantages resulting from the
capability of retaining the message sent in an impressed form, for military or naval
purposes is incalculable.
This result can be accomplished by transforming the pedal referred to into a kind
of electrical manipulator acting by electricity on a receiver of the Morse description
on the spot, or at a distance; but in this case the apparatus which it is essential in
most cases should be light, portable, and strong, would be heavy, and delicate and
susceptible of irregularity in its functions. These drawbacks already serious with
fixed apparatus would become still more so with the portable ones.

page_text: The arrangement we adopt does not comprise any electrical organ.
Fig. of the accompanying drawings represents a front view of an apparatus of
the description embodying our invention. Fig. 2 being a side view both being
in section.
The lever or pedal P, referred to, on which the finger of the operator is placed, acts
directly on the levers L. L', with springs r. in communication with the clock
work H, vide Fig. 2, and produces two effects.
1st. It starts the clock work by the means above referred to which causes a coil of
paper to unwind from a roller, drum or wheel Z¹.
2nd. It acts upon a tracing point or style m¹ connected to the lever L' coming in
direct contact with the moving paper, leaving thereon a mark or impression corre-
sponding in length, with the duration of the luminous rays; these flashes represent the
dashes and dots of the Morse alphabet.
At first starting the pedal by the intermediary of the shaft T, levers L. L' and
springs, starts the clockwork H and consequently the unwinding of the paper Z
from the drum or wheel Z'.
The manipulation of the apparatus is very simple, and can readily be acquired by a
day or two's practice.
This system of communicating messages by light flashes can be applied to all
existing apparatus for the optical transmission of messages, no matter what may be
the nature of the lighting appliances, and can be advantageously employed as well at
sea as by land, for lighthouses, and so forth, whether the light be oil, petroleum, gas,
oxyhydrogen or electric light, whether by arc, incandescence or by solar light.
The blank spaces or separation of the words are produced by manipulating
the button or knob T. O. In pressing this down it acts on the pedal P to a
limited extent and throws the wheel work out of gear, the paper then unwinds
without any impression being made on the paper, nor opening the light emitting
aperture X.
This unwinding is intermittent or continuous by means of the bayonet adjustment g
which when required can fix the knot down, this movement can be quickly and readily
effected.
The impressions on the paper may be effected either by stamping, with a solid lead
pencil, with ink, by means of pens, with a milled wheel or by any convenient method.
A simple way of making these marks is by the use of black lead oiled cloth or tracing
cloth, or chemically prepared paper, the simple contact of a rod of copper, brass,
german silver, or other metal (according to the nature of the chemical coating
employed) on this material will suffice to make the requisite impressions or marks.
In the drawings two screens are shown that can be equally well employed. The
one marked E, takes a large course and for this purpose is provided with a rack R',
and pinion R. With the other screen E¹ shown in dotted lines which describes a
smaller circuit, the rack and pinion are dispensed with, this screen being in direct
contact with the pedal P. As soon as the operator presses on this pedal, either quickly or
slowly a similar movement of the screens E or E (whichever of these may be used)
is effected, and the light emitting aperture X is correspondingly opened and closed.
At the time of depressing the pedal P the shaft T is depressed and acting on the
levers L. L' and their springs r. starts the clock work H. The lever L ungears the
wheel work, and T continuing its course by aid of L' and effects the impression
of the signal and the complete unmasking at the same time of the light emitting
aperture X.
The tracing point or style m² is mounted on the lever L' and as the paper Z is drawn
along it presses on it against the roller m. o.
The slow or quick movement of the pedal P, therefore produces similar movements
of the screens E or E', and simultaneously with their movements corresponding marks
are made on the paper as described, the long or short dashes thus agreeing with the
long or short emissions of light forming the optical message.
The apparatus is always kept in readiness for use, either in transmitting or receiving
communications. Each station thus automatically, and mechanically prints and

page_text: preserves its messages, without any preliminary attention of the operator either in
preparing the paper, setting it in motion, stopping it, or in preparing the signals.
The clock work may be of any suitable description.
When the pedal P is no longer acted on, it quits the lever L' of the tracing point,
the clock work stops and consequently the paper no longer unwinds.
In some cases it may be necessary or expedient to project into space a pencil of
light or luminous rays X. X which is unbroken and sustained for a certain time, not
intended as a message. Whilst this sustained light continues, the action of the pedal P
is suspended, and consequently the movement of the screen over the aperture of emission
of such rays is arrested and kept open.
This is effected as follows, the screw V is screwed up against the piece M this acts
upon the double lever L", which in turn acts on the pedal P causing the rack R' by
aid of the pinion R to bring the screen E, into the position shown by the dotted lines,
thus keeping the light emitting aperture fixedly open.
When the screen is again
released, the mechanism actuating it returns to its normal position aided by the
spring r. e.
La La' are merely drawing rollers. The glasses are not shown as we have not
deemed it necessary to illustrate them.
Having now particularly described and ascertained the nature of the said invention,
and in what manner the same is to be performed we declare that what we claim is
The method of marking or transcribing the messages or communications sent by
flashes of light, such flashes being of short or long duration to correspond with the
dots and dashes of the Morse alphabetical code, the messages sent being recorded or
marked in the manner and by the means herein set forth.
MESSIEURS A. C. HENDERSON & Co.,
46, Southampton Buildings,
and 31, Lincoln Place, Dublin,
Agents for the Applicants.