IMPROVEMENTS IN ELECTRO-PHOTOGRAPHICAL RECEIVERS FOR TELEGRAPHS
Year: 1881

page_text: LETTERS PATENT to Hippolyte Chameroy, of Maison Laffitte, in the Republic
of France, for an Invention of "IMPROVEMENTS IN ELECTRO-PHOTOGRAPHICAL
RECEIVERS FOR TELEGRAPHS."
PROVISIONAL SPECIFICATION left by the said Hippolyte Chameroy at the
Office of the Commissioners of Patents on the 10th February 1881.
HIPPOLYTE CHAMEROY, of Maison Laffitte, in the Republic of France.
IMPROVEMENTS IN ELECTRO-PHOTOGRAPHICAL RECEIVERS FOR TELEGRAPHS."
The currents transmitted in telegraph wires, particularly on long lines, and
specially on submarine cables, are always exceedingly weak, on account of the loss
of energy experienced during their passage, consequently the dispatches transmitted
instead of being recorded by means of a printing receptor, are simply obtained by
means of a mirror galvanometer, which reflects the signs on a screen.
Great attention is requisite to read these dispatches, and besides, after reading,
no traces of such signs remain, consequently it is not possible to check or correct
errors of interpretation or reading.
To obviate these difficulties, I combine the use of a galvanometer with that of
the impression on a photographic paper, and I put this improvement in practice,
according to one mode of construction, as indicated below.
Fig. 1 is a lateral elevation partially in section of the apparatus, and
Fig. 2 a partial front elevation of the same, also partially in section. A is a
photographic box or camera partially in section; in its cover are made two small
holes a, a, above which is suspended as usually the needle B of a galvanometer
provided with a hollow truncated cone C open at both its extremities. A mirrow D
is fixed above this galvanometer for the purpose of reflecting at an angle of
90 degrees the rays of light projected thereon (see arrows, Fig. 1).
-
Within the camera A a sensitized paper E is wound on a reel F, from whence it
is drawn over and under the rollers f,f', and 2, by the cylinder g, g, driven by a
clockwork G. The roller f¹ is immersed in a developing and fixing liquid contained
rn

page_text: in a vase H; the passage of the paper through this liquid causes the flashes of light
directed on the same, as stated below, to be visible. A small metallic plate I is
fixed on the apex of the cone and covers during the oscillations of the cone one or
the other of the holes a, a, so that light can only penetrate in the camera at the
moment when the aperture in the said plate I coincides with one or the other of
the orifices a. A silk thread K is laid across the large base of the cone, and is
fixed on either side by two regulating screws; it serves to prevent the cone from
oscillating in any other direction than the one required for the working of the
apparatus.
According to the intensity of the current, the cone C bearing the magnetic
needle B, occupies the positions indicated in Fig. 2 by the full or by the dotted
lines, and then the luminous ray striking the mirror D is reflected in through the
cone; and when its hole provided for the passage of the light coincides with either
of those a, a, in the camera A, the sensitized paper E is acted on by the light
during the time that the current lasts; consequently, signs identical with those of
the Morse telegraph will be marked on the paper, without the necessity of
developing the same attractive force as required by the latter apparatus; when at
rest id est, when no current is transmitted, the needle is horizontal, and as none of
the holes coincide, the sensitised paper does not receive any luminous ray, and is
not acted upon.

page_text: Fig. 2, a detached part of the same on a larger scale, &
Fig. 3, a modification of the said detached part.
In the said Fig. 1, A is the mirror; B, the truncated cone swung on o, o, and
attached to the magnet or needle I; C is a drum or reel on which the sensitised
paper is rolled; D, a bath containing a developing and fixing liquid or mixture;
E, sensitised paper; F, the clock-work which draws forward the sensitised paper, &
K the box or camera obscura containing and sustaining the apparatus.
The cone B, which is attached to the needle I, is open above and pierced with
two holes on its lower surface, and the needle inclines in one or other of the
positions G or G¹, Fig. 2, according to the direction of the electric current,
consequently the ray of light striking the mirror, is projected through the holes in
the cone, & through the hole H in the cover of the camera K, striking the sensitised
paper all the while the current passes, and consequently produces thereon signs
exactly similar to those of the. Morse telegraph, with an infinitely less attractive
force than that required by the Morse telegraph; by interverting the direction of
the circuit, the needle oscillates in the opposite direction, and if the circuit is
stopped, the rays of light will not strike the paper, as will be readily seen by the
position which the cone assumes in such case, see Fig. 1.
Fig. 3 represents a cone B pierced with only one hole below; the dispatches
produced by this instrument will not be intermittent signs, as above mentioned,
but are recorded in the shape of an unbroken sinuous line.
SECOND ARRANGEMENT. Fig. 4 & 5.
In the Figure, which represents the apparatus in perspective, A is the mirror
fixed in an annular magnet B, shewn more clearly on a larger scale in plan, Fig. 5 ;
o, o, two magnets; D, the drum containing the sensitised paper; E, E, the camera
obscura; F, the clock-work for driving the paper drawing rollers L, L; I, a
cylindrical heated chamber; T, T, T, a partition intended to protect the operator
from the light from without, thereby facitilating the reading of the signs within the
apparatus, and J the paper on which the signs are made apparent.
In practice, the light coming from the direction of o passes through a lens
arranged in the wall of the camera at P and is projected on the concave mirror A,
which concentrates the rays of light at the focus o'; if the current does not pass by
the posts R, R¹, through the galvanometer G the rays of light are projected midway
in the slot H and produce a line in the centre of the paper strip J; if the current
passes from R to R¹ the annular magnet B will incline, and thereby the rays of
light are reflected through the lower part of the slot H; if, on the contrary, the
current is reversed from R¹ to R the rays of light will be projected through the

page_text: J
upper part of the slot H in consequence of the annular magnet B having inclined in
the contrary direction, carrying with it the mirror A. In action the paper drawn
forward from the drum D by the clock-work F passes between the two plates K, K'.
A slot H is cut in the plate K which prevents the rays of light from acting over a
large surface on the band, thereby facilitating the reading of the signs. On leaving
the rollers L, L, the band of paper passes on or over a cylindrical chamber I; this
chamber is heated by a lamp, as indicated, or otherwise, for the purpose of rendering
more visible the signs produced by the rays of light projected by o at o¹. The
paper can be sensitised according to any of the well known photographic
processes, as the gelatino-bromide process answers very well, being one of
the most rapid known, the action of the light or the signs appear there on in black
directly the paper has passed through the developping bath (D, Fig. 1), & which has
not been indicated in Fig. 4.. On the other hand the signs may be made to appear
in blue if the paper is prepared with silicone, or they will appear phosphorescent in
the dark if the preparation is made with metallic sulphurets, fluor of calcium, etc.
The annular magnet or galvanometer, shewn in plan on a large scale in Fig. 5,
consists in a concavė mirror A, mounted in an annular magnet B in two posts
G & G¹, on which the suspension thread D is stretched, and in the superposed
magnets c, c¹, which present to the magnet B their similar poles. This happy
arrangement is the means of overcoming serious difficulties, for when a terrestrial
magnetic current acts on the wedges or the aurora borealis, the magnet B runs
wild, and the oscillations are of the widest extent, and thereby the transmission of
dispatches or signals is rendered impossible.
The present arrangement besides being a directing force maintains the focal
center in the middle of the slot H because the pole of the magnet B, in presence of
the magnets c, c, it follows that the magnet B is animated whichever the direction
fassillation

page_text: bar; c, the diaphragm with a hole in its center; D, the needle connecting the
diaphragm C with the bar B; E, the magnet for a directing force; F, the sensitised
paper; G, the cone pierced with a hole at its basis for the passage of the rays of
light; H, the heated chamber; and I, the lens.
In this arrangement the rays of light which pass through the lens I traverse the
diaphragm C as well as the orifice of the cone and strike the paper F. If a current
passes through the galvanometer A the magnetised bar B will decline and carry
with it the diaphragm C, causing the rays of light to strike the paper either on the
right or on the left according to the direction of the current transmitted in the
galvanometer; it is sufficient that the section of the ray of light be equal to the
stroke of the diaphragm.
It will be readily understood from the above description of my apparatus that
if necessary the dispatches may be preserved, or if not preserved they may still be
read some hours after being made, thus allowing sufficient time for checking the
signs transmitted. As the speed of the galvanometer acting as a receptor is very
considerable the production of the dispatches, according to my new system, can
also be augmented without fatiguing the eyes of the clark as when they have to
read the signs off a mirror.
Having thus fully described the said Invention, and shewn how the same may
be carried into practice, I claim,-
The application of light to electro-photographic receivers as additional means of
the current for acting upon sensitized paper, thereby giving durable signs of the
kind of Morse's system, substantially as above described and for the purposes set
forth.
In witness whereof, I, the said Hippolyte Chameroy, have hereunto set my
hand and seal, this Fourth day of August, in the year of our Lord 1881,
Witnesses,
L. GUDMANN,
LÉON SCHMITZ,
HIPPOLYTE CHAMEROY. (L.S.)