IMPROVEMENTS IN THE MODE OF AND APPARATUS FOR TELEGRAPHING
Year: 1872

page_text: PROVISIONAL. SPECIFICATION left by Silvanus Frederick. Van Choate
at the Office of the Commissioners of Patents, with his Petition, on
the 21st November 1872.
I, SILVANUS FREDERICK VAN CHOATE, of Boston, Massachusetts,
United States of America, now of No. 8, Southampton Buildings, London,
Telegraphic Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MODE OF AND APPARATUS FOR TELEGRAPHING,” to
be as follows :-
My Invention relates to apparatus whereby signals, letters, or other
characters are produced either by the actinism of a beam of light on
sensitive or chemically prepared paper, or other suitable moving surface,
or by a suitable chemical agent or fluid acting on a moving surface
chemically prepared or otherwise.
The beam of light may proceed from a movable reflecting mirror, but
I prefer that the said beam of light should be immovable.
I provide clockwork to move the paper or other body or surface on
which I desire to produce or fix the lotters or characters. At a point in
the clockwork where the paper or other surface passes over a roller

page_text: .
I arrange in a peculiar manner a stationary pattern, stencil, or former,
upon which the beam of light is caused by magnetism to play or move
if a movable ray or beam of light is used. This pattern or stencil is
fixed on the frame of the clockwork in close proximity to a roller
between which and the pattern the paper or other surface moves and
receives the characters or signals. An aperture, is formed in this stencil
dise of the size and shape to produce in connection with the moving
surface beneath the letter or character desired, while the beam of light
is by the movement of the mirror made to play upon it backward and
forward as the case may be, the portion of light that falls or passes
through the aperture in the pattern only determining the shape of the
signal.
In the application and use of my Invention where the fixed or
immovable ray or beam of light is employed I arrange a second stencil,
pattern, or former, but this second one is movable by means of mag-
netism or an clectro or other magnet. This, second disc, pattern, stencil,
or former may be attached to the vibrator or armature of a magnet, and
by the action of a current of electricity or otherwise is made to move
to and fro exactly over the face or surface of the first stencil or pattern,
and in a direction at right angles to the motion of the moving paper
or other surface which is intended to receive the character or signal.
The beam of light is so arranged and focussed as to bear and rest imme-
diately upon the outer face or surface of the movable disc, stencil, or
pattern, and by the movement of the latter to the right or left as the
casc may be its pattern or surface coincides or is brought in unison with
the pattern of the first stencil or former, when the beam of light passes
through and reaches the moving paper or other surface and produces
the desired signal or character thercon. By making two apertures on
one or both of the stencils or formers a signal may be produced for each
movement of the moving stencil or former, one motion representing the
dots and the other the lines.
When necessary I arrange a suitable box or other fixture to contain
a sensitizing compound or mixture or bath, in which the paper or other
material is immersed, or through which it may pass before covering or
passing the aperture in the stencil, pattern, or former; and I also
arrange a similar vessel or bath containing a fixing substance in such a
position that the paper or other moving surface which has just received
the influence of the beam of light shall immediately pass through this

page_text: fixing substance or liquid or bath after receiving the beam of light in
order that the effect of the beam may be " brought out,” as it is com-
monly termed in photographic processes. I may use either one of these
baths or both as may be desired, and I may also use heat in connection
either with one of these baths or both of them, or in connection with
the paper or other surface if it should be desired to aid in wetting,
fixing, drying, or "bringing out” the signals or characters on the paper
more-distinctly.
-
In carrying into practice the second and most important feature of
my Invention, in which the beam of light is entirely dispensed with,
in place of the second stencil, disc, or former I arrange a camel's-
hair pencil or other like instrument, which is attached to the moving
armature of a magnet (or a lever or arm, and otherwise arranged to
move as desired by suitable mechanism,) and is made to play to and fro
upon the surface of the first and immovable stencil or former, the said
pencil or other fixture being in the proper connection with a supply of
chemical liquid or compound for producing the chemical or other effects
upon the moving paper or surface arranged to receive the signals or
letters. It will be observed that by similar movements of the paper and
of the camel's-hair pencil or other device similar characters, signals, or
letters may be produced as by the employment of the beam of light.
I also arrange the armature or other moving device which applies
the chemical fluid or compound to the moving surface or paper to move
to and from the surface of the said moving paper, whereas in the other
or former plan the movement of the armature or other device was a
lateral movement as regards the surface of the moving paper, and in
this arrangement the pattern, stencil, or former is not so essential, and
may be dispensed with altogether, though I prefer to use it in order to
give a peculiar shape to the signal. In this arrangement also there is a
very peculiar arrangement and use of the current of electricity and of
the magnets, as follows :-
The force or magnetic influence that produces the dots and lines
(when the "Morse" code is employed) is produced by a force either
magnetic or otherwise located at the receiving station, and without the
aid or influence of a current of electricity through the line or cable
from the distant or sending station, and the blank spaces separating the
parts of a letter or character as well as the words are produced by a
current or impulse of electricity acting on the receiving magnet when

page_text: the said current is sent from or produced at the distant or sending
station. The reverse of this effect is produced in the ordinary arrango-
ment of the "Morse" and other telegraphic apparatus, as the dots. and
dashes in the latter are produced by the action of the current on the
line and magnets, while the spaces are produced by the break of the
circuit or when the current is not sent over the linc..
The advantages of my system will be seen when it is observed that in
the working of submarine cables it is very difficult to produce a high
speed of signalling' by any system requiring a prolonged closed circuit
such as is necessary in the "Morse" system to produce a dash. Dots
. can be produced rapidly but not dashes; hence the utility of my In-
vention, whereby the dashes are produced by the local action of the
apparatus at the receiving station. By an arrangement of the circuits
and connections together with a peculiar construction of the operating
or breaking key any so-called "Morse" operator can operate my appa-
ratus perfectly, as by the arrangement of the key and wires as above
stated the same movements of the fingers are required in the one as in
the other system.