IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by William Clark at the Office of
the Commissioners of Patents, with his Petition, on the 7th June
1860. A communication from abroad by Pier Alberto Balestrini, of
Paris, in the Empire of France, Engineer.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS,' to be as
follows:-
PRINCIPLE OF THE APPARATUS.
In Morse's telegraph each of the signs of the alphabet is represented by an
isolated and independant type. These types are so arranged that each of them
may be immediately set in action and worked at the will of the person desiring
to transmit the message.
The manipulating apparatus used for this purpose, consists of a small box
(seen at Figs. 2. & 3 of the Drawings annexed), composed of a base F of
considerable thickness and four sides, which are shown, of full size in the
Figure. The parts forming the box may be either of wood, hard india-rubber,
or other solid insulating substance. Three metal partitions A A, B B, C C,
divide the box into four compartments. These metal partitions, have grooves
on both sides, at equal distances apart, for the reception of small transverse
divisions d, d, d, d, also of metal, to the number of thirty-two. On each of these
thirty-two partitions is adjusted a metal plate Y, Figs. 3 & 4, forming a type
representing one of the signs of Morse's alphabet. These types consist of

page_text: surfaces of greater or less length divided into long metal parts for lines, and
very short ones for dots. The spaces between represent the intervals sepa-
rating the one from the other, and these elements compose a sign in Morse's
alphabet.
The intervals between the letters or groups of signs are produced by the
interruption of communication caused by the operator passing his finger from
one rod to another. These intervals are always longer than any other, so that
confusion becomes impossible. When in a state of rest, these parts should
preserve the position shown at Fig. 3, by the action of the spring u and
guide g.
From the foregoing it will be understood that each of the thirty-two types
above mentioned, are in metallic contact with the partitions which carry them,
and that by means of spring u, and the pin or metal screw on which they are
pivoted, each of the thirty-two partitions is in its turn in metallic contact with
the three longitudinal sides; which last also communicate with a thumb-
screw v placed at one side of the apparatus. Thus each telegraphic type is in
inetallic communication with the thumbscrew v, supposing one of the reophores
of the pile, that of the negative pole, for example, to be connected with the
screw v, it is evident that by applying the free end of the positive reophore to
any one of the metal plates constituting a type, a circuit will be established,
and a current set in action.
Supposing, however, that this apparatus be substituted on a telegraph line
instead of Morse's key lever, the wire of the line which is equivalent to the
negative reophore above mentioned, being in communication with the screw v,
it is evident that if one takes the wire of the pile, which here represents the
positive reophore in the preceding instance, & passes it over the inclined
surfaces, s¹, Fig. 3, of any one type, the lever of the Morse apparatus will
mark on the strip of paper which unwinds itself; a line of a certain length,
and which is always (the conditions of movement in the apparatus being
equal) in proportion to the length of space or surface s, s¹, travelled over.
Again, if the surfaces, s¹, instead of being entirely of metal, is made of metal,
see Figs. 4, 4, 4%, and of ivory, for instance, alternately, or in other words, of
first, a conducting and then an insulating substance, and the metal parts be
alternately very short, and of certain length, dots and lines may thus be
obtained on the said strip of paper of the same nature as the signs in Morse's
alphabet. By directing the electric current by means of metallic contact with
á given type, Morse's sign will be obtained on the paper strip representing a
letter corresponding to it. This contact may be effected at the will of the
operator in an expeditious manner, as I will now proceed to describe :-A

page_text: metal rod T, furnished with an insulating knob I, Figs. 1, 2, 3, & 7, is placed
vertically in the centre of each of the small cells formed by the longitudinal
sides & metal partitions. These rods have an up-and-down motion only.
When not in use they are kept in the position seen in Figs. 1 & 3. The
spiral spring which surrounds the lower extremity of each rod, and which.
presses against a stop M. screwed thereto, forcing them upwards. The rods T
take into the holes made in the lid & corresponding holes in the bottom of the
box. They may thus be raised and lowered as described, but cannot turn on.
their axes, being prevented by a metal plate L placed at their lower extremity,
see Figs. 3 & 7, of a T-form, and which engages in grooves made for the
purpose in each of the holes in the bottom of the box. This small plate is
bent back at one side Fig. 7, so as to form a spring, and
metal surface applied in one of the said grooves in the
This plate, in fact, serves to establish an electric contact.
part M, Figs. 1, 2, 3, 4, 5, 5, 5b, forming a kind of support for a cam C,
Figs. 1, 2, 3, 6º, 6b, turning on a screw by which it is held thereto.
takes effect on the
bottom of the box.
Each rod T has a
The cam C, is held in the position shown in the Drawing by means of
a spring e, Fig. 2, which acts on it on the side opposed to the plane s, s¹, of
the type; the cam is of metal, and is insulated on the other side, Fig. 6.
Thus I have the cam in metallic contact with the support M, this latter
in contact with rod T, which is also, by means of a spiral spring and small
plate L, in contact with the metal surface of the groove made in the side
of each of the holes in the bottom of the box or manipulator. The grooves
are all placed in contact with the thumbscrew v, so that each rod T, or cam C,
of the manipulator is in electric communication with screw v¹; from the
foregoing, the action of the several parts will be readily understood. When
at rest, the parts composing this inproved manipulator are placed in such
manner that the cam C, of rod T, Fig. 2, in each cell shall be above the
extremity s; of the corresponding type but so as not to touch it. The electric
circuit will thus be interrupted; communication does not take place until
one of the cams is lowered-so as to touch the type next to it and traverse it.
I will now proceed to describe the action of the manipulator, and how the.
transmission is effected. On the knobs of wood or ivory placed at the upper
ends of the rod-are inscribed the letters of the alphabet & the signs used in.
telegraphy, see Fig. 2, that is to say, on each knob is placed an ordinary.
letter of the alphabet and its corresponding telegraphic signs. If, for example,
it is wished to transmit the letter D, the operator presses with the end of
the forefinger on the knob on which it is inscribed, and forces down the rod.
as far as possible; the cam c then touches the inclined plane of the correspond-

page_text: ing type and traverses it throughout its length, obliging the part Y, Fig. 3,
togive way from left to right, & thus to overcome the resistance of spring u,
which presses it in the contrary direction.
The greater part of the plane traversed by the cam being of metal there is
a prolonged metallic contact, consequently, a line will be produced on the
paper strip of the receiving apparatus; the next part of the plane being of
wod or ivory interrupts the communication, and leaves a blank space on the
stip, the next short metal part, a dot, & then again ivory, as before, will leave an
interval; and, lastly, a small metal part will produce a second dot terminating
the inclined plane.
The cam having arrived at the lower end of this plane, leaves the part Y
or the type at liberty, when the latter is returned by the spring u to its original
position, & the cam also regains its place, passing this time behind the inclined
plane by means of its movement on screw v, & the action of spring e, the
object being to preserve the electric contact as the cam at this time acts, on
the type with its non-conducting part.
By thus pressing on the knob having inscribed on it the letter D, the fol-
lowing sign will be produced on the paper strip (..), which is its equi-
valent in Morse's alphabet. The same method is observed for any other letter.
The parts composing this improved manipulator may be modified, par-
ticularly the part M and cam C. By slightly increasing the dimensions of
the box and of the cells, & modifying the types, a fixed cam may be adapted
to the rod T, which will render it much simpler, but I prefer the arrangement
before described, so as to save space without altering existing arrangements
from those actually in use at telegraph stations.
It is also evident that this improved manipulator may be added to the receiving
apparatus, or the latter to the former, so as to form but one apparatus. It is
unnecessary here to describe the method of combining the two apparatus as
that will be readily understood. I here mention it only as a very important
part of this Invention, especially for telegraph apparatus for field and war
service. In military or field telegraphy, this manipulator may be employed as
it is, with the exception of adding an electro-magnet and a small hammer for
striking on a metal stud, for the purpose of assuring the following indispen-
sible conditions, viz., the means of ascertaining that communication exists,
and that the apparatus works properly, and also the means of reading a
dispatch by the noise produced by the hammer, as it is known that an expe-
rienced hand is able to read a message from the noise produced by the lever
in Morse's apparatus.
Lastly, by means of this improved manipulator, I can invert the order of

page_text: each elimentary sign (either lines or dots) transmitted by the electric current.
This is an important point in certain cases, especially in working submarine
telegraphs. For obtaining such a result it is only necessary to make the
types of insulating materials, of ivory for example, or of bone, and to fix them
on them the dots and lines of metal which are to produce the characters of
Morse's alphabet on the strip of paper. Each metal part will have then
contact and communication with first the screw v, and next the screw v¹.
The metal rod T which is the instrument by which the current is established,
does not in this case have a continuous metallic contact by means of its plate
in the grooves of the holes in the bottom of the box F, but its passage over
the surface is interupted as in the case of the type over which the cam C
passes. Thus the metal parts of this surface are also in contact alternately
with screw v and screw v¹, in such manner that the current first passes from
plate L to the cam and to the type alternately. By adopting this arrange-
ment it will be useful to give a certain developement to the manipulating
apparatus, so as to render easy any repairs that may become necessary.