AN ARRANGEMENT OF SEMI-AUTOMATIC APPARATUS FOR TRANSMITTING TELEGRAPH MESSAGES WITH THE MORSE SYSTEM
Year: 1878

page_text: LETTERS PATENT to Thomas James Smith, of the Firm of Robertson,
Brooman, and Company, of 166, Fleet Street, in the City of London, Patent
Agents, for the Invention of "AN ARRANGEMENT OF SEMI-AUTOMATIC
APPARATUS FOR TRANSMITTING TELEGRAPH MESSAGES WITH THE MORSE
SYSTEM." A communication from abroad by M. le Comte Emile Siccardi, of
Turin, Italy.
Sealed the 3rd May 1878, and dated the 21st January 1878.
PROVISIONAL SPECIFICATION left by the said Thomas James Smith at
the Office of the Commissioners of Patents on the 21st January 1878.
THOMAS JAMES SMITH, of the Firm of Robertson, Brooman, and Company, of 166,
Fleet Street, in the City of London, Patent Agents. "AN ARRANGEMENT OF SEMI-
AUTOMATIC APPARATUS FOR TRANSMITTING TELEGRAPHIC MESSAGES WITH
MORSE SYSTEM." (A communication from abroad by M. le Comte Emile Siccardi,
of Turin, Italy.)
THE
It is well known that in the Morse system signals are formed by the combination
of points or dots, and dashes, lines, or strokes.
The commutator for these signals consists of an oscillatory lever, upon the head
of which the operator leans or presses to close the circuit, and thus to pass the
current into the receiver.
The time during which the lever is kept lowered is short or relatively long,
according as it is desired to produce points or lines at the opposite station. This
operation demands of the workman to whom it is intrusted great skill and practice,
from the marvellous rapidity with which he has to work combined with certainty
of results. These conditions are not always attained, and the result is confused or
illegible dispatches; the object of this Invention is to do away with these incon-
veniences.
The Invention consists essentially in the employment of two contiguous finger

page_text: boards or keys, one for points or dots, and the other for dashes, strokes, or lines.
These finger boards are for this purpose joined by two vertical rods to a double
branched interruptor lever, the lowering of which must determine the contact
which closes the circuit.
The ends of the two branches upon which the rods of the keys act are furnished
with distinct appendages, so combined that the oscillation of the interruption lever
is effected differently, according as it is desired to produce a short or a long contact.
By this arrangement the operator has not to trouble himself about the duration of
the contact to be furnished, it is sufficient for him to lower one or other of the keys
according as he wishes to send lines or points.
Such is the principle of the semi-automatic commutator, the arrangement, action,
and advantages of which will be fully understood by reference to the annexed
Drawings.
The apparatus is represented in side elevation, Figure 1, and in plan, Figure 2.
A is a wooden base or pedestal supporting the column B, also of wood, upon
which are fixed the three metallic supports C, D, E, communicating with the three
bars 1, 2, 3, by conducting wires which pass through the interior of the column B.
Upon this. same pedestal is also fixed the bronze support F. Upon this latter are
movable upon a horizontal axis the two finger boards or keys of strong wood G, G',
one only of which is represented in the side view, Figure 1. These two keys are
surmounted by two vertical metallic rods H, H', which carry at their upper ends
two bronze wheels I, I, movable round a steel axis.
L is a piece screwed in the column B, by means of which can be fastened and
stretched more or less the two helical springs M, M¹, destined to bring back the
two keys G, G', to their original position.
N is a metallic lever screwing into branches b, 61, and movable upon the
support C. At the front end of the branch b, a steel triangle tis fixed, the
branch b¹ supports at the same point a steel ratchet movable upon the carriage x,
which may be caused to advance or recede at will.
S is a conducting wire having for object to establish direct communication
between the lever N and the support. D, which is itself in communication by means
of the wire passing through the interior of the column B with the bar No. 1, which
represents the line.
The lever N carries at its extremity O-a platinum-plate, and at the point O¹¹ a
point or centre, also of platinum, in order to ensure the contacts which must be
established between the lever N, and alternately between the screw U and the little
lever k.
D is a metallic support. upon which is fixed the screw U having, by an interior
wire, communication with the bar No. 2, which establishes contact with the local
receiver.
k is a little metallio lever kept constantly raised by the action of a bossage fixed
under it. This little lever is in communication with the bar No. 3, which represents
The alphabet being composed of lines and dots at a distance established between
them, when it is desired to print a line the key opposite the branch b is lowered,
this being naturally pressed. upon the triangle t, forces the lever N by this movement
to leave the screw u, with which it is in constant contact while in a state of repose,
and to encounter the little lever k, with which it established a strong contact during
the entire course of the key itself; but, as it is known; that it is only the duration
of the contact which can form a dash, it will be easily understood that it would be
impossible in this manner, by going ever so quickly, to print a point instead of a
dash.
Scarcely has the finger of the operator left the key before the latter, brought back
to its original position by the helical spring M³, again puts itself in contact with

page_text: the screw n, thus re-establishing the communication of the line with the local
receiver.
When it is desired to print a dot the key opposite the branch b' is lowered; this
in its descent meets the ratchet x, which is only movable in a direction opposite to
this course, the return movement establishing thus a very rapid contact between
the lever N and the little lever k.
By removing the finger the key returns, but by reason of the movability of the
ratchet it only rises in its return, leaving thus immovable the lever N which had
already re-established its contact with the screw u immediately after its downward
passage upon the ratchet c.
As will be easily understood, anyone adopting this new commutator will derive
the following very important advantages:-
1. The impossibility of faults arising from the formation of the signs, since by
this mechanical system the dots and dashes are invariable, while with the present
arrangement the formation of the signs is entirely dependent upon the attention
and skill of the operator.
2. The work being with this new arrangement necessarily divided between the
two keys, it consequently happens that the required distances between the signs
which form a letter (and without which it would be impossible to read the message)
are established, and perfectly regular after very short practice.
3. The time necessary for the study of this apparatus being much shorter than
for that of the present single key, it can also be adapted with great advantage for
the service of railways where the operators are generally men who, by reason of
performing several kinds of work, cannot of necessity be skilful telegraph officials.
The advantage will be felt both by the new employés who have to be taught and
by those who have had long practice in telegraphy.
4. The speed of the transmission cannot but be remarkably increased, because
having the dots determined with reference to the dashes, these latter may be much
shorter without in the least injuring the clearness of the message, and also because
the time at present employed to repeat defective messages will be saved.
5. Lastly, the working of the new key is much less fatiguing than the present
Morse commutator, since the arm of the operator has no longer any movement to
make nor force to exert.
By an arrangement about to be described, and the Drawings of which are repre-
sented in Sheet 2, the present commutator may furnish in an unfailing manner the
discharge direct to the earth after each live current. It can, therefore, be applied
with great advantage to long aerial lines, to ground cables and underground cables,
and to the submarine cables, which, not having a great length, permit the employ-
ment of ordinary Morse machines.
It will be seen by the following description that the commutator might also
render important services upon long submarine cables when the Morse alphabet is
only composed of dots either for the use of the galvanometer mirror or for that of
the siphon recorder of Mr. Thomson.
The following is a description of the parts relating to the direct discharge of the
line to earth for long aerial lines, and for short cables :-The lever N which indicates
the line, as previously stated (Figures 1 and 2), carries at the side of the branch b¹
destined to print the dash a platinum rod m movable upon a spring, and forming
part of the metallic piece d, which is itself isolated from the lever N, and giving
communication with the earth by means of the spring 8. Now, as the rod t carries
fixed to its upper end a cylinder r', half metal and half glass (Figure 6), each time
the "dash" key is lowered the cylinder r encounters the metallic piece m on its
isolating side, passes over it, and returning encounters it again; but on its metallic
side, and before the contact is re-established with the receiver it is evident that the
discharge of the current will take place direct to earth, since the rod t forms part
of the line. The same result may be obtained, but by a different arrangement for
the key which prints the dots. The branch 6 of the lever N carries screwed to its
front end an elastic plate of steel u, Figure 5. This plate is also isolated from the

page_text: :
lever N, but in communication with the earth by the helical spring S. But as the
"dash" key carries also screwed to its upper end a metallic piece r, Figure 6, this
establishes a contact of the line with the earth as soon as the point has been
printed, and before contact with the receiver can be re-established.
It is evident that the same arrangement may serve for the discharge of sub-
marine cables to the earth, and one could even (either for the discharge of submarine
cables or for long aerial lines) arrange that each emission of the current should take
place between two discharges to the earth. For this purpose it would be sufficient
to arrange the communications with this apparatus in such manner that the dis-
charges to the earth should take place by the contact of the lever N with the little
lever k at the point o¹, see Figure 1, and the sending of the currents upon the line
by arranging below the two keys G, G', Figure 2, metallic pieces in such manner
that this sending of currents should takes place by lowering one key or the other,
and directly by themselves, which will result very easily from the manner in which
the two keys are arranged. These two keys in the state of repose will establish
'contact with the receiver.
In order to have the discharge of the line direct to the earth, before and after each
sign sent, it will be sufficient to substitute for the movable ratchet x, Figure 1, and
the piece or inclined plane which must print the dash, two stops fixed in such
manner that the two keys will in their going and coming movements be com-
pelled to pass over them, establishing contact between the lever N and the little
lever k, Figure 1, that is to say, between the line and the earth.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas James Smith in the Great Seal Patent Office on the
21st June 1878.
"
THOMAS JAMES SMITH, of the Firm of Robertson, Brooman, and Company, of 166,
Fleet Street, in the City of London, Patent Agents. 'AN ARRANGEMENT OF SEMI-
AUTOMATIC APPARATUS FOR TRANSMITTING TELEGRAPHIC MESSAGES WITH THE
MORSE SYSTEM." (A communication from abroad by M. le Comte Emile Siccardi,
of Turin, Italy.)
"
It is well known that in the "Morse" system the messages are formed by com-
binations of dots, or points, and dashes, or strokes.
The commutator sending these messages consists of an oscillatory lever, whose
head is pressed upon to pass the current into the receiver.
The lever is kept lowered for a short or a relatively long time, according as to
whether it is desired to produce dots or strokes at the receiving station. This
operation requires great skill as regards rapidity, coupled with certainty, on the
part of the operator to whom it is intrusted; these conditions are not always
attained, and the result is confused or illegible messages. The new system forming
the object of the present Invention avoids these inconveniences.
This Invention consists essentially in the employment of two contiguous finger
keys, exclusively reserved, one to the dots or points, and the other to the strokes or
lines. These finger keys are for this purpose joined by two vertical rods to
a double-branched interruptor lever, the lowering of which determines the contact
which closes the circuit.
The extremities of the two branches on which the finger-key rod acts are pro-
vided with distinct appendages so contrived that the oscillation of the interruptor
lever is differently effected with the object of producing a short contact for the one,
and a long contact for the other. By this combination the operator's thoughts are
not pre-occupied by the duration of the contact to be furnished; he has only to
press upon one finger key or the other, according as he wishes, to send dots
or lines.
Such is the principle of this semi-automatic commutator apparatus, and its
arrangement, mode of working, and advantages will now be described with
reference to the annexed Drawings.
The commutator is shown in side elevation, Figure 1, and a plan, Figure 2
(Sheet 1).
DESCRIPTION.
A is a wooden base or pedestal supporting the column B, also of wood, on which
are fixed the three metallic supports, C, D, E, communicating with the three bars,
1, 2, 3, by conducting wires passing through the interior of the column B. On this
same base the bronze support F is also fixed; on a horizontal axis on the latter are
the two finger keys G, GI, of hard wood, one only of which is shown in the side
view, Figure 1. These two finger keys are surmounted by two vertical metallic
rods H, H, having at their upper ends two bronze wheels I, I¹, turning on a
steel axis.
L is a projecting piece screwed to the column B, by means of which the two
spiral springs M, M', may be fastened, and more or less distended, for ensuring the
return of the two finger keys G, G', to their place.
N is a metallic lever dividing into two branches b, b¹, and movable upon the
support C; at the front end of the branch b is fixed a steel piece t; the branch b¹
supports at the same place a steel ratchet x, movable on a carriage which may be
advanced or receded when required.
S is a conducting wire whose object is to directly establish the communication
between the lever N and the support D, which is itself in communication by the

page_text: wire passing through the interior of the column B with the bar No. 1 representing
the line.
The lever N carries a piece of platinum at its end O, and at O' a platinum point,
so as to ensure the contacts which are to take place between the lever N, and
alternately between the screw U and the small lever k.
D is a metallic support on which the screw U is fixed in communication by an
interior wire with the bar No. 2, which establishes communication with the local
receiver.
kis a small metallic lever always maintained in a raised position by the action
of a boss fixed beneath it; this small lever is in communication with the bar No. 3,
which represents the battery.
ACTION OF THE APPARATUS.
The alphabet being composed of dots and lines at a certain distance between them;
when it is desired to form a line the finger key opposite the branch b is pressed
down, the latter being thus pressed on the piece t forces by this movement the
lever N to leave the screw U, with which it is always in contact when at rest, and
to come in contact with the little balance k with which it establishes a strong con-
tact during the whole time the finger key moves down and up. Now it is known
that it is the length of time during which the contact is made which alone forms a
dash. It will be easily understood that a dot or point can never, according to this
Invention, be formed by working rapidly. Immediately the finger leaves the finger
key, the latter, sharply brought back to its original position by the spiral spring M,
returns, putting itself in contact with the screw U, thus re-establishing communi-
cation between the line and the local receiver.
When a dot or point is desired to be formed, the finger key on the branch 61 is
presed down; the latter in its downward course encounters the ratchet x which is
movable only in the direction opposite to this course, the return upwards thus
establishing a very rapid contact between the lever N and the little lever k.
On withdrawing the finger the key rises, but by reason of the mobility of the
ratchet it merely ascends in its return, thus leaving immovable the lever N which
has already re-established its contact with the screw U directly after its passage
downward on the ratchet x.
It will be readily understood that in adapting this new apparatus, the following
very important advantages are obtained :-
:-
First. The impossibility of errors resulting from the formation of the signs,
because with this mechanical and invariable system the points or dots as well as
the lines or dashes are provided for, whereas with the present commutator the
formation of the messages depends entirely upon the care, attention, and skill of the
operator.
Secondly. With this new system, the work being necessarily divided between the
two finger keys, it consequently happens that the required distances between the
signals forming a letter (without which it would be impossible to read the message),
are after very short practice established with perfect regularity.
Thirdly. This study of this apparatus being infinitely easier than that of the
present finger key, it may also be adapted with great advantage to the railway
service, in which service are often found employés having several duties to perform,
and who consequently cannot be very expert telegraph operators. This advantage
is also available either for the instruction of new employés, or for those who are
well acquainted with telegraphy.
Fourthly. The rapidity of transmission cannot fail to be great, either because
having the dots or points determined in relation to the lines, the latter may be
much shorter without in any way interfering with the clearness of the message
which increases the rapidity, or because the immense loss of time which is at
present employed in repeating incomprehensible messages caused by defective
transmission would be saved.
Finally. The manipulation of the new key is incontestably much less fatiguing

page_text: than the "Morse" commutator at present in use, for there is no movement of the
operator's arm, nor is there any force required.
APPLICATION OF THE APPARATUS TO THE DISCHARGE TO EARTH FROM AERIAL
OR SUBMARINE LINES.
By an arrangement which will now be described, the Drawings of which are
shown on Sheet 1, Figures 3, 4, 5, and 6, the present commutator may furnish
the discharge direct to earth in a sure and certain manner after each current sent
through the line. Thus it may be applied with great advantage to long aerial
lines, to aerial and subterranean cables, and to submarine cables, which having no
great length permit the ordinary "Morse" apparatus to be made available. This
commutator may also render important services (which will be afterwards
described) on long submarine cables, when the "Morse" alphabet is only composed
of dots, either in using the galvanometer mirror, or Mr. Thomson's siphon recorder.
The following is a description of the parts relating to the direct discharge from
the line to earth for long aerial lines and short cables (see Figures 3, 4, 5, and 6,
Sheet 1). The lever N which represents the line as before stated (see Figures 1
and 2), carries at the side of the branch b' intended to form the lines or strokes a
platinum rod m, Figure 4, moving on a spring and forming part with the metallic
piece d, Figure 5, the latter being insulated from lever N, and giving communi-
cation with earth by means of the spiral wire S. Now as the rod t carries on its
upper end a fixed roller, partly metallic and parly crystal, see Figure 6, each
time the key forming the lines is pressed down the roller r encounters the metallic
piece m on its insulating side, passes over the latter, and returning again encounters
the metallic piece, but on its (the roller's) metallic side and before the contact is
re-established with the receiver, it is evident that the discharge from the line is
made directly to earth, since the rod t forms part with the line. The same result
will be obtained with the key forming the dots or points, but with a different
arrangement. The branch 6 of the lever N carries a flexible steel blade u
(Figure 5) screwed on its front end; this steel blade is also insulated from the
lever N, but is in communication with earth by the spiral spring S. Now as the
key forming dashes or strokes carries also a metallic piece r, Figure 6, screwed
on its upper end, the metallic piece establishes a contact from the line to earth
directly the dot or point is formed, and before it re-establishes contact with the
receiver.
It is evident that the same arrangement may serve for the discharge to earth
from submarine cables, and one emission of the current interposed between two
discharges to earth may even be obtained, either for submarine cable or long aerial
line discharges. This may be effected by simply arranging the communications with
this commutator, so that the discharges to earth are made by the contact of the
lever N with the small lever k at O', Figure 1, and the currents sent through the
line by arranging metallic pieces beneath the two keys G, G¹, (Figure 2,) so that by
pressing down one key or the other the currents are sent or transmitted directly by
them which would easily result in consequence of the arrangement and disposition
of the keys. These two keys when at rest establish contact with the receiver.
For effecting the discharge from the line directly to earth before and after each
signal transmitted it is only necessary to place at the same spot, and instead of the
ratchet x, Figure 1, and the part or inclined plane which causes the impression of
the dash or stroke, two catches fixed in such a manner that the two keys going and
returning being obliged to pass over the establish the contact each time between
the lever N and the small lever k, Figure 1, that is to say, between the line and
earth.
DOUBLE TRANSMITTING AND CURRENT REVERSING COMMUTATOR FOR SUBMARINE

page_text: This arrangement is shown on Sheet II., in which Figure 1 is an end view, and
Figure 2, a plan of the apparatus, Figure 2. The key B and the two metallic pieces
b and b¹ are in communication with the cable. The key A and the two metallic
pieces a and a' (Figure 2) communicate with earth, and the two keys as well as the
said four pieces when in a state of repose are in contact with the bridge P (Figure 2),
that is to say, with the zinc pole of the line battery. The copper pole of the line
battery is at C; the zinc pole of the discharge battery is at d. The copper pole of
the discharge battery communicates with the zinc pole of the line battery.
The following are the results that arise in the action of the apparatus:-When
one or the other of the two keys is pressed down either the cable or the earth is put
into communication with the copper pole of the line battery through the two branches
xor n of the two keys A and B encountering one of the two movable levers a and b,
which by its oscillation establishes contact between the cable, or the earth and the
copper pole of the line battery at C; but when once the key pressed upon is let go
it encounters in its return the movable lever opposite it, forcing the latter to establish
contact at d, that is to say, with the zinc pole of the discharge battery.
Naturally, to obtain these alternative movements, the two branches x and n are
articulated in such a way that they cannot move back before the keys are released,
whilst on the contrary the two branches h, m, remain fixed at their original position
even on the return of the keys, and move back when the keys are lowered.
It is to be observed that the contacts of the liue current or the contacts of the
discharge current are always equal in their length; these two contacts being solely
produced by the passage of the ends of the four branches x, n, ih, m, over the four
steel ratchets u, v, s, t, Figure 1, which by causing the four movable pieces a, a, b, b¹,
to oscillate necessarily produces, as before mentioned, the successive contacts for the
line currents and the discharge currents. The four pieces a, a, b, 61, must be
movable independently from each other, in order to obtain this succession of
movements.
The following is a second arrangement which may be given to this commu-
tator-Instead of the two branches x, m, being articulated or jointed they are fixed.
By this means the contact of the line current will last as long as the key is lowered,
but as soon as it is released the contact of the earth or the cable with the line current
will cease, giving place to the discharge current produced by one or the other of the
two branches h or n, which are allowed to be movable only in the direction of the
lowering of the keys. In this way the discharge contacts will follow without the
least interruption the contacts of the line currents. The direct consequence of this
arrangement is never to allow the insulation of the cable during the transmission of
the line currents and the discharge currents.
; The same apparatus may also be arranged in a more simple manner, as seen in
the Drawing shown on Sheet 2, Figures 3 and 4, being a plan and an elevation of
the commutator.
The two keys A and B in this case only carry one articulated piece c'or m, insulated
from each other, but in permanent communication with the two keys A and B, that
is to say, with the cable and earth; these two articulated pieces are only movable
in the direction of the lowering of the keys, so that they cause the two movable
pieces a and b, Figure 3, to oscillate during the return of the keys, the movable pieces
by this oscillation and through their long rods O, O', establishing the contact of the
earth or the cable with the discharge zinc pole at Z.
The copper pole of the line battery is placed at C, Figures 3 and 4; the zinc pole
of the line at P; the copper pole of the discharge is brought to P by means of the
metallic communication Y, Figure 3.
I may make my system of any shapes, materials, and dimensions, according to the
requirements of its application, of its sale, and its construction.
Having thus described the mechanical arrangement of the apparatus above
described, I do not limit my rights to the special arrangements having reference to
the annexed Drawings, but extend them to all analogous mechanical arrangements
which by a simple lowering and rising or return of the two lever keys, without

page_text: clockwork, wheelwork, or other complicated agencies, permits the attainment of the
contacts of the line currents and the discharge currents alternately; I claim as new
and distinctive features of this Invention,-
First. The production of a semi-automatic commutator for the "Morse" apparatus
carrying two distinct finger keys, one for the dots or points, and the other for the
dashes or strokes, as described, and substantially as shown in the annexed
Drawings.
Secondly. Connecting these finger keys with the single interruptor lever by the
mechanical combination above described and shown, the arrangements of which
combination may however be varied in its details.
Thirdly. The arrangements above described and shown, by which the apparatus
may be utilized for the discharge direct to earth.
In witness whereof, I, the said Thomas James Smith, have hereunto set my
hand and seal, this Eighteenth day of June, One thousand eight hundred
and seventy-eight.
T. J. SMITH. (L.S.\