IMPROVEMENTS IN ELECTRO-MAGNETS APPLICABLE FOR USE IN ELECTRIC AND ELECTRO-TELEGRAPHIC APPARATUS
Year: 1872

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN ELECTRO-MAGNETS APPLICABLE FOR USE IN ELECTRIC AND
ELECTRO-TELEGRAPHIC APPARATUS."-A communication from abroad by
Ludovic Charles Adrien Joseph Guyot d'Arlincourt, of 13, Boulevart
St. Martin, Paris.
Sealed the 28th June 1872, and dated the 25th January 1872.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 25th January 1872.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN ELECTRO-MAGNETS APPLICABLE FOR
USE IN ELECTRIC AND ELECTRO-TELEGRAPHIC APPARATUS," to be as follows:-
This Invention relates, 1st, to the electro-magnets described in the
Specification of a Patent granted to me, bearing date June 23rd
1869, and numbered 1920, as a communication from the said Guyot
A

page_text: d'Arlincourt, and to improvements in the said system of electro-magnets;
and 2ndly, to improvements in telegraphic apparatus by the use of said
electro-magnets in connection therewith.
The 1st part of the Invention relates to a system of electro-magnet
applicable to telegraphic apparatus generally, as described in the former
Patent above referred to.
The principal advantages of this electro-magnet are as follows :—1st,
it has a more rapid action; 2ndly, it requires adjusting less frequently,
and residuary magnetism is suppressed; 3rdly, it may be used as a
reverser with a single current. This latter advantage more especially
renders it useful for telegraph apparatus generally.
The principle of this improved system of electro-magnet consists in
the combination of one, two, or morè ordinary electro-magnet coils with a
permanent magnet, or it may be with an electro-magnet through which a
permanent current passes, said coil (or coils) and magnet being disposed
conjointly end to end, with an oscillating tongue or pallet alternately
attracted and repelled near their point of junction. With such an
arrangement, when a current passes through the coil (supposing one
only to be employed, placed on the end of the magnet) the tongue or
pallet will be attracted; and immediately the current is broken an
inverse magnetic effect will be produced (owing to the presence of the
permanent magnet or permanent electro-magnet), together with a direct
induction current, in this case termed an extra current, which repel the
tongue or pallet. It will be readily understood that by passing the
current in the reverse direction the pallet will be first repelled and then
attracted immediately this current is broken. By using two coils dis-
posed one on each side of the pallet, the power of the apparatus may
be augmented, as they would produce contrary effects, the one attract-
ing while the other repels, and vice versa. The magnets arranged
on this principle may be either of a bar, horse-shoe, or other form.
.
Figure 1 of the accompanying Drawing shows front and side views of
one arrangement of electro-magnet.
Figure 2, an elevation and plan of another arrangement in which the
pallet is magnetized.
Figure 3 shows front and side views of another. arrangement in which
the permanent magnet is replaced by two coils or electro-magnets,

page_text: On passe
що DUIU
iron cores of said coils.
The reference letters apply to all three-Figures.
a, a¹³, ordinary electro-magnet coils or bobbins having soft iron cores;
b, permanent magnet connected to the coils a, a', the soft iron cores of
which form, so to speak, a continuation of magnet b; c, pallet, which is
in all cases pivoted at some suitable point on magnet b, with its free end
(which is polarized) near the point of junction of the coils with said
magnet; d, coils used instead of permanent magnet b.
In this manner,
as above mentioned, if a current be passed in one direction through
coils a, a¹, coil a, for example, will attract tongue or pallet c, while
coil a¹ will repel it, and immediately the current is interrupted the per-
manent magnet 6 or its equivalent (coils d, d¹,) will produce in coils a, a¹,
an inverse magnetic effect, thus causing coil a to repel pallet c while
coil a¹ attracts it.
Instead of a permanent magnet I may use non-polarized iron or steel,
which becomes magnetized by passing the current through the coils, and
retains its magnetism. In this case the pallet could be polarized or
influenced by the presence of a magnet placed in proximity thereto.
may also use two magnets, or divide the magnet attached to the coils
into two parts.
I
into two parts b¹, b¹¹,
These magnets 6ª, 6",
Figure 4 shows the magnet b, Figure 1, divided
forming a prolongation of the cores of coils a, a¹.
may as above mentioned either consist of polarized magnets or of soft
iron or steel, while the pallet may be polarized by the influence of
another magnet.
Figure 5 shows a modified arrangement of Figure 2, the part b¹ of the
magnet being separated from part 6" at E, while the pallet c instead of
being naturally magnetized is influenced by the two ends h, i, of each
magnet b¹, 6", said ends being the same pole.
Figures 7 and 8 show two similar arrangements. X, X, Figure 7,
are two magnets of bent form, the poles of which face each other as in
the preceding Figure, the north being on the side of coil Z, and south
next pallet R. The pallet being influenced by the south pole is caused
to oscillate from right to left and from left to right by the passage and
interruption of the current, and from left to right and right to left by the
simple passage and interruption of a reverse current in coil Z.
0

page_text: The relay represented in Figure 8 is the same as that in Figure 7,
except that there are two coils and two iron cores each connected with
the north pole and separated one from the other.
Figure 6 shows an elevation and plan of an arrangement in which the
pallet is polarized or influenced by a magnet placed in proximity thereto.
A', A', coils; B, non-polarized iron or steel bars replacing the magnet;
C', permanent magnet, isolated from the iron or steel bars B¹, and serving
to polarize the pallet D'. This arrangement, although differing in
construction from that previously described is based on the same
principle.
It will be seen that when I use a magnet connected to the coils, it
has the double effect, 1st, of polarizing the pallet; 2ndly, of producing
an opposite effect to that of the current which has passed through the
coils, and when an equivalent for the magnet is employed, such as the
iron or steel bar B¹ for example, which serves only for producing this
inverse effect, the polarization of the pallet D¹ is obtained by supple-
mentary means, such as a separate magnet C¹ for example. In this
arrangement coils may also be placed on the iron or steel bars B.
In all these arrangements I make use of a polarized soft iron pallet
moving freely in order to render this inverse effect more complete,
which is indispensable with autographic apparatus.
When on the contrary the relay is used for translation, I find it of
advantage to use a soft iron pallet, the reverse movement of which is
produced by the aid of a spring. In this case the principle of the
electro-magnet described is utilized to suppress any residuary magnetism.
I may also have a fixed pallet (which may be a magnet or an iron or
steel bar polarized or not by a magnet), and pivot the coils and bar, or
coils and magnet, so that these may oscillate instead of the pallet as
before. In fact the arrangement of the principal parts of the magnet
may be varied in many ways while still retaining the same principle.
The reverse effect produces on the magnet by the displacement of the
pole the direct induced current or extra current.
Figure 9 shows an arrangement of electro-magnet, which while
serving as a relay may also be used at all times for completely dis-
In this
charging the line, and also the coils of the electro-magnet.
and in the following Figures the line wire is indicated by the letter L,

page_text: and the earth connection by the letter T. a, b, metal plate, insulated
from the part c, d, of the pallet of the electro-magnet, for obtaining a
double communication by means of the relay; a, b, is that portion of
the pallet which communicates with the local battery A, while the other
part c, d, communicates with the earth for discharging the line. Thus
the line current is caused to communicate before entering coils B, B,
with part c, d, of the pallet; and when said part touches contact stud f,
which takes place when there is a current in the coils, the line is con-
nected with the earth by means of said contact stud f. The pallet is
thus caused to vibrate during the whole duration of the current, and the
coils and line are prevented from becoming charged, and when the
current is interrupted, the pallet moves in the direction of the arrow,
bringing the part a, b, in contact with the other stud e; the local
current is thus closed, and may be used for the purpose desired.
Figures 10 and 11 show an elevation and plan of a modified arrange-
ment of the above, designed to accelerate or render the discharge of the
line more effectual, as well as of the coils by a local effect, which
transform (so to speak) the electric waves into well-defined interruptions.
This discharge may be obtained by the aid of a local battery and coils
suitably disposed for producing the effect which I will now describe in
connection with an autographic apparatus. This combination consists
in the use of two additional coils n, n, which may either be placed on
the prolongations x, x, of the cores of coils B of the electro-magnet, and
at the end of said coils, or an additional wire may surround the
line coils, or the additional coils may be applied on the permanent
magnet, or at the base of the cores or otherwise for example, as in
Figure 12, in which these additional coils are applied on the ends of an
electro-magnet B, B¹. In this case, however, the ends x, x, should be
connected by an armature 9 and with the ends R, S, slightly separated
from R¹, S¹, as by a thickness of paper for example. I may also use
the line coils themselves as additional coils, or I may use an induction
coil from which I pass the current for breaking the circuit induced in
the desired direction either into the line coils or into the additional

page_text: following effect, viz., the local circuit indicated by the dotted lines will
be closed by the means before indicated, that is to say, by the aid of the
insulated part a, b, of the pallet, the other part serving to conduct the
circuit of the decomposing battery M. The current from M decomposes
the electro-chemical paper on the roller when the pallet B is in contact
with stud e, but ceases to do so when the circuit or battery M is closed
directly by pallet 6 and contact stud f, this circuit being less resisting
than the paper. During the whole time the line current acts and the
part a, b, of the pallet is in contact with stud e, the local circuit of
battery passing through coils n, n, is closed. This current being
inverse to that of the line repels the pallet, and by means of the line
current furnished by the line battery N causes its vibration in the
manner before referred to. When the line current is interrupted the
pallet is repelled, inasmuch as the local action coincides with that of the
line, that is to say, with the repellent action of the electro-magnet
resulting from the interruption of the line current. But the local
current being thus interrupted the inverse effect natural to the electro-
magnet causes it to be influenced in the direction of a new line current,
and thus facilitates the effect on the pallet of this new line current.
I may also for producing this effect make use of the decomposing
battery M itself, dispensing with the second local battery O and the
insulated part a, b, of the pallet, as represented in Figure 13, by simply
introducing into the local circuit a resistance P, which will make the
local current a little weaker than the line current in such manner that
the pallet no longer vibrates, which would prevent the decomposition
of the paper.
This system when applied to autographic telegraphs
serves to lighten the down strokes and thicken the up strokes of the
writing, which is an important improvement.
The relay may also be used for discharging the line in this case when
transmitting by sending immediately after the current of the positive
battery the discharging current from a negative battery of more or less
power, according to the length of the line, as shown in Figure 14.
When the currents from one battery do not equal those of the other
the longest or strongest current predominates, and a slight current
transmitted by the other battery cannot arrive at and mark its passage
on the receiver relay. To remedy this it is proposed to use the following
arrangement, which is applicable to telegraphic apparatus generally.

page_text: Take for example an autographic apparatus, as shown in Figure 14 of
the Drawings. A is the roller on which is placed the paper foil.
When
the style R passes over the insulating ink it causes the pallet of the
local relay B to oscillate in the direction of the regulating stud C by
interrupting the current of the local battery H. The positive current
from the line battery M passes through the coils D (of an ordinary
relay with antagonistic spring) to the line. If the writing is fine the
relay D will not act, not having time to become magnetised, and the
positive battery transmits its whole current to the line. If the writing
is thick and retains the pallet P on the stud C a longer time the ordinary
relay D will become magnetised, and its pallet will effect contact with
stud F, which by means of connections f will carry off to the earth a
great part of the current from battery M. The line current is thus
reduced in such manner that when the style again touches the foil the
relay B will oscillate the pallet towards stud G, and the negative current
which in the first instance is of full power will neutralize the reduced
positive current, and will act with inverse effect. If this negative
current continues for more than a moment the small ordinary relay D¹
placed opposite to relay D will become magnetised, and produce in the
negative or discharging battery N a deviation similar to that above
mentioned in reference to positive battery M, and so prepare the line to
receive another small positive current by the passage of the style over
the writing.
What has been described with reference to autographic apparatus
applies only to other apparatus in which currents of unequal duration
are transmitted, as in the Morse and other systems.
Another most important feature of the Invention suited to tele-
graphic apparatus generally consists in the application of this improved
electro-magnet relay for the suppression of the discharge or return
current more particularly in translating relays. For this purpose I
utilize the principle of the electro-magnet by which after the current
ceases to act on the same an inverse effect is obtained, owing to the
induction produced by the interruption of said current. Supposing for
example the electro-magnet relay be arranged as shown towards the
left-hand side in Figure 15, with the pallet A in contact with stud C,
and the current be passed in such direction through the electro-magnet
in such a manner that the pallet will bear a little more forcibly on
stud C. The passage of this current will produce no effect, but as soon

page_text: coils M, M, which causes pallet A to momentarily touch stud B,
when it again returns to C, being arranged for this purpose as above
mentioned.
The instantaneous effect above alluded to may be used for connecting
the line to be discharged with the earth (that of London L, for example,
see left side of Figure 15) by means of stud B, which communicates
'with the line and pallet A with the earth, before said line communicates
by means of pallet Q and stud F with the other translating relay N, N¹,
in which this discharge current produces a disturbance as they are now
employed. I place this small additional relay M, M, in the circuit of
the Paris battery X for example, as described in Figure 14, where it is
used for reducing the current of the line battery, while in this case it is
employed to prevent discharge or return currents. The position of the
relay is also analogous, but in Figure 14 I use an ordinary relay while
in the present instance I employ the relay described at the commence-
ment of this Specification. I may also use this small induction relay
for transmitting an instantaneous current in a contrary direction or
discharging current through the line, in which case the pallet A would
be placed in connection with the negative pole of a discharging battery,
instead of with the earth. I reserve this novel application for obtaining
other effects of a similar kind by the aid of stud B, not only with the
relay of this Invention, but any other in which an induction current is
employed for a similar purpose, this novel effect being inherent to the
improved relay.
According to another arrangement, 1st, the two coils of this ad-
ditional relay are divided or separated one from the other, and the effect
above described is obtained with a single coil I, for example, the current
through the same being indicated by the arrows (in line) in Figure 15
(right side). The coil I¹ is used for producing by the aid of the
discharge current the same effect as that already described, but the
'reverse way.
The discharge current passing in the direction of the
arrows shown in dotted lines maintains pallet H in contact with stud G
during the whole duration of this current, and immediately it ceases
the induction (above referred to) produced by its interruption causes
pallet H to pass from stud G to stud J, its original position. Thus
'the effect will be the same as that previously described and represented

page_text: on the left side of Figure 15, except that it is no longer instantaneous
and slackens during the passage of the discharge current.
It should also be remarked that coils P, P¹, cannot be affected at all,
as they only connect with the earth by means of an insulated part of the
pallet and stud J, and this only on the completion of the effect
described.
I would further remark with reference to this arrangement (Figure 15,
right side) that the relay no longer requires regulating (in order to
ensure the pallets always returning to abut against stud G, as before
described), and in order that the coils N, N', shall communicate with
the earth by stud C and pallet A, but this latter, which is an indis-
pensable position of the pallet, is ensured by the passage of the discharge
current, which on being interrupted brings pallet H over on to stud J
for connecting coils P, P¹, with the earth.
In order to obtain a stronger induction current and to augment the
action above described, which is to discharge. the line, the arrangement
shown in Figure 18 is employed. A, A¹, are coils through which the
circuit of the battery passes previous to passing through the inducing
wire of an induction coil K, the induced circuit from which com-
municates with the coils B, B', before described with reference to
Figure 6. This circuit is arranged in such manner that on the inter-
ruption of the inducing current an induction current will pass through
coils B, B³, but in a reverse direction, to reinforce the direct induction
current or extra current natural to coils A, A¹. The same effect may
also be produced by making A, A¹, induction coils, for which purposo
they are covered with an induction wire to communicate with coils B, B'.
This relay is similar to the one previously described, and may be sub-
stituted therefor, as by it a greater inductive effect may be obtained
when used for small additional discharging relays. The same effect may
also be obtained by magnetising an ordinary relay by means of a local
battery, and passing the line battery current in a reverse.direction in the
same circuit as indicated in Figure 19. Either one of these coils may
be used to produce the effect by disposing different resistances acting in
different directions, so that by simply interrupting the line current the
effect is obtained without the aid of an induction current.
The line may also be discharged, or rather the electric waves may be
transformed into well-defined interruntions by the moans desorihod with

page_text: reference to Figures 10, 11, 12, and 13. As the induction current pro-
duced by restoring the pole displaced by the line current reverses the
magnetic effect, and changes the position of the pallet of the electro-
magnet (as before explained), said current may be made to produce the
same effect in any other electro-magnet placed in proximity thereto,
thus dividing the electro-magnet into two separate parts by deriving
the current (which traverses the coils of the electro-magnet of this
Invention with the coils of the electro-magnet placed in proximity, as
shown in Figure 16, in which A is a magnet of any form desired.
B, B', coils placed on one of the poles of the magnet, or on each of
the poles as shown in Figure 17, which thus act as induction coils by
derivation with the coils C, C₁, of the relay. When the circuit breaker I
allows a current to pass it magnetises at same time both coils B, B¹, and
C, C¹, the pallet inclining to one side. On the current being interrupted
by breaker I the induction current produced by the displacement of the
pole of magnet A brings over the pallet D to the other side, and the
reversal is thus effected according to the principle of the improved
electro-magnet relay of this Invention, and the parts of which are
separated.
As before mentioned the coils of the electro-magnet may be covered
with an induction wire, and employ this second circuit for producing
the effect on the relay placed in proximity.
A still more considerable effect is obtained by placing on the
coils B, B¹, an armature such as that indicated in dotted lines in
Figure 17.
An important detail in the construction of the improved translating
relays, and which is rendered necessary owing to the slight noise made
by their pallets, consists in the use of a small pallet mounted on the free
ends of the supplementary relay coils, which pallet is operated by the
passage of the line current, and is intended merely to act as an audible
signal for controlling the transmission.
Another detail relates to simple means of adjusting the poles of
polarized electros, consisting of a small iron stud a³, Figures 20 and 21,
connected with one of the poles, and which is operated by a screwed
stem c provided with a nut b, which (in conjunction with a spiral
spring) serves for regulating the position of stud a with regard to the
pallet.

page_text: I may also employ a supplementary relay or electro-magnet placed
near the translating apparatus or relays of whatever kind for obtaining
the effects produced by the electro-magnet relay herein-before described,
for suppressing the discharge or return current either at the transmitting
or receiving end, or for producing a momentary effect by the means
described.
pursuance of the conditions of the Letters Fatent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 25th July 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of January, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alexander Melville Clark,
Her special licence that I, the said Alexander Melville Clark, my
executors, administrators, and assigns, or such others as I, the said
Alexander Melville Clark, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN ELECTRO-MAGNETS APPLICABLE
FOR USE IN ELECTRIC AND ELECTRO-TELEGRAPHIC APPARATUS," a communication
to me from abroad by Ludovic Charles Adrien Joseph Guyot
d'Arlincourt, of 13, Boulevart St. Martin, Paris, upon the condition
(amongst others) that I, the said Alexander Melville Clark, my executors
or administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent

page_text: Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Alexander Melville Clark, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being, had to the four
Sheets of Drawings hereunto annexed, and to the letters and figures
marked thereon (that is to say) :-
This Invention relates, 1st, to the electro-magnets described in the
Specification of a Patent granted to me bearing date June 23rd, 1869,
and numbered 1920, as a communication from the said Guyot d'Ar-
lincourt, and to improvements in the said system of electro-magnets,
and, 2ndly, to improvements in telegraphic apparatus by the use of
said electro-magnets in connection therewith.
The 1st part of the Invention relates to a system of electro-magnet
applicable to telegraphic apparatus generally, as described in the former
Patent above referred to.
The principal advantages of this electro-magnet are as follows:-
1st, it has a more rapid action; 2ndly, it requires adjusting less
frequently, and residuary magnetism is suppressed; 3rdly, it may be
used as a reverser with a single current. This latter advantage more
especially renders it useful for telegraph apparatus generally.
The principle of this improved system of electro-magnet consists in the
combination of one, two, or more ordinary electro-magnet coils with a
permanent magnet, or it may be with an electro-magnet through which
a permanent current passes, said coil (or coils) and magnet being
disposed conjointly end to end with an oscillating tongue or pallet
alternately attracted and repelled near their point of junction. With
such an arrangement when a current is passed through the coil (sup-
posing one only to be employed placed on the end of the magnet) the
tongue or pallet will be attracted, and immediately the current is broken
an inverse magnetic effect will be produced (owing to the presence of
the permanent magnet or permanent electro-magnet) together with a
break induction current, in this case termed an extra current, which repel
the tongue or pallet. It will be readily understood that by passing the
current in the reverse direction, the pallet will be first repelled and then

page_text: attracted immediately this current is broken. By using two coils
disposed one at each side of the pallet, the power of the apparatus may
be augmented, as they would produce contrary effects, the one attracting
while the other repels, and vice versa. The magnets arranged on this
principle may be either of a bar, horse-shoe, or other form.

page_text: divided into two parts b', 61, forming a prolongation of the cores of
coils a, a¹. These magnets 61, 6¹¹, may as above mentioned either
consist of polarized magnets or of soft iron or steel, while the pallet

page_text: In all these arrangements I make use of a polarized soft iron pallet
moving freely in order to render this inverse effect more complete, which
is indispensable with autographic apparatus.
When on the contrary the relay is used for translation I find it of
advantage to use a soft iron pallet, the reverse movement of which is
produced by the aid of a spring. In this case the principle of the
electro-magnet described is utilized merely to suppress any residuary
magnetism.
I
may
also have a fixed pallet (which may be a magnet or an iron or
steel bar, polarized or not by a magnet), and pivot the coils and bar or
coils and magnet, so that these may oscillate instead of the pallet. In
fact the arrangement of the principal parts of the magnet may be varied
in many ways while still retaining the same principle.
The reverse effect produces on the magnet by the displacement of the
pole the direct induced current or extra current.
Figure 9 shows an arrangement of electro-magnet which while
serving as a relay may also be used at all times for completely dis-
charging the line and also the coils of the electro-magnet. In this and
in the following Figures the line wire is indicated by the letter L and
the earth connection by the letter T. a, b, metal plate insulated from
the part c, d, of the pallet of the electro-magnet for obtaining a double
communication by means of the relay. a, b, is that portion of the pallet
which communicates with the local battery A, while the other part c, d,
communicates with the earth for discharging the line. Thus the line
current is caused to communicate before entering coils B, B, with
part c, d, of the pallet, and when said part touches contact stud f, which
takes place when there is a current in the coils, the line is connected to
earth by means of said contact stud f. The pallet is thus caused to
vibrate during the whole duration of the current, and the coils and line
are prevented from becoming charged, and when the current is inter-
rupted the pallet moves in the direction of the arrow, bringing the
part a, b, in contact with the other stud a; the local current is thus
closed, and may be used for the purpose-desired.
Figures 10 and 11 show an elevation and plan of a modified arrange-
ment of the above, designed to accelerate or render more effectual the
discharge of the line as well as of the coils by local means, which
transforms (so to speak) the electric waves into well-defined inter-

page_text: ruptions. This discharge may be obtained by the aid of a local battery
and coils suitably disposed for producing the effect which I will now
describe in connection with an autographic apparatus.
This com-
bination consists in the use of two additional coils n, n, which may
either be placed on the prolongations x, x, of the cores of coils B of the
electro-magnet and at the end of said coils, or an additional wire may
surround the line coils, or the additional coils may be applied on the
permanent magnet or at the base of the cores or otherwise, for example,
as in Figure 12, in which these additional coils are applied near to the
base of an electro-magnet B, B¹. In this case, however, the ends x, x, 1
should be connected by a piece q, and with the ends R, S, slightly
separated from R', S', as by a thickness of paper, for example. I may
also use the line coils themselves as additional coils, or I may use an
induction coil, from which I pass the current produced by the breaking
of the induced circuit in the desired direction, either into the line coils 1
or into the additional coils.
Again, these coils, through which is passed a local current from a
battery O, Figure 11, placed in proximity to the relay, may be applied
on any point of the relay electro-magnet, provided they produce the
following effect, viz., that the local circuit indicated by the dotted lines 2
be closed by the means before indicated, that is to say, by the aid of the
insulated part a, b, of the pallet, the other part serving to conduct the
circuit of the decomposing battery M. The current from M decomposes
the electro-chemical paper on the roller when the pallet B is in contact
with stud e, but ceases to do so when the circuit or battery M is closed 2
directly by pallet 6 and contact stud f, this circuit being less resisting
than that of the paper. During the whole time the line current acts
and the part a, b, of the pallet is in contact with stud e, the local circuit
of battery O passing through coils n, n, is closed. This current being
inverse to that of the line repels the pallet, and by means of the line
current furnished by the line battery N causes its vibration in the
manner before referred to. When the line current is interrupted the
pallet is repelled, inasmuch as the local action coincides with that of the
line, that is to say, with the repellent action of the electro-magnet
resulting from the interruption of the line current. But the local a
current being thus interrupted the inverse effect natural to the electro-
magnet causes it to be influenced in the direction of a new line current,
and thus facilitates the effect on the pallet of this new line current.

page_text: I may also for producing this effect make use of the decomposing
battery M itself, dispensing with the second local battery O and the
insulated part a, b, of the pallet, as represented in Figure 13, by simply
introducing into the local circuit a resistance P, which will make the
local current a little weaker than the line current in such manner that
the pallet will no longer vibrate, which would otherwise prevent the
decomposition of the paper. This system when applied to autographic
telegraphs serves to lighten the down strokes and thicken the up strokes
of the writing, which is an important improvement.
The relay may also be used for discharging the line (in this case at
the transmitter) by sending immediately after the current of the positive
battery the discharging current from a negative battery of more or less
power, according to the length of the line, as shown in Figure 14.
When the currents from one battery do not equal those of the other
the longest or strongest current predominates, and a slight current
transmitted by the other battery cannot arrive at and mark its passage
on the receiving relay. To remedy this it is proposed to use the
following arrangement, which is applicable to telegraphic apparatus
generally-Take for example an autographic apparatus, as shown in
Figure 14 of the Drawings. A is the roller on which is placed the
paper foil. When the style R passes over the insulating ink it causes
the pallet of the local relay B to oscillate in the direction of the
regulating stud C by interrupting the current of the local battery H.
The positive current from the line battery M passes through the coils D
(of an ordinary relay with antagonistic spring) to the line. If the
writing is fine the relay D will not act, not having time to become
magnetised, and the positive battery transmits its whole current through
the line. If the writing is thick and retains the pallet P for a time on
the stud C the ordinary relay D will become magnetised, and its pallet
will effect contact with stud F, which by means of connections f will
cause derivation to the earth of a great part of the current from
battery M. The line current is thus reduced in such manner that when
the style again touches the coil the relay B will oscillate the pallet
towards stud 9, and the negative current which at first is of full power
will neutralize the diminished positive current, and will act inversely.
This negative current continues for more than a moment the small
ordinary relay D¹ placed opposite to relay D will become magnetised, and
produce in the negative or discharging battery N a derivation similar to
R

page_text: the line to receive another small positive current by the passage of the
style over the writing.
What has been described with reference to autographic apparatus
applies also to other apparatus in which currents of unequal duration
are transmitted, as in the Morse and other systems.
Another most important feature of the Invention suited to telegraphic
apparatus generally consists in the application of this improved electro-
magnet relay for the suppression of the discharge or return current,
more particularly in translating relays. For this purpose I utilize the
principle of the electro-magnet, by which after the current ceases which
has set the same in action an inverse effect is obtained, owing to the
induction produced by the interruption of said current. Suppose for
example the electro-magnet relay be arranged, as shown towards the left
hand side in Figure 15, with the pallet A in contact with stud C, and
the current be passed in such direction through the electro-magnet that
the pallet will bear a little more forcibly on stud C; the passage of this
current will produce no effect, but as soon as it is interrupted an instan-
taneous induced current is produced in coils M, M, which causes pallet
A to momentarily touch stud B, when it again returns to C, being
arranged for this purpose as above mentioned.
The instantaneous effect above alluded to may be used for connecting
the line to be discharged (that of London L, for example, see left side
of Figure 15) with the earth by means of stud B, which communicates
with the line and pallet A, which is to earth, before said line com-
municates by means of pallet Q and stud F with the other translating
relay N, N¹, in which this discharge current produces a disturbance as
they are now employed. I place this small additional relay M, M, in
the circuit of the Paris battery ×, for example, as described in Figure 14,
where it is used for reducing the current of the line battery, while
in this case it is employed to prevent discharge or return currents. The
position of the relay is also analogous, but in Figure 14 I use an
ordinary relay while in the present instance I employ the relay described
at the commencement of this Specification. I may also use this small
induction relay for transmitting an instantaneous current in a contrary
direction, or discharging current, through the line, in which case the
pallet A would be placed in connection with the negative pole of a

page_text: discharging battery instead of with the earth. I reserve this novel
application for obtaining other effects of a similar kind by the aid of
stud B, not only with the relay of this Invention, but any other in which
an induction current is employed for a similar purpose, this novel effect
being inherent to the improved relay.
According to another arrangement, 1st, the two coils of this additional
relay are divided or separated from one another and the effect above
described is obtained with a single coil, I for example, the current
through the same being indicated by the arrows (in unbroken lines) in
Figure 15 (right side). The coil I' is used for producing by the aid of the
discharge current the same effect as that already described but the
reverse way, and the discharge current in passing in the direction of the
arrows shown in dotted lines will maintain pallet H in contact with stud
G during the whole duration of this current, and immediately the same
ceases the induction (above referred to) produced by its interruption
causes pallet H. to pass from stud G to stud J, its original position. Thus
the effect will be the same as that previously described and represented on
the left side of Figure 15, except that it is no longer instantaneous and
will slacken as long as the dischargè current passes.
It should also be remarked that coils P, P¹, cannot be affected at all, as
their connection with the earth is only by means of an insulated part of
the pallet and stud J, which can only take place on the complete
termination of the effect described.
I would further remark with reference to this arrangement (Figure 15
right side) that the relay no longer requires regulating by giving the
pallet a bias to one side (in order to ensure the pallet's always returning
to abut against stud G as before described)," and in order that the coils N,
N', shall be to earth by stud C and pallet A; but this latter which is an
indispensable position of the pallet is insured by the passage of the
discharge current, which on being interrupted brings pallet H over on to
stud J for connecting coils P, P¹, to earth.
In order to obtain a stronger induction current and to augment the
sharp momentary action of the pallet above described, which is to
discharge the line, the arrangement shown in Figure 18 is employed. A,
A', are coils through which the circuit of the battery passes previous to
passing through the inducing wire of an induction coil K, the induced
circuit from which communicates with the coils B, B', before described
B 2

page_text: with reference to Figure 6. This circuit is arranged in such manner that
on the interruption of the inducing current a true induction current will
pass through coils B, B', but in a reverse direction, to reinforce the direct
induction current or extra current natural to coils A, A¹. The same
effect may also be produced by using A, A', as what they really are,
namely, induction coils, for which purpose they are covered with an
induced or secondary wire to communicate with coils B, B¹. This relay
is similar to the one previously described, and may be substituted
therefor, as by it a greater inductive effect may be obtained when used
for small additional discharging relays. The same effect may also be
obtained by magnetising an ordinary relay by means of a local battery,
and passing the line battery current in a reverse direction in the same
circuit as indicated in Figure 19. Either one of these coils may be used
to produce the effect by disposing different resistances acting in different
directions, so that by simply interrupting the line current the sharp
momentary movement of the pallet is obtained without the aid of an

page_text: By constructing the apparatus in the above manner, two relays may
be placed on the same magnet as shown in Figure 4, which is of
advantage for translating relays. Pallet P₁ will in this case simply
have a different pole to pallet P, the former being magnetised by the
part H of the magnet, while pallet P will be magnetised by part F,
and to obtain the same effect will be simply necessary to wind the wires
advantage for
I
have a different pole to pallet P, the former being magnetised by the
part H of the magnet, while pallet P will be magnetised by part F,
and to obtain the same effect will be simply necessary to wind the wires
of the coils C, C¹, accordingly.
The following is the action of such an arrangement of electro-magnet
which operates by residuary magnetism :-The cores of the coils and the
shank although of soft iron will act after the passage of the current as a
magnet, which retains its polarity by virtue of the residuary magnetism.
Thus if on the passage of the current the end N, Figure 25, has received
north polarity and S south polarity, the pallet P which is constantly
south polarized will move towards N and thereby remain, but this takes
place only when the current is interrupted. When the current is passing
besides the principal north pole formed at N, and south pole at S,
another secondary south pole will be formed at 8, as well as a north
pole at n on the opposite sides of the coils, see Figure 26. These latter
poles will predominate, owing to the action of the currènt, and pallet P
will move towards point n. On the breaking of the current, the poles &
and n will vanish, and the principal poles will resume their action, owing
to the residuary magnetism, and cause the pallet to move in the
opposite direction to N, Figure 25. Further, on breaking the current
the extra current (which is in the same direction as the current, and
serves to reinforce the two principal poles,) will still further assist the
action of the relay. By inverting the current the same effects may be
obtained reversed. The superiority of this electro-magnet over others
is due to the fact that the residuary magnetism is made to operate the
pallet as described, instead of retarding its action as in other arrange-
ments. No adjustment is required as the stronger the current acting
in one direction, the greater will be the residuary magnetism acting in
the other.
. In passing the battery current directly to the discharge relays, as
herein-before described, the current necessarily varies according to the
state of the line, and it is preferable to produce the sharp momentary
movement of the pallet in the discharge relays by the aid of a local
battery. The line battery current in this case passes to small electros

page_text: (electros-boiteux) in which the pallet has a bias towards one side, which
also serve as sounders to indicate in an audible manner whether the
translating relays are in working order.
Figure 27 represents a plan of the translating relays. P, P¹, are line
batteries which connect with the studs V, V³, of the translating relays;
A, A, A', A¹, are the coils of the translating relays; K, K², magnets for
polarizing the pallets of all the relays, with which magnets each line is
connected and consequently with the pallets. The translation is effected
in a similar manner to other relays, except that the battery currents are
caused to traverse the coils of sounders M, M¹, before entering the
line B, B; B¹, B³, coils of the discharging relays, which receive a current
from a local battery p, which is to earth on the one hand and on the
other in constant communication with the end leading on to the
coils B, B, B1, B2, the other ends leading off, these coils being connected
to the studs x, x², and pallets N, N¹, of the said coils M, M³, being to
earth. The local circuit will be closed when pallet N makes contact
with stud X, or when pallet N¹ with stud ×¹.. Supposing the pallet N
to be operated the local circuit will pass through coils B, B, without
causing any movement in pallet R, which always remains in contact
with stud O, even during the passage of the current as previously
explained. But on the breaking of the line current and consequently
of the local current the sharp momentary blow takes place, the pallet R
of the discharge relay, which is the line through magnet K, touching
for an instant the stud S in communication with the earth. This line
(London for example) thus becomes discharged, and the return current
no longer passes through pallet L and stud T to the coils A, A³, of the
other translating relays, and produces a disturbance liable to interfere
with the transmission. The Marseilles line (for example) is discharged
in a sounder M³, coils B, B¹, and pallet R¹, which effects momentary
contact with stud S¹.
I may also simplify this above arrangement by using the sounder
itself for producing the discharging content desezibied Bath:

page_text: :
sharply or momentarily the stud u, and as the hammer is to earth and
stud u with the line the latter is thus discharged as before.
I will next describe two other arrangements of the improved relays
of this Invention for operating two pallets at the same time by the aid
of the same electro-magnet, which may be of advantage for making two
contacts at one time.
Figure 29 shows a front and side view of one of these latter arrange-
ments. On the opposite side of the coils A, C, of the electro-magnet of
this Invention, shown in Figure 22, I mount a shank M similar to B,
that is to say, I arrange the electro-magnet in an exactly similar manner
above and below the coils, and I place another pallet at P¹, similar
to P, A, C, to be operated by the same coils and current. A magnet N, O,
of any suitable form is used to polarize the pallets at each of its poles.
In this arrangement the magnetic effect, which constitutes the principle
of the relay of this Invention, is produced at both ends of the electro-
magnet for each pallet in exactly the same manner as in the case of the
pallet P, Figure 22, when the current is broken.
'
Further, instead of leaving the limbs free as in the said Figure 22,
I may, without the addition of a pallet P¹, apply an armature so as to
completely close the electro-magnet, without, however, affecting the
action of the relay, as the magnetic effect will be always produced on
pallet P, when the current is interrupted. The two pallets may also be
placed one above the other, as shown in front and side view in Figure 30,
in which case the action takes place on one side only of the coils, and
the pallet is polarized by the same limb of the magnet. This latter
arrangement may be used with or without a closed base or shank.
I would observe in conclusion that the whole of the above arrange-
ments are based on the same principle of arranging the pallet with
regard to the coils in such manner as to produce by the breaking of the
current an inverse magnetic effect on the said pallet, which causes it to
move to the opposite position to that it occupies during the passage of
the current.
It has been before stated that the principle of the improved relays of
this Invention consists in producing the inverse effect on the pallet by
simply breaking the current, and it will be observed that in the different

page_text: arrangements of relays herein-before described, this reversal is invariably
produced at the shank of the magnet.
I may also on the same principle invert an electro-magnet, and use
the shank end for acting on the pallet in the manner shown in Figure 31
of the Drawings. I use for the purpose any suitable pallet, preferably
magnetized, which is aoted on by the shank of an electro-magnet instead
of by the ends N¹, S¹, as usual.
It will be evident that the same principle of construction is observed
in this arrangement of electro-magnet, also as on the current being
passed through the coils A, B, two minor poles n, 8, will be formed at
the ends A¹, B¹, which will attract the pallet N, S, (previously mag-
netized) in the reverse direction. On the breaking of the current the
reverse effect natural to the electro-magnet takes place, owing to the
action of the ends N', S', being renewed by the residuary magnetism,
and pallet N, S, will be repelled. A spring R may be applied to the
pallet of a relay of this kind to assist in its repulsion.
By arranging the electro-magnet in the above manner, rapidity of
action is ensured, inasmuch as the residuary magnetism will assist
instead of impeding the operation of the relay. I may also slightly
modify the above arrangement, as shown in Figure 32, in which the
pallet N, S, is adapted to the shank of the magnet, but is operated on
by prolongations of the same.
Having described the nature of the Invention, and in what manner
the same is to be performed, I declare that what I claim as the
Invention to be protected by the herein-before in part recited Letters
Patent is,-
1st. The improved arrangements of the electro-magnet relay pre-
viously patented by me, dated January 23rd, 1869.
2ndly. I claim the various applications of this relay mentioned.
3rdly. I claim the several modes of discharging the line before
described and illustrated, viz., 1st, by means of a vibrating pallet, one
portion of which connects the line to the carth; or, 2ndly, by a current
from a local battery, acting inversely to the line and passing into
additional coils; or, 3rdly, at the transmitter by means of a discharging
battery, and small additional relays to reduce the current in one or
other direction so as not to overcharge the line.

page_text: 4thly. I claim suppressing the discharge or return current by the
aid of additional relays as above described.
5thly. I claim the arrangement of translating relays, described and
illustrated in Figure 27 of the Drawings, that is to say, in which the
battery current before entering the line passes to electro-magnets in
which the pallet has a bias to one side (electro-aimants-boiteux).
6thly. I claim producing the sharp momentary contact for effecting
the discharge in translating relays by the aid of the pallet in the said
electro-magnets, as illustrated in Figure 28 of the Drawings.
7thly. I claim the two arrangements of relays, shown in Figures 29
and 30, for operating two pallets at one time by means of the same
electro-magnet.
8thly. I claim the arrangements of inverted electro-magnets, described
and illustrated in Figures 31 and 32 of the Drawings.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Twenty-fourth day of July,
in the year of our Lord One thousand eight hundred and seventy-
two