IMPROVEMENTS IN ELECTRICAL SYNCHRONOUS TELEGRAPHIC " AND OTHER SYSTEMS
Year: 1883

page_text: LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey for an
Invention of "IMPROVEMENTS IN ELECTRICAL SYNCHRONOUS TELEGRAPHIC
"
AND OTHER SYSTEMS communicated to him from abroad by Patrick
B. Delany of the City and State of New York United States of America
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office of
the Commissioners of Patents on the 9th October 1883
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN
ELECTRICAL SYNCHRONOUS TELEGRAPHIC AND OTHER SYSTEMS communicated to
him from abroad by Patrick B. Delany of the City and State of New York
United States of America
"
My Invention relates to the electrical synchronous movement of apparatus at
different stations.
Various devices have heretofore been employed for operating such synchronous
movements. Among these a tuned fork automatically vibrated by a local battery
has been arranged to transinit to the coils of an electro magnet actuating a
vibrating fork at the distant station a series of electric impulses corresponding in
number with its vibrations.
It has also been proposed to employ a tuned fork vibrated by a local battery to
make and break a second circuit for electrically driving and rotating apparatus and
from the apparatus so rotated to send to the distant station by means of suitable
contacts a predetermined number of impulses for each revolution of the apparatus
to vibrate the tuned fork at the distant station.
In an organization like that last referred to it has been proposed to divide the
face of the rotary apparatus at each station into a series of electrically insulated
contacts over which a trailing arm should rotate-some of these contacts being
devoted to the sending of electrical impulses over the line from one end or station
for the purpose of vibrating the fork which makes and breaks the circuit of the
electrically rotated apparatus at the other station-the other contacts being devoted
to other purposes where synchronous movements are required.
It is very difficult to obtain a series of tuned forks which so accurately correspond
as to vibrate at exactly the same rate and from this and other causes it is difficult
to obtain a lasting synchronous movement in electrically connected apparatus of
the above kind.

page_text: The object of my invention is to provide an apparatus in which the synchronism
of the apparatus at the different stations is absolutely insured and can be maintained
for long periods of time with perfect accuracy.
To maintain the synchronous movement of the apparatus I make use of a
vibrator at each station electrically actuated by an independent local circuit-the
vibrator may be a fork or tongue, bar, reed or diaphragm of any kind which can
be vibrated by the action of an electro magnet the circuit in the coils of which is
rapidly made and broken, I prefer however to use a tuned reed or fork.
When the vibrator is started into vibration its local circuit will be automatically
made and broken in the ordinary way and its vibration will be maintained
continuously by the electro-magnet.
The vibrator I cause to make and break another local circuit which I call the
motor circuit which contains the battery and magnet by which a toothed armature
wheel is caused to rotate.
The axis of the armature wheel is connected electrically with the main line and
carries a radial arm at the end of which is a circuit completer which as the armature
wheel rotates traverses over a circle of fixed insulated contacts.
The axis also carries a cylindrical case filled with mercury to equalize the speed
of rotation.
The number of insulated contacts on the circular table of the apparatus at each
station may be varied—a convenient number is to employ say sixty contact pieces
at each station. The sixty contacts I divide into six series each containing ten
contacts. I employ two of the contacts in each series say the 9's and 10's for
maintaining the synchronous movement of the apparatus.
Whenever the armature wheels of the apparatus at the two stations are not
rotating synchronously I cause a current to pass through one or other of these
contacts and this electric impulse I cause to increase the power of the vibrator
magnet and thereby momentarily slow the vibration of the vibrator. Or I cause
it to excite a separate magnet to accelerate the speed of the vibrator. Or if a
vibrator is not employed I cause it to vary the strength of the motor magnet by
which the armature wheel is revolved so as to increase the speed of the armature
wheel. Or I cause it to excite a separate magnet which acts upon the armature
wheel in opposition to the motor magnet so as to decrease the speed of the
armature wheel,
To cause a correcting electric impulse to pass whenever the axes of the apparatus
at the two stations are not revolving synchronously I connect at one of the
stations X three equidistant 9's to one another and to a battery and three equidistant
10's to one another and to the correcting coils of an electro magnet by which
corrections are to be effected. The connected 10's are intermediate of the
connected 9's. At the other station Y the 9's corresponding to those connected to
the battery at station X are not used while the alternate lines which correspond
with those not used at station X are connected with a battery. The 10's also at
station Y which correspond with those not used at X are connected to each other
and to the coils of an electro magnet by which corrections are to be brought
about. At both stations the 10's which are connected are preferably made broader
than the other contacts so as to extend towards the adjoining unconnected 9's.
If the apparatus at X runs a trifle faster than that at Y the radial contact arm
on the axis of the apparatus at X will touch the extended side of a 10 contact
whilst the finger at Y is still on a battery connected 9. A current or impulse of
electricity will therefore be sent over the line from Y to X. The same operation
would occur at Y if the apparatus there ran too fast.
In place of the above arrangement all the 9's may be connected together and to
a battery and all the 10's be connected together and with the correcting devices.
With the contacts thus connected, when the contact arms at both stations are on 9's
the correcting batteries at the two stations would be opposed and no effect produced.
Should either of the fingers run faster than the other the correction will take place
as before described.

page_text: The correcting impulses sent along the line as above described may either be
themselves employed for exciting the controlling magnet or be made to operate a
relay or shunt so as to vary the resistance of the local fork circuit or of the motor
magnet used for revolving the armature wheel.
2
In order that the relay or shunt may operate with great rapidity I cause the
correcting current or impulse to pass through the coils of an electro magnet-the
armature of the magnet when thereby attracted is drawn away from a stop and an
independent local circuit thereby broken-this independent circuit is made to pass
through the coils of another electro magnet. A spring of comparatively high
tension tends to draw back the armature of this magnet so that when the local
circuit is broken the spring instantly draws the armature back and into contact
with a stop whereby a shunt circuit is completed to cut out a resistance which was
previously in the circuit by which the fork was vibrated or the armature wheel
revolved.
The electro magnet and armature serve also as an indicator or sounder to inform
the operator whenever a correcting impulse is received.
Another sounder may also be interposed on the control circuit at the end where
the impulse is transmitted from so that the operators at both ends know that a
control impulse has been sent and also know from which end the impulse was sent
and they can then adjust their instruments accordingly.
Obviously these sounders may be used as telegraph instruments by means of
which the operator at one end of the line in charge of the synchronous movement
may communicate with the operator at the other end of the line.
If the correcting impulses are to be used for accelerating in place of for retarding
as above described it is only necessary to reverse the battery and connecting coil
connections above described and to extend the 9's towards the 10's.
The groups of contacts 1 to 8 in each series of 10 may be connected in telegraphic
circuits or in other circuits. In order to discharge the line after each impulse a
series of discharge contacts are interposed between the several contacts in the circle
of contacts-all these discharge contacts are connected to each other and to the
ground so that as the radial contact arm passes over them the line is put to earth
and statical or other disturbances are thereby eliminated.
For multiplex telegraphic transmission the 1's and 5's in each of the six groups
of contacts may be connected to each other and by a line with a polarized relay
and key. The 2's and 6's the 3's and 7's and the 4's and 8's may each be
correspondingly connected to a relay and key.
As therefore the radial contact arm revolves over the circle of contacts each
group of contacts will be coupled to the line 12 times for every revolution. When
the radial contact arms are on correspondingly numbered contacts at each station
the corresponding instruments connected to those contacts at each station will be
placed in communication over the line and the circuit is complete and entirely
independent of the other circuits and instruments.
The main battery is preferably split and grounded at the middle-and the back
stops of the keys of the transmitting instruments are connected with one pole and
the front stops with the other so that succeeding impulses of opposite polarity are
transmitted to the line.
It will be obvious that it is matter of indifference whether four messages are
being sent simultaneously in one direction or three in one direction and one in the
other or in any other way. It is also obvious that the contacts may be connected
in a greater number of groups.
In place of the intermediate discharge contacts herein before spoken of condensers
may be used in the several telegraphic circuits.
In some cases I employ a non-vibratory circuit-breaker for controlling the
making and breaking of the circuit by which the armature wheel is revolved. For
this purpose a make and break wheel is secured on the axis of the armature
wheel-a spring contact is made to bear against the periphery of this make and
break wheel-a spring contact is also made to bear against the hub of the wheel.

page_text: One spring contact is coupled to one pole of a battery the other to the other.
When an impulse of rotation is given to the wheel the motor circuit will be
automatically made and broken through the make and break wheel and the motor
magnet so that the apparatus will be continuously rotated.
When the motor circuit is made and broken in this way the correcting impulses
which are sent over the main line may be made either to increase the strength of
this motor magnet to accelerate the speed of rotation or may excite another magnet
to act upon the armature wheel in opposition to the motor magnet so as to decrease
the speed of rotation or to act in the same way as the motor magnet to increase the
speed of rotation.
In place of arranging the mechanism so that correcting impulses are sent from
both stations they may be sent from one station only.
At one station X the 10 contacts are thrown out-the 9's are all electrically
connected to each other and to a battery. At station Y the 9's are thrown out
whilst the 10's are connected to each other and to a wire which passes through the
coils of a control magnet.
At station Y one of the 9 contacts may be connected by a wire which passes to
earth through the coil of a ticker or sounder.
Between this contact and the adjoining 8 an extra contact 81, may be placed-
the 9 being reduced in width so that it may together with the extra contact 81/,
only occupy the same width as would be occupied by a full width 9. The extra
81/ contact may be connected by a wire to the coil of an electro magnet for
accelerating the speed of rotation.
If the finger or radial contact arm at Y should run a trifle slower than that at X
it would touch the 81, contact while the finger at X is still on a battery
connected 9 and impulse of electricity would therefore pass.
The mechanism at one station may be set so that the axis at one station tends to
run faster than the axis at the other station.
At one station X the 10's would in this case be unconnected but the 9's
connected to each other and to a battery.
At Y the 9's are unconnected and the 10's connected to each other and to a wire
which passes through the coils of a retarding magnet.
At station X the battery connected 9's are extended towards the adjoining 10's
and Y the connected 10's are extended towards the adjoining unconnected 9's.
By changing the relative connection of the contacts an accelerating magnet may
be used.
When I use a vibrating fork for controlling the making and breaking of the
motor circuit I prefer to employ an adjustable rheostat in the local circuit by which
the fork is kept in movement.
By varying the resistance of the forked circuit the power of the vibrator magnet
will be increased or diminished and there will therefore be a consequent change in
the rate of the fork.
Instead of employing a deterring or accelerating magnet I may make the magnet
pole used to vibrate the fork moveable and connect it to the armature of an electro
magnet through the coils of which the controlling impulses are passed so that
the pole may be moved towards or from the fork when a correcting impulse is
transmitted through the.
When a polarized relay and split battery is used in the telegraphic system above
described I so construct the relays and arrange the circuit that the relay at the
transmitting end of the line is cut out of circuit when the transmitting impulses
are sent into the line but is momentarily thrown into the line before each
completion of the battery circuit and also so that the line at the transmitting
station is put to earth before each reversal of the battery circuit.

page_text: IN
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Sydney Pitt in the Patent Office on the 8th April 1884
SYDNEY PITT of Sutton in the county of Surrey "IMPROVEMENTS
ELECTRICAL SYNCHRONOUS TELEGRAPHIC AND OTHER SYSTEMS A Communication
to me from abroad by Patrick B. Delany, of the City and State of New York
United States of America
"
The following is a description of the invention as communicated to me by my
foreign correspondent.
My invention relates to the electrical synchronous movement of apparatus
at different stations-in other words, the apparatus at the different stations must
move simultaneously and perform each unitary movement in the same time.
Momentary variations within limits either of acceleration or retardation, which
are automatically and immediately corrected by retarding or accelerating electrical
impulses under my system, are not imperfections in the operation of my invention.
Various devices have heretofore been employed for operating such synchronous
movements. Among these, a tuned fork automatically vibrated by a local battery,
has been arranged to transmit to magnets actuating a vibrating fork at the distant
station a series of electric impulses corresponding in number with its vibrations.
It has also been proposed to employ a tuned fork vibrated by a local battery to
make and break a second circuit for electrically driving and rotating apparatus, and
from the apparatus so rotated to send to the distant station, by means of suitable
contacts, a predetermined number of impulses for each revolution of the apparatus,
to vibrate the tuned fork at the distant station, the natural rate of vibration of the
fork, which is tuned at the same pitch as the fork at the sending station, being
relied upon to maintain the synchronism of the two forks during the intervals
between such impulses.
I am also aware that in an organization like that last referred to it has been
proposed to divide the face of the rotary apparatus at each station into a series of
electrically insulated contacts over which a trailing arm should rotate; some of
said contacts being devoted to the sending of predetermined electrical impulses,
over the line from one end or station for the purpose of vibrating the fork which
makes and breaks the circuit of the electrically rotated apparatus at the other
station; the remainder of the contacts being devoted to other purposes where
synchronous movements are required.
The fork vibrating impulses, under the system above outlined are transmitted at
predetermined intervals regardless of the fact whether the fork at the distant
station is vibrating in time with the fork at the transmitting station.
It is very difficult to obtain a series of tuned_forks which so accurately
correspond as to vibrate at exactly the same rate. The forks being vibrated by
electro-magnets through the coils of which the current is automatically made and
broken for each vibration of the fork, the tines of the fork necessarily vibrate
more or less through a magnetic field, and for this reason their normal rate of
vibration is modified. In vibrating against the contacts which are necessarily
very light and elastic, the tines of the fork alternately follow up the contact of the
spring in vibrating in one direction, and are followed by the spring contact in
vibrating in the opposite direction, so that the impulses of magnetic attraction in
the vibrator magnet are more or less prolonged, and for this reason the vibration
of the fork is modified.
Owing to these considerations, and perhaps to others, which it is deemed
unnecessary to here recite, it is difficult to obtain a lasting synchronous movement
of electrically connected apparatus.

page_text: The object of my invention is to remedy all the difficulties which have
heretofore been experienced in obtaining and maintaining such movements, and to
provide an apparatus in which the synchronism of the apparatus at the different
stations is absolutely insured, and can be maintained for long periods of time
without adjustment and with perfect accuracy.
To maintain the synchronous movement of the apparatus, I make use of a
vibrator at each station electrically actuated by an independent local circuit.
These vibrators may be of any character, the sole condition being that they shall
vibrate in response to the action of electro magnets, the circuit in the coils of
which is rapidly made and broken, or be vibrated by electrically controlled
apparatus. Thus, a vibratory tongue, bar, reed or diaphragm, of any character
suitable to fulfil the conditions of the apparatus, may be employed; but it is not
necessary that the vibrator shall be confined at one end and free at the other, as a
vibratory strip confined at both ends and held either under tension or not may be
employed; and such vibrators confined at the ends may vary from a straight metal
strip to a diaphragm. I prefer, however, to avail myself of tuned reeds or forks
which possess a normal rate of vibration depending upon the tone to which they
are tuned. I have shown in the drawings tuned forks of ordinary construction,
and I prefer to employ them on account of the ease with which they may be
adjusted, although my invention as above mentioned, is not dependent upon their
use.
By employing forks which are tuned to correspond as nearly as possible so as
to give equal, or approximately equal, numbers of vibrations per second, the
apparatus at the different stations may be arranged so that when the forks are
vibrated by their independent local circuits at each station, their rates of vibration
may be approximately equal. Of course the more equal the rates of vibration the
more easily the apparatus can be brought to synchronism, and the synchronous
movement may be maintained with fewer correcting impulses than where the
normal rates of vibration of the different vibrators are more unequal.
I also employ non-vibratory circuit breakers with my synchronal system of
correction as fully illustrated in Figures 6, 7 and 8 of the accompanying drawings,
and hereafter fully described.
With this general explanation I will proceed to a detailed description of my
invention, which will render the entire system clear to those skilled in the art.
Referring to Figures 1, 2 and 3, and first with reference to figure 3, two
stations X and Y are shown organized according to one form of my improved way
of sending synchronal corrections reciprocally from one station to the other. The
apparatus at the two stations is substantially identical so far as the main features
of the operation are concerned; but there are some differences of detail especially
relating to the manner in which correcting impulses are made effective when
received. A different organization in this regard, at each end of the main line,
has been illustrated for convenience, and to avoid the unnecessary multiplication
of drawing. The organization at Y may be identical in every respect with that
at X and vice versa.
I will first describe the organization at station X. The vibrator or fork M is
automatically vibrated by a local battery P, and magnet N. This local circuit is
indicated by the fine dotted line. The cores of the vibrator-magnet are provided
with extension screws n, of magnetic metal so that the position of the poles of the
magnet may be varied relatively to the tines of the fork to regulate their rate of
vibration.
On the inner ends of the tines of the fork platinum contacts cc, xl, are placed,
which make and break contact with delicate spring fingers y y' which are carried
upon adjustable insulated levers m m' pivotted upon the bed-plate of the apparatus.
These arms are adjusted by thumb screws m' against which they are drawn by
spiral springs, so that they may be adjusted with great delicacy relatively to the
contacts on the tines of the fork. The local circuit p runs from the positive pole
of the battery P through the coils of the vibrator magnet N to the head M¹ of the

page_text: fork, through the right hand tine of the fork, contacts x and y', insulated lever m³,
to the point p¹ in the local circuit, and then to the opposite pole of the battery.
A shunt, containing a resistance R¹, is run from the head M' of the fork to the
point p' in the local circuit, to prevent sparking between the contacts x and y'.
When the fork is mechanically started into vibration its local circuit will be
automatically made and broken in the ordinary way, and its vibration be
maintained continuously by the electro-magnet N.
The contact ¹ on the opposite tine of the fork vibrates against the platinum
finger y on the arm m, and makes and breaks another local circuit which contains
the battery and magnet which continuously rotate the armature wheel D and the
transmission apparatus. This motor circuit is indicated by the broken lines and
runs from one pole of the battery O through the coils of the motor maget E, line o
to the head M of the fork, through the left hand tine of the fork, contacts x and y,
insulated lever m, and by line o to the opposite pole of the battery.
A shunt, containing a resistance R, is also thrown around the contacts a¹ and y
to prevent sparking. As the fork is continuously actuated by its local circuit at
each vibration it will make and break the motor circuit, and alternately magnetise
and demagnetise the cores of the magnet E. The cores of this magnet are
preferably somewhat pointed, as illustrated, to permit the teeth d of the armature-
wheel D to pass in close proximity to them.
The transmission apparatus consists essentially of a stationary table of
contacts C, arranged concentrically around the vertical rotating shaft B, fast on the
armature-wheel and driven thereby.
A radial-arm F, connected electrically with the main line preferably through the
shaft B, projects from said shaft, and carries a trailing circuit completer f, which
traverses the contacts on the circular table.
The transmission apparatus is illustrated in detail in Figures 1 and 2, and I will
now describe it before proceeding further.
The base plate A, which is provided with the usual binding screws for electrical
connections, carries a vertical shaft B, which has its lower bearing in the bed-plate
and its upper bearing in a bridge G. A circular table C upon which is the series
of insulated contacts is arranged concentrically around the shaft B. The radial
arm F, mounted on the shaft, is provided with a socket and set screw at its end for
holding the trailing contact-finger or circuit completer f, which sweeps over the
series of contacts. A contact-arm H electrically connected with the main line,
projects from a post and bears upon the enlargement or hub f' on the shaft B.
There is, therefore, electrical connection from the main line through the arm H,
hub f, and trailing finger f with the insulated contacts arranged on the circular-
table. Above the hub f¹ the armature disc D is keyed to the shaft B.
A cylindrical-case D₁, arranged concentrically with the shaft B, is carried on the
upper face of the toothed-armature disc, and is filled with mercury to equalize the
speed of rotation. The magnet E is carried by a right angled standard e' in the
foot of which is an elongated slot for the reception of the set screw e³. This
standard is adjusted to approach the cores of the magnet to or withdraw them
from the armature teeth of the disc by means of a screw e carried in the upright
part of the fixed plate e.
Referring again to the diagram view, Figure 3, when the motor circuit is
automatically made and broken at each vibration of the fork, the cores of the
magnet E are alternately magnetized and demagnetized, and the armature disc D
caused to rotate rapidly. In starting the disc an impulse of rotation of somewhat
greater speed than the speed by which it would be rotated by its actuating
magnet should be imparted to it, and then as the speed of the disc gradually
decreases, the armature teeth will come into proper relation to the poles of the
magnet, and into time with the makes and breaks of the motor circuit, and the
disc will be continuously driven.
The construction and arrangement thus far described is identical at both the
stations X and Y.

page_text: I have shown on the circular tables of contacts at each station sixty contact
pieces, the contacts on each table being divided into six independent series, each
containing ten contacts. I employ two of the contacts, say the 9's and 10's in
each series for maintaining the synchronous movement of the apparatus, as
presently described. The remaining eight contacts in each series may be connected
up for telegraphic transmission, as hereinafter described, or may be connected in
any way and used for any suitable purpose, and where synchronism only is desired,
and no other than synchronal correcting impulses are sent into the line, the space
occupied by them may be left blank.
At
I will now describe the manner of maintaining the synchronal movement of the
apparatus at the two stations. At station X three of the 9's, furthest removed
from each other, are connected together and to a battery Q, and three of the 10's,
furthest removed from each other, are connected together and to a line n' which
passes through two supplementary correcting or regulating coils N¹ on the cores
of the vibrator magnet N, and thence to ground. The remaining three inter-
mediate 9's and 10's are thrown out, or unconnected with any circuit.
station Y the 9's, corresponding to those connected to the battery at station X,
are thrown out, while the alternate 9's, which correspond with those thrown out
at station X, are connected with battery Q; and the 10's at station Y which are
connected with each other, and through the wire N¹ with the correcting devices,
which will be presently described, correspond with those which are thrown out at
station X, the 10's at station Y, corresponding to the connected 10's at station X,
being also thrown out or unconnected. At both stations the three 10's which are
connected with the correcting devices through the lines n³, are preferably extended
or built out toward the adjoining unconnected 9's
When the trailing arms f at both stations are moving synchronously and rest
on corresponding contacts on about the same portions of those contacts, the circuits
from a contact at one station to the corresponding contact at the other station
will be complete and independent of any of the other contacts, and such an
independent circuit is successively given to each pair of corresponding contacts as
the circuit completers synchronously rotate. If the apparatus at X runs a trifle
faster than at Y the finger f at X will touch the extended side of a 10-contact,
while the finger at Y is still on a battery connected 9. A current or impulse of
electricity will, therefore, be sent from the battery Q at station Y through the
9-contact and finger f over the line, and through the 10-contact and line n¹
through the correcting coils N₁ on the cores of the vibrator magnet N. The effect
of this pulsation of electricity is to increase the power of the vibrator-magnet and
momentarily slow the vibration of the fork, and consequently the rotation of the
armature disc and finger, and the trailing contact finger f will immediately drop
back into its proper relative position.
Exactly the same operation would occur at station Y, when the apparatus there
ran too fast, if the wire n¹ were connected with supplementary coils on the
vibrator-magnet as it might be but at this station I have shown another means of
making effective the correcting impulses, which I will presently describe, and
I again repeat that the arrangement at station X might, if desired, be the same as
at station Y.
As the connected 10s. are extended towards the adjoining 9s, a variation of
speed very much less than that sufficient to carry one trailing finger across the
space between any two of the other contacts, is immediately corrected, and where
such other contacts are used there is no danger of bridging before the variation is
corrected.
I prefer to connect the correcting contacts, as above described, so that three
correcting impulses of electricity may be received over the line for each revolution
of the trailing fingers. Under this organization, when the finger at one station is
on a connected 10, the finger at the other station will be on the corresponding
unconnected 10, and the circuit will be open; and when the fingers are on the 98
one of them will be connected to a correcting battery, and the other will be

page_text: unconnected. If desired, however, all the 9s, may be connected to each other,
and to the batteries at each station, and all the 10s. may be connected to each
other and with the correcting devices. With the contacts thus connected, when
the fingers at both stations are upon 9s. the correcting batteries will be opposed
to each other and no effect will be produced, and when they are upon 10s. there
will be a complete circuit from the ground, and correcting devices at one station
to the ground at the other station, but there will be no battery on the line.
Should either one of the fingers run faster than the other, the correction will take
place exactly as before described, and six correcting impulses may be received in
one revolution of the trailing fingers.
In explanation of the fact that an increase in the strength in the fork magnets.
causes the tines of the fork to vibrate more slowly, I desire to say that I have
demonstrated it frequently by experiment. Practically the correcting impulses may
operate to prolong the magnetism of the vibrator magnet. In any event the tines
of the fork have a greater amplitude and a slower rate when the power of the
vibrator-magnet is increased.
Referring now to station Y, the correcting impulses are made effective by
automatically varying the resistance of the local fork circuit. The local circuit p
runs normally through an adjustable box of resistances R'. When the apparatus
at Y runs too fast however and a correcting impulse is received from X into the
line n¹ a relay S in that line is energized, so that its armature is drawn from its
back stop, thus breaking the local circuit of a second electro-magnet S¹, and
permitting its armature to fall to its back stop, thus completing a shunt circuit
around the resistance R³, and cutting it out of the fork vibrating circuit. The
electro-motive force of the vibrator-circuit is therefore momentarily increased, the
vibration of the fork momentarily retarded, and the rotation of the trailing finger
slowed, so that it drops back to the proper point.
It will be observed that when the correcting impulse actuates the relay S the
moment the armature of that relay leaves its back stop, the local circuit of the
magnet S¹ is broken, and its armature is instantly drawn to its back stop, thus
completing the shunt around the resistance. The adjustment of the armature of
the relay S is very delicate, so that it responds immediately to any correcting
impulse, while the spring of the magnet or sounder S¹ is of a comparatively high
tension, so that it moves to its back stop instantaneously. This plan of making the
correcting impulse effective, when the armature of the relay S leaves its back stop,
I consider very important, as the corrections are practically instantaneously made
effective, whereas if they were not made effective until the armature of the relay S
had been drawn to its front stop, the action of the correcting devices would be
sluggish. This feature of my invention is not limited to the intervention of the
magnet S¹ between the first relay and the shunt circuit; nor to any particular
manner of utilising the correcting impulse. But I consider my invention broadly
to consist in the feature of making the correcting impulse effective when contact
with the back stop of the relay is broken.
I have shown the apparatus organised for correcting by deterring impulses only,
but it may just as well be arranged for acceleration when the instrument at one
station runs slower than that at the other. At station Y this would be accomplished
by so arranging the relays and circuits as to normally shunt the resistance, but
throw it into the forked circuit to decrease the electro motive force whenever a
correcting impulse is received. Such a variation is obvious, an illustration of it
is unnecessary.
At station X the apparatus may also just as well be arranged for acceleration.
The only modification necessary is to reverse the battery and correcting coil
connections, extend the 9s. toward the 10s, and place the acceleration magnet
between the tines of the fork, as illustrated in figure 9, of the accompanying
drawings, which figure will hereinafter be described in detail. A corresponding.
change of contacts would also be required at station Y were it arranged for
acceleration as above described.

page_text: In explanation of such an accelerating magnet, I desire to say the vibrator
magnet, when placed outside of the contacts of the fork, as here illustrated,
creates magnetic fields, through which the tines vibrate, and which, to some extent,
retard and interfere with their normal rate. Any impulse of electricity, therefore
which increases the strength of these fields, acts as a retardation, as above
described; while on the contrary, if the vibrator magnet is placed on the outside
and another magnet be placed between the tines of the fork, any magnetic impulse
in such an interposed magnet operates to neutralize the effect of the magnetic
fields of the magnet on the outside of the fork, and the tines of the fork are
therefore permitted to vibrate in response to makes and breaks in the vibrator
circuit with more freedom, and consequently with greater rapidity.
In the organisation shown at station Y the electro magnet or sounder S¹ serves
as an indicator or tell-tale to inform the operator when a correcting impulse is
received. In order that the operator may also know when correcting impulses are
sent from his battery to the distant station, I place a relay T in the line q which
connects the 9-contacts with the correcting battery Q, so that whenever a
correcting impulse of electricity is sent into the line at station Y, the sounder T¹
gives a stroke. I find this very convenient in practice, as when both stations are
equipped in the manner illustrated at Y, the operators at both ends of the line can
tell whether their apparatus is running fast or slow, and can adjust accordingly.
In starting the apparatus the instrument at station X is put in motion, as
described, and the adjustment of the apparatus is preferably completed by the
operator at station Y, though when both stations are organised as illustrated at
station Y, both operators may adjust with advantage. At station Y the switches q²
and n² are closed, and the operator can tell by the indicators S¹ and T¹ how the
apparatus is running, and may adjust his instrument by moving the pole pieces n,
or by adjusting the box of resistances R2, and when correcting impulses cease to be
sent or received, or are only of occasional occurrence of course the apparatus will
be running synchronously.
I have found in practice that where the apparatus at the two stations is running
at approximately the same speed within liberal limits, and the switches are all
closed the apparatus will of itself in a few moments come into synchronism without
the intervention of the operators, for it will be apparent that if the circuit
completer at one station is travelling more rapidly than that at the other, its excess
of speed soon causes it to overtake the circuit completer at the other station, and
brings them both into such relation to the battery connected 9s and correcting 10s.
that the correcting impulses will thereafter maintain them in the correct position.
Instead of placing the deterring coils N' on the cores of the vibrator magnet, a
supplementary magnet, the poles of which are outside of the tines of the fork,
might be employed, as illustrated in figure 9, which is hereinafter described.
Instead of placing the contacts, devoted to synchronism, in the same circle with
the other contacts, they might be placed on the same table on the edge or outside
of the circle, and the radial arm extended and provided with another trailing
finger, or a trailing finger of extra width, to sweep both sets of contacts, might be
employed, or the contacts might be arranged upon a separate table placed above or
below the first table and traversed by a separate finger.. Such modifications are
mere changes of mechanical detail and not variations from the spirit of my
invention, and many such changes may readily be devised by persons familiar with
such matters; and my invention is not limited to all the details illustrated and
described.
These remarks apply with equal force to the other forms of my invention herein
described.
Where the groups of contacts, 1 to 8, in each series of 10, are connected in
telegraphic circuits, as hereinafter described, or in any circuits, and also for the
purpose of discharging the line after correcting impulses have been sent into it,
I employ a series of static discharge contacts c¹, which are illustrated at station X
in figure 3, but which should be used at both stations. These discharge contacts

page_text: are placed between the other contacts, and are connected to each other and to the
ground through the line q', q, so that as the trailing fingers rotate after each
completion of the circuit from a contact at one station to a corresponding contact
at the other station, the line is put to ground and statical or other disturbances are
eliminated. The static inductive disturbances, where the apparatus is used on a
long line, operate to mar the perfect working of the system, but by means of the
static discharge contacts, which successively put the line to ground after each
completion of the circuit, such disturbances are absolutely and completely obliterated
on lines of any length, and the apparatus works with as absolute accuracy as if
such induced currents did not exist. These contacts instead of being arranged
between the other contacts may be carried on a separate disc, or in a circle outside
of the other contacts. I prefer the arrangement shewn however. While I have
referred to the discharge contacts as being specially for the purpose of eliminating
static disturbances, obviously they will operate to put any charge on the line to
the ground.
Before proceeding to a description of the other forms of my system for
maintaining synchronous movements, which, while differing somewhat in detail
from the organization which I have already described, are in principle substantially
similar.
I will proceed to describe the organization of the apparatus for multiplex
telegraphic transmission.
Figure 4 illustrates diagramatically the circular table of contacts with the
telegraphic connections at a single station, and of course the organization is the
Bame at both stations.
Upon reference to this figure it will be seen that the 1s. and 5s. in each of the
six groups of contacts are connected to each other and by a line u with a
polarized relay U and key; that the 2s, and 6s. are correspondingly connected
with each other and to a relay V and key; that the 38. and 78. are correspondingly
connected to each other and to a relay W and key; and that the 4s. and 8s are
correspondingly connected and to a relay X and key. The contacts from 1 to 8 in
cach group or series are therefore apportioned among four independent circuits, and
as there are six series or groups, each circuit will receive twelve contacts and
twelve electrical impulses, as hereinafter described, for each revolution of the
trailing finger f. The instruments and circuits at both stations are arranged as
illustrated in this figure, and are hereinafter specifically described. For the
present, however, it is sufficient to bear in mind that the corresponding instruments
at each station are connected with the corresponding number of contacts. When,
therefore, the trailing finger fat each station is upon the contacts bearing the same
number, the corresponding instruments connected to those contacts at each station
will be placed in communication over the line, the circuit being completed through
the trailing contact finger f, the radial arm, the vertical shaft, and the spring
arm H (Figure 2). As the trailing fingers of the two stations continue to move
synchronously, they will pass to the next contact, and successively over all the
contacts at each station. During the moment when the moving contact fingers f
are upon correspondingly numbered contact pieces at each station, the circuit is
complete, and entirely independent of the other circuits and instruments from the
instrument at one station to the corresponding instrument at the other station.
Assuming that the forks vibrate normally at the rate of 85 vibrations per second,
and I have operated telegraphically with a fork vibrating at that rate, and that
there are thirty armature teeth on each of the discs D, the discs and trailing
fingers will rotate two and five-sixths times per second, and the corresponding
instruments at the two stations will therefore be placed in independent electrical
communications thirty-four times in every second. Such a number of contacts
per second gives to each set of operators a practically unbroken circuit. The
operators at the corresponding instruments at the two stations may therefore

page_text: communicate with each other in either direction as if they were operating upon
an independent line devoted entirely to their own use.
The arrangement of instruments is as follows:-
The relays U V W X are connected as described with the series of contacts on
the table and the circuit is completed from each relay either to the ground through
the upper buttons of the switches U, V, W* and X2, as illustrated at V and X' or
to the keys and main battery Z if the switches are on their lower contact buttons,
as at U and W. In the former case the operators will be ready for receiving, and
in the latter for transmitting. The main battery Z is preferably split and grounded
at the middle, and the back stops of the keys are connected with one pole and the
front stops with the other.
In transmitting, therefore, succeeding impulses of opposite polarity are employed,
and for this reason I preferably use polarized relays. I do not, however, limit my
invention to reverse current transmission or polarized relays. Polarized relays
may, however, be used to great advantage in such a system as this where each
signal or working impulse is made up of a series of fine independent electrical
impulses or vibrations, because by the use of such a relay any singing or chattering
upon the sounder is prevented. Various other ways of obviating this chattering
are well known and others may readily be devised.
The local batteries Y are connected up in multiple arc, as indicated in the dotted
lines y, and as will be plain from the drawing, without describing the circuits.
The polarized relays and sounders operate in the usual well known way.
It will be obvious that it is a matter of indifference whether four messages are
being sent in one direction simultaneously or three in one direction and one in the
other, or in any other way. It is also obvious that the contacts on the tables may
be connected in a greater number of groups, so as to give five, six, seven, eight, or
more operators at each end of the line, and it is also within the scope of this
invention to increase the number of contacts, and also the speed of the apparatus;
but there is of course a limit to such variations which may readily be
ascertained.
The apparatus at each station is started as before described; but aside from
the means already described for indicating how the apparatus is running, the
telegraphic instruments themselves serve as indicators, as I will now describe. If,
when the discs are started at both stations, they do not run synchronously and the
finger at one station is on a battery connected 9, an impulse of electricity will be
sent over the line through one of the instrument contacts on which the finger fat
the other station happens to rest, and the operator in charge of the apparatus will
hear the sounds caused by such impulses of electricity on the sounders of the four
instruments say at station Y, where the apparatus is adjusted. If the finger at Y
is moving faster than at X, the sound will pass successively from one instrument
to the other say from U to V, to W, to X-and the operator will then know that
his contact finger f is moving faster than the finger at the other station. By
adjusting the screw pole pieces of the vibrator magnet he can diminish the speed
of vibration of the fork at his station until the sounds on the instrument cease.
He will then know that the fingers at each station are moving together, and will
close the switches n' and g' and any variations of motion that subsequently occur
will be automatically corrected from either end of the line by impulses from the
batteries and Q. I prefer to employ a supplementary ticker or sounder connected
with one of the unconnected 9 contacts at each station, so that when the apparatus
is running synchronously there will be one stroke of the ticker at each station for
each revolution of the trailing fingers. When the operator therefore, hears a
continued sounding on the ticker he knows that the apparatus is running
synchronously. This ticker may be connected with any one of the unconnected
contacts, and is illustrated at T in Figure 9.
The operation just described assumes that the four sets of instruments at 5

page_text: station Y are within the hearing of the operator. In practice, however, the four
instruments may be placed in different parts of a city, or even in adjoining
cities.
In order to enable the operator in charge of synchronous movements to hear or
know whether his instrument is running out of time with that at station X, I place
a relay or indicator u³ in each circuit, as indicated in the line u. Obviously such
indicators may be practically telegraph instruments, as illustrated in the line u,
where a relay u³ and a key us are placed in a branch with the line u, and may be
cut either in or out by switch u². By means of such instruments the operator in
charge of the synchronous movement may of course communicate with the operator
at the distant terminals of the line. In practice these indicating instruments are
arranged in a case as indicated in Figure 5, through which the lines to the different
operators instruments pass.
The switches v¹, w₁, a¹ are provided as described in connection with the line v.
The organization and operation of the synchronous devices have been described
in connection with figures 1 and 2. When the apparatus at each station is,
however, connected up with instruments for telegraphic transmission, as illustrated
in Figure 4, the correcting battery 9s, will be connected through the wire 3, 2',
and 2 with one pole of the split battery Z, which also serves as the main battery
for telegraphic transmission. There is, therefore, but one main battery at each
station.
Instead of the static discharge contacts, which have already been described, in
order to neutralize the static disturbances, condensers U³ may be placed in each of
the telegraphic circuits, as illustrated in the circuit u in Figure 4. The operation of
such a condenser is well understood, and needs no description. This organization
for telegraphic transmission is of course equally applicable to the other forms of
synchronous movement hereinafter described, whether vibratory or non-vibratory
circuit interrupters are employed or not.
In Figures 6, 7 and 8 I have shown a synchronous apparatus in which the same
arrangement of connected correcting contacts and battery connected contacts, as is
illustrated in Figure 3, is employed. In this organization I employ, however, a
non-vibratory circuit-breaker for controlling the apparatus.
First, referring to Figures 6 and 7, it will be observed that the apparatus is in
many respects identical with that illustrated in Figures 1 and 2 and where
corresponding letters appear they refer to like parts in the two sheets of drawing.
A make and break-wheel or circuit interrupter J is secured on the vertical
rotating shaft B, just above the mercury cup D¹.
A spring contact L bears upon the periphery of this break-wheel, and the
electrical connection is alternately broken and completed through the wheel, its
hub, and the spring contact finger K which bears on the hub. The spring K is
electrically connected with one pole of a local battery circuit in which the motor
magnet E which actuates the rotary disc D, is placed, and the spring arm L
is connected with the other pole of this local circuit (Figure 8). The local circuit is
indicated by the fine dotted lines and the letter o, and Ŏ is the local battery.
In order to prevent sparking a shunt, containing a resistance R, is thrown around
the battery. An impulse of rotation having been imparted to the shaft B, the
motor circuit will be automatically made and broken through the break-wheel J,
and the magnet E E, magnetized and demagnetized, so that the apparatus will be
continuously rotated, as already described.
The magnet I is for the purpose of regulating the speed of rotation, and acts
directly upon the armature teeth d whenever correcting impulses of electricity are
received over the line. This magnet is mounted upon a sliding support which is
adjusted towards and from the armature teeth by means of a thumb screw 23
mounted in a vertical bracket on on the base piece i. This base piece is adjustable
on the bed-plate A by means of curved slots and screws so that it may be
adjusted sidewise concentrically with the armature disc. By this adjustment the
poles of the magnet I can be brought into the proper relation to the teeth on the

page_text: armature disc, so that the correcting impulses of electricity will act properly upon
the teeth of the disc to regulate its movement, as is presently described.
In Figure 8 the apparatus which I have just described in detail is illustrated
diagrammatically, and the stationary table of contacts is, for convenience, shown as
placed above the armature disc and interposed between that disc and the trailing
finger f.
I will here state that while the motor, illustrated in these drawings, consisting
of a motor magnet and toothed armature disc and the interrupted local circuit, is
old, so far as I am aware, such motors have been actuated by an automatic vibrator,
and not by means of a rotary circuit interrupter; nor by circuit breaker, operated
directly by the rotation of the disc itself.
The contacts 1 to 8 inclusive may be employed as before described in connection
with the other figures, or in any suitable manner, and the instruments may be
caused to rotate two or three times per second more or less. The speed of rotation
may be regulated by adjusting the inotor magnet E to or from the armature disc.
The closer the magnet is adjusted the higher the speed of rotation. Thirty breaks
are shown in the break wheel, and thirty teeth on the armature disc, and the break
wheel is of course so fixed relatively to the teeth that the energizing of the magnet
is timed relatively to the teeth of the armature disc to maintain the continuous
rotation of the disc.
In the diagrammatic view, Figure 8, for convenience of illustration, I have shown
a slightly different arrangement at the two stations--that is at station X, instead
of employing a separate magnet I for correcting the rotation of the disc, I have
shown supplementary coils I, placed upon the poles of the motor magnet E. The
operation is of course precisely the same as at station Y. A shunt, containing a
resistance R, is also thrown around the local battery O to prevent sparking at the
break-wheel. When a correcting impulse is sent from one station to the other it
passes through the coils I and corrects the speed of the apparatus at the station
receiving it.
At station Y, when the correcting magnet I, is arranged to retard it is placed
relatively to the motor magnet E and armature teeth as shown; that is when two
armature teeth are directly opposite the poles of the motor-magnet, and the motor-
circuit is just broken, two teeth on the opposite side of the disc have almost passed
from in front of the poles of the correcting magnet I. If, therefore, the correcting-
magnet is energized at this moment it will momentarily attract the teeth just
passing from its poles and retard the speed of rotation. If, when the motor
magnet E is energised and is attracting the two teeth approaching its poles,
a correcting impulse is received, the correcting-magnet will momentarily tend to
hold the two teeth which are in front of its poles, and so retard the speed of
rotation. Of course both stations may be organized alike either as illustrated at
station X or station Y.
At station X when the correcting coils I are mounted on the motor-magnet
cores, the effect of correcting electrical impulses, which prolong the magnetism of
these cores, is to hold the armature teeth in front of them and retard the rotation
of the disc.
In the organization illustrated at Y the correcting-magnet I may be so adjusted
relatively to the armature teeth d as to correct either by impulses of acceleration or
retardation. Where the apparatus is arranged for accelerating correction, the
relative connection of the 9 and 10 contacts must be reversed, and the 9's extended
towards the 10's instead of the 10s toward the 9s.
Under the organization illustrated in this figure as the local motor circuit at both
stations is broken by the wheel J, the same number of times in a single revolution
with an approximately equal battery power, the apparatus at the two stations will
revolve at about the same speed, and when once brought into synchronism their
continuous uniform rotation is automatically maintained by the reciprocal correcting
impulses transmitted from either station, according as the apparatus at one station
runs faster than that at the other.

page_text: In Figure 8 Q are the correcting batteries and q the wires leading from the
extended 10s. to the correcting coils and from the 9s. to the correcting battery.
In Figure 9 I have shown an organization in which correcting impulses are sent
from one station only, such corrections being accelerating or retarding according as
the apparatus at the corrected station runs faster or slower than that at the other
station. In the organization here diagrammatically illustrated the vibrating fork
and motor-magnet and circuit operate in exactly the same manner as fully described
in Figure 3, and it is therefore deemed unnecessary to repeat the description.
Corresponding letters refer to like parts in the two figures. In this figure I have
shown the contacts on the table connected in groups, as described, in connection
with Figure 4, but of course they may be connected in any way, or omitted
altogether where synchronism merely is desired.
As in the other figures I preferably employ the 9 and 10 contacts to maintain
the synchronous movement of the apparatus, and the arrangement is as
follows-
At station X the 10 contacts are thrown out or unconnected with any circuit.
The 9s. are, however, all electrically connected to each other, and to the correcting
battery Q, At station Y the 9s. are all thrown out or unconnected, with the
exception of one, which is made use of for a particular purpose presently described;
while the 10's are electrically connected to each other and to a wire n' which passes
through the coils of a deterring magnet S, the poles of which are placed outside the
tines of the vibrating fork M, thence to ground.
The single 9, above referred to, is connected to a wire q which passes to ground
through the coil of a ticker or sounder T. At this point in the table an extra
contact, 8, is introduced, and the adjoining 9-that one connected to the
sounder is reduced in width. The reduced 9 and the extra contact 81/, together
only occupy the space that would be occupied by a full width 9, so that the relative
arrangement of contacts and separating spaces is maintained. The extra contact 8'/,
is connected by a line s through the coil 8 of a magnet interposed between the tines
of the fork, and thence to ground.
It will be noticed that the 10s. are built out or extended towards the adjoining 9s,
as in the other cases already described. The outer magnet S, connected to the.
extended 10s. is the deterring magnet, and as there are six 10s. in the circle of
contacts, six retarding impulses may be received over the line for each revolution
of the trailing finger. The magnet & interposed between the tines of the fork is
connected with the single extra contact 8%. This is the accelerating magnet, and
one impulse of acceleration for each revolution of the trailing finger may be
received. If the apparatus is running synchronously when the fingers at the two
stations are upon the corresponding 9-contacts there will be no current on the line
except when the finger at Y is on the reduced 9 connected with the sounder T,
then the sounder will tick once in each revolution of the finger, and the operator
will know that the apparatus is running properly. If, while the finger at X is on
a battery-connected 9, the finger at Y should move a trifle faster so as to strike the
side of the extended 10 before the finger at X had left the 9, an impulse of
electricity would be sent from the correcting battery Q to station X and through
the line n¹ into the coils of the deterring magnet S. If the finger at Y should run
a trifle slower than that at X it would touch the extra contact at 81/,, while the
finger at X is on a battery connected 9. An impulse of electricity would therefore
pass through the coil of the accelerating magnet's and increase the vibration of the
fork, and the consequent rotation of the trailing finger at Y. When the trailing
fingers are therefore once brought into synchronous movement, the finger at Y will
be locked as it were between the extra contact 8%, and the 10s. so that any
acceleration in speed will be promptly met by an automatic retardation, and any
retardation by an automatic acceleration.
In practice the apparatus is so adjusted that the rotating disc at Y tends to move
faster than at X. This tendency is overcome by the six retarding contacts. The
accelerating contact may be brought into service where too great an impulse of

page_text: retardation has been imparted to the apparatus, or where, from any cause, the
normal tendency to acceleration is momentarily disturbed.
In starting the apparatus the discs at both stations are put in motion and the
speed of vibration of the forks regulated by the adjustable pole-pieces on the
vibrator magnet.
In practice the apparatus at X is started independently of any special adjustment
the adjustment being made at Y.
In connecting up the apparatus, the switches n³ ³ at Y are open.
If the fingers
start in synchronism the sounder T will tick, and if the ticking continues for a
short time the operator at Y will adjust the pole piece of the vibrator-magnet
slightly away from the tines of the fork, so as to tend to increase its rate, and then
close the switches. If the apparatus does not start synchronously there will be no
sound at first on the ticker T, but the operator at Ỷ, by screwing the pole-pieces
away from the tines of the fork will cause them to vibrate at a speed, which, by
previous understanding, he will know to be very much greater than that at the
station X. The finger at Y will therefore gain rapidly on the finger at X, and as
they occasionally come into conjunction there will be a stroke on the ticker, then
by gradually adjusting the pole-pieces to approach them to the tines of the fork
the strokes on the sounder will become less frequent, and by continuing the
adjustment, the fingers will travel together sufficiently long to give a series of ticks
on the sounder, when the switches 8³ ³ may be closed, and any subsequent
variation will be automatically corrected.
The magnet S has been described as a retarding magnet, and its poles are on the
outside of the tines of the fork, as are also the poles of the vibrator-magnet. The
tines therefore vibrate in magnetic fields which modify, or in a measure overcome
the normal or fundamental rate of vibration. As this field is decreased in strength,
the tines vibrate more freely, and consequently more rapidly. When these
exterior magnetic fields are increased or supplemented by the action of the
deterring magnet S, the resistance to the vibration of the fork is increased, and
there is a consequent diminution in the rate of vibration. On the contrary when
an impulse of electricity is passed through the interposed accelerating coil 8, the
magnetic fields created thereby are opposed to and neutralize more or less the
effect of the vibrator-magnet, thus reducing the opposition to the normal
vibration of the fork, or the sum of the exterior attraction on the tines of the
fork and permitting a freer and consequently more accelerated rate of vibration.
If, for any reason, fewer retarding impulses are desired, some of the 10s. at Y,
or 9s. at X, or some at each station may be left unconnected, and if more
accelerated impulses are needed additional 81%, contacts may be added. Obviously
the greater number of correcting contacts might be connected to the accelerating
magnet, and the lesser number to the deterring magnet, and when thus arranged
the apparatus at Y should be set with a tendency to run slower than that at X.
A ticker T, such as here illustrated, may be used in connection with any of the
other organizations herein illustrated.
In Figure 10 I have shewn an organization in which the apparatus at one station
is run faster than that at the other, and is constantly corrected by impulses sent
from the correcting station. The arrangement of the vibrator, its local circuit, the
motor-magnet, and its circuit, and the disc and trailing finger at each station is the
same as in the figures already described. In this organization the correcting
contacts are arranged as follows.―
At X the 10 contacts are unconnected, the 9s. are however all connected to each
other, and to the correcting battery Q. At Y the 9s. are unconnected, while the
10s. are connected to each other and to a wire n¹ which passes through the coils of
the deterring-magnet S, the poles of which are placed outside of the tines of the
fork. In this case, as in figure 9, I have shewn a ticker T at station Y, connected
with one of the otherwise unconnected 9-contacts. As there are six 10s. in the
circle of contacts it is possible for six retarding impulses to be sent into the line
for each revolution of the apparatus. At station X the battery-connected 98. are

page_text: extended towards the adjoining unconnected 10%, and at Y the connected 10. are
extended towards the adjoining unconnected 93. The operation will be readily
understood from the description of the previous figures. As the 9's at X are all
built out towards the 10s, the contact or finger f at this station will be prolonged
so as to give a greater period of time within which the correcting-battery will be
in circuit on each of the 9 contacts. On the other hand at Y the 9s are of the
ordinary size, while the connected 10s. are extended towards the 93, so that the
contact of the trailing finger f, after leaving a 9 at station Y, is made very quickly
with the extended 10s. The result of this prolongation of contact at ✗, and the
quickening of the contact with the 10s. at Y, is that if there is the slightest
variation of speed, however small, a retarding impulse will be sent through the
coils of the magnet S. By changing the relative connection of contacts, and using
an accelerating magnet, instead of a retarding one, accelerating correcting impulses
may be employed, as will be well understood. In this case, as in the other figures
already described, the rate of vibration of the fork may be regulated by adjusting
the pole-pieces of the vibrator magnet M. I prefer, however, to regulate the speed
of vibration of the forks by an adjustable rheostat R2, placed directly in the forked
circuit. By varying the resistance of the forked circuit the power of the vibrator
magnet will be increased or decreased, and there will be a consequent change in the
rate of the fork. I prefer this means of adjusting the forks in bringing the
apparatus into synchronism, for the reason that the resistance R* may be placed at
a distance from the fork, and on a separate base-board;
Instead of employing a deterring magnet I may use an apparatus such as
illustrated in Figure 11. The line n¹ instead of passing to a deterring-magnet S,
as shown in Figure 10, may be connected with the coil of an electro-magnet N',
in front of which a pivotted armature N', having adjustable front and back stops,
is vibrated. The armature is normally drawn away from the magnet by a coiled
spring.
The vibrator magnet, the poles of which are placed outside the tines of the fork
which makes and breaks the local circuits, instead of having a screw extension
piece, as shown in the other figures, is provided with a soft iron pole piece n', which
slides back and forth in an aperture or socket in the pole of the magnet, the ends
of the pole-piece being enlarged to prevent its withdrawal therefrom. A spring n'
normally presses the pole-piece away from the tine of the fork. The thumb screw
on the lower end of the armature can be adjusted to rest against the outer end of
the pole-piece. When the parts are approximately properly adjusted, the further
adjustment may be accomplished by a rheostat, as described. Ordinarily when the
magnet N¹ is neutral, the coiled spring on the armature draws the thumb-screw
away from the pole-piece, which is held away from the tine of the fork by the
spring n². When a correcting impulse of electricity is received, the armature-lever
is drawn toward the magnet, and the loose pole-piece is advanced toward the tine
of the fork, thus increasing the strength of the magnetic field, and retarding the
rate of vibration. Such an apparatus has a much more vigorous effect upon the
fork than when the action of the retarding magnet is applied directly to the tine
of the fork, because in the latter case the magnetic field within which the fork
vibrates is only increased by the sum of the magnetism of the retarding-magnet.
But under the organization shown in Figure 11, the approach of the pole-piece to
the tine of the fork materially increases the strength of the field because the
attraction of the magnet is equal to the square of its distance.
The apparatus shown in Figure 10 may be started substantially in the same
manner as that shown in figure 9, and no description of that operation is deemed
necessary.
In Figure 12 I have shown an arrangement by which accelerating impulses may
be employed in connection with the moving pole piece. The operation will be
obvious and detailed description is unnecessary, like corresponding letters of
reference refer to like parts in the two figures.

page_text: In Figure 13 I have shown an arrangement of split battery and polarized relay,
which is specially applicable to the telegraphic system described and illustrated in
figure 4. The object of the invention is to so organize the circuit that the relay at
the transmitting end of the line is cut out of the circuit when the transmitting
impulses are sent into the line, but is momentarily thrown into the line before
each completion of the battery circuit. By this arrangement it is not necessary
in transmitting to work through the relay at the transmitting station, and yet
the operator at the receiving station may stop or "break" the operator at the
transmitting station whenever desired.
The primary advantage of such a system of transmission is that the resistance of
the relay at the transmitting station is taken out, of the line, and at the same time
the extra induced currents from the core and helices of the relay are also kept out
of the circuit.
Another feature of considerable importance, incident to my improved arrange-
ment, is that the line at the transmitting station is put to ground before each
reversal of the battery circuit. This eliminates from the line any static distur-
bances, and consequently very much improves the condition of the circuit for
transmission.
The transmitting key C is placed in a local circuit containing a magnet A¹ which
actuates an armature A vibrating between two adjustable stops. The stops are
electrically connected with the opposite poles of the split battery G, grounded in
the middle. The main line H may, by means of a switch h, be placed in connection
with the armature A through the line i, when the apparatus is arranged for trans-
mission; or the main line may be connected with a line l, which passes through
the relay to earth for reception.
A spring-arm B, secured on a suitable post and controlled by an adjusting screw,
is connected with the line 1, between the relay and the main line. The end of this
spring arm carries a wedge-shaped projection which lies in the path of the wedge-
shaped end of the vibrating armature A, so that as this armature moves from one
stop to the other, it momentarily completes the circuit from the armature through
the spring B, line 1, and relay to ground. With the switch h put over to the
right so as to throw the relay into the main line for receiving a message, the
operation is common and well known. With the switch put over to the left,
however, when the key is worked the armature A will be vibrated and will alter-
Between each
nately send currents of opposite polarity into the main line.
completion of the circuit, however, through the armature A the relay D is thrown
into the main line through the wedge shaped projection b and arm B.
Although the relay is included in the main line circuit for a very brief period, it
will respond to a signal from the receiving operator at the distant station to stop
or "break" the transmitting operator.
The arrangement is obviously applicable to the various systems of telegraphy
whether of single or multiplex transmission, and whether synchronous or not.
I am aware of the invention of Poul La Cour, heretofore patented in Great
Britain. That system has been referred to in general terms at the beginning of
this specification and consists in sending predetermined impulses of electricity from
one station to the other which actuate the fork at the receiving station and do not
independently correct its speed. The difference between this system and mine will
be obvious upon a comparison of the inventions.
I am also aware of the British patent of Baudot N° 436-1882, in this patent
the apparatus at each end of the main line is independently actuated and a pre-
determined correcting impulse is sent over the line in every revolution of the
apparatus, but is only made effective when the apparatus at the station receiving
the impulse runs out of time with that of the other station. Baudot corrected
the speed of the apparatus through a system of levers or gearings. While it is
possible that such a system might be efficient in an organization like his in which
large contacts are used and the motion is comparatively slow, in my organization

page_text: involving high speed and small contacts such a system of corrections would
obviously be impractical. The differences between the two plans will be obvious
upon a comparison of them.
Having thus described my Invention what I claim is :-
First. The reciprocal system of synchronous correction substantially as illustrated
in Figure 3.
Second. The method of making the received correcting impulses effective which
consists in varying the resistance of the controlling circuit substantially as illustrated
at y in figure 3.
Third. The combination with the synchronously actuated apparatus, of indicators
or tell-tales which indicate when a correcting impulse of electricity is received at a
station, and when one is sent out.
Fourth. The combination of a main line, continuously actuated apparatus con-
nected therewith, mechanism for actuating said apparatus, means for transmitting
correcting impulses from one station to the other when the apparatus at one station
runs out of time with that of the other, and means for making said correcting
impulses effective by direct electro-magnetic action on the actuating mechanism.
Fifth. The combination substantially as set forth of a main line, continuously
actuated apparatus connected therewith, mechanism for actuating it, means for
sending correcting impulses from one station to the other, and means for making
such correcting impulses effective by direct electro-magnetic action upon the driven
mechanism.
Sixth. The combination of an electric circuit, an independently actuated
armature disc, means for actuating it, and an independent correcting coil which
acts directly upon the armature disc to correct its speed of rotation independently
of the actuating devices.
Seventh. The method of controlling synchronously moving apparatus by vibrators
the speed of which is corrected as occasion requires.
Eighth. The method of maintaining synchronous movements by correcting the
speed of a non-vibratory circuit interrupter which controls the speed of the
synchronous apparatus.
Ninth. The extended contacts as illustrated in the several figures.
Tenth. The arrangement for maintaining the synchronous movement of
electrically connected apparatus by means of correcting impulses either of
acceleration or retardation substantially as described and illustrated in Figure 9.
Eleventh. The combination of a vibrator, means for vibrating it, and a
retarding or accelerating magnet or both, which act on said vibrator to control its
speed.
Twelfth. The arrangement of correcting contacts and circuits substantially as
described and illustrated in figure 9.
Thirteenth. The arrangement of correcting contacts and circuits substantially
as described and illustrated in figure 10.
Fourteenth. The combination of a vibrator, its local circuit, a vibrator magnet,
and an adjustable resistance placed in the local circuit to control the speed of
vibration.
Fifteenth. The combination with electrically connecting synchronously moving
apparatus of a ticker or tell-tale which indicates to the operator when the apparatus
is running synchronously.
Sixteenth. The manner of controlling the speed of the vibrator when a cor-
recting impulse is received by changing the position of a magnet core relatively to
said vibrator.
Seventeenth. The alternating arrangement of contacts for reciprocal correction
substantially as illustrated in figure 3.
Eighteenth. The combination of a main line apparatus connected therewith,
means for synchronously actuating said apparatus, and means for sending correcting
impulses of electricity from one station to the other only when the apparatus runs
out of time.

page_text: Nineteenth. The manner of eliminating static and other disturbances from the
circuit in my improved system of synchronous movements and telegraphic trans-
mission in connection therewith which consists in employing static discharge
contacts substantially as illustrated at X in figure 3.
Twentieth. The combination of a main line, the series of contacts arranged in a
circle and electrically connected in independent groups so that the circuit of each
group is connected with a number of contacts placed at intervals around the circle,
a circuit completer which traverses the circle of contacts and successively and
rapidly makes and breaks the line circuit through each of the contacts, whereby the
circuit of each group of contacts is placed in communication with the main line a
number of times in each traverse of the circuit completer, and a series of line dis-
charged contacts connected with the ground placed alternately between the first
mentioned contacts so as to alternately make the main line circuit through each of
the first named contacts, and discharge the line to ground through each of the other
contacts.
Twenty first. The combination, at electrically connected stations, of a series of
contacts connected in independent groups so that the circuit of each group includes
a number of contacts placed at intervals in the series, mechanism at each station
for successively completing and breaking the line circuit through said contacts,
telegraphic instruments in the circuit of each group of contacts, continuously
actuating circuit completing mechanism and means for automatically and indepen-
dently correcting the speed of such mechanism.
Twenty second.-The combination, at electrically connected stations, of branch
lines at each station, apparatus for successively placing the branch lines in commu-
munication with the main line several times in each revolution, mechanism for
actuating the apparatus at both stations, and means for independently correcting
the speed of the apparatus to maintain their synchronous movement so that the
corresponding branch lines at the two stations will be successively placed in
communication several times in each traverse of the circuit completing apparatus.
Twenty third. The system of Multiplex Telegraphic transmission substantially
as described and illustrated.
Twenty fourth. The method of Multiplex Telegraphy, which consists in grouping
the contacts in different circuits, substantially as illustrated, and then by means of
synchronously moving apparatus successively placing the corresponding contacts at
two stations in communication.
Twenty-fifth. The combination at electrically connected stations, of continuously
actuated apparatus at each station, mechanism for actuating such apparatus, and
means for automatically and reciprocally correcting the movement of the apparatus
at either of the stations whenever it runs out of time with that of the other.
Twenty-sixth. The method of maintaining synchronous movement by indepen-
dently actuating each apparatus, running one of them at a different speed from the
other, and constantly correcting the speed of the latter apparatus by correcting
impulses from the other station which act electro-magnetically.
Twenty-seventh.-The combination with my system of telegraph transmission
and synchronous movement of indicators or signalling devices substantially as
illustrated at Figures 4 and 5 placed in the telegraph circuits at each station.
Twenty-eighth.-The arrangement of batteries and circuits for transmission
substantially as illustrated in Figure 13.
In witness whereof I said Sydney Pitt have hereunto set my hand and seal
this twentieth day of February in the year of our Lord One thousand eight hundred
and eighty four.