IMPROVEMENTS IN FAC-SIMILE TELEGRAPHS
Year: 1881

page_text: LETTERS PATENT to Edward Griffith Brewer, of 33, Chancery Lane, in the
County of Middlesex, for an Invention of "IMPROVEMENTS IN FAC-SIMILE
TELEGRAPHS." A communication from abroad by Thomas Alva Edison, of
Menlo Park, New Jersey, and Patrick Kenny, of the City and State of New
York, both in the United States of America.
PROVISIONAL SPECIFICATION left by the said Edward Griffith Brewer at
the Office of the Commissioners of Patents on the 19th July 1881.
_EDWARD GRIFFITH BREWER, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN FAC-SIMILE TELEGRAPHS." (A communication from abroad by
Thomas Alva Edison, of Menlo Park, New Jersey, and Patrick Kenny, of the City
and State of New York, both in the United States of America.)
The object of this Invention is to produce telegraphic apparatus for recording at
the receiving station a fac-simile of the original dispatch, which apparatus will be
simple in the arrangement and construction of its parts, will be commercially
efficient and economical in operation, and will require no special preparation of the
original dispatch, or particular skill on the part of the operator.
In carrying out this Invention use is made of the depressions produced upon the
surface of paper by marking, writing, or sketching thereon with a hard lead pencil
or other suitable instrument. For this purpose only slightly more than the
ordinary pressure is required upon paper having sufficient body to retain the
impressions.
A slip or sheet having the message written thereon in this manner is mounted
upon a cylinder of insulating material (such as wood), its ends being secured close
together in a groove or grooves of the cylinder. The receiving sheet used in the
instrument at the other end of the line may be of about the same size as the
transmitting sheet, and is soaked in any of the well known solutions heretofore
used in electro chemical telegraphs. This slip or sheet is secured upon a metal
cylinder, being removably fastened thereto in any suitable manner.
These insulating and conducting cylinders are mounted respectively upon the

page_text: '
revolving spindles of the machines at the ends of the lines, which spindles are
preferably arranged in vertical positions and turn through metal base plates resting
on insulating supports.
The spindles are revolved by electro motors of the Pacinotti or other pattern.
Each motor is arranged with its ring armature in a horizontal position centrally
below the cylinder carrying spindle of the machine. The axle of the motor
armature has a crank arm on its upper end to which is secured a slotted curved
plate. An inclined rod carrying a centrifugal ball has a box on its lower end
which slides in and is held by the slot of this curved plate. The inclined rod
passes up into the collar of an universal rocking joint located centrally below the
cylinder spindle. From this universal rocking joint the inclined rod projects a
short distance upwardly into a small box held by a curved slotted crank arm on
the lower end of the cylinder spindle. The electro motor is run by a current from
a battery, Faradic generator, or other source of electrical energy, and an adjustable
resistance is placed in the circuit to regulate the speed of the motor.
Click springs are struck by a pin on the upper end of the inclined rod when the
motor has more or less than its normal speed.
In the operation of the apparatus it is essential that the movements of the two
machines should be synchronous, or such parts thereof as effect the transmitting
and receiving of the message, so that an exact copy of the original can be produced.
This is accomplished in the following manner :-
On the cylinder spindle of one of the machines, which is termed the synchronistic
machine, is a sleeve which is held in frictional contact therewith by spring pressure,
the sleeve resting upon a shoulder or collar on the spindle, and being forced down
upon the same by nuts on the upper end of the spindle which press on an inter-
mediate spiral spring. This sleeve carries the cylinder of that machine instead of
the spindle itself, as in the other machine, which is hereinafter designated the
"simple machine." Since each machine is adapted, by changing the form of style
and character of cylinder which are removable parts, to be used either for trans-
mitting or receiving, it is evident that it makes no difference which machine is
provided with the cylinder carrying sleeve. The spindle of one machine and sleeve
of the other are provided near the base plates with similar cams, each having a
smooth concentric surface and a single depression. One each base plate is pivoted
a horizontal T shaped lever, the central stem of which has a projection working
on the cam. The projection on the stem of this lever is thrown into the depression
of the cam by a spring, which spring is connected with the line through a switch
which is designated for clearness the "line switch."
To the head of each T lever is secured a metal plate which is insulated from all
parts of the lever except the spring just referred to. This plate carried by the
T lever plays at one end between two adjustable contacts, being closed against the
inner contact by the concentric surface of the cam, and thrown against the outer
contact by the spring when the projection on the stem of the T lever enters the
depression of the cam. The outer contact of each machine is connected with the
coils of an electro-magnet having a suitable armature, and from thence on one
machine the wire runs through a battery to the ground, while on the other machine
it passes from the electro-magnet directly to the ground. When the outer contacts
of the machines are made at the same time a circuit will be completed through the
electro magnets.
On the simple machine the armature of the magnet is used simply as a sounder,
while on the synchronistic machine it has the additional function of making and
breaking the circuit of a local battery. This local circuit energizes an electro
magnet supported by the base plate of the machine, the armature of which when
attracted trips a latch engaging with a catch arm on the cylinder carrying sleeve
before described, the latch engaging the catch and stopping the further revolution
of the sleeve until tripped, at the same moment the T lever enters the cam
depression and the relay magnet is thrown in connection with the line by the
making of the outer contact.

page_text: The motor of the "synchronistic machine" is regulated to run with a slightly
greater speed than that of the "simple machine," so that its T lever will make
the outer contact, and the catch arm of the sleeve will be locked by the latch just
in advance of the making of the outer contact by the "simple machine." When
the outer contact is made however by the T lever of the "simple machine," the line
circuit will be completed through the relay magnets, and the local circuit of the
"synchronistic machine" will be closed, attracting the latch armature, and releasing
the catch arm of the sleeve, allowing the cylinder to continue its revolving
movement. In this manner the two cylinders will be made to start exactly
together at each revolution by checking one of them.
In starting the machines the latch is withdrawn by a lever until the "synchronistic
machine" overtakes the "simple machine," and the two outer contacts are made
simultaneously. This will be indicated by the click of the relay magnet armatures.
The latch is then released immediately, and checks the cylinder on the next
revolution.
The slightly increased speed given one cylinder does not affect the record
produced sufficiently to injure its practical value as a fac-simile; but for producing
an exact copy in every respect, the cylinder used on the "synchronistic machine"
may be made slightly smaller than those of the "simple machine."
For giving the necessary signals in starting the machine a Morse key is placed in
circuit between a contact of the "line switch" and the electro magnet of each
machine. By swinging the "line switch" on to this second contact, each machine
will be cut out of circuit and the "Morse key" thrown in. After signals are
exchanged the line switches are shifted, throwing in the machines and cutting out
the Morse keys.
The cylinders being revolved synchronously, as described, the message is trans-
mitted and received by the following mechanism :-
Each machine is provided with a weighted carriage travelling vertically and
supported by a rack and pinion. The downward drop of each carriage is regulated
by an escapement operated by a continuation of the depression in the revolving
cam, into which depression takes a projection on the end of the escapement lever.
The carriage is connected electrically with the base plate through a switch, which is
termed the "style switch," while a vertical guide near the carriage has connection
with the inner contact of the T lever. The base plate of each machine is connected
with a switch (the battery switch), one contact of which is connected through a
battery to the ground, while the other has a direct ground connection.
The transmitting style carries two contacts, one connected with the carriage
when the style is placed in position thereon, and through it to the base plate and
"battery switch," and the other by a spring with the vertical guide, and through it
with the "style switch."
One of these contacts is carried by a spring having a point pressing upon the
surface of the paper on the insulating cylinder. The smooth surface of the paper
keeps the contacts separated, but when the point drops into the depression made
by a line the contacts come together, completing the circuit through the "style
switch" and the inner contact of the T lever. The receiving style is insulated
from its carriage, and has a spring connecting with the vertical guide. This style
carries a point bearing upon the surface of the paper, and when the "style switch"
is closed the current passes through the receiving style, the recording paper, and the
metal cylinder to the base plate, from whence it passes to ground through the
'battery switch."
26
When the message is completed the operator at the transmitting station throws
the style off of the cylinder by a lever. This allows the contacts of the style to
close, and a continuous line is recorded at the receiving station. This may be used
as a signal that the message has been completed. The "style switches'
thrown open and a new set of cylinders put in position.
"
are then
A latch is arranged to lock the escapement when each carriage reaches its lowest
position, such latch being released by the movement of the carriage.

page_text: In order to neutralize the effect of the static charge in working long lines, and
produce clear sharp lines at the receiving instruments, the plate on the head of the
T lever is extended in the form of a spring to the other end of the lever head,
where it strikes a contact connected to the ground through an electro-magnet or
resistance, or both. This ground contact is made when the inner contact at the
other end of the lever is also made, and the ground contact is further retained for
an instant after the inner contact is broken, so that the static charge will pass off
into the ground after the battery circuit is opened by the T lever, and will not
operate the relay.
This ground contact however is broken before the outer or relay contact is made
by the movement of the T lever.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Griffith Brewer in the Great Seal Patent Office on the
19th January 1882.
EDWARD GRIFFITH BREWER, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN FAC-SIMILE TELEGRAPHS.' A communication from abroad by
Thomas Alva Edison, of Menlo Park, New Jersey, and Patrick Kenny, of the City
and State of New York, both in the United States of America.
"
"
The object of this Invention is to produce telegraphic apparatus for recording at
the receiving station a fac-simile of the original dispatch, which apparatus will be
simple in the arrangement and construction of its parts, will be commercially
efficient and economical in operation, and will require no special preparation of the
original dispatch, or particular skill on the part of the operator.
In carrying out this Invention, the depressions produced upon the service of
paper by marking, writing, or sketching thereon with a hard lead pencil or other
suitable instrument are made use of. For this purpose only slightly more than the
ordinary pressure is required upon paper having sufficient body to retain the
impressions. A slip or sheet having the message written thereon in this manner
is mounted upon a cylinder of insulating material (preferably of wood), its ends
being secured close together in a groove or grooves of the cylinder. The receiving
sheet used in the instrument at the other end of the line may be of about the same
size as the transmitting sheet, and is soaked in any of the well known solutions
heretofore used in electro chemical telegraphs. This slip or sheet is secured upon
These
a metal cylinder, being removably fastened thereto in any suitable manner.
insulating and conducting cylinders are mounted respectively upon the revolving
spindles of the machines at the ends of the line, which spindles are preferably
arranged in vertical positions, and turn through metal base plates resting on
insulating supports.
The spindles are revolved by electro-motors of the Paccinotti or other pattern.
Each motor is arranged with its ring armature in a horizontal position centrally
The axle of the motor
below the cylinder-carrying spindle of the machine.
armature has a crank arm on its upper end, to which is secured a slotted curved
plate. An inclined rod carrying a centrifugal ball has a box on its lower end which
slides in and is held by the slot of this curved plate. The inclined rod passes up
into the collar of a universal rocking joint located centrally below the cylinder
spindle. From this universal rocking joint the inclined rod projects a short
distance upwardly into a small box held by a curved slotted crank arm on the
lower end of the cylinder spindle. The electro-motor is run by the current from a
battery, Faradic generator, or other source of electrical energy, and an adjustable
resistance is placed in the circuit to regulate the speed of the motor.
Click springs are struck by a pin on the upper end of the inclined rod when
the motor has more or less than its normal speed.
In the operation of the apparatus it is essential that the movements of the two
machines should be synchronous, or such parts thereof as effect the transmitting
and receiving of the message, so that an exact copy of the original can be produced.
This is accomplished in the following manner :-
On the cylinder spindle of one of the machines, which is termed the
Synchronistic Machine," is a sleeve which is held in frictional contact therewith
by spring pressure, the sleeve resting upon a shoulder or collar on the spindle, and
being forced down upon the same by nuts on the upper end of the spindle, which
press on an intermediate spiral spring. This sleeve carries the cylinder of that

page_text: machine instead of the spindle itself, as in the other machine, which is hereinafter
designated the "simple machine." Since each machine is adapted by changing the
form of style and character of cylinder, which are removable parts, to be used either
for transmitting or receiving, it is evident that it makes no difference which
machine is provided with the cylinder-carrying sleeve. The spindle of one
machine and sleeve of the other are provided near the base-plates with similar
cams, each having a smooth concentric surface and a single depression. On each
base-plate is pivoted a horizontal T-shaped lever, the central stem of which has
a projection working on the cam.
The projection on the stem of this lever is thrown into the depression of the cam
by a spring, which spring is connected with the line through a switch, which is
designated for clearness the "lineswitch."
To the head of each T lever is secured a metal plate, which is insulated from all
parts of the lever except the spring just referred to. This plate, carried by the
T lever, plays at one end between two adjustable contacts, being closed against the
inner contact by the concentric surface of the cam, and thrown against the outer
contact by the spring when the projection on the stem of the T-lever enters the
depression of the cam. The outer contact of each machine is connected with the
coils of an electro-magnet having a suitable armature, and from thence on one
machine the wire runs through a battery to the ground, while on the other
machine it passes from the electro-magnet directly to the ground.
When the outer contacts of the machines are made at the same time a circuit
will be completed through the electro-magnets.
On the simple machine the armature of the magnet is used simply as a sounder,
while on the "synchronistic machine" it has the additional function of making
and breaking the circuit of a local battery. This local circuit energizes an electro-
magnet supported by the base plate of the machine, the armature of which, when
attracted, trips a latch engaging with a catch arm on the cylinder carrying sleeve
before described, the latch engaging the catch and stopping the further revolution
of the sleeve until tripped; at the same moment the T lever enters the cam
depression and the relay magnet is thrown in connection with the line by the
making of the outer contact.
The motor of the "synchronistic machine" is regulated to run with a slightly
greater speed than that of the "simple machine," so that its T lever will make the
outer contact, and the catch arm of the sleeve will be locked by the latch just in
advance of the making of the outer contact of the "simple machine." When the
outer contact is made, however, by the T lever of the "simple machine" the line
circuit will be completed through the relay magnets and the local circuit of the
"synchronistic machine" will be closed, attracting the latch armature and releasing
the catch arm of the sleeve, allowing the cylinder to continue its revolving movement.
In this manner the two cylinders will be made to start exactly together at each
revolution by checking one of them.
"
"
"
In starting the machines the latch is withdrawn by a lever until the
"synchronistic machine overtakes the simple machine," and the two outer
contacts are made simultaneously. This will be indicated by the click of the relay
magnet armatures. The latch is then released immediately and checks the cylinder
on the next revolution.
The slightly increased speed given one cylinder does not affect the record
produced sufficiently to injure its practical value as a fac-simile, but for producing
an exact copy in every respect the cylinders used on the "synchronistic machine"
may be made slightly smaller than those of the "simple machine."
For giving the necessary signals in starting the machines a Morse key is placed
in circuit between a contact of the "line switch" and the electro magnet of each
machine. By swinging the "line switch" on to this second contact each machine
will be cut out of circuit and the Morse key thrown in. After signals are
exchanged the "line switches" are shifted, throwing in the machines and cutting
out the Morse. keys.

page_text: The cylinders being revolved synchronously, as described, the message is
transmitted and received by the following mechanism :-
Each machine is provided with a weighted carriage travelling vertically and
supported by a rack and pinion. The downward drop of each carriage is regulated
by an escapement operated by a continuation of the depression in the revolving
cam, into which depression takes a projection on the end of the escapement lever.
The carriage is connected electrically with the base plate, while a vertical guide
near the carriage has connection with the inner contact of the T lever through a
switch, which is termed the style switch. The base plate of each machine is
connected with a switch (the "battery switch "), one contact of which is
connected through a battery to the ground, while the other has a direct ground
connection.
The transmitting style carries two contacts, one connected with the carriage when
the style is placed in position thereon, and through it to the base-plate and "battery
switch," and the other by a spring with the vertical guide and through it with the
"style switch."
One of these contacts is carried by a spring having a point pressing upon
the
surface of the paper on the insulating cylinder. The smooth surface of the paper
keeps the contacts separated, but when the point drops into the depression made
by a line the contacts come together, completing the circuit through the "style
switch" and the inner contact of the T-lever. The receiving style is insulated
from its carriage and has a spring connecting with the vertical guide. This style
carries a point bearing upon the surface of the paper, and when the "style
switch is closed the current passes through the receiving style, the recording
paper, and the metal cylinder to the base-plate, from whence it passes to ground
through the "battery switch."
"
When the message is completed, the operator at the transmitting station throws
the style off of the cylinder by a lever. This allows the contacts of the style to
close, and a continuous line is recorded at the receiving station. This may be used
as a signal that the message has been completed. The "style switches are then
thrown open and a new set of cylinders put in position.
"
A latch is arranged to lock the escapement when each carriage reaches its
lowest position, such latch being released by the movement of the carriage.
In order to neutralize the effect of the static charge in working long lines and
produce clear sharp lines at the receiving instruments, the plate on the head of the
T-lever is extended in the form of a spring to the other end of the lever head,
where it strikes a contact connected to the ground through an electro-magnet or
resistance, or both.
This ground contact is made when the inner contact at the other end of the
lever is also made, and the ground contact is further retained for an instant after
the inner contact is broken, so that the static charge will pass off into the ground
after the battery circuit is opened by the T-lever, and will not operate the relay.
This ground contact however is broken before the outer or relay contact is made
by the movement of the T-lever.
The foregoing will be better understood from the Drawings, in which
Figure 1 is a diagramatic view of the circuits and connections.
Figure 2 a vertical section through the motor case, showing the motor in
elevation.
Figure 3 a top view of the "synchronistic machine."
Figure 4 an elevation of the upper part of the "synchronistic machine,"
the T lever being removed for clearness, and the cylinder and sleeve being in
vertical section.
ז
the man
and the mechanism for reculating
:

page_text: Figures 7 and 8, top views respectively of the transmitting and receiving styles,
and
Figure 9, an end view of one of the cylinders, showing the means for securing
the paper thereto.
Like letters denote corresponding parts in all the Figures.
A and B are respectively the "simple" and "synchronistic" machines. Each
has a base plate C mounted on insulating supports above another plate C¹ which
is supported upon the case C2 inclosing the motor. Through the centre of
plates C, C', passes the vertical metal spindle D; E is the electro-motor, situated
in the bottom of case C³, and preferably of the Pacinnotti or Gramine pattern. It
is arranged horizontally and bas a slotted curved crank arm a on the upper end of
its vertical spindle. The spindle D also has a slotted curved crank arm b on its
lower end, and in the slots of the arms a and b move boxes on the ends of a rod F,
having a centrifugal regulating ball F¹ near its lower end. Near arm b the rod F
is carried by a universal rocking joint F. The motor circuit and the adjustable
resistance placed therein are not shown. The click springs for indicating when the
motor is running at a higher or lower rate of speed than desirable are shewn
at c, c; G is the sleeve of the synchronistic machine, held in frictional contact
upon the spindle D by a spring d and nut d¹. This sleeve and the spindle of the
simple machine have the can depression e (shown in dotted lines), and are
provided above the same with an arm e¹ having a pin which holds and locates
correctly either the transmitting or receiving cylinder H.
I is the T-shaped lever, pivoted on base-plate C. Its central stem f has a
projection which is thrown into the depression e by a spring g, which spring is
connected to the line through the "line switch" S¹. The metal plate f¹ on the
head of lever I has electrical connection with 9, and plays at one end between the
adjustable outer and inner contacts h, i, while at the other end it springs outwardly
and makes contact with J.
The contacts i of the two machines are connected with the coils of electro-
magnets K, K. From K the wire passes through a battery B¹ to the ground,
which battery may be the main battery at that end of the line.
From K¹ the wire passes directly to ground. The armature K acts simply as a
sounder K, besides performing that function makes and breaks the circuit of the
local battery B³ at the synchronistic machine; L is the electro-magnet in the
circuit of the local battery B³. The pivoted lever 7 carrying the armature of this
magnet forces back a spring latch ' which engages a catch-arm 12 carried by the
sleeve G. The spring of keeps it forward in the path of 12, but the closing of
the local circuit forces l¹ back, allowing the point of to swing clear. The lever
for withdrawing the latch ' is shown at m. It is worked by a pushrod m¹ and
forces the armature against the magnet L, holding it there whether such magnet
is energized or not.
M, M', are the Morse keys for signalling placed between contacts of S¹ and the
electro-magnets K, K'. The weighted carriage of each machine is designated by N.
It slides vertically on ways rising from plate C, as shown, and has a horizontally
pivoted spring block n upon which either style is placed, the spring throwing the
style inwardly against the cylinder. This carriage has a rack 0 projecting down-
wardly therefrom and engaging a pinion o just above plate C. On the same
spindle with pinion O is an escape wheel O¹, with which engage the pallets of an
anchor O. This anchor has an arm o¹ provided with a head which is thrown
into the depression e by the anchor-spring, allowing the anchor to swing in that
direction while it is thrown in the opposite direction by the forcing of the head of
arm o¹ out of the depression e as the spindle revolves. Thus at every revolution
of the cylinder the escape wheel will move two teeth. The pinion o and escape
wheel O¹ are supported by a pivoted lever Q, by moving which the pinion can be
thrown out of gear with the rack, so that the carriage can be raised independent
of the escapement.
The carriage has a finger p, which when it reaches its lowest position pushes a

page_text: pin p¹ and forces a hook lever Q1 from under a sustaining lug p², allowing such
lever to drop and engage the arm O' of the anchor O' so as to prevent the head of
such arm from again entering the depression e and stopping the further operation
of the escapement. The carriage is connected electrically with the base plate C by
its ways, while the vertical guide q has connection with the inner contact h
through the "style switch" S. The base-plate of each machine is connected with
the "battery switch" S³, one contact of which connects with main battery B' or B³,
and the other contact has a direct ground connection.
T is the transmitting style, having two contacts, one carried by spring which
is connected by rl with the guide when the style is in position on the carriage,
and the other by arm 8 connected by spring 8¹ with the carriage.
The spring has a point which traverses the surface of the paper and
separates the contacts against the pressure of spring except when it drops into
a depression. The contacts are shown for clearness in Figure 7 as forced apart,
the normal position when the style is removed from the carriage being the reverse.
The receiving style U (Figure 8) has its point t connected by a spring t¹ only
with the guide q, the current being carried off through the cylinder to the base-
plate and thence to ground.
A pivoted lever u is used to throw either pen off of the cylinder when the
message is complete. V represents the electro-magnet, or resistance, or both,
through which the contact j of each machine is connected with the ground.
In Figure 9 is shown means for securing the paper upon the cylinder. This
consists of a spring plate v which is forced under the projecting edge of a slot in
the cylinder; but any other efficient device can be used.
The binding posts numbered on the diagram (Figure 1) are for the following
circuits:-1, the base plate circuit; 2, the sounder and relay circuit; 3, the
compensation circuit; 4, the line circuit; 5 and 6, the style circuit; and 7 and 8,
the local circuit.
What is claimed is,-
First. The method of producing fac-similies by electricity consisting in con-
trolling an electric current by the depressions formed by marking upon paper or
other suitable material, substantially as set forth.
Second. A fac-simile telegraph having transmitting and receiving instruments,
the transmitting circuit being controlled by the depressions produced by marking
upon paper or other suitable material, substantially as set forth.
Third. In fac-simile telegraphs, the combination of the transmitting and receiving
instruments of a transmitting style having circuit connections, and contacts in
circuit controlled by the uneven surface of the prepared massage, substantially as
set forth.
Fourth. In fac-simile telegraphs, the synchronously revolving cylinders, one
carrying the message prepared by depressed lines, and the other a chemically
prepared recording paper, in combination with the transmitting and receiving
styles having a movement at right angles to the cylinder, the said transmitting
style having contacts in circuit controlled by the uneven surface of the message,
substantially as set forth.
Fifth. In fac-simile telegraphs, the combination with the synchronously revolving
cylinders of movable contacts, operated by the machines for breaking the circuit
when the styles are passing the secured edges of the paper, substantially as set
forth.
Sixth. In fac-simile telegraphs, the two revolving cylinders, one of which has a
slightly greater speed than the other, in combination with a device for checking the
cylinder having the faster movement, substantially as set forth.
Seventh. In fac-simile telegraphs, the two cylinders having slightly different.
speeds of revolution, in combination with a latch operated by an electro-magnet
for checking the cylinder having the faster movement, substantially as set forth.
Eighth. In fac-simile telegraphs, the combinations of the two machines having
cylinders revolving at slightly different speeds, with a device for checking the

page_text: faster cylinder, and contacts made simultaneously by the two machines for
operating the checking device by completing the circuit through the same,
substantially as set forth.
Ninth. In fac-simile telegraphs, the combination of the two machines having
cylinders revolving at slightly different speeds, of a checking device for the faster
cylinder operated by an electro magnet in the circuit of a local battery, and
contacts made simultaneously by the two machines, and completing the main
circuit through an electro magnet controlling said local circuit, substantially as set
forth.
Tenth. In fac-simile telegraphs, the combination of the cylinders and the electro-
magnetic checking device controlled by the main circuit, of sounders for indicating
the synchronism of the cylinders, substantially as set forth.
Eleventh. In fac-simile telegraphs, the combination of the cylinders and the
electro-magnetic checking device of sounders for indicating the synchronism of the
cylinders, signalling keys placed between the sounders and line in shunts around
the machines, and switches for throwing in and out of the machines and keys
alternately, whereby the sounders will be operated by the machines or keys
according to the position of the switches, substantially as set forth.
Twelfth. In fac-simile telegraphs, the combination of the two machines having
cylinders revolving at different speeds, and an electro-magnetic checking device for
one of them with a pivoted lever on each machine, connected to line, and two
contacts between said lever plays, one connected through the syle circuit to battery
or ground, and the other through the relay and sounder circuit, such lever being
moved once during each revolution of each cylinder to break the style circuit and
make the relay and sounder circuit, substantially as set forth.
Thirteenth. In fac-simile telegraphs, the combination with the synchronously
revolving cylinders and the transmitting and receiving styles, of the compensation
circuit for neutralizing the effect of the static charge, substantially as set forth.
Fourteenth. In fac-simile telegraphs, the combination with the synchronously
revolving cylinders, and the transmitting and receiving styles, of cams revolving
with the cylinders, pivoted levers worked by said cams and connected to line, and
making contacts for completing the "style," the "sounder," and the "compensation"
circuits, substantially as set forth.
Fifteenth. In fac-simile telegraphs, the combination with the revolving cylinders
of the revolving cams and the style carriages controlled by escapements worked
by said cams, substantially as set forth.
Sixteenth. In fac-simile telegraphs, the combination of the electro motors with
weighted centrifugal arms carried by universal rocking joints, and connecting the
motors with the driven mechanisms, substantially as set forth.
Seventeenth. In fac-simile telegraphs, the combination of the horizontal electro-
motors with the weighted centrifugal arms carried by universal rocking joints and
the slotted cranks, substantially as set forth.
In witness whereof, I, the said Edward Griffith Brewer, have hereunto set
my hand and seal, this Eighteenth day of January, in the year of our Lord
One thousand eight hundred and eighty two.