IMPROVEMENTS IN ELECTRIC TELEGRAPHS
Year: 1870

page_text: LETTERS PATENT to Cromwell Fleetwood Varley, of Beckenham, in
the County of Kent, for the Invention of "IMPROVEMENTS IN ELECTRIC
TELEGRAPHS."
Scaled the 7th June 1870, and dated the 8th April 1870.
PROVISIONAL SPECIFICATION left by the said Cromwell Fleetwood
Varley at the Office of the Commissioners of Patents, with his
Petition, on the Sth April 1870.
I, CROMWELL FLEETWOOD VARLEY, of Beckenham, in the County of
Kent, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN ELECTRIC TELEGRAPHS," to be as follows:-
:-
This Invention has for its object the increase of the transmitting power
of telegraph circuits by enabling more than one operator to signal
independent messuages at the same time upon one and the same wire to
and from independent stations.
In working land lines it is usual to produce the signals by means of
the passage of a current of electricity producing magnetic action, as in

page_text: the Morse or Hughes instruments, or chemical action, as in the Baines
machines.
By my Invention I superpose upon the currents used for working the
ordinary telegraphs rapid undulations or waves which do not practically
alter the mechanical or chemical power of the ordinary signal currents,
and by new apparatus herein-after described these undulations are made
to produce distinct and independent audible or other signals so long as
these undulations are produced, whether ordinary signal currents be
flowing or not.
As a rough mechanical illustration of the way in which I propose to
pass two sets of electric signals simultanously and in either direction
through the same line wire without interference I will suppose a rope
stretched over two distant pulleys by means of weights at each end; if
the near weight be raised the distant one falls. In this way signals
are transmitted by the connecting rope, which may be called current
signals; if now two small pulleys capable of rising and falling rest upon
the rope between but near to the supports they will simply rotate when
the rope is shifted backwards and forwards; if now an operator at onc
end strike the rope vibrations or waves will be produced which will cause
the other small pulley to dance or make vibration signals. Consequently
the operator who shifts and the operator who strikes the rope can cach
produce independent signals on one and the same rope. Suppose the rope
to travel over several fixed pulleys the operation of shifting the ropc will
produce distinct current signals from end to end of the line as before,
but between each fixed pulley vibrations can be produced, and so a number
of intermediate stations can communicate independently of each other
and independently of the current signals through the line.
With this mechanical simile the following will be more easily under-
stood.
The way in which I carry my electric Invention into operation is as
follows:-
An electro-magnet offers at the first moment great opposition to the
passage of a current of electricity, and therefore it may be considered
as partially opaque to the transmission of very rapid alternations or
electric waves. I attach to the line at desirable parts condensers. In
the first instance I will assume only two condensers, one at each end,
attached near each end of an ordinary telegraph line. The first or
communicating station produces in its condenser rapid charges and

page_text: discharges; these add to and take from the line a number of small
electric impulses without affecting the mean magnetizing power of the
currents through the line. These impulses charge and discharge the
second condenser at the other end.
These undulations in the second condenser can be utilized in tho
following manner :—
1. If the condenser be made of
paper and metal foil the rapid
charges and discharges produce a musical sound.
2. If those rapid alternations be made to pass round a helix con-
taining an iron rod a musical sound is produced.
3. If these currents pass round a helix containing a magnetized
harmonium tongue the currents make it vibrate audibly if the currents
be properly timed, and the effect is increased if a feeble current of air be
passing the tongue. By adding tubes of proper length and sounding
boards and other appliances for communicating vibrations the power of
the signal is increased.
4. By placing the magnetized tongue of a musical comb between the
poles of an electro-magnet with only a small iron core, or inside a coil,
it is made to vibrate whenever these undulations aro passing.
Another method of producing sound from the undulations consists of
stretching a music wire through hollow trelices; the currents magnetize
and demagnetize the tone, this wire being also placed between the poles
of permanent magnets. Harmonious currents cause this wire to vibrate.
In some cases it may be useful to employ inharmonious currents to
stop or silence the vibrations. The two latter methods will only speak
when vibrations or harmony with the tongue are made to pass, and
consequently in some cases two or more distinct sets of vibrations can be
made to act on two or more sets of apparatus differently tuned, and to
permit of several distinct communications to be transmitted simulta-
neously upon the same section of a single line wire. By introducing,
between the receiving condenser and a Morse or other ordinary receiving:
instrument a current reverser keeping time with the vibrations, these
alternating currents are made to flow through the receiving instrument
in one direction, and are then competent to work the Morse or other
ordinary receiving instrument.
6. When it is desirable to subdivide the vibrating sections of a line
an electro-magnet, or, what is better, two electro-magnets are inserted in

page_text: the circuit, and a condenser may with advantage be placed between the
circuit and the earth connecting the condenser with the circuit between
the two electro-magnets. In this way, without interfering materially
with the ordinary signals through the line, the vibrating sections are
separated from each other by withdrawing the iron cores from the
electro-magnets, or short circuiting the electro-magnets the vibrations
are passed through to the next station.
7. Another method consists of inserting a reflecting galvanometer
between the condenser and the earth (or between the line and the con-
denser); the vibratory or secondary signals can be read off by observing
its vibrations.
8. Vibrations are rendered sensible by placing a moveable iron bar
between the poles of an electro-magnet or inside a helix, and one or both
of its ends between the poles of permanent magnets; the latter are
covered with brass or any non-magnetic matter; the vibration currents
cause it to vibrate between the poles of the electro or permanent magnets,
and so produce distinctly audible sounds.
9. There are other methods of utilizing these superposed vibrations,
such as connecting to the condenser an electrometer like that of Milner
or Pettier. An intermediate Morse or other such line instrument would
cut off the vibration signals or reduce them much; this opposition
of the intermediate electro-magnet may be cut off by connecting the
terminals of a condenser to the circuit on each side of the magnet.
There are several methods of producing these vibrations in the
wire :-
1st. If a tuning fork be placed between the poles of an electro-magnet
with a spring contact so arranged that when at rest the battery current
flows through the electro-magnet the latter will attract the tuning fork
and break the circuit; the magnetism then ceases and the tuning fork
springs back and renews the circuit; in this way it keeps vibrating so
long as the battery is in action. A secondary wire around this magnet
produces currents in opposite directions, and by placing this secondary
wire in circuit with the line wire the necessary vibrations aro
produced.
2nd. The secondary wire may be connected between the earth and the
condenser attached to the line wire; this method does not add to the

page_text: 3rd. A tongue similar to those used in harmoniums is made to vibrate
by air between contact points, and so connect the condenser alternately
with the battery and the ground, and so produce the alternations, or it
may be made to connect the condenser alternately to the + or-pole of
a bettery whose opposite poles are connected to the earth.
4th. A magneto machine rapidly rotating will do the above duty
equally well if its speed of rotation be controlled by a good governor.
The tuning fork and vibrating tongue arrangement can be set to and can
keep up any desirable rate of vibrations. The ordinary telegraph keys
and switches are used for connecting the various parts of the apparatus
together. In constructing the dry paper condensers it is best to dip the
paper in varnish and attach metal leaf (such as gold, silver, or copper)
to the paper, and lay these metal-coated papers between metal foil.
The double-speaking apparatus of Dr. Gintl, or of Firschen, can be used.
on lines working with the above-described vibrations. When these are
used I prefer inserting a hollow helix between the double speaker and
the line, and by inserting iron rods in this helix the difficulty arising
from the inductive capacity of the line is almost wholly removed. This
is a new improvement, and will render these apparatus actually useful
instruments.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Cromwell Fleetwood Varley in the Great Seal Patent
Office on the 8th October 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, J, CROMWELL
FLEETWOOD VARLEY, of Beckenham, in the County of Kent, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of April, in the year of our
Lord One thousand eight hundred and seventy, in the thirty-third year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Cromwell Fleetwood Varley, IIer special licence that
I, the said Cromwell Fleetwood Varley, my executors, administrators, and
assigns, or such others as I, the said Cromwell Fleetwood Varley, my
executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term

page_text: therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
ELECTRIC TELEGRAPHS," upon the condition (amongst others) that I, the
said Cromwell Fleetwood Varley, my executors or administrators, by an f
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters 1
Patent.
NOW KNOW YE, that I, the said Cromwell Fleetwood Varley, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by
the following statement thereof, that is to say:—
]
This Invention has for its object the increase of the transmitting
power of telegraph circuits by enabling more than one operator to
signal independent messages at the same time upon one and the same
wire to and from independent stations.
In working land lines it is usual to produce the signals by means of 2
the passage of a current of electricity producing magnetic action, as in
the Morse or Hughes instruments, or chemical action, as in the Baines
machines.
By my Invention I superpose upon the currents used for working
the ordinary telegraphs rapid undulations or waves which do not prac- 2
tically alter the mechanical or chemical power of the ordinary signal
currents, and by new apparatus herein-after described these undulations
are made to produce distinct and independent audible or other signals
so long as these undulations are produced, whether ordinary signal
currents be flowing or not.
As a rough mechanical illustration of the way in which I propose to
pass two sets of electric signals simultaneously and in either direction
through the same line wire without interference, I will suppose a rope
stretched over two distant pulleys by means of weights at each end.
With such an apparatus, if the near weight be raised the distant one
falls, and in this way signals may be transmitted by the connecting rope,
which may be called current signals. If now two small pullies capable
of rising and falling rest upon the rope between but near to the

page_text: supports they will simply rotate when the rope is shifted backwards
and forwards; but if now an operator at one end strike the rope vibra-
tions or waves will be produced, and will cause the small pulley at
the other end to dance, and so vibration signals may be given. Con-
sequently the operator who shifts and the operator who strikes the rope
can each produce independent signals on one and the same commu-
nicating cord. Suppose the rope to travel over several fixed pulleys the
operation of shifting the rope will produce distinct current signals
from end to end of the line as before, but between each fixed pulley
and the next to it vibrations can be produced, and so a number of
intermediate stations can communicate independently of each other and
independently of the current signals through the line.
With this mechanical simile the following will be more easily under-
stood.
The way in which I carry my electric Invention into operation is as
follows:-
:-
Condensers are attached to the line at the places where the wave
In the first place
signals are to be communicated and received.
let us assume only two condensers, one at each end, attached near
The first or com-
each end of an ordinary Morse telegraph circuit.
municating station to make a signal produces in its condenser rapid
charges and discharges by means described; further on these add to
and take from the line a number of small electric impulses without
affecting the mean magnetizing power of the ordinary Morse currents
through the line. These impulses charge and discharge the second.
condenser at the other end, and this condenser is coupled with a
receiving instrument which is sensitive to these undulations and renders
them apparent by sound or otherwise.
Figure 1 is a diagram of the instruments at one of the stations of
such a line; a is the line wire, I will suppose it to be an ordinary land
line wire 50 miles long and suspended in the usual way; b is the Morse
instrument, c the sending key for the Morse signals, d the battery in
connection with this key, and e its earth connection; is a condenser of
about 3 micro-farads, one armature of which I couple with the line wire
and the other with a key g, which when not depressed puts the condenser
in communication with the wave signal receiving instrument h, which
I call a cymaphen;" this instrument is shown at Figures 2, 3, and 4.
The key when depressed for sending a wave signal puts the condenser in
"

page_text: connection with the apparatus by which such waves are generated; this
apparatus consists of a battery i; ten quart cells of Daniel's battery will
be suitable. One pole of the battery i is connected with the tuning
fork k; this fork may conveniently be of such dimensions as to make 200
vibrations in a second. P, F, are two platina pointed contact-making
springs, capable of fine adjustment by means of screws. The spring /
when the fork is at rest is in metallic contact with it or with a metal arm
attached to it, and the spring & is removed just out of contact. The current
from the battery i then passes in the coils of the electro-magnet m, the
poles of which have between them the two horns of the tuning fork. The
coils of this magnet may be about 3 inches long, and 11 inches diameter,
and of No. 16 (B.W.G.) silk-covered copper wire. When the current
is flowing through the coils of the electro-magnet the horns of the fork /
are drawn apart and the spring loses its contact; then as the attraction
of the magnet ceases the horns of the fork spring back; this re-makes the
contact, and so a continual tremor is communicated to the tuning fork.
In the same circuit with the electro-magnet there is at na primary coil
wound upon a bundle of iron wires as a core, and on the same core but
wound in the opposite direction is a second primary coil which is in
connection with the spring P, so that currents pass alternately in the
two primary coils, and at each alternation the polarity of the core is
reversed. On the core there is also another or secondary coil, in which
currents are induced by the changes of polarity of the iron corc. One
end of this secondary coil is connected with the carth, and the other
when a wave signal is to be sent is by the key g put in connection with
the condenser f, and produces in it rapid charges and discharges.
The core may conveniently consist of a bundle of thin soft iron wires,
1 inch in diameter and 32 inches long. On the centre of the bundle
is wound for a length of eight, the first primary coil consisting of four
layers of No. 16 silk-covered copper wire. Over this is wound the second
primary coil, consisting also of four layers, and outside this again is wound
the secondary coil consisting of eight layers of No. 21 silk-covered wire.
The ends of the bundle composing the core are folded over so as com-
pletely to enclose the coils. A small resistance coil o, or a condenser of
about two micro-farads, is placed between the poles of the secondary coil
to take off the violence of the shock, so that the operator shall not be
inconvenienced. The wave signal receiving instrument is shown in
plan at Figure 2, in longitudinal section at Figure 3, and in transverse
section at Figure 4. It consists of an iron frame containing a sounding

page_text: board a over bridges, at the ends of which a hard drawn iron or steel
wire is stretched from one end to the other; this wire is about four
feet and six inches long between the bridges; it is of No. 14 gauge,
and is strained so as to sound the same note as the tuning fork of the
sending instrument. This wire passes through a hollow helix c, three
inches in length, & of an inch internal diameter and 14 inches external
diameter. The helix is wound with No. 35 B.W.G. copper wire
insulated with silk. This coil is attached to the frame supporting the
sounding board, but does not touch the latter. Two horse-shoe magnets &
are placed one on each side of the wire. The currents magnetize the
ccase.
wire inside the helix, and so cause it to be attracted and repelled from
one magnet to the other. When the wire is properly tuned so as to
vibrate synchronously with the apparatus at the distant end making the
alternations in the current the sound from very feeble currents is distinctly
audible. A piece of felt or leather resting against the wire is sometimes
used to "damp" the wire and stop its vibrations as soon as the impulses
A small piece of metal similar in dimensions to a gold five-franc
picce may be made to rest by a spring lightly against the sounding board
somewhere near its centre. When the vibrations of the latter are powerful
enough to make this piece of metal dance, the sound is increased in power
four or five times by this little disc or sound reinforcer, or the sound may
be augmented by clipping on to the wire near the helix a disc of about
the size of a penny piece of thin sheet metal; this causes the vibration
of the wire to produce a greater disturbance in the air than it otherwise
would, and a louder sound is perceived. By attaching a stethescope
to the sounding board for the reader to rest his ear against very feeble
sounds are rendered sufficiently audible; I prefer to use a Scott Allison's
stethescope. The sounding board may be replaced by a a strained
diaphragm or drum-head, on which one of the bridges over which the wire
is strained is supported; this arrangement gives a better sound with
very feeble currents, but with moderate currents the sounding board
appears to have the advantage. Two sets of wave signals may be
transmitted and received simultaneously through the same wire, and
independently of the current signals if a sufficient difference be made
in the periods of the two sets of waves. Thus, if waves of 200 vibrations
in the second, and waves 850 or 900 vibrations in the second, be
simultaneously transmitted and received by two separate cymaphens,
the one adjusted to the slow, and the other to the rapid vibrations, they

page_text: inoperative on the other. This arrangement is not applicable when
working long distances, as the rapid waves would in a long distance
bc lost.
Figure 5 is a diagram illustrating the arrangements I make when the
wave signals are used to communicate between intermediate or branch
stations without interfering with the working by ordinary instruments
of the main line; a is the line wire, say between London and Southampton,
and through it it is desired that the intermediate station, Basingstoke,
shall without interference with the through messages be able to com-
municate to and fro with the branch stations, Windsor and Salisbury.
At these branch stations I provide wave signal apparatus such as already
described in respect to Figure 1, coupled with condensers ', b²,
at the places where the branches run into the main line. At the
intermediate station, Basingstoke, I divide the line wire into two sections
(as far as the wave signals are concerned) by introducing at c an
instrument which is opaque to these waves, whilst it allows the ordinary
long current signals to pass freely. This opaque instrument c I call
"echocyme," and on either side of it I connect with the line wire a
condenser d', d³, and wave signalling apparatus, as already described. An
electro-magnet offers at the first moment great opposition to the passage
of a current of electricity, and may be considered as nearly opaque
to the transmission of very rapid alternations of current or clectric
waves. The "echocyme" may consequently be a simple electro-magnet,
or what is better is to wrap an induction coil with two wires so as to
form one continuous coil; this is put into the line circuit. The junction
between these coils is connected to the one armature of the condenser,
whose other armature is connected to the earth. The momentary action
of a current on passing through one wire charges the condenser. The
secondary action upon the other wire checks the current that the
condenser would have sent on through the other wire on to the remainder
of the main line circuit; by varying the size of the condenser according
to the nature of the line and currents employed a nearly absolute
stopper of the vibrations signals is produced. The coil which I have
used for this purpose has the following dimensions: iron bundle one inch
in diameter, length of coil 8 inches, and wound with No. 26 insulated
copper wire to a diameter of 2 inches. The condenser connected between

page_text: the "echocyme" and the earth in the case which I have taken for
illustration should be of about 1 of a micro-farad. At the termini Morse
or other ordinary instruments may be used.
There are various ways in which the wave signal receiving apparatus
may be constructed, although that which I have already described I
prefer; thus the condenser itself may be the receiving instrument.
If the condenser be made in the following manner the rapid
charges and discharges will produce a musical sound. Sheets of tinfoil
(for example, one foot square) are separated by one or more sheets of
thin dry paper; the 1st, 3rd, 5th, &c. sheets are joined together;
the 2nd, 4th, 6th, &c. also join together. The odd numbered sheets
are connected to a binding screw or terminal, and the even numbered
sheets to another terminal. Such a condenser consisting of from 20
to 50 sheets will be found to be much agitated and to produce a loud
note with 500 alternations of current per second if the potential be 50
to 100 votts.
In constructing the dry paper condensers the following method seems
to answer best:-Very thin uniform paper is dipped in shellac varnish
coated on one side with gold leaf and then dried. The non-gilt surfaces
of 2 sheets of paper are put together so as to leave the gilt surfaces
outside; the tinfoil plates are placed outside of these and built up in the
usual manner, connecting the 1st, 3rd, 5th, 7th, &c. plates to one
armature of the condenser, the 2nd, 4th, 6th, 8th, &c. being joined to
the other armature of the condenser. If the rapid alternations of current
be made to pass round a helix containing an iron rod, the iron rod will
issue a feeble but distinct sound. The rod used may be th of an inch
in thickness, 18 inches in length, and covered to a diameter of one inch
with No. 35 insulated copper wire. This arrangement requires strong
currents. If the currents pass round a flat coil in which a magnetized
harmonium tongue is placed, the currents will act upon it like the
needle of a galvanometer and cause it to vibrate. The sound is increased
by causing a feeble current of air to pass the tongue. If a steel tongue,
similar to one of those used in a musical box, be magnetized and placed
inside a helix of fine wire, and its lip is placed between the poles of a
powerful permanent magnet, the alternating currents will cause the
tongue to vibrate and produce a musical sound so long as the alternations
are operating. By coating a wire, strained, as is shown in Figures 2
and 3, near the coil, with a short tube of gold or platinum, and letting a

page_text: light spring formed of the same metals rest against the wire, a relay is
produced, which bringing into operation a local battery can be used to
increase the sound or to relay on the signals to another line.
A thick music wire, much thicker than those used in pianofortes, is
found to give the best results for sound. A thin wire is thrown into
greater oscillation than a thick one, and admits of being utilized for
visible signals in the following way:-A steel wire of about No. 40
gauge is stretched through the helix in front of a very narrow slit. A
flame is passed behind the slit, but the light coming through is checked
by the wire; the moment, however, the wire is put into vibration light
passes, a lens is placed in front, and by it a magnified image of the
luminous slit is projected upon a white screen so long as the wire
vibrates. Vibration are rendered sensible by placing a moveable iron
bar between the poles of an electro-magnet or inside a helix, and one or
both of its ends between the poles of permanent magnets; the latter
are covered with brass or any non-magnetic matter. The vibration
currents cause it to vibrate between the poles of the electro or permanent
magnets, and so produce distinctly audible sounds.
Another method of utilizing these alternations is by introducing
between the receiving condenser and a Morse or other ordinary receiving :
instrument a current reverser keeping time with the vibrations; these
alternating currents may be made to flow through the receiving instru-
ment in one direction, and are then competent to work the Morse or
other ordinary receiving instrument. Or a similar result may be
obtained by the arrangement shown at Figure 6, which consists in a
connecting the receiving condenser to two "Geisler's" vacuum tubes a
and ; the latter are connected with voltaic batteries C, Z, consisting of
a large number of clements. The one tube a is connected to the
"positive pole" of a battery whose "negative pole" is connected to the
earth. The second tube is connected to the " negative pole" of a 3
battery whose " positive pole" is to carth. These batteries must have
nearly power enough to make a current pass through the tubes; for
example, supposing three hundred cells of a battery be able to leap
across the exhausted tube 290 should be used with cach tube. When a
positive current arrives it will help the battery whose positive pole is a
connected to the earth and cause a current to pass through its tube b.
The next instant the current is reversed; this causes a current to pass
through the other tube a; in this way an electric valve is produced

page_text: separating the positive from the negative currents, and producing a
rapidly intermittent current in one direction only. If a reflecting
galvanometer be enclosed in the circuit formed by the batteries and the
tubes the wave signals will be indicated by it.
Another method of producing an electric valve for separating the
positive from the negative currents is illustrated by Figure 7, and consists
in connecting, say, 5 cells of Daniels' battery with 3 cups containing
dilute sulphuric acid with platinum plates joined up so as to form 3
decomposition cells in series. Between the battery and the 3 cups is
inserted the galvanometer or other instrument that is to be worked; the
junction between the instrument and the cups or decomposition cells is
connected to the condenser. The other junction between the battery
The first action
and the decomposition cells is connected to the earth.
of the battery is to polarize the platinum plates when the current almost
entirely ceases, the three pairs of polarized platinum plates balancing
the 5 Daniell's cells. The moment a current arrives from the condenser it
finds two channels open to the earth,-the one the battery, the other the
decomposition cells. Suppose the positive pole of the battery to be in
connection with the earth and a positive current arriving from the con-
denser, at first it divides itself, part going through the battery, part
through the decomposition cells. The action of the current upon the
latter is to depolarize them, and they then immediately resist its flow.
The next moment a negative current flows from the condenser; this
negative current is assisted by the partly depolarized plates, and the
battery and the former become repolarized. It is best to wrap the
instrument, as the diagram shows, with two wires connecting the one
with the cups, the other wire with the battery, and their junction with
the condenser. The result is that whether it be a negative or positive
current that is sent into this arrangement the action upon the instrument
is the same, and thus out of alternating currents a continuous action is
produced. The platinum plates for this purpose must be very small and
very close together, to reduce as much as possible their inductive capacity
and resistance.
Another method consists of inserting a reflecting galvanometer between
the condenser and the earth (or between the line and the condenser);
the vibratory or secondary signals can be read off by observing its tremor.
The mirror of this galvanometer must be deadened by water or other
damper, and it is best to produce the signals by interrupting the vibrations

page_text: instead of the reverse. The vibrations keep the mirror oscillating, the
image becomes spread out, and the light enfeebled. The moment the
vibrations are cut off the light contracts. The effect is the "spread out”
light is feeble, the "concentrated" is bright, and thus the signals can be
flashed by long and short duration like the Morse alphabet.
A
Another method of utilizing these superposed vibrations is to connect
to the condenser an electrometer like that of Milner or Pettier.
resistance coil of about 1,000 ohms. is connected between the condenser
and the cart as a shunt to the electrometer to prevent the Morse
signals from affecting it to any sensible extent; or the wave signals
may be read by the sense of touch. For this purpose I use a handle
made of hard charcoal, and divided into two parts longitudinally. The
parts are separated by a sheet of gutta percha, and are connected the one
with the armature of the condenser, the other with the earth. The
handle being moistened and covered with a rag wetted with weak salt
and water is firmly grasped in the hand. An intermediate Morse or
other such line instrument would cut off the vibration signals or reduce
them too much; this opposition or opacity of the intermediate instrument
is destroyed by connecting the terminals of a condenser to the circuit on
each side of the magnet. Thus, if I wish wave signals to pass a Morse
instrument I couple the armatures of a condenser of 3 to 10 micro-farads
with the line wire, one on either side of the Morse instrument. The
working of the Morse line, if there are many instruments in circuit, is
also in this way improved.
There are several methods of producing electric waves in the lines
in addition to that already described. A tongue similar to those used
in harmoniums is made to vibrate by air between contact points, and
so connect the condenser alternately with the battery and the ground,
and so produce the alternations, or it may be made to connect the
condenser alternately to the + or pole of a battery whose opposite
poles are connected to the earth.
-
A magneto machine rapidly rotating will do the above duty equally
well if its speed of rotation be controlled by a good governor.
The double-speaking apparatus of Dr. Gintl, or of Frischen, can be
used on lines working with the above-described vibrations.
Figure S is a diagram of this arrangement.
a is the line wire; b, b,
the condensors; c, c, the cymapheus, wave signal transmitters, and parts

page_text: connected therewith; d, d, are the current signal keys and batteries; and
e, e, are the magnets of Dr. Gintl or Frischen's receiving instruments;
and are their resistance coils. I prefer wrapping the magnets e, e,
with 3 or 4 wires, using one wire between the key and the earth through
its resistance coil, and the two or three wires joined into one circuit
attached to the line wire. I insert a hollow helix between the double
speaker and the line, and by putting iron rods in this helix the difficulty
arising from the inductive capacity of the line is almost wholly removed;
this is a new improvement and will render these apparatus actually
useful instruments. The helix may conveniently be of No. 20 silk-
covered wire and 10 inches long, with a diameter inside of 1½ inches,
and outside of 4 inches; small iron rods are placed in this helix one
by one until it is found that the finger-key does not affect the indicator
of the home receiving instrument. By using these instruments, these
apparatus together with cymaphens, as is shewn in Figure S, three
messages can be sent from end to end of such a circuit at the same
time independently of each other; for this purpose the cymaphen key
must have a spring contact so that the circuit between the condenser
and the earth is never broken until the contact with the secondary coil
is complete.
I would remark that in electric telegraphs the use of sound signals
is not claimed by me and is not new; for example, in working step
by step instruments in which a pointer should indicate the desired letter
on a dial it has been common when the instrument is out of order and
fails to indicate correctly to give sound signals; by its means such sound
signals are read according to the Morse alphabet, a short sound such
as the escapement of the receiving instrument makes when moving
a few steps only representing a dot, and a long sound such as the
escapement makes when moving over many steps representing a dash.
Having thus described the nature of my Invention, and the manner
of performing the same, I would have it understood that I claim the
construction of electric telegraphs in such manner that current signals
and wave signals may be simultaneously transmitted through the same
line wire, and may be rendered sensible at the receiving station by
separate instruments, the one sensitive to currents of appreciable duration
and the other to electric waves or vibrations.
I also claim the construction of electric telegraphs with, at the
transmitting station, an instrument capable of originating in the line

page_text: wire a succession of rapid and regular electric waves, and at the
receiving station a strained wire, a tongue, or such like instrument
adjusted to vibrate in unison with the electric waves, and being
magnetized by them oscillating to and from the pole or poles of a
magnet in its vicinity.
I also claim in the construction of electric telegraphs the dividing
a conducting wire into sections by instruments which I have called
echocyme," which allow current signals to pass freely but stop wave
signals, so that whilst the wire is being used as a whole for through
signals the sections into which it is divided may each or all be employed
for the transmission of local messages.
I also claim the construction of electric telegraphs with, at tho
transmitting station, an instrument capable of originating in the line
wire a succession of rapid and regular electric waves, and at the
receiving station a condenser consisting of thin sheets capable of being
agitated by such waves.
I also claim the construction of electric telegraphs with, at the
transmitting station, an instrument capable of originating in the line
wire a succession of rapid and regular electric waves, and at the
receiving station an instrument which on receiving such waves delivers
a current of electricity to an indicating or receiving instrument suitable
to be worked with ordinary current signals.
I also claim the combination with Dr. Gintl and Frischen's double-
speaking apparatus of a hollow helix connected between the receiving
instrument and the line wire, such helix having rods or pieces of iron
inserted into it.
In witness whereof, I, the said Cromwell Fleetwood Varley, have
hercunto set my hand and scal, this Seventh day of October,
in the year of our Lord One thousand eight hundred and seventy.