IMPROVEMENTS IN INSTRUMENTS FOR TRANSMITTING AND RECORDING ELECTRIC SIGNALS, PART OF THE INVENTION BEING APPLICABLE TO OTHER PURPOSES
Year: 1869

page_text: LETTERS PATENT to Octavius Varley and Frederick Henry Varley,
of 23, Stonecutter Street, Farringdon Street, in the City of London,
for the Invention of "IMPROVEMENTS IN INSTRUMENTS FOR TRANSMITTING
AND RECORDING ELECTRIC SIGNALS, PART OF THE INVENTION BEING APPLICABLE
TO OTHER PURPOSES."
Sealed the 22nd February 1870, and dated the 25th August 1869.
PROVISIONAL SPECIFICATION left by the said Octavius Varley and
Frederick Henry Varley at the Office of the Commissioners of
Patents, with their Petition, on the 25th August 1869.
We, OCTAVIUS VARLEY and FREDERICK HENRY VARLEY, of 23, Stone-
cutter Street, Farringdon Street, in the City of London, do hereby.
declare the nature of the said Invention for "IMPROVEMENTS IN. INSTRUMENTS.
FOR TRANSMITTING AND RECORDING ELECTRIC SIGNALS, PART OF THE INVENTION.
BEING APPLICABLE TO OTHER PURPOSES," to be as follows:-
The Invention has for its object an improved means of generating.
dynamic currents, and transmitting and recording electric signals derived
therefrom.

page_text: Accordingly in our Invention we employ an electro-dynamic machine
in conjunction with induction plates herein-after described, by which a
continuous dynamic current is obtained of sufficient quantity and
intensity for transmitting signals. This part of the Invention consists
of two iron bars with semicircular flanges attached at each end and
fixed firmly on a stand parallel to each other with the planes of the semi-
circular flanges in a line with one and another. These bars are wrapped
with insulated wire and form two bar electro-magnets. An axle of non-
magnetic substance is placed parallel with the bar electro-magnets in
the centre between the semicircular flanges which are hollowed out to
form a bearing for the axle to turn in. The axle projects some little
distance beyond the flanges and is capable of rapid rotation. The axle
has at each end a circular iron flange to which are screwed two short iron
bars with semicircular flanges corresponding to the semicircular flanges
on the long bars. These short bars are also wrapped with insulated wire,
the ends of which are attached to reversing commutators. On rendering
the long bars magnetic by the passage of an electric current traversing
the surrounding insulated wire, and at the same time rotating the axle, a
dynamic current is set up in the coils of wire surrounding the short bars
attached to the circular flanges, which thus become rotary magnetic
armatures giving electric currents in alternate directions, but which are
commutated to flow from the terminals in one direction only. The
current thus set up in one of the rotary armatures is made to flow round
the insulated wire of the long bar magnets; a continuous current is kept
up whilst the axle is being rotated; this we call the closed circuit. The
current generated in the other rotary armature is made to flow into
induction plates. The advantage of this form over other dynamo-mag-
neto machines consists in the employment of induction plates and the
arrangement of the rotary armatures. These machines convert rotary
movement into electricity and magnetism; the electric current gene-
rated being made to develope the magnetism in the machine. The
amount of magnetic retardation increases until it becomes so powerful
as to put a check on the rotation of the armatures. A limit is soon
arrived at when the magnetism developed within the machine over-
powers the rotation.
This is chiefly due to the retardation produced by
the passage of powerful dynamic currents set up in the insulated wire
surrounding the rotary armatures, for, when the armatures are rotated
and a large resistance is inserted in the circuit of the rotary armatures,
the labor of rotation is reduced in proportion to the diminished amount

page_text: of current.
This magnetic retardation we reduce in the following
manner: When the circuit is completed through induction plates the
charge will continue to flow until the induction plates are polarized
when the resistance in circuit becomes augmented proportionably to
the tension or potential of the accumulated charge. When fully
charged no appreciable current traverses the armature. The potential
of the charge is then at its highest whilst the magneto-dynamic retarda-
tion is reduced and the labor of rotating the armature is consequently
diminished. The dynamic electric charge stored up in the induction
plates can be employed to work the signals of several transmitting instru-
ments simultaneously. We sometimes shunt a portion of the current
flowing through the closed circuit by means of a resistance inserted
between the terminals. We also insert induction plates between the
same terminals. On first starting the machine the principal portion of the
current flows through the circuit of least resistance, namely, the un-
charged induction plates, which when charged offer an increased resistance
as heretofore described; by this arrangement instead of the labor becoming
greater as the potential of the current increases, the induction plates
act as valves shutting off the circuit when the machine is fully charged,
relieving the labour of rotation. We construct the induction plates of
two or more pieces of carbon and paladium plates inserted in a cell
filled with acid and water or plates of carbon and metallic arsenic, or
platinum substituted for the paladium or arsenic plates, or two lead or
other metal plates, or two carbon plates. The current is made to generate
hydrogen on the paladium, arsenic, and platinum plates (when those
metals are used) and oxygen on the carbon. The capacity which paladium
and arsenic have for storing hydrogen renders them very efficient
induction plates, becoming when charged a powerful gas battery.
increase the capacity of the carbon plates for oxygen, by rendering the
plates porous in the following manner;-We select carbon obtained from
gas retorts which contain silica and submit it to the action of hydro-
fluoric acid, the silica is dissolved leaving a porous network of carbon.
We
The machine is first started into action by magnetizing the long bars
by a galvanic current. We prefer for this purpose a Daniel's or sulphate
of copper battery, or neutral salt constant battery made in the following
manner, which we term à gravity and diffusion battery. The cells with their
respective salts and metals or elements we prefer formed in the following
way The cell has two partitions, the first extending from the bottom

page_text: con-
to within about one-third of the top, and the second reaching from the
top to within a short space of the bottom. The purpose of these two
partitions is to separate the positive and negative elements by a
ducting column of fluid to prevent the too rapid intermixture by
diffusion of the salts, as is herein-after described. At the bottom of the
compartment adjoining the second partition, which we term the positive
compartment, we place sawdust or other suitable materials so as to. cover
the opening between the second partition and the bottom of the cell by
a porous diaphragm. Into the first or negative compartment we place a
piece of copper with its connecting strap, and fill in the space with
We
crystals of sulphate of copper to the height of the first partition.
next place the zinc with its connecting strap into the second or positive
compartment. We then fill the cell with acidulated water or suitable
excitants a little higher than the first partition. The copper salt dis-
solves and is kept in close proximity to the copper plate by the partition;
the densest solution falls to the bottom of the compartment. When the
circuit is completed between the negative and positive poles of the
battery the sulphuric acid liberated from the copper ascends over the
top of the first partition diffusing itself through the fluid column and
gravitates where it meets with the porous diaphragm through which it
percolates to react upon the zinc, this battery preventing the rapid
diffusion of the salts while in or out of use and is more steady and better
suited in circuits where only occasional and reliable source of electricity
is required.
In transmitting the signals there are certain mechanical and electrical
difficulties, such as the wear and tear of the working portions and
consequent looseness of fittings which frequently cause the loss of a
signal or the irregular insertion of resistance due to bad contacts. The
platinum contacts will become burned by the continued effect of the
disruptive spark and become either eaten out or so roughened as to make
imperfect contacts; these defects apply chiefly to such instruments, as
needle instruments and transmitting keys, which by certain definite
contacts transmit positive and negative currents or positive or negative
only.
We accordingly in our Invention make an improved form of axle and
bearings by which we obtain greater durability of the working parts and
greater strength with greater ease, lightness, or freedom of movement.
For this purpose the moving axle when of the ordinary cylindrical form

page_text: works in a V shaped piece, and is kept in its place by a segmental circular
bearing or an inverted V which holds the axle down but does not grasp
it tightly; a little play or shake is allowed in the bearings. A spring is
made to press the axle against the under V bearing which secures the
rubbing surface to be always in contact with the under V bearing or
cradle and the spring aforesaid. The upper V bearings are made to
remove easily by means of screw nuts; this admits of the axle and
handle being made in one piece when required, giving greater strength
and durability to the axle. We prefer in all cases where a reciprocated
or limited amount of motion is required to make the axle of a segment of
a cylinder cut radially and parallel to its axis forming a knife edge at its
centre; this is placed in the V bearing or cradle, and the axle is made to
rock in its bearing like the knife edge of a scale beam. A spring
carrying a friction roller is made to press upon the curved side of the
rock bar or axle; this keeps the rock bar firmly in the lower cradle or
bearing whilst the friction rollers affords it facility of movement.
some cases we attach to the rock bar a steel rod or parallel and coincident
with the axis of the rock bar; this is placed in the cradle and pressed
home by springs in the manner described with the knife edge axle.
We sometimes in the form last described cut out a portion of the
lower edge of the segmental rock bar so as to give two or more
places for affixing the central wire to admit of plates or springs pressing
down the steel wire and to hold it to the lower bearing. In this con-
struction the rock bar turns with the central wire analagous to a common
hinge, with the difference that the central wire is permanently attached
to the rock bar, and is therefore in better contact and receives the whole
strength and support of the rock bar. This form combines great strength
with small wearing surfaces. The plates or springs being easy to remove
enable the axles to be taken out with great facility when it is desirable
to examine, clean, or repair the platinum contacts, &c.
In
The forms above described are chiefly applicable to the commutating
axles of telegraph needle instruments. The axle above described can
also be made in one piece of steel or iron. We also employ the same
form of axles in transmitting keys in which the transverse lever axles
of the ordinary key is replaced by the rock bar axle, friction roller,
springs, and cradles herein-before described, but in some cases we use two
spiral springs; these spiral springs are attached by means of clamping
screws, bolts, or pins. One spring is placed on the lever behind the

page_text: axle or rock bar, and the other a weaker spring, is attached to the lever
in front of the axle; these two springs keep the lever firmly into its
bearings or cradle whilst the stronger spring keeps the lever raised ready
for depression to transmit signals which we prefer to receive and record
by instruments constructed in the following manner:-Between the poles
of a powerful magnet we suspend by means of tortion wires moving coils
which are deflected by the passage of electric currents through them.
These coils we prefer to construct and insulate as follows:-When fine
silver wire is used for the convolutions of the coil we submit the wire.
to the action of sulphuretted hydrogen, sulphide of ammonium, or
sulphurous vapours which forms on the surface of the wire an insulating
coating of black sulphuret of silver. When copper or gold wire is used
we prefer to coat them with silver to enable us to insulate them as
aforesaid. A moderately efficient insulator is obtained by the action of
sulphur on pure copper.
We sometimes insulate the wire by coating it
with zinc and afterwards oxydising or converting it into carbonate of
zinc. The wire thus insulated is then wrapped in the form of a
coil, each layer being insulated from the preceding one by a dry paper,
The wire is
gutta percha, or other suitable insulating lamina.
then protected from the corrosive effects of the atmosphere by
sealing the coils in shellac or parafine, or other suitable insulating
materials. We generally construct the coils in two forms, a hollow
cylindrical coil or compact oblong coil. When the cylindrical coil is
used, we generally place a piece of soft iron between the poles of the
magnet in such a manner as to leave an annular space in which the coil
suspended by tortion wires can move. The rays of magnetism pass
through the coil into the soft iron, which becomes magnetic by induction.
On the passage of a current through the tortion wires and the coil, to
When the electric
which is attached an indicator, the coil is deflected.
current is sufficiently strong force is obtained capable of marking
either by embossing the paper with a small point, as in a ordinary Morse
machine, or can carry an ink pen or pencil attached by an arm to the
coil. When we employ the oblong coil we also support it by means of
tortion wires between the poles of the magnet, but without employing
the intervening piece of soft iron. The poles of the magnet are brought
closer together generally about a of an inch apart. The passage of
electric current through these coils flows transversely to the plane of the
magnetic rays. The coil then turns on the tortion wires, the amount of
. The direction of
motion being dependant on the force of the current.

page_text: the movement depends on the direction of the passage of the current
through the coils. We find by employing these forms of coils placed
between powerful magnets we get a greater amount of sensitiveness
than hitherto obtained for working recording instruments, whilst the
defects which so frequently occur when employing magnetic needles
to move inside hollow coils through the magnets becoming demagnetized
either in constant use or by powerful earth currents flowing through the
telegraph circuit are avoided, there being no iron attached to the
moving coils, as in electro-magnets, which invariably impedes the rapid
action by its retention of magnetism is also avoided. The wire insulated
in the manner herein-before described has a very thin and perfect coat-
ing of a most efficient insulator, and enables us to get a greater number
of convolutions in a given space. Silk or other insulating coverings,
generally employed to cover fine wire, occupy about nine-tenths of the
bulk of the coil, we are thus able to get in a coil when wound with wire
004 of an inch diameter, about twelve times the number of turns in a
given space than when silk-covered wire of the same size is used. With
finer wire our method of insulating effects a greater gain.
Wire thus
insulated is employed with advantage in other forms of coils especially
where a great number of convolutions are required. The moving coil
herein-before described is especially suited for alphabetic telegraphs in
which rapid reciprocating motions are requisite to actuate the movement of
the anchor piece pallets or claws giving a step-by-step motion to a ratchet
wheel. We also use a hollow cylindrical coil, in the centre of which is
a small iron armature mounted on pivots so that it can move freely.
Two permanent magnets are fixed near the extremities of the soft-iron
armature to deflect it when a current traverses the coils. At the end of
the iron armature we fix a light spring which is made to fit into a
corresponding slit at the end of the anchor piece, which being a negative
lever and made to diminish the motion requisite for the movement of
the pallets enables the instrument to be adjusted so that a very small
amount of movement of the iron armature gives the requisite step-by-
step motion. To adjust the poles of the permanent magnet so that they
shall give the greatest amount of force, we make them in their simplest
form of two curved steel arms jointed in the centre like a pair of
engineer's callipers; this enables us to increase or diminish the intensity
of the magnetic focus. We also couple compound magnets with a
moveable joint when employing them for any of the above forms of
coils herein-before mentioned. The moving armature in the hollow coil

page_text: with the connecting spring we only employ in reciprocating or step-by-
step recording telegraph, but the connecting spring we also employ
with our improved form of moving. coils, the friction of the spring being
to overcome the force of momentum which carries the armature or
moving coils beyond the amount required for the movement of the
pallets, this excess of motion being taken up by the spring. A force
equal, but in the opposite direction, is set up which reacts and aids the
reversing current in throwing off the armature. In this way a more
rapid and certain vibration of the moving armature or moving coil is
obtained.
In the Invention above described the electro-dynamic machine is.
applicable to the following purposes, viz., generating ozone for bleaching
purposes, refining sugar, electro-metallurgy, and all electro-dynamic
purposes. The currents generated by these machines being powerful
quantity currents are especially applicable to the drawing of wire, as by
its means the wire is kept red hot until it reaches the draw plates or
rollers.
The fluid induction plates described are very efficient when used in
connection with intensity batteries for all such electrical purposes as
require accumulated charges of electricity.
The method of insulating the wire is applicable to all electrical
purposes where a great number of convolutions are required in a given
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Octavius Varley and Frederick Henry Varley in
the Great Seal Patent Office on the 25th February 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, OCTAVIUS
VARLEY and FREDERICK HENRY VARLEY, Telegraph Engineers, late
of 23, Stonecutter Street, in the City of London, and now of 11, Poultry,
in the City of London, and of Mildmay Park Works, Mildmay Avenue,
Stoke Newington, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of August, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors,

page_text: give and grant unto us, the said Octavius Varley and Frederick Henry,
Varley, Her special licence that we, the said Octavius Varley, and
Frederick Henry Varley, our excecutors, administrators, and assigns, or,
such others as we, the said Octavius Varley and Frederick Henry
Varley, our executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN INSTRUMENTS FOR TRANSMITTING AND RECORDING ELECTRIC
SIGNALS, PART OF THE INVENTION BEING APPLICABLE TO OTHER PURPOSES," upon
the condition (amongst others) that we, the said Octavius Varley and
Frederick Henry Varley, our executors or administrators, by an instru-
ment in writing under our, 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 Patent.;
i
NOW KNOW YE, that we, the said Octavius Varley and Frederick
Henry Varley, do hereby declare the nature of the said Invention, and ia
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:-
The Invention has for its object an improved means of generating
dynamic currents, and transmitting and recording electric signals derived
therefrom.
Accordingly we employ an electro-dynamic machine in conjunction
with induction plates as shown in Figures 1, 2, 3, and 4 by which a
continuous dynamic current is obtained of sufficient quantity and
intensity for transmitting signals.
This part of the Invention consists of two iron bars A and B, Figures
1 and 2, with flanges generally of the form shown at C, D, E, F,
Figures 1 and 2, attached at each end, by which the bars are fixed firmly
on a stand parallel to each other with the planes of the flanges in a
line with one and another. . These bars are wrapped with insulated
wire G and form two bar electro-magnets. An axle H, Figure 1, of
non-magnetic substance, generally of brass or gun metal, is placed.
parallel with the bar electro-magnets A and B, Figures 1 and 2, in the

page_text: centre between the flanges C, D, E, and F, which are hollowed out lo
form a bearing for the axle to turn in. The axle projects some little
distance beyond the flanges, and is capable of being rotated rapidly.
This axle has at each end a circular iron flange 1 and J, to which are
screwed the short iron bar electro-magnets K, L, M, and N the insulated
wires of which are attached to reversing commutators O and P, forming
two rotary magnetic arniatures. On rendering the long bars magnetic
by the passage of an electric current traversing the surrounding
insulated wire, and at the same time rotating the axle, a dynamic current
is set up in the coils of wire surrounding the short bars of the rotary
magnetic armatures which flows in alternate directions, but which are
commutated by O and to flow from the terminals Q, R, S, and T in
one direction only. The current thus set up in one of the rotary
armatures is made to flow through the wire G and reinforces the
magnetism in the bars A and B, which reacts on the rotary armatures
giving rise to a continuous electric current so long as the axle is rotated.
This we call the closed circuit. The current generated in the other
rotary armature is made to flow into the induction plates A and B,
Figure 4. The advantage of this form over other dynamo-magneto
machines consists in the employment of induction plates and the
arrangement of the rotary armatures which are made of the form
'described to conserve the magnetism developed, by which we are able to
get a more powerful dynamic electric current with less magnetic
retardation. The electric current generated by the rotation of the
armatures, being made to develope the magnetism in the machine the
magnetic retardation increases until it becomes so powerful as to put a
check on the rotation of the armatures, a limit is soon arrived at when
the magnetism developed in the machine overpowers the rotation; this
is chiefly due to the retardation produced by the passage of powerful
'dynamic currents set up in the insulated wire surrounding the rotary
armatures. For when the armatures are rotated and a large resistance
is inserted in the circuit the labor of rotation is reduced in proportion
to the diminished amount of current. This magnetic retardation we
reduce in the following manner:-We insert in the circuit fluid induc-
tion plates A and B, Figure 4. The charge continues to flow until the
induction plates are polarized, when the resistance in circuit becomes
augmented proportionally to the tension or potential of the accumulated
charge, when fully charged no appreciable current traverses the
armature. The potential of the charge is then at its highest whilst the

page_text: magnetic dynamic retardation is reduced, and the labor of rotating the
armatures is consequently diminished. The dynamic electric charge
stored up in the induction plates can be employed to work the signals of
We sometimes shunt
several transmitting instruments simultaneously.
We
The induction
a portion of the current flowing through the closed circuit by means of
resistance inserted between the terminal R and wire G, Figure 1.
also insert induction plates between the same terminals.
plates act as valves shutting off the circuit when the machine is fully
charged relieving the labor of rotation. We construct the induction
plates of two or more pieces of carbon and palladium plates inserted in
a cell filled with acid and water or plates of metallic arsenic and carbon
or platinum substituted for the palladium or arsenic plates, or two lead
or other metal plates, or two or more pieces of carbon. The current is
made to generate hydrogen on the palladium, arsenic, or platinum plates.
The capacity
when those metals are used, and oxygen on the carbon.
which palladium and arsenic have for storing hydrogen renders them
very efficient induction plates, becoming when charged powerful gas
batteries. We increase the capacity of the carbon plates for oxygen by
rendering the plates porous in the following manner-We select carbon
obtained from gas retorts which contain silica, and submit it to the
action of fluoric acid which dissolves the silica and leaves a porous net-
work of carbon. We prefer to magnetize the long bars A and B,
Figure 1, by a galvanic current derived from a Daniel's or sulphate of
copper battery or neutral salt constant battery made in the following
The cells with
manner, which we term a gravity and diffusion battery.
their respective salts and metals or elements we prefer formed in the
following manner;-The cell, Figure 5, has two partitions A and B, the
first A extending from the bottom to within one-third of the top, the
second B reaching from the top to within a short space from the bottom.
The purpose of these two partitions is to separate the positive and
negative elements by a conducting column of fluid F to prevent the too
rapid intermixture by diffusion of the salts as herein-after described.
the bottom of the compartment adjoining the second partition B we
place sawdust or other suitable materials so as to cover the opening D
between the second partition B and the bottom of the cell by a porous
diaphragm. Into the first compartment C we place a piece of copper
with its connecting strap, and fill in the space with crystals of sulphate
of copper or other exciting salt to the height of the partition A; we next
At

page_text: The
place the zinc with its connecting strap into the second compartment E.
We fill the cells with acidulated water or suitable excitants a little
higher than the first partition A as shown by the dotted line.
copper salt dissolves, and is kept in close proximity to the copper plate
by the partition A; the densest solution falls to the bottom of the com-
partment. When the circuit is completed between the negative and
positive poles of the battery N and P the acid liberated from the
copper ascends over the top of the first partition A diffusing itself
through the fluid column F and gravitates where it meets with the
porous diaphragm covering the aperture D through which it percolates
to react upon the zinc in E.
The battery preventing the rapid diffusion
of the salts while in or out of use is more steady and better suited in
circuits where only occasional yet a reliable source of electricity is
required.
In transmitting the signals there are certain mechanical and electrical
difficulties, such as the wear and tear of the working portions and
consequent looseness of fittings which frequently cause the loss of a
signal or the irregular insertion of resistance due to bad contacts.
The platinum contacts will become burned by the continued effect of
the disruptive spark and become either eaten out or so roughened as
to make imperfect contacts. These defects apply chiefly to such
instruments, as needle instruments and transmitting keys, which by
certain definite contacts transmit positive and negative currents or
positive or negative only. We accordingly in our Invention make an
improved form of axle and bearings by which we obtain greater
durability of the working parts and greater strength with greater
case, lightness, or freedom of movement. For this purpose the moving
axle when of the ordinary cylindrical form works in V-shaped pieces
A, B, Figures 6 and 7, and is kept in its place by a segmental circular
bearing or an inverted V; C and D, which holds the axle down but does
not grasp it tightly, a little play or shake is allowed in the bearings,
and the springs E and F are made to press the axle upon the under V
bearings A and B, which secures the rubbing surface to be always in
contact with the under V bearings or cradle A & B, and the springs
E and F aforesaid. The upper V bearings are made to remove easily by
means of the screw nuts G. This admits of the axle I and the handle
pin H, being made of one piece when required, giving greater strength

page_text: and durability to the axle. We prefer in all cases where a reciprocated
or limited amount of motion is required to make the axle a segment of
a cylinder, cut radially parallel to its axis, forming a knife edge Hat
its centre; Figure S shows the axis in section seen from an end view,
Figure showing the axle from a side view. This axle is placed in
V bearings or cradle, Figures 10 and 11; the axle is made to rock in its
bearings like the knife edge of a scale beam, Figure 11. Springs carrying
the friction rollers are made to press upon the curved side of the rock
bar or axle as shown at A, Figure S, A and B, Figure 11; this keeps the
rock bar firmly on the lower cradle or bearing C, Figure 11, the friction
rollers affording it facility of movement. In some cases we attach to
the rock bar a steel rod parallel and coincident with the axis.
Figure 12
shows the rock bar in section as seen from an end view in which "A" is
the rock bar, B the steel rod. Figure 13 shows a side view of the rock bar
in its position in the cradle bearing C, C, in which D is the lower contact
piece, and F the upper contact piece insulated from the rock bar by the
plates E, E, and connected to the terminal G by means of a flexible
conductor and tweezer spring H. Figures 14 and 15 show the com-
mutating arrangement more in detail, Figure 14 showing the arrangement
as seen from the handle or front view and fitted with the earth and line
contact springs T, L, of the form usually employed, J being the bridge
contact, the connections and fittings being in every other respect the
same as those of the ordinary needle instrument. Figure 15 shows the
commutating arrangement from a back view, with our improved form of
standard or cock for carrying the springs L, T, which protect the springs
from injury and carry at the top a piece of chonite or any suitable
insulator to which is fixed the bridge contact J. The mode of making
contacts with our commutators being the same as that employed in
Sir William Fothergill Cooke's needle instrument, but differing from it
in the mechanical arrangement and construction, which by a right or
left movement of the handle transmits alternately positive or negative
currents. We sometimes in the form of rock bar last described cut out
a portion of the lower edge so as to leave two or more places for fixing
the central wire, as shown at A, A, A, in Figure 16 to admit of plates
or springs S, S, S, pressing down the steel rod on its cradle or
bearing C, C, C. In this construction the rock bar turns with the central
wire B analogous to a common hinge, with the difference that the central
wire is permanently attached to the rock bar, and is therefore in better
contact and receives the whole strength and support of the rock bar.

page_text: This form combines great strength with small wearing surfaces, the
plates or springs being easy to remove enable the axle to be taken out
with great facility when it is desirable to examine, clean, or repair the
platinum contacts, &c., &c. The rock bars or axles above described can
also be made in one piece of steel or iron, the handle being fixed on to
the rock bar direct without requiring squaring and screwing on as is
necessary in the ordinary axle. This makes the rock bar axle a stronger
and simpler form of construction. We also employ the same form of
axles in transmitting keys in which the transverse lever axle of the
ordinary key is replaced by the rock bar axle, friction rollers, springs,
and cradles herein-before described, but in some cases we use two spiral
springs. These spiral springs are attached by means of clamping screws,
bolts, or pins, one spring is placed on the lever behind the axle or rock
bar, and the other, a weaker spring, is attached to the lever in front of
the axle.
These forms are shown by Figures 17, 18, and 19. Figure 17, shows
the cradle C and key lever with the rock bar A and B; Figure 18, a
side view of the key; Figure 19, the key with the two spiral springs S
and T, in which T is the stronger spring, S, the lighter or weaker spring;
it is not necessary that the springs S and T should be spiral springs; of
a bent form, similar in form to those used in gun locks, may be sub-
stituted, in which case the springs work on suitable bearing plates
attached to the lever of the key aforesaid, the action of these springs
being to keep the lever axle firmly into its bearing or cradle, whilst the
stronger spring keeps the lever raised ready for depression to transmit
signals, which we prefer to receive and record by instruments constructed
in the following manner:-Between the poles of a powerful magnet we
suspend by means of torsion wires moving coils, which are deflected by
the passage of electric currents through them. These coils we prefer
to construct and insulate as follows:-When fine silver wire is employed
for the convolutions of the coil we subinit the wire to the action of
sulphuretted hydrogen, sulphide of ammonium, or sulphurous vapours,
which form on the surface of the wire an insulating coating of black
sulphuret of silver. When copper or gold wire is used we prefer to coat
them with silver to enable us to insulate them as aforesaid.
moderately efficient insulator is obtained by the action of sulphur on
copper. We sometimes insulate the wire by coating it with zinc, and
afterwards oxidizing it or converting it into a subchloride or carbonite
A

page_text: of zinc; other oxides and sulphurets of metallic bases may be deposited
on the wire by electrolysis. The wire thus insulated is then wrapped
in the form of a coil; each layer is insulated from the preceding one by
dry paper, gutta percha, or other suitable insulating lamina. The wire is
then protected from the corrosive effects of the atmosphere by sealing the
coils in shellac or parafin, or other suitable insulating materials; we
generally construct the coils in two forms, a hollow cylindrical coil or a
compact oblong coil. Figure 20 shows the cylindrical coil; A, a front
view; B, a side view of the hollow, cylindrical coil. Figure 21, the
oblong coil; A, a front view; B, a side view. When the hollow
cylindrical coil is used we generally place a piece of soft iron I,
Figure 22, between the poles of the magnet N, S, in such a manner as
to leave an annular space, in which the coil suspended by torsion can
move; the rays of magnetism pass through the coil into the soft iron,
which becomes magnetic by induction. On the passage of a current
through the torsion wires and coil, to which is attached an indicator or
mirror the coil is deflected. These coils are exceedingly sensitive, and
indicate weak currents, but when the electric current is sufficiently
strong, a force is obtained capable of marking, either by embossing the
paper with a small point, as in an ordinary Morse machine, or it can carry
an ink pen or pencil attached by an arm to the coil. When we employ
the oblong coil we also support it by means of torsion wires between the
poles of the magnet; as shown in Figure 23. The poles of the magnet
are brought close together, generally about a quarter of an inch apart;
the passage of electric current through these coils flow, transversely to
the plane of the magnetic rays. The coil then turns on the torsion wires,
the amount of motion being dependent on the force of the currents. The
direction of the movement depends on the direction of passage of current
through the coils. We find by employing these forms of coils placed
between powerful magnets we get a greater amount of sensitiveness than
hitherto obtained for working recording instruments, whilst the defects
which so frequently occur when employing magnetic needles to move
inside hollow coils through the magnets becoming demagnetized either
in constant use or by powerful carth currents flowing through telegraph
circuit are avoided, there being no iron attached to the moving coils;
the rapidity of its action is not impeded by the retention of magnetism,
The wire
which invariably impedes the working of electro-magnets.
insulated in the manner herein-before described has a very thin and
perfect coating of a most efficient insulator, and enables us to obtain

page_text: a greater number of convolutions in a given space. Silk or other
insulating coverings generally employed to cover fine wire occupy about
nine-tenths of the bulk of the coil. By employing our insulated wire
we are able to get in a coil when wound with wire 004 of an inch
diameter about twelve times the number of turns in a given space than
when silk covered wire of the same size is used. With finer wire our
method of insulating effects a greater gain. Wire thus insulated is
employed with advantage in other forms of coils, and specially where a
great number of convolutions are required. The moving coils herein-
before described are especially suitable for alphabetic telegraphs, in which
rapid reciprocating motions are requisite to actuate the movement of the
anchor piece, pallets giving a step-by-step motion to a ratchet or escape-
ment wheel. We also use a hollow cylindrical coil, in the centre of
which is a small iron armature mounted on pivots, so that it can move
freely. Two permanent magnets are fixed to the coil near the extremities
of the soft iron armature to deflect it when a current traverses the coil.
'At the end of the armatures we fix a light spring, which is made to fit
into a corresponding slit at the end of the anchor piece, which being a
negative lever, and made to diminish the motion requisite for the move-
ments of the pallets enables the instrument to be adjusted, so that a very
small amount of movement of the iron armature gives the requisite step-
by-step movement. To adjust the poles of the permanent magnet so
that they should give the greatest amount of force we make them in
the simplest form of two curved steel bars jointed in the centre like a
pair of engineer's callipers; this enables us to increase or decrease the
intensity of the magnetic focus. We also couple compound magnets
with a moveable joint, as shown at J, Figures 22 and 23, when employ-
ing them for any of the above form of coils herein-before mentioned.
The moving armature in the hollow coil with the connecting spring we
only employ in reciprocating or step-by-step recording telegraphs.
The hollow, coil with the moving armature attached to the anchor
piece is shown in its simplest form by Figure 24, in which A is the anchor
piece; B, the armature; C, the recoil spring; D, D, a section of the
hollow coil; E, E, blocks with adjusting screws for limiting the play of
the spring C; F, cock carrying the axle pivots of the armature N, S,
permanent magnets to deflect the armature B. On sending rapid and
alternate currents, the armature B oscillates between the poles of the
magnets N, S, N, S, actuating the movement of the escapement wheel

page_text: in the usual manner. The functions of the spring C attached to the
armature being to overcome the force of momentum which carries the
armature beyond the amount required for the movement of the pallets
or anchor pieces, this excess of motion being taken up by the spring, a
force equal but in the opposite direction is set up which reacts and aids
the reversing current in throwing off the armature, in this way a more
rapid and certain vibration of the moving armature is obtained, we also
employ the recoil spring in connection with our moving coils to over-
come their inertia when employed in reciprocating telegraphs.
Figure 25 shows an arrangement of moving coil A of our improved
construction, which is supported on knife edges and oscillates between
the poles N, S, of a powerful magnet.
This form being of great
mechanical strength, and the knife edge support allowing freedom of
movement and also giving a greater facility for connecting the wire of
coils, is in many cases better adapted for needle telegraphs and for
carrying the contact arms of relays and Morse telegraph or ink writers,
in which case the moving arm carrying either the contact piece of a
relay, or the arm with the embossing point of a Morse machine, or the
ink pen or pencil of an instrument known as an ink writer is attached
firmly to the knife edge as shown at D.
Figure 26 shows the Invention connected for working.
In the Invention herein-before described,-
First. We clain the arrangement of magneto-dynamic machine and
the mode of conserving the magnetism.
Second. The mode of reducing the magnetic retardation when the
machine is used with induction plates.
Third. The use of fluid induction plates in conjunction with magneto-
dynamic machines.
Fourth. The use of palladium for fluid induction plates, its well
known capacity for absorbing hydrogen makes it especially adapted
for accumulating powerful induced charges.
Fifth. The mode of increasing the capacity of carbon for oxygen by
rendering it porous with fluoric acid.
Sixth. The gravity diffusion battery with the conducting fluid column
which prevents the rapid intermixture of the salts by diffusion.
Seventh. The mode of making the bearings for needle telegraph
instrument commutating axles, enabling them to be made in one piece

page_text: Eighth. The knife edge, axle, or rock bar.
Ninth. The use of springs with or without friction rollers to press the
rock bar down into its bearings.
Tenth. The use of a steel rod attached parallel and coincident with
the axis of the rock bar.
Eleventh. The improved form of the standard or cock for supporting
the springs and keeping them protected from injury as shown at
Figure 15.
Twelfth. The mode of affixing steel axes to the rock bar by which we
are able to hold the rock bar down in its bearing or cradle by means of
plates or springs on the steel axis of rock bar, Figure 16.
Thirteenth. The use of the rock bar axle applied to the transverse axle
of transinitting keys, Figures 17, 18, & 19.
Fourteenth. The use of moving coils supported on torsion wires in the
focus of powerful magnetic fields insulated with a very thin and perfect
coating of a most efficient insulator obtained in the manner herein-before
described.
Fifteenth. The mode of insulating the wire with sulphuret of silver,
oxydes, carbonates, and subchlorides of zinc or other metallic bases de-
posited by electrolysis on the surface of the wire.
Sixteenth. The coil mounted on knife edges in the field of a magnetic
focus as shown at Figure 25.
In witness whereof, we, the said Octavius Varley and Frederick
Henry Varley, have hereunto set our hands and seals, this Twenty-
fifth day of February, in the year of our Lord One thousand
eight hundred and seventy.
OCTAVIUS VARLEY.
(L.S.)
FREDERICK HENRY VARLEY. (L.S.)