IMPROVEMENTS IN ELECTRIC AND MAGNETIC-TELEGRAPH APPARATUS, AND IN LIGHTNING PROTECTORS TO BE USED THEREWITH, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE FOR OTHER PURPOSES
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Samuel Alfred Varley at the
Office of the Commissioners of Patents, with his Petition, on the
18th January 1871.
I, SAMUEL ALFRED VARLEY, of Roman Road, Holloway, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN ELECTRIC AND MAGNETIC-TELEGRAPH APPARATUS, AND IN
LIGHTNING PROTECTORS TO BE USED THEREWITH, PARTS OF WHICH IMPROVEMENTS
ARE APPLICABLE FOR OTHER PURPOSES," to be as follows:-
.
My Invention consists of firstly, improvements in the construction of
apparatus for developing electric currents by means of mechanical force
which I term the "electric current generator."
And also in the construction of mechanism which I call the "indi-
cator" to be used in connection with the "electric current generator"
for communicating a step-by-step motion to a ratchet wheel carrying an
index or pointer which indicates the letters of the alphabet or other
signals on a dial by pointing towards them.
Secondly. In the construction of relays or peckers which are put in
action by electric currents passing through them, and which open and
close local electrical circuits.

page_text: ▾
.
Thirdly. In the construction of commutators for opening and
closing electric circuits and for changing the direction of electric
currents.
Fourthly. In the construction of lightning protectors or lightning
bridges for protecting telegraph apparatus from being damaged by
lightning discharges.
I construct the apparatus for generating electricity of a number of
bar magnets, these magnets I prefer to make of round steel bars cut
into suitable lengths and tempered and magnetized, they may however
be made of flat or square plates of steel. The magnets are usually laid
parallel to one another and form a compound bar magnet, all the north
poles being at one end, and all the south poles at the other. The steel
bars are kept a little distance apart from one another by means of plates
of metal or any other suitable substance, through which holes are
drilled for the magnets to pass through. These plates keep the bars at
a fixed distance from one another, and hold them together so that the
magnets can be more readily put in their places. The bar magnets
may be arranged in two or more bundles or groups, and are placed
between two iron plates which for distinction I call numbers "1" and
"2" armature plates. The armature plates may be made of either
common cast iron or of wrought iron or of malleable cast iron. I prefer
malleable cast iron. The inner sides of the armature plates rest against
the poles of the bar magnets and are brought into close contact with
the poles by means of screw bolts and nuts made of brass or other
suitable metal which pull the armature plates towards each other.
The magnets are made as nearly as practicable of equal lengths, but
as in practice they vary in length iron screws corresponding in number
to the magnetized bars are screwed through one of the armature plates
(say number "2" armature plate) and press against the ends of the bar.
magnets, by means of these screws each individual magnet is forced
into close metallic contact with "number"1" armature plate at one
end, and with an iron screw at the other end.
To prevent the magnets shifting laterally, and also to keep the whole
of the apparatus more firmly together, plates of metal are usually
attached to the inner sides of the armature plates either by rivets or
screws. These plates have holes drilled through, them corresponding
to the bar magnets which pass through the plates, or holes may be
drilled a little way into the armature plates for the poles of the magnets

page_text: to fit into. In the centre of each of the armature plates a piece of iron
projects, which may be cast in one solid piece with the armature plates.
The projection from number "1" armature plate is usually longer
than the projection from number "2" armature plate, and a hole which
I prefer to be conical, and which I term the seat, is bored into the pro-
jection of number "1" armature plate. A wheel mounted on an
axle and which I prefer to make of malleable cast iron, but which may
be made of wrought iron or of common cast iron is constructed usually
with thirteen teeth, but the number of teeth can be varied. The axle on
one side of the wheel has a handle attached to it on the other side, the
axle accurately fits the seat in which it works, and for distinction I term
this portion of the axle the "wheel bearing."
"
To ensure freedom of working the "seat is usually closed at the
bottom to enable it to hold a supply of oil, and it is constructed with
channels or air ways which allow the air or any superfluous oil to
escape on the insertion of the
wheel bearing." Two iron bars are
attached at the one end to the projection of number "2" armature
plate, the other ends of these bars approach the toothed wheel, the
teeth of which they nearly touch, sufficient space only being left to
allow the teeth of the wheel to pass without actually touching. These
iron bars are surrounded with convolutions of insulated wire which
I term the "generator coils." When the toothed wheel is revolved the
magnetic circuit is closed through the two iron bars alternately and
electric currents are developed in the convolutions of insulated wire, and
the circuit in which they are connected during the time occupied in
magnetizing the iron bars, and also during the time taken by the iron
bars in becoming demagnetized. The two "generator coils" are so
connected together that the electric currents developed by the cessation
of the magnetization in the one bar, and the assumption of a magnetized
condition in the other bar are in the same direction, and consequently
when the toothed wheel is revolved currents of positive and negative
electricity are alternately developed.
I do not confine myself in carrying out my Invention to the precise
details herein-before described as the arrangement of the different parts
admits of modifications, for example, the toothed wheel' of the "electric
current generator" may work in a seat placed at an equal distance from
the poles of the armature plates, and the generator coils may be attached
to number "1" as well as to number "2" armature plates.

page_text: :
When greater power is required two or three sets of magnets may be
arranged side by side. When two sets of magnets are employed they
are arranged with opposite poles facing one another and the construction
of the armature plates is slightly altered. A flat iron plate is sub-
stituted for "2" armature plate, and number "1" armature plate is
divided into two plates, which now form two armed poles of a compound
magnet on one of these the "wheel bearing" works in a scat," on the
other is attached the generator coils. When three sets of magnets are
employed the "seat" in which the "wheel bearing" works is attached
to the central set of magnets, and gencrator coils are attached to the two
outer sets of magnets.
<<
When it is desirable to obtain the greatest amount of magnetic force
from a given weight of steel I employ in place of the round steel rods
bundles of tempered steel wire. These are bound together and filed or
ground at the ends to an even surface on which iron is electro-plated.
The bundles of wire are now magnetized by placing them in a coil of
insulated wire excited by a powerful voltaic battery or magneto-electric
machine and the iron deposited on the ends unites the steel wires
together and forms "armed poles.".
When the "electric current generator" is employed instead of a
galvanic battery for working relays or peckers, the greater portion of the
toothed wheel may be cut away leaving only a segment with two teeth
to which a reciprocating motion is given by means of a handle which
works in a similar way to an ordinary double current key or commu-
tator such as is used for working "Morse" and other systems of electric
telegraphs.
When the "electric current generator" is used for working an alpha-
betical telegraph the iron wheel is usually constructed with thirteen
teeth and the handle by means of which motion is communicated to the
wheel passes over a divided circle having twenty-six letters or signals
on it. If a greater number of signals than twenty-six be required the
number of teeth in the iron wheel is increased one tooth for two signals,
if a less number of signals than twenty-six be required the number of
the teeth in the wheel may be proportionately reduced. One revolution
of the wheel of thirteen teeth causes the circulation through the electric
circuit in which the "electric current generator" is connected of
thirteen positive and thirteen negative currents of electricity: These
currents actuate a propelling escapement which drives a ratchet wheel,

page_text: and by means of an index or pointer attached to the ratchet wheel
signals or letters of the alphabet on a dial are indicated..
"
The propelling escapement is constructed in the following way :-I
mount two small levers attached to axles in a light metal frame which
I term the "pallet frame one above the other, the axles are pivotted
into the frame and the arms of the levers are usually made to project on
both sides of the frame. The extremities of these levers on the one side
are formed into pawls or pallets and rest upon the teeth of the ratchet
wheel on opposite sides of the wheel.
To ensure the levers being kept in contact with the ratchet wheel
they may be actuated by two delicate springs or the levers may be con-
nected together with a light spiral spring which pulls the pallet ends
of the levers towards one another, their motion in this direction I prefer
however to limit, and this I usually do by means of small screws
working through projections from the frame and which press against the
levers on the other side of the axles. I prefer, however, to make use of
magnetic attraction in place of springs for keeping the "pallet levers" in
close contact with the ratchet wheel, and this I do by making the "pallet
levers," the ratchet wheel, and its axle either of steel, of iron, or of tem-
pered steel, and then either magnetizing the different parts by rubbing
them on the poles of a magnet, or I render the ratchet wheel magnetic by
induction from a permanent magnet in the neighbourhood which causes
the ratchet wheel to attract the "pallet levers." This enables me to do
away with the springs which are liable to get out of order. The "pallet
frame" is attached to the end of a bar or lever, to which a reciprocating
motion is communicated when the instrument is in work, and when the
frame is moved in one direction, say, to the right, one of the small levers
mounted in the frame (usually the upper one) pushes the ratchet wheel
forward one tooth, and at the same time the other small lever passes
over the back of the opposite tooth and drops into a space between the
teeth; when the "pallet frame" is moved the opposite way the lower
pallet lever, which is hook-shaped, pulls the escape wheel another tooth
forward, and at the same time the upper pallet lever passes over the
tooth of the ratchet wheel and drops into a space between the teeth
ready to push the ratchet wheel another tooth forward at the next
movement of the "pallet frame."
The motion of the "pallet frame "is regulated and limited by means of
adjusting screws, and the ratchet wheel is prevented from moving more

page_text: than one tooth at each alternate movement of the "pallet frame" by
adjusting screws which come in contact with the ends of the pallet levers
and which are formed of a suitable shape for this purpose. The number of
teeth in the ratchet wheel corresponds to the number of teeth in the
wheel of the electric current generator, and consequently when the
current generator has thirteen teeth the number of teeth in the ratchet
wheel is also thirteen. A pointer is attached to the ratchet wheel which
passes over a divided dial having the letters of the alphabet or other
signals upon it, which are indicated by the pointer pointing towards
them.
"
The reciprocating motion may be communicated to the "pallet frame
by,,any of the well-known methods, I prefer however the following
method on account of its simplicity :-I mount a cylinder of soft iron
in a hollow bobbin surrounded with convolutions of insulated wire, the
cylinder of soft iron is mounted on pivots and has horns or projecting
pieces of soft iron outside the bobbin, when the instrument is at work,
the alternate positive and negative currents developed by the "clectric
current generator" pass through the convolutions of insulated wire
surrounding the iron cylinder, rendering it temporarily magnetic, first in
the one direction and then in the other the horns attached to the cylinder
play between the poles of two permanent magnets which alternately
attract and repel the horns in accordance with the direction of the
magnetic polarity induced in the iron cylinder, and in this way a recipro-
cating motion is, given to them. The "pallet frame" is mounted on
a lever which is attached to the iron cylinder, and consequently partakes.
of the reciprocating motion communicated to the horns of the cylinder.
The apparatus containing the ratchet wheel and the mechanism by which
it is propelled I term the "indicator."
As it is desirable that the tooth wheel of the "electric current
generator" should be turned round in only one direction, I usually
mount upon it a disc made of wood or other suitable material. One or
more levers rest upon the periphery of this disc at an angle and allow
the disc to pass freely in one direction, but prevent its being turned in
the opposite direction by sticking into the wood if the wheel be attempted
to be turned in the wrong direction and stopping its further movement.
I do not however confine myself to this particular method of preventing
the wheel of the "electric current generator" being turned the wrong
way. The handle of the "electric current generator". pases: over a

page_text: divided dial having letters or signals corresponding to those on the
indicator dial, and the handle usually passes over a ring having notches
corresponding to the letters or signals for the handle to drop into when
over the desired signal. To allow the handle to be raised over the ring
and also to. be dropped into the notches it is jointed to the axle. A
commutator is usually attached to the "electric current generator" by
means of which the indicator can be cut out of the circuit, this enables
the handle of the "electric current generator" to be set to the same
signal as that to which the index of the indicator is pointing should
they not agree.
66
After a message has been sent the handle of the "electric current
generator" is moved round to the signal on the top of the dial marked
"O" and the instrument is now ready to receive the acknowledgement
or reply. When the handle of the "electric current generator" is in
this position it comes in contact with a spring, and the instrument is
so connected that the coils of the "electric current generator" are then
connected across so that the receiving current only passes through the
coils of the indicator. The lever to which the handle is attached is
made of iron or steel and makes contact with the spring by simple
gravity, but it is also attracted down by the magnets of the "electric
current generator," and the notch in the ring facing the signal "O" is
usually made deeper than the rest of the notches to allow of a greater
downward movement of the handle lever when in this position. When
the "electric current generator" is used in the place of a galvanic
battery for developing electrical currents the notched ring and divided
dial may be dispensed with. The "electric current generator" is very
suitable for actuating electric alarms. I would remark that in a Specifi-
cation of a former Patent granted to myself conjointly with Samuel
Manley Martin, bearing date the Twenty-ninth day of January 1868,
Number 315, a machine is described for generating electricity by means
of mechanical force, having a notched wheel somewhat similar to the
toothed wheel of the "electric current generator," the machine there
described is however not so effective as the "electric current generator."
for developing rapid alternations of positive and negative electricity.
16
In the construction of relays or peckers used in connection with
Morse," and other systems of telegraphs for closing local circuits,
cylinders of soft iron, which work freely inside hollow bobbins wrapped
with convolutions of insulated wire are sometimes employed. These

page_text: relays are usually put in action by alternate positive and negative.
currents of electricity passing through the insulated wire, and rendering
the iron cylinders magnetic. The magnetized iron cylinders are alter-
nately attracted and repelled by the poles of permanent magnets
arranged for the purpose in accordance with the direction of the magnetic
polarization induced in the cylinders of iron. The sensitiveness of
relays constructed in this way to feeble clectric currents is impaired
owing to the iron cylinder becoming permanently magnetized by the
passage, say, of a current of positive electricity through the convolutions
of insulated wire, which permanent magnetism has to be overcome by the
succeeding negative current before the magnetic polarization of the iron
cylinder can be reversed, their sensitiveness is also impaired owing to
the mass of iron in the cylinder to be rendered magnetic.
My improvement consists in wrapping a soft iron wire spirally over
a light cylinder of wood or other suitable material which I employ in
place of the iron cylinder, or I electroplate a cylinder or tube of non-
magnetic metal with iron. I prefer, however to take a cylinder of a
light material, such as a straw or a piece of light wood, over which I
brush a coating of blacklead. On this I deposit by electro-plating
a thin deposit of copper which I afterwards electroplate with iron.
I obtain in this way a soft iron core containing very little iron and
which does not become permanently magnetized to the same degree as
a soft iron cylinder as ordinarily constructed. The soft iron core thus
obtained I prefer to attach to a torsion wire, but it may be mounted on
pivots or in any other suitable way. I place the hollow bobbin wrapped
with insulated wire in which the soft iron core works, by preference,
between the poles of a single horse-shoe magnet which is constructed of
much larger dimensions than those usually employed in connection with
relays, and the poles of which extend laterally to about the same length
as the soft iron core.
I construct my commutator for opening and closing electric circuits
and changing the direction of electric currents in the following way :-
I construct a lever which I call the "key lever" having a handle
attached to it at one end, and having two metal discs attached to it
at the other. These discs are mechanically connected to the "key
lever" but are electrically insulated from it, and the whole works on
pivots placed centrally with the metal discs between uprights or
standards. Jointed levers called numbers "1" and "2" rest against

page_text: the upper and lower sides of the discs, but portions of the discs are cut
away so that when the handle of the key lever is upwards number " 1"
lever rests against the upper side of, say, the right-hand disc, and
number "2" lever rests against the under side of the left-hand disc.
When the handle is fully depressed the number "1" lever rests upori
the upper side of the left-hand disc, and number "2" lever rests against
the under side of the right hand disc. On number "1" lever another
jointed lever number "3" rests, which also projects over the end of
number "1" lever. The key lever is actuated by a spring which tends
to keep the handle upwards. The metal discs are made, by preference;
of iron and caseliardened. Numbers "1," 2," and "3," levers are
made, by preference, of tempered steel magnetized, so that numbers "1"
and "2" levers are held against the discs by magnetic attraction, and
number "3" lever is also held against number "1" lever in the same
manner. These levers may, however, be actuated by springs. The
"key lever" has a projection upon its upper side which when the handle
is upwards rests against number "3" lever and just removes it from
contact with number "1" lever.
66
"
•
1
The different parts are connected as follows:-The "key lever” is
connected with the relay which closes the local circuit for working the
Morse or other systems of electric telegraphs, number "3" lever is
connected with the line wire and number 2" lever with the carth.
The two discs are connected to the two poles of a voltaic battery.
66
The action of the commutator is as follows:- When the handle is
upwards, which is its position when at rest, number "3" lever is removed
from number "1", lever and is in connection with the "key lever."
The line wire is now in electrical connection with the relay and the
instrument is ready to receive a message. When the handle is partially
depressed number "3" lever comes in contact with number "1" lever;
which is now in connection with the right-hand disc connecting the
line through number "1" lever to, say, the negative pole of the
galvanic battery. Number "2" lever now rests against the under side
of the left-hand disc connecting the positive pole of the battery to the
carth and consequently the line wire is negatively electrified. On the
handle being fully depressed the. connections of the batteries in respect
to the line wire, and the earth connections become reversed, the line
wire being in contact with the positive pole and the earth with the

page_text: negative pole of the galvanic battery causing the line now to be
positively electrified or polarized. When the handle is again raised
the battery connections, in respect to the line and the earth connections,
become again reversed, and on the handle being fully raised the line
wire is removed from the battery connection and connected to the relay
connection.
*
When commutators are used for closing electric circuits either for
calling attention or for raising an alarm it is sometimes desirable there
should be a tell-tale attached to the commutator, which leaves a record
of the circuit having been closed, and which cannot be removed by
the person who has sent the signal. When used for this purpose
I construct the commutator as follows:-The commutator or key
lever" is attached to a metal barrel or pin which works in a bush
attached to a box, the barrel passing into the inside of the box, the key
lever and handle only being outside. The motion of the handle is
determined by stops between which it works. Attached to the barrel,
inside the box, there is a lever or projection which I term the "barrel
lever." The "barrel lever" rests against another lever which is attached
to a segment of a circle working on an axis, and which for distinction
I term the "segment lever." A V-shaped piece of metal attached to
a spring, and which I term the "detent," rests in a notch cut into the
circumference of the " segment lever" and retains it in its position.
When the handle is moved, say, to the right, the “ barrel lever " presses
against the segment lever," forcing the "detent" out of the notch,
on moving the handle still further the "detent". passes over the
circumference of the " segment lever" and drops into a second notch
and retains the " segment lever" in this position. Attached to the
"detent lever" there is an arm which is usually painted red, and which
moves behind a screen having a hole or a slot cut through it and which
is covered by a plate of glass. This arm now covers the opening in the
screen, giving a red signal, and the electric circuit is either permanently
closed by the "segment lever" when in this position coming in contact
with a contact spring or stud, or it may be temporarily closed by the
commutator handle making contact with a contact spring as long as
the handle is held over. The red signal remains permanent until the
apparatus has been reset by a suitable key constructed for the purpose,
which unlocks the "detent" and allows the "segment lever" to assume
its orignal position.
$6

page_text: I construct my protectors for protecting electric circuits from being
damaged by lightning, and which I term "lightning bridges" in the
following way I take a piece of wood or other suitable material and
bore a hole through it; this wood is placed between standards through
which pointed cylinders of metal pass and enter into the wooden
cylinders. A second hole is cut in the wood, usually at right angles to
the first hole. This second hole forms a chamber into, which into which
the points of the metal cylinders enter and approach one another to within,
say, 'one-thirtieth of an inch, more or less. This chamber is filled nearly
full with a mixture of carbon and a non-conducting material in, a minute
state of division; the top of the chamber is then closed. The piece
of wood moves freely enough on the pointed cylinders to enable the
wood to be turned round, which may be done from time to time
in order to bring fresh particles of the powder between the pointed
conductors.
This part of my Invention is an improvement on a former Inven-
tion for which Letters Patent were granted to myself conjointly
with Cornelius Varley, bearing date the Seventeenth day of July 1866
Number 1867.
The improvement consists in being able, after powerful electric dis-
charges have passed across the "lightning bridge," or at any other time
if desired, to arrange fresh particles of powdered matter between the
pointed conductors. The reason why it is desirable to be able to shift
the particles of minutely divided matter between the pointed conductors
is that powerful discharges of high tension electricity have a tendency
to alter the resistance which the bridge of minutely divided matter
opposes to the passage of electrical currents. When the "lightning
bridge" is connected to a telegraph instrument one of the pointed
cylinders or conductors of the "lightning bridge" is connected to the
terminal or binding screw where the line wire joins one end of the
insulated wire forming the coils of the instrument, and the other pointed
conductor is connected to the binding screw, to which the other end of
the coil wires is joined, and through which the electric current usually
passes to the earth.
When a lightning discharge takes place through a telegraph wire the

page_text: insulated wire forming the coils momentarily oppose a very great
resistance to electric polarization, the lightning finds an easier passage
across the "lightning bridge" than through the coils, and the particles
of finely divided matter form a bridge which opposes very much less
resistance than a space of air for the electricity to pass. The electricity
in its passage renders the particles of matter highly incandescent.
Incandescent matter opposes very little resistance, comparitively
speaking, to the passage of electricity, and the secondary current
developed by the rapid demagnetization of the line wire which imme-
diately follows after the lightning discharge finds an easier passage
through the incandescent particles than through the convolutions of
insulated wire, and consequently they escape being fused or damaged..
The "electric current generator" may be used to develope electricity
for various purposes, and the commutator which leaves a record of a
signal having been sent is also applicable to electrical signalling
apparatus in railway trains.