IMPROVEMENTS IN ELECTRO-MAGNETIC TELEGRAPHS AND APPARATUS USED FOR TRANSMITTING SIGNS OR INDICATIONS .TO. DISTANT PLACES BY MEANS OF ELECTRICITY.
Year: 1858

page_text: LETTERS PATENT to Charles Wheatstone, of Hammersmith, in the County
of Middlesex, for the Invention of "IMPROVEMENTS IN ELECTRO-MAGNETIC
TELEGRAPHS AND APPARATUS USED FOR TRANSMITTING SIGNS OR INDICATIONS
.TO. DISTANT PLACES BY MEANS OF ELECTRICITY.".
Sealed the 2nd August 1858, and dated the 2nd June 1858.
PROVISIONAL SPECIFICATION left by the said Charles Wheatstone at
the Office of the Commissioners of Patents, with his Petition, on the.
2nd June 1858.
i,
CHARLES WHEATSTONE, of Hammersmith, in the County of Middlesex,
do hereby declare the nature of the Invention for "IMPROVEMENTS IN ELECTRO-
MAGNETIC TELEGRAPES AND APPARATUS USED FOR TRANSMITTING SIGNS OR INDICATIONS
TO DISTANT PLACES BY MEANS OF ELECTRICITY," to be as follows:-
On January 21st, 1840, a Patent was granted to myself and Mr. W. F. Cooke
for "Improvements in Giving Signals and Sounding Alarums by Means of
Electric Currents:" the Specification of this Patent contained the description
of electro-magnetic telegraphs, in which the letters of the alphabet or other
characters were indicated by a moveable, hand pointing to them on a fixed
dial, or by a moveable dial presenting the characters behind a fixed aperture.
In one form of instrument the hand or dial was caused to advance step by step
by the action of an electro-magnet on an armature of soft iron, in another by.

page_text: the action of alternately inverted currents on magnetic needles noved
alternately in opposite directions. Instruments there called communicators
for working these signal telegraphs were also described, one acting by voltaic
electricity, the other by magneto-electricity.
In the Specification of the Patent for which I am now applying, I propose!
to describe various new improvements on electro-magnetic telegraphs, con-
structed on the same general principles, and on other clectro-magnetic
instruments to which the same modifications are applicable.
The first part of .my Invention relates to improvements in the signal
instrument, the main object of which is to cause its movements to be effected
with greater steadiness, certainty, and rapidity than hitherto, and especially
with electric currents or shocks of less'energy than have hitherto been employed
for such purpose, whether proceeding from a voltaic battery a magneto-electric
machine, or any other applicable source of electric power.
The first improvement is in the construction of the mechanism which
converts the oscillatory motion of a magnetic needle or bar, or the armature of
an electro-magnet, into the rotary step-by-step-motion of the 'hand. This
mechanism is constructed of great delicacy and lightness so that a small force
will cause it to act efficiently, and the improved forms of propelment which I
have adopted are intended to cause the hand to move with regularity, so that,
either jumps or cessations of action shall be less liable to occur; I use the
word propelment in contradistinction to escapement, which requires a main-
taining power for its action. In one method the two pallets which act on the
propelling wheel have each an independent motion moving as levers round
fixed axes; their longer ends act on the inclined teeth of the wheel at opposite
points of its circumference, and their shorter ends are connected by a hair
spring. A pin attached to the axis of the magnetic needle or bar or the
armature of the electro-magnet acts in its alternate motion on each pallet, and
presses it firmly against a tooth of the wheel, while at the same time the hair
spring presses the other pallet against the opposite tooth, but so lightly and
yieldingly as to offer no sensible impediment to its motion. By this construc-
tion greater certainty and regularity in the motion of the hand is ensured than
when the pallets are rigidly attached to each other. In a second method the
axis of the propelling wheel, instead of being fixed, is attached to the end of a
short lever, the other arm of which is acted upon by a pin connected with the
axis of the magnetic needle or bar, or the armature of the electro-magnet.
The two pallets which act on straight teeth at opposite points of the circun:-
ference of the wheel are fixed so that the rotary motion of the wheel is
occasioned by the lever to which it is fixed being moved with it towards the two

page_text: pallets alternately; the motion being limited by two fixed pins, against
which the pallet wheel impinges at the opposite limits of its oscillation. Each
pallet consists of a very light spring placed tangentially to the circumference,
of the wheel, and readily yields to a tooth passing beneath it when the opposite
tooth is propelled by the other pallet, and then falls in its place ready to propel
the tooth which has passed beneath it. To prevent the oscillatory motion of
the wheel being communicated to the hand, the axis of the latter is attached
from that of the former, and is caused to rotate by means of a driving pin
attached thereto. -
.
The second improvement is in the construction of the electro-magnetic
arrangement employed to produce the motions, of the step-by-step index and
dial telegraphs, and is equally applicable to other forms of electro-magnetic
telegraphs and alarms. Two magnetic needles or bars with their poles in
opposite directions are placed near each other on opposite sides of and parallel
to the axis round, which they move; two straight electro-magnets are placed
one on each side of the axis of motion of the needles and parallel thereto;
when a current is transmitted through the coils of these electro-magnets in
such manner that the adjacent poles of each shall have at the same time
opposite polarities, the dissimilar-poles of the two needles aro simultaneously.
acted upon, so that each of their poles is attracted by one pole of one electro-
magnet, and repelled by one pole of the other electro-magnet, the attracting.
and repelling actions all conspiring. to move the axis in the same direction.
Instead of being straight, the magnetic needles or bars may be curved inwards
towards each other, so that their weight .shall be thrown nearer the axis of
motion. By this construction the force of the electro-maguets is applied near
the axis of motion of the magnetic bars instead of at a considerable distance
from it, as is the case when electro-magnets are applied to the poles of a
straight magnetised bar moving on an axis to which it is perpendicular;
another of its advantages is, that the moving parts, being balanced, the at
traction of the residual magnetismn remaining in the electro-magnets after the
current has ceased, is sufficient to hold the needles with firmness even in spite
of concussions. While the principle of this electro-magnetic arrangement
remains it admits of various modifications. 1. The magnetic needles or bars
may be inclined to each other at a small angle crossing at the axis of motion,
their opposite poles being at opposite sides of the axis. 2. A single magnetic
needle, balanced or unbalanced, may be employed in conjunction with two
electro-magnets, or a single electro-magnet may be used in conjunction with
two magnetic needles. 3. Instead of the electro-magnets being parallel to
the magnetic needles or bars, they may be curved so that their two poles shall

page_text: LI
act, one attracting, the other repelling, on the poles of the magnetic needles
between them. 4. Several such pairs of balanced magnetic needles may be
fixed on the same axis, the poles of those adjacent being of opposite kinds, so
that the planes in which they lie shall 'be at equal angular distances from each
other. As many straight electro-magnets as there are needles are placed
parallel to the axis, and in the angles between them, and the wires are so
disposed that when the current in either direction passes through the coils the
joint attracting and repelling actions drive the needles to move round the
axis in the same direction. In such arrangements there must be an even
number of magnetic needles and electro-magnets.
4
The third improvement consists in a modification of the apparatus of the
second improvement before explained, which renders it capable of acting upon
another circuit, so as alternately to invert the current originating from 'a
voltaic battery interposed therein, in order to produce simultaneous and corre-
sponding motions in another similar apparatus, forming part of a signal
telegraph at a distant station. For this purpose, the axis on which the
magnetic needles or bars are mounted is made in two parts, connected
together by a piece of ivory or other insulating material, and one end of the
axis is in connection with one pole of the battery, and the other end is in
connection with the other pole of the battery. Of the magnetic needles or
bars mounted on the axis, one is in metallic connection with one part of the
axis, and the other is in metallic connection with the other part, and each of
these needles is carefully insulated from the part of the axis with which the
other is in metallic contact. When by the passage of a current or shock in
the line wire, and consequently in the coils of the relay instrument the
magnetic needles or bars are caused to move, each of them comes in contact
with a spring stop in connection with the wires of the circuit which the relay
instrument is to complete, and this circuit is so completed. If now by a
current or shock passing in the line wire in a direction opposite to that which
produced the first motion, the magnetic needles or bars are caused to move in
the other direction, then they come in contact with two other spring stops, so
as to complete the circuit in the opposite direction.
The second part of my Invention relates to improvements in the com-
municator or apparatus for transmitting into the telegraphic circuit the proper
number of currents or shocks required to indicate the various letters or
characters, whether the source of power be a voltaic battery, a magneto-electric
machine, an electro-magnetic machine, or any other kind of rheomotor, and
to improvements in magneto-electric and electro-magnetic machines employed
in coniunction therewith.

page_text: The fourth improvement is a new construction of the communicator when a.
voltaic battery is employed; it may be considered as a modification of that:
figured and described in the Specification of the Patent granted to myself and
Mr. W. F..Cooke on the 21st of January 1840. It differs therefrom in the
following particulars: 1stly. It alternately inverts the currents instead of.
transmitting to the telegraphic circuit successive currents in the same direction..
2ndly. The alternation of conducting and insulating contacts are done away
with. 3rdly. The letter circle or wheel, which in the former is solid, consists
of a number of flexible spokes or radii corresponding to the different letters or
signs employed proceeding from a common. centre, and each carrying at its
free extremity a finger pin; when letter is required to be indicated, the
spoke on which it is engraved is moved by means of the finger pin at its
extremity so as to give the wheel a rotary motion, and is at the same tinie
pressed down, so that a prolongation of the finger pin comes in contact with a
fixed stop, and thus prevents the continuance of the motion. Instead of
flexible spokes with fixed pins at their extremities, as here described, the rigid
wheel may be retained, and stops or pins may be arranged on its circumference
with springs so fixed to them that they may recover their original positions
when the pressure of the fingers is removed.
The mechanism for producing the alternation in the direction of the
currents admits of considerable modifications. I will describe one of the
simplest and most efficient methods:-A toothed wheel is fixed to the axis of
the letter wheel of the communicator, so as to rotate with it; this gears into
a pinion, which during one revolution of the wheel rotates half as many times
as there are letters engraven upon it. On the axis of the pinion is a small
grooved.disc insulated from it, and carrying a short pin fixed parallel to the
axis; the axis of the pinion is placed between two spring bars insulated from
each other, and as it rotates, the pin raises each of them alternately, and
becomes respectively in metallic communication with them; while the pin is
raising .one spring bar, the other rests on the axis of the pinion; a spring
also rests upon the insulated grooved disc of the pinion.
The terminal wires of the battery are brought to binding screws in metallic
communication with the axis of the pinion and with the spring bar, which
rests on the insulated disc respectively, and the terminal wires of the tele-
graphic circuit are brought to binding screws in metallic communication with
the two spring bars on which the pin of the pinion acts. This construction
of the communicator is equally adapted for working the step-by-step tele-
graphs, either when the direct current of a voltaic battery is employed, or when
induction currents are made use of. In the latter case the terminal wires of

page_text: the voltaic battery are to be brought to the binding screws, which are in
connection with the spring bars. The terminals of the primary coil of an
induction apparatus are to be fastened in the binding screws, which are in
metallic communication with the pinion and its insulated disc, while the
terminals of the telegraphic circuit are to be brought in permanent connection.
with the terminals of the secondary or induction coil. By this arrangement
the battery circuit is never broken. When the current. is not transmitted to
the telegraphic wires it continues to circulate for a moment in a short closed
"circuit; thus the spark which occurs on breaking the circuit is obviated.
The fifth improvement consists in the application of the letter circles
described in the fourth improvement, in combination with a magneto-electric
machine instead of with a voltaic battery. The axis of the letter circle is so
geared with the armature of the magneto-electric machine that during one
revolution of' the former the shocks are inverted as many times as there are
letters engraved on the circle. Communicators thus constructed are efficient
only when the magnets are of comparatively small dimensions.
The sixth improvement consists of new methods of constructing the com-
municator when a magueto-electric or an electro-magnetic machine produces
the currents or shocks, which are transmitted by its means into the tele-
graphic circuit. In this improvement the armature of the permanent or
electro-magnet is kept in continuous motion by the hand of the operator, or
by being connected with any moving power, and finger stops corresponding
with the letters on the dial of the telegraph being respectively pressed down
regulate the passage of the currents or shooks into the telegraphic circuit.for
the purpose of acting on the detached telegraph. By this means, however
large and powerful the magnet which is employed may be, the operator may
act upon the finger keys with the same facility, which would not be the case
were the motion of the armature itself to be arrested thereby. The two
principal mechanical arrangements by which this improvement, is effected are
the following:-In the first construction the axis of the armature of the;
magnet is independent of the axis which carries the index, but is capable of
being geared thereto by the depression of either one of a series of finger stops
: or keys arranged round the apparatus, and corresponding with the letters of
the alphabet; this action also disjoins a cross connection, and thus allows the
L currents generated in the coils of the armature, which were before confined to
a short circuit, to pass into the telegraphic line, and projects forward a lever
corresponding 'with the stop or key into such a position that a spring catch
carried by the axis of the index when it is brought opposite.to it by the
revolution of its axis strikes it, and by so doing it sets free the stop or key

page_text: previously held depressed; on the release of the key, the cross connection
which diverts the currents from the telegraphic circuit is recompleted, and
the axis carrying the arm with the spring catch is thrown out of gear with
the axis of the armature; but while the index is passing from the point
at which it is thrown into gear to the point at which it comes in contact
with the lever projected forward by the stop or key, the requisite number
of shocks or currents have passed into the telegraphic circuit. The gearing
between the armature axis and the axis of the index is such that when
it is in operation the index axis rotates at the same speed as the hand
or index of the receiving instrument.
In order that imperfect currents
may not be thrown into the telegraphic circuit, the apparatus is so arranged
that the axis of the index is not at all times thrown into gear with the
armature axis immediately on the depressing of the stop or key. If the
armature is not in a proper position for communicating a shock or current,
the toothed wheel in connection with the index axis is prevented from falling
into.gear with the toothed wheel in connection with the armature axis unțil
the moment at which the inversion, of the current takes place. In a second
method of construction, the arbor which is geared with the axis of the
armature carries a toothed wheel; an arm, to which the index is fixed,
moves freely round this "arbor, and is carried with it when any tooth of the
wheel is in contact with a spring catch at the end of the arm, and the tele-
graphic circuit is complete all the time this contact lasts. The index arm is
separately.stopped by pressing down either of the finger stops while the arbor
and all the other parts connected with it continues its motion, and the trans-
mission of the currents to the telegraphic circuit remains interrupted so long
as the motion of the.arm is arrested. As the circuit is not completed when the
arm is released, but at the moment when the contact is made between the tooth
of the wheel. and the catch of the arm which corresponds with the moment
of the inversion of the current, imperfect currents are prevented from entering.
into the circuit. As in this construction the currents continue to pass into
the telegraphic circuit so long as a key is not pressed down, a provision, is
made for keeping the stop, which corresponds with the sign indicating the
termination of a message, permanently depressed when required, and which at
the same time, completes the telegraphic circuit, omitting from it the coils of
the armature of the magnet. To avoid this additional movement, which has
to be attended to by the operator, another contrivance is adopted, by which
any one of the finger stops being depressed it remains so, even when the
finger is removed until another stop is touched, when the former is restored
to its normal position. This is effected by an endless chain passing round

page_text: a series of friction rollers so placed that it forms a circle concentric with the
circle in which the finger stops are arranged. The finger stops arc-so con-
structed that when either of them is depressed it. presses against the endless
chain and tightens it, and when another stop is subsequently depressed, and
bears in like manner against the chain, the flexure made by the first step is
obliterated, and 'the stop restored to its normal position. It is the peculiar
character of these magneto-electric communicators that none of their parts
are mechanically connected with the signal telegraph of the transmitting
station, as in some arrangements which have been previously proposed, but. the
former is complete in itself and entirely independent of the latter, except by
its action upon it, in consequence of the transmission of the currents. through
the conducting wire.'
The magneto-electric or electro-magnetic machine I usually adopt for: the
communicators forming the fifth and sixth improvements is of the ordinary
construction with a rotating armature. In this disposition four shocks or
currents are available during each revolution of the armature, the first two
following being in one and the same direction, and the next two following
being in the opposite direction. No contrivance is herė required to invert or
to stop out the alternate currents, the two successive currents in the same
direction give additional security that the index of the telegraph shall advance
a single step. Either of the following new forms of the magneto-electric
machine constituting the 7th, 8th, and 9th improvements may be substituteḍ
for the one above. mentioned.
The seventh improvement is a modification of the magneto-electric machine,
in which instead of the armature revolving before the poles. of a magnet, it
is caused alternately to approach to and recede from them by means of a cam
fixed. to a wheel, or by other suitable means. If a single magnet is employed,
a contrivance for alternately inverting the direction of the currents: must be
had recourse to, but this is unnecessary when the armature oscillates between
the poles of two similar magnets, so disposed that the currents shall pass
through the circuit in opposite directions according as the armature moves
towards one or the other magnet. This method may be advantageously applied
to the communicator of the 5th improvement as the motion of the letter wheel
may be more immediately and certainly stopped at 'any required point, in
consequence of there being no momentum generated by the rotation of the
armature.
"
:
The eighth improvement consists of a construction of the magneto-electric
machine, in which neither the-magnet nor the coil of wire is put into motion,
but only the soft iron core which is enveloped by the wire. A coil of insulated

page_text: wire is fixed, and within it is fitted a cylindrical core of soft iron capable of
rotating on its axis without carrying the coil with it. The opposite ends of this
soft iron core have lateral prolongations also of soft iron; these äre of equal
length, are at equal angular distances from each other, and extend. over the ends
of the coil so as to be brought in' close proximity to the poles of a magnet, those
at opposite ends to opposite poles. Ou causing: the core to rotate once, as many
double currents are produced in the coil as there are prolongations on each end
of the soft iron cylinder. Instead of a single magnet several may be arranged
with their poles in two parallel circles, and placed at distances from each other
corresponding with the distances of the prolongations; by this means the strength
of the currents is considerably augmented. If the poles of the magnets
contained in the same circle are similar; the successive currents are alternate
in direction and unequal in intensity, but if the poles are alternately dissimilar
two currents in one direction are followed by two currents in the opposite
direction available for the purpose required; in the latter case the number
of the magnets must be even, and the angular distances of the prolongations
must be double the angular distances of the magnetic poles, so that they
shall not be at the same time opposite adjacent magnets.
The ninth improvement consists in substituting for a single magnet and
ärmature- in any of the magneto-electric machines employed for working
-telegraphs,-several magnets and armatures so arranged that the instantaneous
currents or shocks originated by each shall be produced simultaneously, and
pass-through the same conducting wire... A number of small magnets and
armatures. thus. combined will produce a more efficient result than a single
magnet and armature of proportionate dimensions. Electro-magnets may be
substituted for permanent magnets in any of the modes of construction
described as the 7th, 8th, and 9th improvements..
The third part of my Invention relates to improvements in electro-magnetic
alarums, clocks, and registers or counters.
'
The tenth improvement consists in the application of the.electro-magnetic
arrangements described under the second head of my improvements to the
withdrawal of detents for the purpose of permitting alarums to sound.
The eleventh improvement consists of appropriate mechanism to prevent the
detent of an electro-magnetic alarum from escaping until several currents or
shocks have been sent through the circuit, and consequently until the.magnetic
bars have moved to and fro several times. For this purpose the electro-
magnetic apparatus is caused to actuate a species of escapement, which at each
movement allows to escape one tooth of a short rack in connection with the

page_text: alarum. By this arrangement. one or more accidental jars will not cause the
detent to escape.
The twelfth improvement consists in an appropriate mechanism to prevent
the hammer of a bell from moving, unless the magnets are acted upon by the
electric force. Tho sounding of the bell is thus, rendered independent of
accidental shakes or jolts. For this purpose a pin is fixed to the periphery of
.the.toothed wheel, which gives vibratory motion to the hammer in such a
position that just as the motion of this wheel is arrested, when the alarum
ceases to sound, the pin acts on a catch, and places it so as to restrain or limit
the vibrations of the hammer arising from concussions to which the instrument
may be subjected. When the alarum is next acted on by currents or shocks
passing in the line wire, and the obstacle, which retains the train of wheels is
thus removed, the motion of the toothed wheel which carries the pin above
mentioned, immediately liberates the hammer and allows the alarum to sound
freely.
.
The thirteenth improvement consists in the application of the 1st and 2nd
improvements above specified to the construction of electro-magnetic telegraphic
or sympathetic clocks. These clocks resemble the step-by-step telegraphs in
many particulars, differing from them only in the following:-1stly, the dial,
instead of shewing the letters of the alphabet, shows the hours with their usual
divisions; 2ndly, the power acting primarily on the axis of the second's hand,
is communicated by a small train of wheels to the minute and hour hands. A
rheotrope is adapted to the regulating clock for the purpose of alternately
inverting the current proceeding from a voltaic battery instead of a rheotome,
which merely determines a succession of currents in the same direction.
The fourteenth improvement consists in the adaptation of the 1st and 2nd
improvements to electro-magnetic telegraphic registers or counters, instruments
to indicate and number at a distance the periodically recurring motions of
machines, the opening of gates or doors, &c. These differ from the,clocks of
the 13th improvement merely in the proportion of the wheels of the train, and
.the mode of division of the dials.
The fifteenth improvement consists in the substitution of magneto-electricity
for voltaic electricity in order. to produce the currents or shocks necessary to
work.such registers or counters. The axis of the armature of the magneto-
: electric machine is attached in a suitable manner to the machine, the motions
of which require to be registered.

page_text: .
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Wheatstone in the Great Seal Patent Office on the
2nd December 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WHEATSTONE, of Hammersmith, in the County.of Middlesex, send.
nd.greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent,-bearing date the Second day of June, in the..year. of our Lord One
thousand eight hundred and fifty-eight, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto .me, the said
Charles Wheatstone, Her special licence that I, the said Charles Wheatstone,
my executors, administrators, and assigns, or such others as I, the said Charles
Wheatstone, 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 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
ELECTRO-MAGNETIC TELEGRAPHS AND APPARATUS USED FOR TRANSMITTING SIGNS OR
INDICATIONS. TO DISTANT PLACES BY MEANS OF ELECTRICITY," upon the condition
(amongst others) that I,. the said Charles Wheatstone, my executors or
'administrators, by an 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 Patent.
NOW KNOW YE, that I, the said Charles Wheatstone, do hereby declare
the nature of the said Invention, and in what manuer the same is to be
performed, to be particularly described, and ascertained. in and by the following
statement thereof, that is to say:-.
On January the 21st, 1840, a Patent. was granted to myself. and
Mr. W., F. Cooke for.. "Improvements in Giving Signals and. Sounding
Alarums by Means of Electric Currents;", the Specification of this Patent.
contained the description of electro-magnetic telegraphs, in which the letters
of the alphabet or other characters were indicated by a moveable hand point-
ing to them on a fixed dial, or by a moveable dial presenting the characters
behind a fixed aperture. In one form of instrument the. hand.or dial was
Icaused to advance step by step by the action of an electro-magnet on an
'armature of soft iron; in another, by the action of alternately inverted
currents on magnetic needles, moved alternately in opposite directions.

page_text: Instruments, there called communicators, for working these signal telegraphs
were also described, one acting by voltaic electricity, the other by magneto-
electricity.
In the present Specification, I propose to describe various new improvements
in electro-magnetic telegraphs constructed on the same general principles, and on
other electro-magnetic instruments to which the same modifications are applicable.
The first part of my Invention relates to improvements in the signal instrument,
the main object of which is to cause its movements to be effected with greater
steadinesss, certainty, and rapidity than hitherto, and especially with electric
currents, or:shocks of less energy than have hitherto been employed, for such
purpose, whether proceeding from a voltaic battery, a magneto-electric machine,
or any other applicable source of electric power.
The first improvement isi.in the construction of the mechanism which
converts the oscillatory motion of a magnetic needle or bar or the armature
of an electro-magnet.into the rotary step-by-step motion of the hand. This
mechanism. is constructed of. great, delicacy and lightness, so that a small
force will cause it to act efficiently, and.the.improved forms of propelment which
I have adopted are intended to cause the hand to move with regularity, so that
either. jumps or cessations of action shall be less liable to occur. I use the
word propelment in. contradistinction to, escapement, which requires a main-
taining power for its action. In one method, the two pallots which act on the
propelling wheel have each an independent).motion, moving as levers round
fixed axes;. their longer: ends act on the inclined teeth of the wheel at
opposite points of its circumference, and their shorter ends. are connected by
a hair spring. A pin attached to the axis of the magnetic needle or bar, or to
the armature of the electro-magnet, acts in its alternate motion on each pallet,
and presses it firmly against a tooth of the wheel, while at the same time-the
bair spring presses the other pallet against the opposite tooth, but so lightly
and yieldingly as to offer no sensible impediment to its motion. By this con-
struction, greater certainty and regularity: in, the motion of the hand is insured
than when the pallets are rigidly attached to each other.
Figure 1 is a front view of a propelment constructed in this manner, and
shewn on a magnified.scale; a isra. wheel with inclined teeth mounted on tho
axis of the index or pointer; and b, b,.are two lovers centred to the frame
at c, c; at .their lower ends they are connected together by a hair spring d.
The electrical arrangement: which actuates the propelment (that which I
prefer to employ.will be hereafter described) is applied so as to, press the
inclined ends or pallets of the levers b,.b, alternately, against the teeth of the
wheel.a, and thus a step-by-step rotary motion is communicated to the wheel

page_text: with the index or pointer mounted on its axis. It will be seen that the action
of the spring d is such as to keep the pallets constantly in contact with the
propelled wheel; when the electrical arrangement presses one of them firmly.
against the wheel, thereby moving it a step forward, the other yields to: let a
tooth of the wheel pass, but yet bears sufficiently to prevent a sudden jump
of the propelled wheel a. It will be seen that when the pallet has (by being
pressed against the 'wheel) produced.a forward step, it serves as a stop to
prevent the wheel advancing more than one step, and also that the length of
the step produced. by each motion, is such as to carry a tooth of the wheel
just over the angle of the other pallet. In a second method; the axis of the
propelling wheel, instead of being fixed, is attached to the end of a short lever,
the other arm of which is acted upon by a pin connected with the axis of the
magnetic needle or bar, or the armature of the electro-magnet. The two
pallets which act on teeth-at opposite points of the circumference of the wheel
are fixed. so that the rotary motion of the wheel. is occasioned by the lever
to which it is fixed being moved with it towards the two pallets alternately,
the motion being. limited by, two-fixed pins, against which the pallet wheel
impinges at the opposite limits of its oscillation. Each pallet consists of a
very light spring, placed. tangentially to the circumference of the wheel, and
readily yields.to a tooth passing beneath it when the opposite tooth is propelled
by the other pallet, and then falls in its place ready to propel the tooth which
has passed berieath it. To prevent the oscillating motion. of the wheel being
communicated to the hand, the axis of the latter is detached from that of the
former, and is caused to rotate by means of a driving pin-attached thereto..
Figure 2 is a front view of this form of propelment. a is the axis of the
electrical arrangement; it turns on centres on the frame, and carries an arm b,
which is continued below its axis to balance its upper end; the toothed wheel.
c. is mounted so that it can turn freely on,its axis. The partial rotation,
alternately in either direction, of the axis of the electrical arrangement. carries
the arm.6 from side to side, and with it the wheel c, until it is stopped by
coming in contact with the adjustable screw stops d. d: In place of mounting.
the arm.6. directly on the axis of the electrical arrangement, a pin on this axis
may be arranged to come in contact with the lower arm of the lever 6; at
each motion of the wheel c it is rotated half, a tooth by the action of pallets
formed on the ends of the air springs e, e, the pallets acting similarly to those
in the propelment before described; that is to say, while one pallet is propelling.
the other, though still bearing on the wheel, yields to allow the tooth to pass..
...Figure 3 is a side. view of part of the arrangement, shewing the manner in
which the rotary motion of the wheel c is communicated to the index or pointer.

page_text: fis the axis of the wheel; candg is the axis of the index or pointer; they are
as shewi, linked together at their ends, "so that the one can assume 'au
inclined position without carrying the other with it. On the axis f a driving
pin h is fixed, and this passes up between two pins carried by a piece mounted
on the end of the axis g; thus this axis is caused to partake of the rotary
motion of the axis f, but not of its angular motion.
',
The second iniprovement is in the construction of the electro-magnetic.
arrangement employed to produce the motions of the step-by-step index and
dial telegraphs, and is equally applicable to other forms of electro-magnetic
telegraphs and alarums. Two magnetic needles or bars with their poles in
opposite directions, are placed near each other on' opposite sides and parallel to
the axis, round which they move; 'two'straight electro-magnets are: placed
one on each side of the axis of motion of the needles, and parallel thereto;
when a current is transmitted through the coils of these electro-magnets in
such manner that the adjacent poles of each shall have at the sanie tinie
opposite polarities, the dissimilar poles of the two needles are simultaneously
acted upon, so that each of their poles is attracted by one pole of one electro-"
magnet, and repelled by one pole of the other electro-magnet, the attracting"
and repelling actions all conspiring to move the axis in the same direction.
Instead of being straight, the magnetic needles or bars may be curved inwards
towards each other, so that their weight shall be thrown nearer the axis of:
motion. By this construction, the force of the electro-magnets is applied near
the axis of motion of the magnetic bars instead of-at a considerable distance:
from it, as is the case when electro-magnets are applied to the poles of a
straight magnetized bar moving on an axis to which it is perpendicular;
another of its advantages is, that the moving parts being balanced, the attraction.
of the residual magnetismi remaining in the electro-magnets after the current
has ceased, is sufficient to hold the needles with firmness, even in spite of con-
cussions. Figure 4 is a plan, Figure 5 a side view, and Figure 6 a longi
tudinal section, of an electro-magnetic arrangement, constructed according to:
this improvement, and it is shewn combined with one of the propelients
already described, so as to form a step-by-step instrument; Figure 7 shews the:
dial of this instrument a, a. Figures 4, 5, and 6, are two electro-magnets, of
which the coils communicate with the line wire, so that when a current or shock
passes therein it produces opposite polarities in the adjacent extremities of the
magnets. Figure 8 shows the form of the pole pieces of these magnets; b, b
are two frames in which the magnets are mounted separately; they are con-
nected to tlie base plate c'of the instrument by screws d; d, which pass, through
slots in the plate c; e, e, are springs acting on the screws 'd; d, and tending to

page_text: press them to the end of their slots, and to separate the electro-magnets as far.
as possible; ffff, are four small screws, the ends of which come in contact
witli the frames b, b, and by means of these the distance between the poles of
the electro-magnets can be adjusted. Between the two electro-magnets an
axis g is mounted on suitable pivots, so as to turn freely, and to this axis two:
magnetic needles h, h, are attached. The magnetic needles h, h, have at their**
adjacent ends opposite polarities, so that when a current or shock passes in the
line wire, each of the electro-magnets attracts the two ends of one of the
needles, and repels the two ends of the other, and these attractions and re-
pulsions both tend to cause the axis to rotate in one or other direction according
to the direction of the current or shock in the line wire. The arm which carries
the pallet wheel of the propelment is mounted on the axis 'g, and it receives
its motion and communicates it to the index or pointer in the manner already
fully described, and there being in this case thirty signs on the dial, the pallet
wheel should have fifteen teeth. h is a button placed at the top of the dial
for the purpose of working the index or pointer round the dial to set it with
the communicating instrument, if from any accident the position of the index
of the one instrument should cease to correspond with that of the other; the
button h works a spring fork i, which passes between two pins j,j, so that the
prongs of the fork, when the button.is not acted on, rest against the two pins;
the axis of the pallet wheel passes between the prongs of the fork, and, when
the button is partially turned, one of the prongs of the fork yields, and allows
the other to come in contact with the axis and push it to its extreme position
in one direction, so as to cause the index to advance one step; by moving the
button in the other direction the index is caused to move another step, and so
on; it will be seen that the prongs of the fork act as springs to bring the button
to its central position when out of use.
While the principle of this electro-magnetic arrangement remains, it admits
of various modifications. 1. The magnetic needles or bars may be inclined to
each other at a small angle crossing at the axis of motion, their opposito poles
being at opposite sides of the axis. 2. A single 'magnetic needle, balanced or
unbalanced, may be employed in conjunction with two electro-magnets, or a
single electro-magnet may be used in conjunction with two magnetic needles,
the electro-magnet being placed on one side of the needles only, but neither of
these constructions is as advantageous as that which I have already described.
3. Instead of the electro-magnets being parallel to the magnetic needles or
bars, they may be curved, so that their two poles shall act, one attracting, the
other repelling on the poles of the magnetic needles between them. Two
curved electro-magnets arranged in this manner, each to act on one of tho

page_text: polcs of each of the magnetic needles, will operate as efficiently as straight
electro-magnets applied in the manner before described, but the arrangement
is not so convenient. 4. Several-such pairs of balanced magnetic needles may
be fixed on the same axis, the poles of those adjacent being of opposite kinds;
so that the planes in which they lie shall be at equal angular distances from
each other. As many straight electro-magnetic bars as there are needles are
placed parallel to the axis and in the angles between them, and the wires are
so disposed that when the current in either direction passes through the coils,
the joint attracting and repelling actions drive the needles to move round the
axis in the same direction. In such arrangements there must be an even
number of magnetic needles and electro-magnets.
Figure 9 is a plan, and Figure 10 an end view, of an arrangement in which
four electro-magnets and four magnetic needles are employed. This instru-
ment so, nearly resembles that already described, that no detailed description
of it will be necessary.
'
The third improvement consists in a modification of the apparatus of the
second improvement before explained, which renders it capable of acting upon
another circuit, so as alternately to-invert the current originating from a
voltaic battery interposed therein; in order to produce simultaneous and corre-
sponding motions in another similar apparatus forming part of a signal
telegraph at a distant station. For this purpose, the axis on which the
magnetic needles or bars are mounted is made in two parts connected together
by a piece of ivory or other insulating material, and one end of the axis is in-
connection, with one pole of the battery, and the other end is in connection
with the other pole of the battery of the magnetic needles or bars mounted on
the axis; one,is: in metallic connection with one part of the axis, and the other
is in metallic connection with the other part; and each of these needles is
carefully insulated from-the part of the axis with which the other is in metallic
contact. When by the passage of a current or shock in the line wire, and
consequently in the coils of the relay instrument, the magnetic needles or bars
are caused to move, each of them comes in contact with a spring stop in con-
nection with the wires of the circuit which the relay instrument is to complete,
and this circuit is so completed. If now, by a current or shock passing in the
line wire in a direction opposite to that which produced the first motion, the
magnetio needles.or bars are caused to move in the other direction, then they
come in contact with two other spring stops, so as to completo the circuit in
the opposite direction.
Figure 11 is a longitudinal section, and Figure 12 is a transverse section,
of parts of an instrument constructed according to this improvement. The

page_text: frame of the instrument is 'made in two parts a and b, which are separated
from each other by insulating pieces c. Each part of the frame carries one of
the standards which support the axis d. e is a piece of ivory, which insulates
the two parts, of the axis the one from the other; f.f, are magnetic needles
mounted between the poles of electro-magnets,, as already shown and
described; but these electro-magnets are not shewn in this Drawing. The
needles, are connected to their axis d by pieces of ivory g, g, and each of
them is put in metallic contact with one part of the axis by a' metallic strap h:.
The magnetic needles at one of their ends carry pins i, i, and these, when the
needles are caused by a current or shock passing in the coils of their electro-
magnets to move to either side, come 'in contact with two of the four spring
stops j, j, and k, k; these stops are in connection respectively with: the earth
and with the line wire of the circuit into which the instrument is required to
transmit currents or shocks, and the battery'poles are connected to the two
parts a and 6 of the frame, and consequently with the needles f. f. Thus it
will be seen that when the needles move to one side they complete the circuit
in one direction, and when to the other side in the opposite direction, that is.
to say, the instrument transmits into its circuit currents or shocks corrc-.
sponding in direction to those which produce its motions.
The second part of my Invention relates to improvements in the commu-
nicator or apparatus for transmitting into the telegraphic circuit the proper
number of currents or shocks required to indicate the various; letters or
characters, whether the source of power be a voltaic battery, a magneto-electric
machine, an electro-magnetic machine, or any other kind of rheomotor, and to
improvements in magneto-electric and electro-magnetic machines employed.in
conjunction therewith.
The fourth improvement is a new construction of the communicator when
a voltaic, battery is employed. It may be considered as a modification of that
figured and described in the Specification of the Patent granted to myself and
Mr. W. F. Cooke on the 21st of January 1840. It differs therefrom in the
following particulars:-1stly, it alternately inverts the currents; instead of
transmitting to the telegraphic circuit successive currents in the same direction;
2ndly, the alternation of conducting and 'insulating contacts are done away
with; 3rdly, the letter circle or wheel, which in the former is solid, consists
of a number of flexible spokes or. radii, corresponding to the different letters
or signs employed proceeding from a common centre, and each carrying at its
free extremity a finger pin. When any letter is required to be indicated, the
spoke on which it is engraved is moved by means of the finger pin at its
extremity, so as to give the wheel a rotary motion, and is at the same time

page_text: pressed, down; so that a prolongation of the finger pin.comes in contact with a
fixed stop, and thus: prevents, the continuance of the motion: Instead of
flexible spokes with fixed pins at their extremities, as here; described, the rigid
wheel may be retained, and stops or pius may be arranged on; its circumi:
ference with springs so fixed to them. that they may recover their original
positions when the pressure of the fingers is removed. (This arrangement
of letter circle is shown in the Drawings which illustrato my seventh improve:
ment, and is explained in connection with that part. of my Invention.)
.
The inechanism for producing the:alternation in the direction of the currents
admits of considerable modifications. I'will describe one of the simplest and
most efficient. methods.. A toothed wheel is. fixed to the axis of the letter
wheel of the communicator so as to rotate with it; this gears. into a pinion;
which during one revolution of the wheel rotates half, as many times as there
are letters.engraven upon: it. On the axis of the pinion is a small grooved disc
insulated from it, and carrying a short pin fixed parallel to the axis. The axis
of the pinion is placed between two spring bars insulated from each other, and
as it rotates, the pin raises each of them,alternately, and becomes respectively
in metallic communication with them; while the pin is raising one spring bar,
the other rests on the.axis of the pinion,;, a spring also rests upon the insulated
grooved disc of the pinion. The terminal wires of the battery are brought to
binding screws in metallic. communication, with the axis of the pinion and
with the spring bar: which rests on, the insulated disc respectively, and the
terminal wires of the, telegraphic circuit, are brought to binding screws in
metallic communication with the two spring bars on which the pin of the
pinion acts.
Figure 13 is a side view, Figure 14 a vertical section, Figure 15.a.plan, and
Figure 16 an under side view, of an apparatus constructed according to this
improvement. a,is a wooden. base, on the top of which the metal plate bis
fixed by screws; this plate; has a, hole through its centre for receiving the
flanged:tube c, which is fixed to it by screws; d is an axis passing down through
this tubes at the upper end of this axis the wheel e is fixed, and on the upper
surface of this, wheel the radial spring spokes f, f, are fixed; they are clamped
down on to its upper surface by the covering plate 9; each of the spokes f
has a letter orisign engraved on it, and. it, carries a finger pin hat its end.
When the apparatus is. in use, and it is required to indicate'a particular, letter
For sin on the dial, of the receiving instrument, it is done by pressing down
the finger!pin-of-the spoke, having the same sign, engraved on it, until it is
stopped by coming, against the periphery of the wheel e, and then by tho
finger pin the wheel is turned until it is arrested by the lower end of the pin

page_text: coming in contact with the fixed. projection i; by this motion of the wheel'a!
sufficient number of currents or shocks is. transmitted through the line wire to
cause the index or pointer. of the receiving instrument to pass from the letter,
or sign last indicated to the letter or sign which it is now desired to indicate;
this it does in the following manner. :-At the 'lower end of the axis d, the
toothed wheel is fixed; it drives the pinion k on the axis 1, so as to cause it
to revolve half as many times as there are signs engraved on the spring,
spokes; mais a metal disc, mounted on the axis 7, but insulated from it; on
this disc a spring n presses. The spring n is insulated from the other parts
of: the instrument, and is put in connection with one pole of the battery, and
the other pole of the battery is brought into metallic connection with the
axis ; o and p are two springs, which when left to themselves spring into
metallic contact with the axis l, but are alternately lifted off it by the pin q
carried by the metal disc m. The springs o' and p are insulated, 'and, aro
respectively in metallic contact with the line wire and the earth; thus, for
each revolution of the axis l, two currents or shocks, one in each direction,
are transmitted into the line wire.
This construction of the communicator. is equally adapted for working the
step-by-step telegraphs, either when the direct current of a voltaic battery is,
employed, or when induction currents' are made use of. In the latter caso
the terminal wires of the voltaic battery are to be brought to the binding
screws which are in connection with the spring bars; the terminals of the
primary coil of an induction apparatus are to be: fastened in the binding;
screws which are in metallic' coinmunication with the pinion and its insulated.
disc, while the terminals of the telegraphic circuit. are to be brought in per-:
manent:connection with the terminals of the secondary or induction coil; by:
this arrangement the battery circuit is never broken; when the current is not
transmitted, to the telegraphic wires; it continues to circulate for a moment
in a short closed circuit; thus the spark which occurs on breaking the circuit
is obviated.
The fifth improvement consists in the application of the letter circle.
described in the fourth improvement, in combination with a magneto-electric
machine, instead of with a voltaic battery: The axis of the letter circle is so.
geared with the armature of the magneto-electric.. machine that during one
revolution of the former the shocks are .inverted as many times: as, there are
letters engraved on the circle. Communicators thus constructed are efficient
only when the magnets are of comparatively small dimensions.
Figure 17 is a longitudinal section of an instrument constructed according.
to this improvement. a is the letter circle constructed in all respects like the.

page_text: letter circle. shewn at. Figures 13, 14, 15, and 16; it is mounted on an axis b,
which carries a toothed wheel.c; this wheel drives the pinion.d on the axis e
of the armaturefin such a manner that the axis e makes fifteen revolutions
while the axis b makes one.;: this suits,a step-by-step instrument having thirty
signs on its dial; if this number. be changed, a similar change must be made
in the gear. g is a permanent magnet. One end of the coil of the armature is
connected with the frame of the instrument, and the other end. to the insulated
metal disc on the axis e; from this the current passes by the spring i to the
insulated standard.j, which is connected' with the line wire; the frame of the
instrument is connected with the earth: Thus, it will be seen that the arma-
ture is so actuated by the letter circle that the moving this through a space
corresponding with one letter causes. one effective current to pass into the
line wire. ..
The sixth improvement consists of new methods of constructing the com-
municator when a magneto-electric or electro-magnetic machine produces the
currents or shocks, which are transmitted by its means into the telegraphic
.circuit. In this improvement the armature. of the permanent or electro-
magnet is kept in continuous motion by the hand of the operator, or by being
connected with any moving power, and finger stops corresponding with the
letters on the dial of the telegraph being respectively-pressed down, regulate
the passage of the currents or shocks into the. telegraphic circuit, for the
purpose of acting on the detached télegraph. By this, means, however large
and powerful the magnet which is employed may bé, the operator may act
upon the finger keys with the same facility, which would not be the case were
the motion of the armature itself to be arrested thereby. The two principal
mechanical arrangements. by which this improvement is effected are the
following: In the first construction, the axis of the armature of the magnot
is independent of the axis which carries the index, but is capable of being
geared thereto by the depression of either one of a series of finger stops or
keys arranged round the apparatus, and corresponding with the letters of the
alphabet; this action also disjoins a cross connection, and thus allows the
currents generated in the coils: of the armature, which were before.confined to
a short circuit to pass into the telegraphic line,.and projects forward a lever
corresponding with the stop or key into such a position that a spring catch
carried by the axis of the index when it is brought opposite to it by the
revolution of its axis strikes it, and by so doing it sets free the stop or key-pre-
viously held depressed; on the release of the key the cross connection which
diverts the currents from the telegraphic circuit is recompleted, and the axis
carrying the arm with the spring catch. is thrown out of gear with the axis of

page_text: the armature; but while the index is passing from the point at which it is
thrown into gear to the point at which it comes in contact with the lever
projected forward by the stop or key, the requisite number of shocks of
currents have passed into the telegraphic circuit. The gearing between the
armature axis and the axis of the index is such that when it is in operation
the index axis rotates at the same speed as the hand or index of the receiving
instrument. In order that imperfect currents may not be thrown into the
telegraphic circuit, the apparatus is so arranged that the axis of the index is
not at all times thrown into gear with the armature axis immediately on the
depressing of the stop or key. If the armature is not in a proper position for
communicating a shock or current, the toothed wheel in connection with the
index axis is prevented from falling into gear with the toothed wheel in con-
nection with the armature axis until-the moment at which the inversion of the
current takes place.
Figure 18 is a 'side view of a communicator constructed in this manner; a
portion of the case is removed in order to allow the arrangement of the appa-
ratus to be clearly seen; Figure 19' is a plan of the same instrument as it
appears with its case; Figure 20 is a transverse section of a portion of the
instrument;, and Figure 21 is a plan partly in section of the same parts.
á is a magnet furnished with an armature 6, arranged to revolve in front of its
poles on the vertical axis c; this axis is driven by a band passing to the wheel d;
to which rotary motion is given by hand. On the upper end of the axis c, a
disc e is, mounted, and this disc is is furnished with two pins which drive the
toothed wheel fon the axis g, thus causing it to take two steps at each
revolution of the axis e; the wheel has thirty teeth. h is another wheel on
the same axis; it is furnished with fifteen teeth, and is so fixed on the axis
that its position thereon may be exactly adjusted. i is an axis mounted in the
centre of the frame; it carries at its upper end an index or pointer 2, which
when the axis i is thrown into gear with the axis g, in the manner herein-
after explained, passes step by step round the dial, and points in succession
to each of the letters and signs marked on it. These letters or signs have
also each a corresponding finger key k, furnished with a spiral spring 1, which
constantly acts to press it upwards, but when one of these finger keys is
depressed, it is held in that position by a corresponding lever m, the tail of
which is forced into a notch in the stem of the key by its spring n; the
depression of any one of the finger keys also acts on the end of one of the
levers p, and by causing it to rock on its support q, it raises its inner end,
and this pressing under the flange of the boss q', on the axis i, lifts it vertically in
opposition to the spring ", which tends always to draw it downwards. On the

page_text: axis i'are two toothed wheels s and t, having fifteen and thirty-teeth respec-
tively; they are fixed together or formed in one piece, and mounted loosely on
the axis; but they are prevented from, turning independently of the axis' by
the pins,u, on the boss g', which enter holes, in the wheel t, but they can
slide longitudinally on the axis; visa spring which has a tendency to force
the wheels's and t to their highest, position. When the axis i. is-lifted by
depressing, a finger key as before explained, the wheels gears with the
wheel h; either immediately, if the key happens to be depressed, when the teeth
are properly placed, or if not, then after the wheel h has moved through a
sufficient space to place its teeth in a suitable relative position, the wheel s
boing then projected upwards, by the spring. v. w is an axis on which a
fork is mounted; this embraces the wheels, so that the rise and fall of this
wheel causes the axis w partially to rotate; the rise of the wheel lifts the
picce y out of the teeth of the wheel t, which with the axis i was thus pre-
yiously locked: On the axis wa metal-spring is also fixed, and this by the
rise of the wheel s is withdrawn from contact with the insulated knob A.
The levers m which lock the finger keys, when depressed as already described,
have, as will be seen by the Drawing, hooks formed at their ends, which when
the other end of the lever falls into the. notch in the key,' project forward
slightly, so that as the spring catch B, which is fixed on the axis i, is carried
round by the revolution of the axis, it strikes the lever: so projected forward,
and withdraws its other end from the notch of the key, which then springs up,
and allows the axis to be drawn down out of gear with the axis g. The
communication between the coils of the armature 6 and the instrument is
b
made in the following manner :-On the axis e of the armature an insulated
metal ring C, only shown in dotted lines in Figure 18, is mounted, and with
this ring one end of the coils is in metallic connection; D is a metal spring.
constantly in contact with the ring C; the spring D is insulated from the
frame, and is connected by a wire with the knob A; it is also connected with
the line wire; the other end of the coil of the armature is connected with the
frame of the instrument, and an electric communication is established between
this and the earth. The action of the instrument is as follows:-At coni-.
mencing, both the index of the communicator and the index of the receiving.
.step-by-step, instrument are set to the same sign, viz, the cross; at the top of
the dial; the armature is then caused to rotate; but so long as none of the
finger keys are depressed, the currents or shocks do not pass into, the line
wire, but prefer the shorter-path through the spring, but as soon as a finger
key is depressed, and the wheels gears with the wheel h, the spring passes;
out of contact with the knob A, and the currents or shocks, then begin to pass.

page_text: into the circuit. As two effective; currents or shocks are generated by each
revolution of the armature, and as a revolution of the armature corresponds
with two steps of the index or pointer j, it follows that an effective current or.
shock is transmitted for each step of the index, and consequently the com..
municator and the receiving instrument will keep pace the one with the other:
This goes on till the spring catch B strikes the end of the lever m, corresponding
to the finger key depressed; this liberates the key, throws the index axis. out of
gear, and re-establishes, the short circuit for the currents; when another finger,
key is depressed the action is repeated. It will be seen from the arrange
ment of the wheel-work that it is impossible for imperfect currents to pass
into the circuits when the wheel h has once; been adjusted on its axis, for the
gearing together of the wheels hand & can only take place when the armature,
is in one of two positions, both of which are-arranged to be when the current
or shock commences to be produced. Further, the gearing does not take
place at either of these positions indifferently, otherwise currents in the wrong
direction might be transmitted, but it can only take place when the armature
is in the same position as it was when the wheels last fell out of gear..
In a second method of construction the arbor which is geared with the
axis of the armature carries a toothed wheel; 'an arm to which the index is
fixed moves freely round this arbor, and is carried with it when any tooth of
the wheel is in contact with a spring 'catch at the end of the arm; and the
telegraphic circuit is complete all the time this contact lasts. The index arm
is separately stopped by pressing down either of the finger-stops; while the
arbor and all the other parts, connected with it continues its motion, and the
transmission of the currents to the telegraphic circuit remains interrupted.so
long as the motion of the arm'is arrested....
..
"
As the circuit is not completed when the arm is released, but at the moment
when the contact is made between the tooth of the wheel and the catch of the
arm, which corresponds with the moment of the inversion of the current,
imperfect currents are prevented from entering into the circuit. As in this
construction the currents continue to pass into the telegraphic, circuit so
long as a key is not pressed down; a provision is made for keeping the stop
which corresponds with the sign indicating: the termination of a message,
permanently depressed when required, and which at the same time completes
the telegraphic circuit, omitting, from it, the coils of the: armature of the
magnet.
Figure 22 is a longitudinal section of a communicator constructed according
to this second method; the instrument is not shown complete, but, only those
Darts which are necessary for its explanation arc. indicated. a is an axis

page_text: carrying an armaturo o; this axis is caused to rotate by hand or otherwise in
front of the poles of a magnet, as in communicators already described; c. is a
pinion on the axis a; driving the toothed wheel d on the axis e, so that the
axis a miakes fifteen revolutions while the axis e 'makes one; f is a wheel also
fixed on the axis e; it lias fifteen teeth in its periphery, as is shewn in plan in
Figure 23 g is an arm mounted loosely on the axis e, and insulated from it by
the piece of ivory h; the arm g is also tipped with ivory at its other end; i is a
spring catch-mounted on the arm g, and so placed as to engage with the teeth
of the wheel f; j is an index or pointer fixed to the arm g (but insulated from
it), it travels round the dial k; and points in succession to the thirty letters and
signs marked on it; this dial corresponds to that shown in Figure 19. lis
one of a series of finger keys, of which there are thirty ranged round the dial;
it is as is shewn enlarged in diameter at its upper end, and when one of these
keys is held-depressed the arm 9 comes in contact with it, and is stopped, but
the revolution of the armature continues as before, the spring catch i giving
way to allow the teeth of the wheelf to pass. The armature coils are con-
nected with the instrument in the following manner :-One end of the coils is
connected directly to the frame of the instrument, and the other end of the
cuils is connected with the insulated metal ring on the axis a, and from thence
the metallic connection is continued by the spring m to the standard n; this is
connected with the earth and also with the insulated standard o. When none
of the finger keys are depressed, the spring catch,i is in contact with the
wheel f; and the currents or shocks' pass from the frame of the instrument to
the arm g, and thence by-the spring p, which constantly bears' on it to the
insulated standard q, which is coupled up with the line wire, and all the
currents or shocks produced by -the armature thus pass into the circuit; but
when a finger key is depressed and the arm g stopped, the spring catch i-no
longer remains in contact with the wheel f; and the circuit is broken, being
re-established only as the teeth of the wheel ƒ click in passing, but as these
points correspond with the inversion of the currents or shocks, no effect is
produced on the indicating instrument. It will be seen that imperfect currents
or shocks cannot be introduced into the circuit, for the circuit can only be
completed when the armature is in position to send a perfect current or
shock in the direction required. The finger. key which corresponds with the
zero point is provided with a screw to fix it down so 'as to hold the arm ġ in the
position shewn in the Drawing, and then a short circuit is completed by the
spring .carried by the standard o coming in contact with the pins carried by
the arm g. When the instrument is in this position currents or shocks
transinitted from a distant station do not have to traverse the coils of the
gi

page_text: armature. To avoid the necessity of locking the finger key corresponding
with the zero point of the dial, a movement. which has to be attended to by the
operator, another contrivance is adopted by which any one of the finger stops
being depressed, it remains so even when the finger is removed,. until another
stop is touched, when the former is restored to its normal position. This is
effected by an endless chain passing round a series of friction rollers so placed
that it forms a circle concentric with the circle in which the finger stops are
arranged; the fingers stops are so constructed that when either of them is
depressed it presses against the endless chain and tightens it, and when
another stop is subsequently depressed, and bears in like manner against the
chain, the flexure made by the first stop is obliterated and the stop restored to
its normal position.
.
Figure 24 is a vertical section of a communicator constructed in this
manner; Figure 25 is a horizontal section taken at the line 1, 1, Figure 24;
and Figure 26 is a plan of the same. The instrument. is so similar to that
last described, that it will not be necessary to repeat the whole of the descrip-
tion. Some of the parts, which are similar to those described at Figures 22
and 23, are marked with the same letters. A, A, are finger keys, of which
there are thirty, as before, but their form is considerably changed; they are
ranged round. the ring B, and fit into notches in the plate C; D, D¹, are other
plates, they are notched to receive the lower ends of the keys A; A, and have
between them small friction pullies E, E, round which. a chain F passes; a
top view of the plate D is shewn at Figure 27, and a similar view of the plate
D', with the friction pullies and chain, at Figure 28. G, G, are small springs;
there is one to each finger key; it is connected with the stem of the key at
one end, and at the other end with the plate D; the ends of these springs
have a tendency to spring from each other, so that when the key is up it tends
to keep it up, and when down (in the position shewn by the dotted lines in
Figure 24) to keep it down. The depression of one of the finger keys, besides
acting on the apparatus; as already described, takes up the slack of the chain,
and when another key is depressed it pulls on the chain, so as to raise the first
against the resistance of its spring.
It is a peculiar character of these magneto-electric communicators, that
none of their parts are mechanically connected with the signal telegraph of
the transmitting station, as in some arrangements which have been previously
proposed, but the former is complete in itself and entirely independent of the
latter, except by its action upon it in consequence of the transmission of the
currents through the conducting wire. The magneto-electric or electro-
magnetic machine I usually adopt for the communicators forming the fifth

page_text: and sixth, improvements, is of the ordinary construction with a rotating
armature. In this disposition four shocks or currents are available during
each revolution of the armature, the first two following being in one and the
same direction, and the next two following being in the opposite direction. No
contrivance is here required to invert or to stop out the alternate currents the
two successive currents in the same direction (the first only of which is
effective) give additional security that the index of the telegraph shall advance
a single step..
:
:
Either of the following new forms of the magneto-electric machine, consti-
tuting the seventh, eighth, and ninth improvements, may be substituted for the
one above mentioned..
The seventh improvement is a modification of the magneto-electric machine;
in which, instead of the armature revolving before the poles of a magnet, it is
caused alternately to approach to and recede from them by means of a cam,
fixed to a wheel, or by other suitable means.. If a single magnet is employed
a contrivance for alternately inverting the direction of the currents must be
had recourse to; but this is unnecessary when the armature oscillates between
the poles of two similar magnets so disposed, that the currents shall pass through
the circuit in opposite directions, according as the armature moves towards
one or other magnet. This method may be advantageously applied to the
communicator of the fifth improvement, as the motion of the letter wheel may
be more immediately and certainly stopped at any required point, in con-
sequence of there being no momentum generated by the rotation. of the
armature.
Figure 29 is an exterior view, and Figure 30 is a transverse section, of a
magneto-electric machine constructed according to this improvement. a is a
letter circle mounted on a vertical axis; it is not furnished with flexible spokes,
as the letter circles already described, but with keys b, b, which correspond in
number with the spokes for which they are substituted, although, to avoid
confusion, but two of them are shown in the Drawing. These keys b, b, pass
through sockets in the periphery of the letter circle a, and they have springs
c, c, which press them upwards; when they are depressed by hand, they
project below the circle a, and when the circle is turned round on its axis, the
lower part of the key comes against a fixed projection, and stops. the circle at
the required point. On the axis of the letter circle a cam d is mounted; this
cam is shewn separately at Figure 31. e is an armature; it is attached to the
plato f, and this is carried by one end of the lever g, the axis-h of which is
carried by the standard i; the upper end of the lever g is furnished with a
small friction pulley, and enters the groove in the face of the cam,; the cam

page_text: has fifteen rises and falls, and the extremes in both directions correspond with
the commencement of a fresh current or shock;, hence thirty.are produced, by
one revolution of the cain. The permanent magnets hare placed with their,
similar poles opposite each other, so that the successive currents are in opposite
directions:
:.
• you
The eighth improvement consists of a construction of the magneto-electric
machine, in which neither the magnet nor the coil of wire is put into motion,,
but only the soft iron core which is enveloped by the wire.. A coil of insu
lated wire is fixed, and within it is fitted a cylindrical core of soft iron capable
of rotating on its axis without carrying the coil with it. The opposite ends of
this soft iron core bave lateral prolongations also of soft iron; these are of
equal length, are at equal angular distances from each other; and extend over
the ends of the coil so as to be brought in close proximity to the poles of a
magnet, those at opposite ends, to opposite poles. On causing the core to
rotate once; as many double currents are produced in the coil, as there are
prolongations on each end of -the soft iron cylinder.. Instead of a single
magnet several may be arranged with their poles in two parallel circles, and
placed at, distances from each other corresponding with the-distances of the
prolongations:; by this means the, strength of the currents, is considerably,
augmented... If the poles of the magnets contained in the same circle are.
similar, the successive currents are alternate in direction and unequal in
intensity; but, if the poles are alternately dissimilar, two currents in, one
direction are followed by two currents in the opposite direction available for
the purpose required.;; in the latter case the number of the magnets must be
even, and the angular distances of the, prolongations must be double the
angular distances of the magnetic poles, so that they shall not be at the same
time opposite adjacent magnets.
+ :
Figure 32 is a plan, and Figure. 33 a vertical. section, of a magneto-electric
machine: constructed according to this improvement: a, a, a, are, six per-
manent: magnets arranged round in a circle with their poles directed inwards;
the centre of the circle is occupied by the axis b, and on this is mounted the
cylindrical core of soft iron c; this core is furnished at each end with three
projections d, d, which are in fact the armatures of the magnets, and is sur-
rounded by a fixed coil e. The axis bis driven by a band from the, hand-
wheel f, and thus the projections from the core are caused to pass successively:
in front of the poles of the magnets. In some cases I modify this arrange-.
ment in the following manner:-In place of employing a single stationary,
coil e, and that in connection with the armatures, I surround cach of the

page_text: poles of the magnets a (the arrangement of magnets shewn at Figure 32
being still retained) with such a coil, or, what is better, I fix a short cylinder
of soft iron on each of the extremities of the magnets, and surround these
with the coils. These coils are all coupled up together, so as to deliver the
currents or shocks induced in them into a single circuit. The magnets are
furnished with armatures, one for. each magnet, and these armatures are fixed
on an axis corresponding with the axis b; thus, when the axis revolves they
are carried in succession before the poles of the magnets or the soft iron con-
tinuations of the magnets, and currents or 'shocks are thus induced in the
stationary coils.
The ninth improvement consists in substituting for a single magnet and
armature in any" of the magneto-electric machine's employed for working
telegraphs, several magnets and armatures so arranged that the instantaneous
currents or shocks originated by each shall be produced simultaneously, and
pass through the same conducting wire. A number of small magnets and
armatures thus combined will produce a more efficient result than a single
magnet and armature" of proportionate dimensions. A convenient arrange-
ment for carrying out this improvement is to gear together several magneto-
electric machines so that the armatures of all of them shall revolve at the
same speed and occupy at all times the same angular positions with respect to
their magnets; the wires of the coils of all the armatures are coupled up to
one wire, from which the currents or shocks are led away as if a single
inagneto-electric machine were employed. Electro-magnets. may be sub-
stituted for permanent magnets in any of the modes of construction described
as the seventh, eighth, and ninth improvements.
¦
The third part of my Invention relates to improvements in electro-magnetic
alarums, clocks, and registers or counters.
The tenth improvement consists in the application of the electro-magnetic
arrangements described under the second head of my improvements to the
withdrawal of detents for the purpose of permitting alarunis to sound. The
manner in which I prefer to make this application is shewn at Figures 34
to 40, herein-after described.
.
The eleventh improvement consists of appropriate mechanism to prevent the
detent of an electro-magnetic alarum from escaping..until several currents or
shocks have been sent through the circuit, and.consequently until the magnetic
bars have moved to and fro several times. For this purpose the electro-magnetic
apparatus is caused to actuate a species of escapement, which at each inove-
ment allows to escape one tooth of a short rack in connection with the

page_text: alarum. By this arrangement one or more accidental jars will not cause
the detent to escape. The mechanism above mentioned is also shewn at
Figures-34 to 40, herein-after described..
The twelfth improvement consists of an appropriate mechanism. to prevent
the hammer of a bell from moving unless the magnets are acted upon by the
electric force: The sounding of the bell. is thus rendered independent of
accidental shakes or jolts. For this purpose: a pin is fixed to the periphery
of the toothed: wheel, which gives vibratory motion to the hammer in such
a position that just as the motion of this wheel is arrested, when thie.alarum
ceases to sound, the pin acts on a catch, and places it so.. as to restrain or
limit the vibrations of the hammer arising from concussions to. which the
instrument may be subjected. When the alarum is next acted on by currents
or shocks passing in the line wire, and the obstacle which retains the train of
wheels is thus removed, the motion of the toothed wheel which carries the pin
above mentioned immediately liberates the hammer, and allows the alarum to
sound freely.
:
Figure 34 is a front view (with part of the case removed) of an alarum
arranged according to the tenth, eleventh, and twelfth improvements; it is
shown contained within the base of a step-by-step instrument, such as I have
before described; Figure 35 is an end view;. Figure. 36 is a' plan.;. Figure.37
is an under side view; and Figure 38 a 'back view of the same; Figure 39 is
a longitudinal section taken at the line 1, 1; Figure 36 and Figures 40 show.
some of the parts separately. a is a barrel containing a spring which is wound
up from time to time by the handle b; a¹ is a toothed wheel on the drum a, it
drives a pinion c on the axis c³; on this axis is also the wheel.c, which, by.means
of it's inclined teeth acting on inclines on the vertical axis d, gives motion to the
hammer e in the usual manner, when the train of wheels is set free; c is an
arm on the axis c, and which rests on the pin f on the axis.f, so that the
alarum cannot sound until this axis f¹ is allowed to turn'; it is retained (till
set free by the electro-magnetic apparatus) by the armi f³, the end of. which
rests under the axis g; this axis is flattened at 9', and the arm få can only pass
when the axis g is turned so as to bring this flattened part opposite its end;
gis an arm carried by the axis g, it has three.teeth formed at its end, as is shewn
on a.larger.scale at Figure 41; h is the axis of an electro-magnetic arrange-
ment, similar to that already described as actuating the propelment of the step-
by-step instrument; on this axis the short arm h¹ is mounted, and it carries two
pins ha, ha, which act in the following manner :-The arm g² being at its highest
position, and its first tooth being pressed down upon the upper pin h² by, the
spring g', the first motion of the axis h allows this tooth to descend on to the

page_text: lower pin.h; the motion of the axis:in: the opposite direction allows this tooth
to escape between the pins.h2, h3, and then the second, tooth of the arm g³
descends on to the upper pin h³, and .so by successive motions of the axis h
the whole of the teeth of the arm are enabled to escape; the axis g then
turns by the pressure of the spring g'; so as to allow the end of the arm to
pass.; the arm frisés sufficiently to allow the arm ³ to pass. the pin f, and is
then immediately. brought down again by the spring i, as soon as the arm c³
escapes the alarum commences to sound; cis a cam on the axis c;, as that
axis revolves it acts on the lever j, so is to cause it to raise the arm g³ ito its
former position; in consequence of the form of the teeth on the arm g³, and of
the pins h*, h³, they pass each other freely when the armi gis. moving upwards.
By this motion the arm f* is again locked, and when the arm again comes
against the pin f, the motion of the train of wheels is stopped; c is a pin on
the wheel 'c, which just as the alarum 'ceases to sound raises the catch k, in
which a notch is formed; into this notch the stud d' on the axis d drops,
and thus the oscillation of the hammer is limited. is a handle which actuates
the contact maker, for the purpose of putting either, the step-by-step instru-
ment or the alarum into circuit as may be desired; this contact maker is of an
ordinary description; there is a cami. on the same axis, which when the alarum
is turned out of circuit, prevents the possibility of the arm 9³ descending.
The thirteenth improvement consists in the application of the first and
second improvements: above:specified, to the construction of electro-magnetic
telegraphic ior sympathetic clocks. These clocks resemble the step-by-step
télegraphs in many particulars, differing from them' only in the following:-
1stly, the dial instead of showing the letters of the alphabet shews the hours
with their usual divisions. 2ndly, the power acting primarily on the axis of
the second's hand. is communicated by 'a small train of wheels to the minute
and hour hands. A rehotrope is adapted to the regulating clock, for the pur-
pose of alternately inverting the current proceeding from a voltaic battery
instead of a rheotome, which merely determines a succession of currents in the
same direction.
.
This arrangement is fully illustrated by the step-by-step instrument, Figures.
4, 5, 6, 7, and 8; the only changes are that the pallet wheel has thirty teeth
in place of fifteen (if the regulating clock transmits one current or shock. per.
second), and that the pallet wheel, as before inentioned, actuates.a. train of
wheels as in.an.ordinary clock..
i
The fourteenth improvement consists in the.adaptation of the first and second!
improvements to electro-magnetic. telegraphic registers or counters, instru-
ments to indicate and number at a distance the periodically recurring motions

page_text: of machines, the opening of gates or. doors, &c. These differ. from the clocks'
of the thirteenth improvement merely in the proportion of the wheels of the
train and the mode of division of the dials. These I arrange according to the
circumstances of the case, but a convenient arrangement of: the dials is that
adopted in gas meters, where the first dial indicates units, the second tens, the
third hundreds, and the fourth thousands; the pallet wheel may have 1.5*teeth,
and then the gearing of the units.' axis, index, or pointer will be arranged to
increase the speed three times, and the gearing to the tens: index to decrease
the-speed, so that the tens' index may make one revolution for one hundred
steps, or 3 revolutions of the pallet wheel.
'
}
The fifteenth improvement consists in the substitution of magneto-electricity.
for: voltaic. electricity, in order to produce the currents or shocks necessary to
work such registers or counters. The axis of the armature of the magneto-
electric. machine is attached in 'a suitable manner to the machine, the motions
of which require to be registered. For example, if it be the openings of a'
door that it is desired to register, I attach a permanent magnet to the door;
and an armature with suitable coils to the frame. When the door is shut the
poles of the magnet come close up to the armature, and when the door is
opened and the magnet and armature separated, a current or shock passes
through the coils of the armature, iand causes. the units' index of a counter,
such as before described, to move one step; in a similar manner the strokes of
a steam engine may be counted and indicated at a distance, and the improve-
ment may be applied to many other similar uses, as will be clearly seen from
the above description.
.
Having thus described the nature of my said-Invention and the manner of
performing the same, I would have it understood that I do not confine myself
to the exact details described; as the: mechanical arrangements may be much
varied without departing from my Invention. What I claim, is,
First, the methods of. arranging the propelment of a step-by-step receiving
instrument, described as the first improvement..
.. Second, the methods of constructing the electro-magnetic arrangement
employed to produce the motions of step-by-step index and dial telegraphs,
described as the second improvement.
:
Third, the modifying the electro-magnetic arrangement of the second
improvement so as to render it capable of acting upon another circuit, so as
alternately to invert the current originating from a voltaic battery interposed
therein, as herein described.
:
Fourth, the arranging, as herein described, the communicator or instrumenti

page_text: employed, to, transmit currents derived from a voltaic battery into the tele--
graphic circuit, or, into, the primary, coil of an. induction apparatus, the
secondary coil of which is in connection with the télégraphic circuit.: ;
Fifth, the method of arranging the magneto-electric communicator described
as the fifth improvement..
.:
.:Sixth, the arranging communicators as herein described. for transmitting
into a telegraphic circuit, currents or shocks. produced by-magneto-electric or
electro-magnetic machines in continuous action,. in a suitable manner to
actuate a step-by-step receiving instrument included' in the telegraphic circuit;
each such instrument consisting of a series of finger keys, equal in number
and corresponding with the letters and signs on the dial of the step-by-step
receiving instrument; those keys being so arranged that when acted on they
cause such a number of efficient, currents or shocks to pass into the telegraphic
circuit as is required to move the index or pointer of the receiving instrument
from the position in which it last stopped to the letter or sign corresponding
with the key acted on...
.
I also claim the method of preventing imperfect currents or shocks from
passing into the telegraphic circuit. by. so arranging such communicators as
herein-before described, that whatever may be the position of tlie parts of the
magneto-electric or electro-magnetic; machine, when a finger key is acted on
the coils of the machine may not be put into electric communication with the
telegraphic line until the parts of the machine are in a proper position for
communicating an efficient shock or current...
I also claim the so connecting together the finger keys that the depression
of or the acting on any one of them, may restore 'to its original position the
key last operated on...
Seventh, the method of arranging a magneto-electric machine described as
the seventh improvement.
.
Eighth, the method of arranging a magneto-electric machine described as
the eighth improvement, that is to say, the arranging such machines with
stationary coils combined with a series of armatures,-which, are in succession
caused to move past the poles of a magnet or a series of magnets, as herein-
before described.
Ninth, the combining or gearing together a number of magneto-electric
machines in the manner herein-before described as the ninth improvement.
Tenth, the application of the electro-magnetic arrangements described under
the second head of my improvements to the withdrawal. of, detents for the
purpose of permitting alarums to sound..

page_text: Eleventh, the application of mechanism to electro-magnetic alarums to
prevent the detent from escaping until several currents or shocks have been
sent through the circuit, as herein described.
Twelfth, the application of mechanism for retaining the hammer of electro-
magnetic alarums, as herein described.
Thirteenth, the application of the propelments and the electro-magnetic
arrangements described as the first and second improvements to electro-
magnetic or sympathetic clocks, as herein described.
Fourteenth, the application of the propelments and the electro-magnetic
arrangements described as the first and second improvements to telegraphic
registers or counters, as herein described.
Fifteenth, the substition of magneto-electricity for voltaic electricity, in
order to produce the currents or shocks necessary to work telegraphic registers
or counters, as herein described.
In witness whereof, I, the said Charles Wheatstone, have hereunto set
my hand and seal, this Thirtieth day of November, in the year of our
Lord One thousand eight hundred and fifty-eight.
Witness,
JNO. ALCOCK.
C. WHEATSTONE. (L.S.)