IMPROVEMENTS IN APPARATUS FOR MAKING TELEGRAPHIC COMMUNI- CATIONS OR SIGNALS BY MEANS OF ELECTRIC CURRENTS, PARTS OF SUCH APPARATUS BEING APPLICABLE TO OBTAINING, REGULATING, OR MEASURING ELECTRIC CURRENTS FOR OTHER PURPOSES
Year: 1838

page_text: THESE PRESEN SHALL COME, I, I, EDWARD
DAVY, of Fleet Street, in the City of London, Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Fourth day of July, in the second year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Edward
Davy, Her especial license, full power, sole privilege and authority, that I, the
said Edward Davy, my exors, admors, and assigns, or such others as I, the
said Edward Davy, my exors, adññiors, or assigns, should at any time agree
with, and no others, from time to time, and at all times during the term of
years, therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "IMPROVEMENTS IN APPARATUS FOR MAKING TELEGRAPHIC COMMUNI-
CATIONS OR SIGNALS BY MEANS OF ELECTRIC CURRENTS, PARTS OF SUCH APPARATUS
BEING APPLICABLE TO OBTAINING, REGULATING, OR MEASURING ELECTRIC CURRENTS
FOR OTHER PURPOSES;" in which said Letters Patent is contained a proviso,
that I, the said James Davy, shall cause a particular description of the nature
of my said Invention, and in what manner the same is to be performed, to be
enrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Edward Davy, do hereby declare that the nature of my said Invention, and the

page_text: manner in which the same is to be performed, are fully described and ascer-
tained in and by the following statement thereof, reference being had to the
Drawing hereunto annexed, and to the figures and letters marked thereon
(that is to say):
My Invention relates to certain improvements in the apparatus to be
employed for making telegraphic communications or signals by means of
electric currents, parts of such apparatus being applicable to other purposes,
as hereafter explained. The principles on which currents of electricity are
caused to be transmitted through metallic circuits being well understood, it
will not be necessary for me to enter into a general description of such
principles; and I would at the outset state that various propositions have been
made and apparatus designed for employing electric currents passing through
metallic circuits to the purposes of making communications and signals from
one place to another, some of which have been secured by Letters Patent. I
wish it therefore to be understood that I make no claim to the general use of
electric currents transmitted through metallic circuits, but my Invention only
relates to certain apparatus employed for such purposes. And in order to
give the best information in my power for carrying out my Invention, I will
suppose that it is desired to have the means of transmitting communica-
tions or signals by electric currents passing through metallic circuits from
London to Birmingham and to Liverpool; and it will readily be understood
that although I have selected these three places what will be hereafter said
of them will equally apply to any other three places, and I have only selected
them for convenience of description, and I will suppose that certain wires
have been laid down from London to Liverpool through Birmingham, such
wires being isolated one from another so that there can be no lateral
metallic contact of one wire with the other, and this may be performed in
various ways. The one I recommend is to cut longitudinal slits or grooves by
circular saws or other proper means in lengths of wood joined one to another
and a single wire laid in each groove, and the grooves filled by calking in like
manner to the seams of ships. At London is to be applied certain apparatus
to the wires which I will first describe; there is also to be a certain other
apparatus at Birmingham and Liverpool, which I will next describe, for
receiving the signals, signs, or indications; I will then describe the apparatus
which is to be applied at various intermediate places or distances, in order to
renew the electric currents passing through metallic circuits, in such cases where
the place from which the communication is transmitted is very distant from the
place where the communication can be received in order that the currents pass-
ing through the various circuits of wire, notwithstanding the distance of one

page_text: point to another, that the currents shall be sufficiently powerful throughout to
perform with certainty, facility, and quickness. And, further, according to my
Invention the apparatus can be so arranged that (although currents of
electricity can be transmitted from London to Liverpool through Birmingham)
5 by the working of the Invention, a communication may be made from London
to Liverpool or to Birmingham, without the necessity of making the same
communications or signals at Birmingham and at Liverpool, at the same time
the.
person making the communication at London can (by the working of the
apparatus) so operate as to determine at which place the communications or
signals shall be made. I shall lastly describe such details in the apparatus as
will be used under particular circumstances, and also point out how much and
in what manner some of the parts are applicable to other purposes.
The Drawing No. 1 represents the apparatus employed at the place of
making a communication or signal, say London, and that at the place where
the communication or signals are received, say Birmingham or Liverpool.
The wires A, B, C, are those laid down between those two places; Figure 1
representing a plan; Figure 2, a longitudinal view of the apparatus in elevation;
and Figure 3, a front view of the key board employed, by which the metallic
circuits capable of being obtained by the wires A, B, C, may be greatly varied,
as will be hereafter explained. D, E, F, G, H, and I, are six wooden finger
keys or instruments, which the person desirous of making a communication
depresses in such manner as to indicate such signs as the apparatus is capable
of at a distance; and according to the order in which these keys are depressed,
so will be the varied metallic circuits produced, and consequently the varied
compounding of the signs the apparatus is made capable of. The finger keys
are all similar to each other, and they move on axes at one end, the other end
of each being free to be depressed when required, and each key has a spring
and wire or rod J, by which the key is at all times pressed upwards out of
contact with the metallic surfaces below, the object of which will be better
understood hereafter; the wire (passing freely through the key) having a head
or enlargement prevents the key being forced too high by the spring J; hence
when the keys are not acted on, they retain their horizontal position. On the
under side of each of the keys are applied two metallic buttons or surfaces
K, L, they being applied thereto by means of small springs, in order to obtain
uch a degree of play that when the key is depressed downwards the contact
f both may be ensured. With respect to the metallic surfaces below I would
ere state that the principle on which this apparatus works is this: that there
re two or more wires which communicate with another wire, and for distinc-
ion sake I will call the two or more wires the, signal wires, and the other

page_text: wire the common communicator; for it should be understood that no metallic
circuit can be formed between any two or more of the signal wires of them-
selves, and it is only by the aid of the common communicating wire that a
metallic circuit for transmitting electric currents can be obtained with one
or more of the signal wires; and, further, whatever be the number of wires
employed so having a connection with a common communicating wire, there is
to be a suitable electric apparatus, such as a voltaic battery to each signal
wire. The Drawing shews the apparatus to consist of two signal wires A and B,
and a common communicating wire C, and the Drawing further shews the
apparatus to have three separate batteries, but this is not essential; the object in
using the third is to obtain a greater extent of signals or indications by the three
wires so used than can be obtained by the employment of only two batteries,
which is the number of signal wires employed in this case, but by this means
the common communicating wire may have needles and suitable apparatus,
and become also a means of communicating signals as well as the signal wires.
D, E, are the pair of finger keys which cause electric currents to pass through
a circuit partly made up of the signal wire A, and it will be found that the
parts are so arranged, that by depressing the key D, it will bring the signal
wire A in metallic communication with the negative pole of the battery No. 1,
and at the same time cause the common communicating wire C to be in
metallic communication with the positive pole of the same battery No. 1;
consequently the electric currents would, by so depressing the key D, pass
positively through the wire C, and negatively through the wire A; for it will
be seen that the wire A is brought into metallic communication with the short
wire A¹ of the negative pole of the battery in the following manner :-The wire
A at its end is turned up at right angles under the button or surface K of the
key D, and such is the case with the wire A'; it is attached to the negative
pole of the battery No. 1, and is turned up at right angles at the other end
under the surface K; consequently on the descent of the button or surface K,
by the pressing on the key D, it will produce suitable metallic contact and
communication to allow of the current passing from the wire A, through the
wire A', to the negative pole of the battery No. 1, and the positive current is
caused to pass from the battery No. 1, through the wire C, by means of the
short wire A², which is connected with the positive pole of the battery No. 1;
the short wire A2 is turned up at right angles under the button or surface K
of the key E, and the wire A² is connected with or soldered to the short wire
C', which is turned up under the button or surface L of the key D; and the
end of the wire C is also turned up at its end under the button or surface L,
and it will thus be seen that- by depressing the key D, there will be a metallic

page_text: circuit completed through the wires A, C, in the following manner :-The.
positive currents of electricity from the battery No. 1 will pass through the
wire A2, through the wire C, through the wire C, through the signal wire A,
back to the negative pole of the battery No. 1, by passing through the short
wire A'; and the course of the electric currents may be reversed through
the wires A, C, by depressing the key E in place of the key D, for by
this means the button or surface K of the key E will cause a metallic
contact or communication between the short wire A² and the wire A, and
will consequently cause a metallic communication between the wire A and
the positive pole of the battery No. 1, and the button or surface L of the
key E will effect a metallic communication between the wire C and the
negative pole of the battery No. 1, by means of the short branch wire C2
from the wire C, the short wire C being turned up at right angles under
the button or surface L of the key E; by this means a complete and suitable
metallic circuit is again obtained between the wires A, C; but in this case
the electric currents pass from the positive pole of the battery No. 1, through
the wire A2, then through the wire A, and return to the battery through the
wire C, through the branch wire C, thence through the wire A³, to the
negative pole of the battery No. 1, by the short wire A¹, all which will readily
be understood by examining the Drawing No. 1, Figures 1, 2, and 3, bearing
in mind that at the distant place where the wires A, B, C, terminate, they
are at all times in metallic contact; it should be stated that, although the short
wires As and C¹ cross each other, they must be isolated or kept out of metallic
contact one of the other. There is no metallic circuit formed between the
wires A and C, unless the key D or the key E is depressed, as above explained;
and a metallic circuit will be kept complete between the wires A and C, so
long as either of those keys are depressed, and the positive current will pass
through A or through C, as the case may be, and as above explained.. The
key H and I act on the wires B and C, and produce metallic circuits through
which electric currents from the battery No. .2, may be transmitted in like
manner to what has been described in respect of the wires A and C, and the
battery No. 1, by the keys D, E; no further description of the keys H and I,
and their mode of action, will be therefore necessary. I will now proceed to
describe an apparatus for receiving the communications at Birmingham or
other place, which apparatus is also shewn at Figures 1 and 2. The wires
A, B, C, just before being connected together are each made into two coils or
convolutions of the wire, similar to what are employed for, galvanometers, in
order to give such an effect by the electric currents as to operate with
sufficient power on the needles, as to cause them to move on their axes in a

page_text: direction according to that in which the electric current is passing. M, N,
shows these coils or convolutions of each of the wires A, B, C, but in place of
having some twenty or more convolutions of each wire, the Drawing
shows only one turn or convolution to each coil M, N, which is done in order
to show the needle and working parts more clearly. The needles employed
consists of magnetized plates of steel O, P, moving on points similar to magnetic
needles, as is shewn in the Drawing, and when at rest and pointing north and
south, they are to be in a line with the wire coils in which they move. To
the upper part of each needle is affixed the brass finger or cross needle or
contacting piece Q, as is shown; one end of such cross needle or contacting
piece being bent down at right angles till it descends sufficiently low to pass
under the bearing of the axis or point on which the needle O or P moves; the
cross needle is then bent inwards and passes under the axis or point, and is
again turned down at right angles, where the point enters a small cup of mercury,
and the object of so bending the cross needles or contacting piece Q is, that
their points shall work in the same lines as the axes or points on which their
needles move, as by that means the lower ends of the cross needles or con-
tacting pieces move in the mercury with little friction. R, R, are stops against
which the cross needles come in contact at times when not acted on by electric
currents. S, T, are wires against which the cross needles or contacting pieces
Q at times come in contact, in order to produce metallic circuits for the purpose
of producing marks or indications on chemically prepared fabrics, as herein-
after explained. V is a compound battery, from the positive pole of which a
'wire W communicates with each and all of the cups containing mercury;
consequently when either of the cross needles is caused to touch the wire S
or T, there will be a metallic contact or communication from the positive pole
of the battery V and the wire S or T, depending on the course in which electric
'currents are passing through the circuits produced by the wires A, B, C. Thus,
supposing a positive current to be passing through the wire A, the cross
needles or contacting pieces Q of the needle O of the wire A, would
be deflected towards and come in contact with the wire S, and produce
a metallic contact or communication between the wire S and the positive pole
of the battery V; and on the other hand if a negative current is passing
through the wire A, the cross needle or contacting piece Q of the needle P
would be brought in contact with the wire T. The cross needles or contacting
pieces of the needles O, P, are so arranged and operated upon, that when
'one of them is caused to touch its wire S or T, the other will be borne away
from its wire S or T and rest against its stop. Thus it will be seem that each
wire has a capability of giving two separate indications by their wires S, T,

page_text: and these indications may be increased by compounding to eight, according to
the order in which those indications are communicated; and such number may,
be increased by applying needles O, P, Q, to the wire C, and applying a third
battery, which I have marked No. 3, and two extra keys F, G, to the key
board, the object of which extra battery No. 3 will be hereafter described.
The pairs of wires S, T, pass through a block of wood X, which acts as a
support; the ends of such wires S, T, are forked, and embrace the metallic
rings Y affixed on the wooden cylinder Z. The axis of this cylinder turns on
points Z'; the metallic rings Y of platina are kept closely against the cylinder
a, which turns in suitable bearings carried by the framing, as shown in
the Drawing; b is a cog wheel affixed on the cylinder a. This cylinder a
has a constant tendency to revolve in one direction, communicated to it by a
spring or weighted cord, but is only permitted to turn a certain distance each
time that an indication has been made through the wires A, B, C, and after"
the hand has been removed from the keys. c is an upright axis having a
pinion d, which takes into and is driven by the wheel b, and on the
axis c is affixed the cog wheel e, which takes into and drives the pinion f
on the axis f, there being on that axis f a fly vane g, which has two
notches h and i; j is a plate of soft iron, which is carried by the lever j',
which moves on a horizontal axis j. k is a lever moving on a vertical axis,
the lever carrying the axis j2; consequently the plate j is capable of
receiving an up-and-down movement on its own axis, and a portion of a rota-
tory motion on the axis of the lever k. Through the lever j' there is a pin or
projection j³, against which the end h of the fly vane g is now stopped; and the
apparatus is in the position proper for receiving an indication or sign through
any of the wires A, B, C, and such indication or indications will be per-
manently recorded, as hereafter explained. It should be stated that there is
at all times a metallic contact between the negative pole of the battery V and
the metallic cylinder a by means of the wire m, which is coiled round a bent
bar or horse shoe of soft iron, in order to produce an electro-magnet n, and
from thence the wire m passes, and is held in contact with the end of the
cylinder a. Consequently whenever any one or more of the contacting pieces of
the needles O, P, come in contact with their wires S or T, a metallic circuit
or circuits will be formed, and it will be evident, that if properly prepared
fabric, such as calico (impregnated with hydriodate of potash and muriate of
lime) be placed between the metallic rings Y and the cylinder a, whichever of
the rings Y are for the time being in the metallic circuit which has been
established, will by its pressing against the cylinder a pass the current through
the prepared fabric and produce a mark thereon, whilst those rings Y which

page_text: have not electric currents passing through them will not make any mark on
such fabric, consequently on observing the fabric it will readily be ascertained
which and how many of the wires S, T, have been caused to communicate an
indication by electric currents being transmitted through them; and it will only
be necessary to assign to each mark so produced or indicated on the fabric a
definite cypher referrable to a proper key book, as is well understood in tele-
graphic communications, in order to obtain a means of rapid communication
from one place to another by the aid of electric currents. In establishing a
metallic circuit by the wires A, B, C, and consequently with some or other of
the wires S or T, the electro-magnet n will attract the plate j, and thus release
the end of the fly vane g, and allow it to make a half révolution and be
again stopped by the pin j³, and consequently allow the fabric to be moved
forward a short distance by the roller or cylinder a. When the hand of the
person making the communication is removed from the key or keys, the
contact of the plate with the electro-magnet n will be broken, and the fabric
allowed to be moved forward by the cylinder a, a distance equal to that at
which the indications should be apart on the fabric for the sake of distinctness.
The stud in the revolution of the wheel e coming against a curved surface at
the end of the lever k forces that end of the lever to move towards the centre
of the wheel e, and places the pin js in such a position as to intercept the fly
vane g, and again be in the position shewn in the Drawing; consequently these
parts act as an escapement which works by the currents of electricity pro-
duced by the person making the communication through the wires A, B, C.
'The fabric as it is carried forward by the cylinder a is conducted away over
a guide roller and drawn forward by a weight, or in any other suitable
manner. And I would remark that, although I have recommended the use
of calico prepared in the manner above stated, as the fabric to be used for
receiving the marks, I do not confine myself thereto, as other fabrics may be
used, and the chemical materials employed may be varied so long as they will
be similarly marked by the passage or action of electric currents. The fabric
so employed may be printed with sub-divisions, as is shewn in the Drawing,
or it may be used plain, because the marks made, whether a single one or more
than one at a time, will be in rows across the fabric, and each row, whatever
be the number of marks, will be' a communication or signal; and this mode of
receiving marks in rows across and lengthwise of the fabric constitutes an
important feature in my Invention; for although I profer that the marks
should be produced by the chemical action of the electric currents acting on
fabrics properly prepared, yet it will be evident that other means of producing
a series of marks in rows, crossways and lengthwise of the fabric, may be

page_text: resorted to, such as pencils or ink connected to or carried by proper holders
acted on by electro-magnets, one pencil or other marking instrument to each
wire S, T, by which means every time a metallic circuit was produced by the
aid of any of the wires S, T, they would cause their electro-magnets to bring
the marking instrument in contact with paper or other suitable fabric, and
give marks thereto across such fabric, and as the fabric was moved forward the
next row of marks would be made at a distance from the preceding row and
separated therefrom, the same instrument producing its mark at all times in
the same longitudinal row.
I would remark that I am aware that it has been proposed to use a mark-
ing instrument with lead or ink, by the aid of an electro magnet, to make a
number of dots or marks to a moving surface of paper, and by the number of
dots that are marked in immediate succession to indicate the signification of
such communication. I do not therefore claim the use of marking instruments
generally, but only when they are adapted to make communications by marks
across and lengthwise of the fabric which receives them as above described. .
It has been found that electric currents in passing through considerable
lengths of metallic circuits decrease in energy; consequently, where the point
from which the communication or signal is given is very distant from the point
or place at which the communication or signal is received, it is necessary to
have some means of overcoming this difficulty, and it has been proposed to
have a number of apparatus at comparatively short distances, and persons to
attend thereto to receive and transmit the various communications on from
place to place, (in like manner to what is now done in communicating from
place to place by telegraphs depending on sight,) till tlie communications or
signals reach the destined place, which is necessarily an expensive means and
attended with greater liability to error in making a communication. Now,
by my Invention, I so arrange the metallic circuits that at the requisite
intervals, the apparatus itself will bring into action a succession of wires having
their own batteries which I call renewers. Let it be supposed it has been
determined that the energy of the currents passed through the wires A, B, C,
will be sufficient for the purposes to which they are applied for a length of ten
miles, and this will readily be ascertained by a galvenometer, which will, by
testing the wires at different distances, indicate the extent those wire will
transmit electric currents with the degree of energy which will act on the
needles employed with sufficient correctness and quickness to make or trans-
mit the communications or signals with the degree of velocity desired; and
the arrangement is such that the electric currents which are transmitted
from and to the batteries No. 1 and No. 2, by the wires A, B, C, do not pass

page_text: on to the distant place where the communication is to be received, (if that
place be too far distant for such electric currents transmitted through A, B, C,
to act with the energy desired,) but further electric currents are obtained and
pass through other metallic circuits brought into action by the working of the
apparatus by the person, say at London, who is transmitting the communi-
cation or signal; by this means the person making the communication or
signal does so direct to the distant place, say from London to Birmingham,
without the intervention of other persons, aided only by the requisite apparatus
for receiving and transmitting such communication or signals from place to
place until they arrive at the ultimate place desired.
In the Drawing No. 2, Figure 1 is a plan of the apparatus for renewing,
which is to be applied at such places or distances as may be determined
on. A, B, C, are the ends of the wires before spoken of in respect to Draw-
ing No. 1 (but it will be seen that their positions have been transposed by
error in this Drawing); A, B, C, the three wires through which fresh
electric currents are to be transmitted, such fresh currents corresponding in
effect with those already described in respect to the wires A, B, C, the wire
A having a positive or negative current transmitted through it when there is
á positive or negative current transmitted through the wire A, and so on in
respect to the others, and this is accomplished in the following manner:
No. 4, No. 5, are two batteries, and O, P, Q, are needles and their contacting
pieces, such as I have before described, and the cups containing mercury are
connected to the positive and negative poles; thus the wires colored pink
from the cups connect those cups with the positive poles of the batteries;
and the wires colored green connect their cups with the negative poles of the
batteries, as will readily be understood on examining Figure 1 of Drawing
No. 2. Thus, the cups of the needles are connected with the negative
poles of the batteries, and the cups of the needles P are connected with the
positive poles of the batteries. By this arrangement it will be evident, that if
a positive electric current be passing in the wire A, it will cause the contact-
ing needle Q to come in contact with a branch projection on the wire A*, and
thus produce a metallic connection or communication with the positive pole
of the battery No 4; and the needle Q¹ would come in contact with a short
branch from the wire C³, which would produce a metallic contact with the
negative pole of the battery No. 4; hence a positive electric current would be
transmitted through the wire A°, and return by the wire C³, and if the end of
the circuit produced by the wires A, C, be not the place at which the com-
munication is to be received, then another circuit will be by a similar means
communicated to another arrangement or relay of wires, till the distance is

page_text: accomplished; and, further, supposing a negative current to be passing through
the wire A, then the contacting needles Q3, Q³, would be brought into action,"
Qopening a metallic communication with the wire C", and the positive pole
of the battery No 4; and the contacting needle Q3 would effect a metallic
communication between the negative pole of the battery No. 4 and the wire
A, as will readily be traced in this Drawing; and a like effect will take place
in respect to the wires B, C, from and to the battery No. 5, when electric
currents are transmitted through the wires B, C. In making communications
or signals by means of electric currents from such a place as London (from
which wires may be laid to various towns, such as Birmingham, Liverpool,
Manchester, and many other places), it becomes desirable that all communi-
cations or signals made for one place should not of necessity be communicated
to the whole of the places with which the apparatus is arranged to commu-
nicate, but that a signal or communication, if for Liverpool, should be delivered
only at that place.
Now, according to my Invention this may be effected with great facility,
however many the branches, by means of electric currents acting on suitable
apparatus, and the course the communication shall take, can be determined
by the person making the communication. Figures 2 and 3 of Drawing
No. 2 show an arrangement of apparatus suitable for carrying out this part
of my Invention; in this case, similar needles O, P, and contacting 'needles
Qin coils of wire are employed, in order to determine the course of the signals;
these parts are marked with the same letters of reference. The description
and mode of working hereafter will readily be understood, by again supposing
that A, B, C, are continuations of the same wires as have been before spoken of.
At any point between London and the place where the signals or communi-
cations are received at Birmingham, these wires are each caused to branch
in two directions, one branch of each wire for communicating with Liverpool,
and one branch of each wire for communicating with Birmingham. Each
branch is turned up at right angles, as shewn at Figure 3, in order to come
under suitable buttons or metallic surfaces, for making contacts with the ends.
of two wires. Each button is similar to what has been described for the finger
keys already explained, and there is for each branch of wire A, B, C, to be a
wire leading to Birmingham and to Liverpool, the ends of such wires being
turned up in like manner to the ends of the branches of wires A, B, C, and
coming under the same buttons or surfaces on the balance bar (1), which
moves on an axis (2), there being a rod rising from the bar (1), having a
weight at top and a piece or plate of soft iron which rests against one or other
of the electro-magnets (3), (4), as will be seen in the Drawing; and the

page_text: contacts are so arranged in the Drawing, that the electric current would be
transmitted to Birmingham and make their communication there, but in case
it be desired to change that state of things, and to deliver the communications
or signals at Liverpool, in such case the person making a communication
would pass electric currents through the wires A, B, positive through B, and
negative through A; by this means the contacting needle Qb would come in
contact with a branch of the green wire leading from the cup of Q, which
should produce a metallic communication between that cup and the cup
of the needle Qb, and the electric current through the wire A would cause
the needle Q to come in contact with a branch wire from the electro-magnet
(4), and thus produce a metallic circuit through the wire around that magnet,
as the magnets are at all times in contact with the other pole of the battery;
the consequence of which would be that the plate would be drawn from the
magnet (3) to the magnet (4), and thus produce contact of the wires to
Liverpool with one set of the branch wires of A, B, C, and at the same time
will break off the contact with the wires to Birmingham, and so long as the
apparatus remains in this condition the communications transmitted will be
to Liverpool; and it will be evident that by passing currents of electricity
through the wires A, B, in the opposite directions, contacts may be, again
established with the Birmingham wires by means of the other contacting
needles on the wires A, B.
Another part of my Invention relates to an improved construction of gal-
venometer, whereby the strength or energy of electric currents may be
ascertained, whether it be for the purpose of ascertaining at what distances
the apparatus I have called the renewers should be applied, or for measuring
the energy of electric currents for other purposes; the apparatus acts on the
principle of a scale beam or of a stilliard.
Figures 4 and 5 of Drawing No. 2 shew an apparatus made according to
my Invention.
a is a coil of wire similar to what is used in ordinary galveno-
meters, and b is a horizontal axis to the needles c, so that the needle will be
operated on in such manner as to dip; d is a scale for receiving weights
attached to one end of the beam or lever c, and I prefer that the end of the
needle c with the scale should slightly preponderate over the other end of the
needle, and f is an upright on to which the other end of the needle is drawn
by the force of the electric currents. In using this apparatus, negative and
positive wires are to be connected with the ends of the wire of the coil a,
and elcetric currents passed through, and the strength of the currents will be
ascertained by the weight it will overcome in the scale.
.:
Having thus described the nature of my Invention, I would have it under-

page_text: stood that although I have mentioned three wires A, B, acting with C, yet it
will be evident that this number may be varied according as the requirements
of the places. between which the wires are laid, the number of wires used
depending on the intricacy of communications likely to be made. Thus, three
5 wires A, B, C, with two batteries, Nos. 1 and 2, will produce eight different
signals, signs, or indications; and by using a third battery, No. 3, and having
needles applied to the common communicating wire C, twelve different signals,
indications, or signs may be transmitted; the object in using a third battery
in such case being to give greater quantity of electricity to certain currents.
Thus, supposing a positive electric current to be passing through the wire A
and a negative electric current to be passing through the wire B, there would
be two electric currents passing to the wire C in opposite directions; con-
sequently the needles in the wire C would not be acted on in such manner
as to obtain a certain and definite indication or signal by the needles of such
wire unless the positive or negative current passing to the wire C in opposite
directions be made more powerful than the other; and this may readily be
effected by the keys F, G, which can bring the wires A, C, B, C, in connection
or metallic communication with the battery No. 3 in addition to their own
batteries, and thus give more power to one of the currents passing through
the wire C in one direction than the current coming in the other direction.
And I would remark that although I have shewn particular instruments
for making and breaking metallic circuits for regulating the place to which
communications shall be made (in an apparatus arranged suitably for com-
municating with many places), yet I do not confine myself thereto so long as
the apparatus is suitably arranged to enable the person making the com-
munication by means of electric currents to determine and regulate the place
to which the communications or signals shall be transmitted. And in respect
of the means of transmitting communications or signals through metallic
circuits to distant places (too far distant for a single circuit to transmit
electric currents with sufficient effect), and which may be said to be the
employment of relays of metallic circuits and electic currents, however
obtained, the apparatus or instruments may be varied without departing from
my Invention; my Invention not depending on the instrument, but on the so
Arranging metallic circuits that they can be brought into action in the manner.
above described. It will be desirable to observe, that although I have shewn
and described the various parts of the apparatus to be worked by only one
mode of: obtaining metallic circuits by two or more wires working with one
common communicating wire, it will be evident that some of the parts of my
Invention may be used with other means of obtaining metallic circuits: I do

page_text: .
not therefore confine myself to the employment of all the improvements
herein described in the same apparatus, nor do I confine myself to the mode
of receiving signals or communications from the other parts of the apparatus,
as arranged and combined according to my Invention, as other modes may be
resorted to if desired, and in other respects retain much of the utility of the
other parts of the Invention; and I would have it understood that I lay no
claim to the separate parts of the apparatus shewn and described when
uncombined and not used as above described, and I recommend the use of
compound batteries in all cases where batteries are used, and I have only
shewn single ones to simplify the Drawing; and in using electro-magnets for
any purpose of telegraphic communication, as herein explained, there should
not be positive contact of the soft iron with the ends of the magnets, but
a portion of thin leather or other material should be interposed. It will be
evident that the apparatus employed by me and described above for varying
the directions of electric currents from one set of wires to another set of
wires may be used generally where electric currents are desired to be
obtained, and their course regulated by the apparatus itself are required, and
such is the case in respect to the apparatus or galvenometer for measuring
the strength of electric currents. And, further, the apparatus described for
producing an escapement will be applicable for most purposes where a like
description of escapement is required in making communications or signals
for telegraphic purposes.
And I would have it understood that what I claim as my Invention is,
first, the mode of obtaining suitable metallic circuits for transmitting com-
munications or signals by electric currents by means of two or more wires,
which I have called signal wires, communicating with a common communi-
cating wire, and each of the signal wires having a separate battery, and, if
desired, additional batteries for giving a preponderance of electric currents
through the common communicating wire, as above described..
Secondly, I claim the employment of suitably prepared fabrics for receiving
marks by the action of electric currents for recording telegraphic signals,
signs, or communications, whether the same be used with the apparatus above
described or otherwise.
Thirdly, I claim the mode of receiving signs or marks in rows across and
lengthwise of the fabric, as herein described.
Fourthly, I claim the mode of making telegraphic signals or communi-
cations from one distant place to another by the employment of relays of
metallic circuits brought into operation by electric currents.
Fifthly, the adapting and arranging of metallic circuits in making tele-

page_text: graphic communications or signals by electric currents in such manner that
the person making the communication shall by electric currents and suitable
apparatus regulate or determine the place to which the signals or .com-
munication shall be conveyed.
Sixthly, I claim the mode of constructing the apparatus which I have
called the escapement, whether it be applied in the manner shewn or for
other purposes where electric currents are used for communicating from one
place to another.
Seventhly, I claim the mode of constructing the galvenometer herein
described.
And, lastly, I claim such parts as I have herein pointed out as being useful
for other purposes, as above described.
In witness whereof, I, the said Edward Davy, have hereunto set my hand
and seal, this Fourth day of January, One thousand eight hundred
Inrolled the Fourth day of January, in the year of our Lord Ono
thousand eight hundred and thirty-nine.