IMPROVEMENTS IN THE MODE OF WORKING TELEGRAPHIC LINES, AND IN INSTRUMENTS AND APPARATUS EMPLOYED FOR TELEGRAPHIC PURPOSES
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by William Hickling Burnett at the
Office of the Commissioners of Patents, with his Petition, on the 21st
May 1862.
I, WILLIAM HICKLING BURNETT, of Margaret Street, Cavendish Square, in
the County of Middlesex, Gentleman, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MODE OF WORKING TELEGRAPHIC
LINES, AND IN INSTRUMENTS AND APPARATUS EMPLOYED FOR TELEGRAPHIC PURPOSES,"
to be as follows:—
Firstly, my improvements in the mode of working telegraphic lines consist
in various arrangements, by which increased rapidity, certainty, and economy
are produced in signalling by means of electricity, especially where subter-
ranean and submarine lines are used, and by some of which the obstructions
now caused by terrestrial, marine, or atmospheric induction, and by static
charge and discharge of the line are either wholly or partially removed, and
the evil effects of leakage are considerably reduced.
Secondly, in improvements in certain apparatus used in working telegraphic
lines.
1:1
My first improvement has for its objects to diminish or remove the evil
effects of earth, and other accidental currents. I do this by having a second
line parallel to the working line. Both lines, when signalling is not taking place,
go to earth at each end without connexion with any battery through coils
wound in opposite directions round the instruments, or coils wound round

page_text: separate electro-magnets arranged to balance, each other's effect on the armature,
so that whenever earth or other accidental currents set in as the two lines
are exposed to the same influences these currents balance each other, and when
a signal has to be made a current from a battery is sent through one of these
lines and acts on the instrument without any disturbance or interference from
the accidental currents. By coiling the two lines in opposite directions round
instruments arranged on the plan of those I hereafter explain when describing
my mode of working two or three distinct systems of telegraph through one
I make each
line wire simultaneously, and using batteries of unequal forces.
of the two lines a working line, at the same time the instruments of both
being quite independent of accidental currents, and of each other.
My next improvement is intended to obviate the delay caused in the present
mode of working a line by the loss of time required to charge and discharge
it. In this arrangement the working line is always kept charged to the full
degree without indicating at the instrument except when it is required to do
So. Here also I use two lines which are connected at the receiving station
so as to form one circuit. One of the ends of the coils of the instrument is
connected to this junction, and the other to earth. Of the two lines one is
attached to one, and the other to the other pole of a battery at the sending
end, and when so arranged a current will be constantly flowing round the
two lines, but none through the instrument unless either pole of the battery
is put to earth when a current will immediately pass through it, and make a
signal. However in order that part of the current may still continue to
flow round the second line, I sometimes put a resisting medium between
the instrument and the earth, and I sometimes use a third wire instead of
the earth, making the signals by touching either pole of the battery and earth
alternately with this wire at the sending station. To obviate an evil or
irregularity caused by earth or other inductive currents, and even to make
.these currents assist the working of the instruments I adopt a very simple
expedient. The two lines being parallel or nearly so, and tolerably close
together will be subject to the same inductive influences, and therefore earth
and other currents will assist the circulation in one line and oppose it in
the other, I therefore so arrange that I can make either line the working
line by giving the operator power to put either pole to earth, and therefore to
employ whichever line the earth or other current favors.
The next arrangement I adopt has the same advantages, but shews how
I am enabled to cause either end of a line to become the sending line at
At each
pleasure. Here the two stations are also joined by two lines.

page_text: station is a battery and the two lines connect the positive pole of each battery
to the negative pole of the other, and in this which is the normal state a
current is constantly flowing round the two lines. The coils of the instrument
at the two stations are connected respectively with earth at one end through
resisting media, whilst the other end can be put in connexion with either pole.
of the battery at the station. If those ends are in contact with similar poles
of the two batteries no effective current will pass through either instrument when
the batteries have about equal force, and the lines are in pretty similar con-
dition. If now at either end it is wished to send a message the end of the
instrument coil is made to touch the other pole when the current from both
batteries will flow through the instruments, and make a signal, and by alter-
nately making and breaking contacts with this pole signals will be: sent..
The resisting mediums. mentioned are not absolutely necessary, but they
are very useful as they serve to keep a certain amount of charge in the non-
working wire.
By my next arrangement I also obtain more rapid signalling through
telegraphic lines, especially submarine and subterranean ones. In this case
I use but one wire. The signalling battery is placed at the receiving station
and at the sending station is a coil of suitable length insulate like the line
wire, and in preference submerged; or in lieu of a coil, other available arrange-
ment for receiving a charge of electricity. The signals are made by alternately
touching the end of the line wire and earth with one end of this coil. Or
instead of using the contrivance just described, I sometimes have a battery at
each end of the line, which is attached to a dissimilar pole of each, thus forming
oue battery. The other poles go to earth through the instruments. In this
state a current is constantly flowing through the instruments, and the signals
are made by breaking contact with earth at either end. Or I sometimes signalize
without forming a circuit through the earth, and yet employing but one line
wire, thereby avoiding the necessity for the very perfect insulation now required
in the line wire. In this case I have a reservoir for electricity of the kind
I have just described at both ends of the line well insulated from earth as well
as a battery at each terminal, the line being attached to dissimilar poles of the
two batteries or one battery only is used. By making contact of the reservoir
at the sending end alternately with line and earth the signals are made.
The chief object of my next arrangement is economy in the battery power
required for the line; by it I am enabled to work a line backwards or for-
wards, or between intermediate stations with nearly the same number of cells
now required, only at one end of the line, thus dispensing with a battery .at

page_text: one of the ends, and at all the intermediate stations as is now generally
required. But when I use the new system, described in the Specification of
my Patent, No. 1271, of May 23rd; 1860, I am enabled to work an immense
number of telegraphs. in both directions, as well as between intermediate
stations simultaneously by means of this one line battery. Let us .sup-
pose a line of any given length (say, for instance, 100 miles) to require
fifty couples to work it; instead of: having a battery of fifty couples at
each end of the line, and other batteries at all the intermediate stationis, I
make portions of the line itself take the places: of the copper arcs, .which
usually unite each pair of plates, and thus spread the battery, as it were, all
along the line; thus at every two miles distance I may have a couple at every
four miles distance, two couples, or any other arrangement in like proportions.
If, therefore, I were communicating from station No. 1 to a station at 50
-miles. distance, I should, only use half the battery, and could use the other half
to communicate between any other places on the remaining 50 miles. I can
also communicate-from station 1 to station 2, from 2 to 3, 3 to 4, and so on,
or in any other degrees of distance, in all cases using only a part of the
battery proportionate to the distance; of course the coils of the instruments
actuated by the line currents would require. to be varied in length and thick-
-ness of wire so as to adapt them to the distances from which they would. be
worked, but as those instruments whose résistances best suit them for receiving
communications from short distances are not so well adapted for doing so from
long ones, and vice versa, I sometimes fit each instrument with a certain
,number of relay electro-magnets, offering different degrees of resistance in
their coils, either of which, by means of suitable switches, can. be used at
pleasure according to the distance from which the message comes, and the
cost of these electro-magnets is trifling when compared with the great con-
stant saving in line-battery power; or I have but one electro-magnet, and
arrange by switches to vary the length and thickness of the coils through
which the current passes.. I sometimes adopt a different arrangement, which
has the advantage of being. cheaper, and of greatly reducing the cost of time;
in signalling the leakage, and the effects of earth, and other accidental cur-
rents, I only, allow the, current from a given number of pairs to travel a
distance.equal to the fraction of the line belonging to them, and I cause relay
instruments to set in action the current of the next set of pairs,, which takes
-the message another stage automatically, and so on, by which arrangement
messages from all distances can be made, to shew equally well by means of
only one instrument.. As a certain time is required to make an electro-magnet

page_text: by the current if the common form of relay were used at each stage, the
pulsation sent would become less and less, until, after a certain number of
stages, it would no longer be able to attract an armature. To obviate this
evil, I have invented self-conipensating relay instruments, and I prevent any
shortening of the duration of the pulsation, and am enabled to carry it on
automatically step by step any distance by recalling the armature of the relay
electro-magnet caused by the line current by another electro-magnet formed
at the cessation of that line current by another fresh current sent from a local
battery. Of course, also, by confining the range of the current within short
distances, the necessity of working the instruments by means of relay batteries
is often prevented.
My next improvement has for its object the simultaneous working of two
or even three distinct systems of telegraph through one line wire. By the
first plan which I am. about to explain, I can work the instruments in part
from one and in part from the other end of a line, or all the instruments at
one end of a line from the other end, and I can at the same time deliver one
or more of these messages at any intermediate station or stations; or I can
use one or more powers of the line to intercommunicate between the terminals,
delivering the messages by the way, if required, at any intermediate station or
stations whilst I am using tlie other power or powers of the line to commu-
nicate separate messages to or between various intermediate stations; in
short, I can with one line do all, or nearly all that is now usually done with
two or three. In doing this, I use batteries of unequal force to deliver the
different messages; and in my first plan. I prefer causing the currents to flow
in different directions. My object for this arrangement is to lessen the number
of varying degrees of force required to work a given number of instruments,
as it is difficult to make many degrees of force distinguishable. To work two
two systems on this plan when currents in opposite directions are- used, I
require to be able to send along the line in either direction working currents
of one degree of force, and in but one direction an extra force current, or vice
versâ; and to work three systems, I require to be able to send along the line
.in either direction working currents of three degrees of force, and in one
direction a current of a fourth degree of force. When employing only two
systems, the current of that strength which always goes in one direction acts
on the first instrument, the current which goes in the opposite direction on
the second instrument; and the third current on both instruments. When
working three
systems, the current of the greatest degree of strength works the
first instrument; the current of the same kind of the next degree of strength

page_text: works both the first and second instruments; the current of the same kind of
'the third degree of strength works the first and third instruments; and the
current of the same kind of the fourth degree of strength works all the
instruments. The strongest current in the opposite direction works the second
and third instruments; the next in force works the third instrument, and the
next in force works the second instrument...
Where two or three instruments exist for the purpose of receiving the
messages sent by these currents I use a compound relay instrument, which
delivers the particular message intended to each telegraphic instrument, but
when only one receiving instrument is required at any station, the relay is
more simple. The compound relay for two systems requires for its most
effectual working one or more electro-magnets, formed by the passage of the
line current, and three armatures with recall springs of two different degrees
of strength. All these armatures should. be magnets. The compound relay
for three systems requires for its most effective working one or more electro-
magnets, and at least five armatures, two of which must be magnets with
recall springs of four different degrees of strength; and I arrange for the
local battery current to be sent to the instruments intended by the contacts
made and broken as the different armatures are drawn in, according to the
quality and force of the current sent along the line. Of course, at any inter-
mediate station, as well as at the terminals, where one or more instruments
are required to shew the messages passed along the line, one of these relays,
with the proper number of telegraphic instruments attached, must be placed
at that station. When I wish one or more of the messages to go no further
along the line than a particular station, but the other message or messages to
travel onwards, I disconnect the up-and-down lines, and make the currents go
to earth by means of a switch, and, by an arrangement similar in principle
to that explained for carrying on a message step by step, I carry forward
automatically from a fresh battery the message or messages intended to travel
further, and, by having a proper manipulating key or keys at that station also,
send on a fresh message or messages in lieu of those stopped. When sending
two messages from one end of the line, I arrange the manipulating keys as
to their contacts so that when one key is depressed alone, the weaker current
only is sent through the line. When the other key is put down alone, the
stronger force current only is sent, but when both keys are depressed simul-
taneously, a force equivalent to the resultant. in tension of the two batteries
is sent. When sending three messages from one end of the line, I make
-similar arrangements for the manipulating keys suited to the various possible.

page_text: combinations of the three keys. I sometimes adopt another plan of working
two systems. In this case, also, I use batteries of different degrees of force
and in different directions for sending the line signals, and I also use a small
local battery whose current is regulated as to its power by a rheostat to
modify in a particular manner the action of the relay instrument. To form
this relay instrument I require two electro-magnets made by the line current,
which I shall call electro-magnets Nos. 1 and 2, and three armatures, two of
which are magnets, and belong to electro-magnet No. 2, the third being of
soft iron, and belonging to electro-magnet No. 1. The electro-magnet No. 1
has, in addition to the coils through which the line currents pass, additional
coils, through which the current from the above-named small local battery is
made to flow whenever a line current is passing, but in an opposite direction
to that line current, and so arranged as to its force by the rheostat as to
balance the single-force current of the line; if, therefore, a single-force P. or
N. current is sent, it causes the electro-magnet No. 2 to attract one of the
magnet armatures, and close the local circuit round No. 1 in a different
direction to itself, and this electro-magnet therefore becomes inactive on its
armature, and does not attract it, but if a double-force current is sent, the
soft-iron armature will be also attracted by No. 1. According to the nature
and direction of the currents sent, I cause those contacts to take place which
make either or both of the instruments 1 and 2 to come into action. I
arrange for three systems on the same principle, and require to use three
electro-magnets and four armatures, two of which must be magnets, by
throwing local currents of varying force round the relay cores in different
directions to the line currents.
In order that I may be enabled to use the arrangement already explained
for economising battery power by spreading the couples along the line when
I require to work two or more instruments simultaneously with distinct
messages, I make, when signalling the communications with earth direct
through the instruments, or also through mediums of different degrees of
resistance; or I sometimes use batteries with opposing forces, whereby I get
currents along the line of varying degrees of power, and am thus enabled to
work at pleasure either or both of all the particular instruments described.
I also sometimes use these arrangements slightly modified when employing
batteries as now generally placed, as well as when I keep a current constantly
flowing through the line.
Although I have only spoken of voltaic batteries in describing my improved
modes of working telegraphic lines, I, of course, wish to imply also any other

page_text: source of electricity which may be applicable, and although I only speak of
relay instruments, I mean also the telegraphs themselves when no relay
batteries are used.
My last improvement consists in using a compound receiving instrument,
in which the clockwork and many other parts are single, the marking electro-
magnets and their accessories alone being multiple as the number of messages
capable of being received, the markers being so placed as to act on the same
strip of paper.