IMPROVEMENTS IN ELECTRIC TELEGRAPHS
Year: 1875

page_text: LETTERS PATENT to George Allan, Civil Engineer, and James Wallace
Brown, Electrician, both of 18, Leadenhall Street, London, for the
Sealed the 20th April 1875, and dated the 12th February 1875.
PROVISIONAL SPECIFICATION left by the said George Allan and
James Wallace Brown at the Office of the Commissioners of
Patents, with their Petition, on the 12th February 1875.
We, GEORGE ALLAN, Civil Engineer, and JAMES WALLACE BROWN,
Electrician, both of 18, Leadenhall Street, London, do hereby declare
the nature of our Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS,”
to be as follows:-
The object of our Invention is to record. dots and dashes transmitted
through a submarine cable or other difficult circuit by closing and
breaking local circuit on any of the well-known recorders, either
chemical or otherwise, at a superior rate of speed.
Also to translate or retranslate electric telegraph signals from one
circuit to another at a superior rate of speed by a simple arrangement of

page_text: i
And, further, to relay or retranslate from land line to submarine or
other insulated cable without sending land line current through the
cable, or vice versa.
Our first improvement consists in what we style a movable contact,
constructed as follows:-A small bar of metal or otherwise has platina
discs or stops, insulated from one another, fitted thereon, such discs or
stops being fixed or adjustable as required. The said bar has suitable
bearings provided and is free to move, so that when an armature of a
relay or pecker plays against or between the said stops such bar will
move the same distance as the armature. We do not confine ourselves
to having the movable contact constructed as described, its form being
varied to suit any certain instrument. In some cases the said contact
bar may be suspended by torsion threads instead of riding in bearings,
or it may float on liquid. In all cases there must be a something
playing against or between the stops of the movable contact, such as
an armature or its equivalent.
: Our second improvement consists of a circular disc, one half of which
is an insulator and the other half a conductor. Such disc is fitted upon
a small shaft or spindle, supported in bearings on an arm attached to the
armature mentioned under the above first head, or the said armature
may itself have bearings to accomodate the disc, which is free to revolve
(by adjustment) to any extent that may be desirable. The said disc
bears against a metal surface which has a local wire attached to it. As
the armature moves in direction to record a signal the disc revolves to
the extent allowed by its adjustment. The metal or conductor of the
disc which is provided with a local wire now comes into contact with
the local wire provided metal surface above mentioned, thus closing the
local circuit and keeping said circuit closed as long as the armature
moves in said direction, or stands in the position in which the current
versus magnetism has forced it. As soon as the current ceases in the
magnet the armature and disc move back until the local circuit is
broken. If desirable instead of a circular disc two short bars or their
equivalent joined together and slightly rounded at their ends may be
used; one of the bars serves as insulator, and the other as conductor; or
a metal disc with a small insulator inserted in its periphery may be
used.

page_text: its equivalent. We attach two or more spiral or other springs to the
armature and arrange them by means of adjusting screws to pull one
against the other. By means of said springs the armature can be
adjusted to any required distance from the poles of the magnet. The
springs perform another duty also, that of compensating. The action is
as follows:- -When a current influences the magnet the armature moves
towards the pole of the magnet until the pull of the spring or springs
exactly balances or balance the magnetism exerted. During the said
motion of the armature such armature makes contact with the stops on
the movable bar contact and moves said bar to the same distance.
When a fall of potential has occurred in the magnet the armature falls
back in obedience to the spring or springs which is or are then stronger
than the magnetism exerted, but the spring or springs only bring the
armature back into position when the spring or springs and magnetism
act equally upon the armature. In the above retrograde movement of
armature such armature breaks contact and strikes back the stops on
bar, moving such bar back. It will be readily seen that as the magnet
has not to be entirely discharged but the potential only slightly reduced
to transmit signals such signals will be correctly transmitted through
the most difficult circuits at a superior rate of speed. In cases where
soft iron relays or peckers are used only one spring or springs is or are
necessary, and we prefer that the spring or springs should be in front of
the armature so that when the armature is attracted it presses against
such spring. We prefer the spring or springs and adjusting screws
should be so arranged that the tension of the spring or springs can be
adjusted without disturbing its or their position, or causing it or them
to bear against the armature when the said armature is in its normal
position. The screw that forms the bearing or bearings of the spring or
springs is so arranged that as a whole it can be adjusted in relation to
the armature, thus obviating the necessity of having springs made of
na tongions.

page_text: or, vice versa, to the poles of a battery, the said battery having been
earthed from its centre. The above arrangement with a polarized relay
or pecker will not require any switch as the armature will always be in
position to translate signals either from the up or down line.
Our fifth improvement consists of a receiving relay or pecker or its
equivalent having a line wire connected through and to its armature or
equivalent; it also consists in what we style a receiving battery, the
centre of which is put to earth and extreme positive pole to the right-
hand stop of relay or pecker, and the extreme negative pole to the left-
hand stop of relay or pecker, or vice versa. By this arrangement when
a current is sent from transmitting end, say by the commutator making
contact with the negative pole of transmitting battery, the current will
be in the same direction as that of battery at the receiving end. This
receiving battery being connected to line through stop armature and
coils of relay or pecker will so influence the armature that it immediately
moves from the stop which it was against. The line then becomes
insulated and remains so until the armature makes contact with the
opposite stop which is connected to negative pole of receiving battery.
Now as the transmitting and receiving battery have same poles to line
there is no current or appreciable current passing to line, so this may be
termed compensation; but now if the commutator breaks contact at
transmitting end and makes contact with the positive pole of trans-
mitting battery, it instantly sends a current in line wire. When the said
current coincides in direction to that of receiving battery through stop
coils and armature of receiving relay or pecker the armature moves
from its stop and the line becomes insulated as before until the armature
takes up its original position against stop, putting opposed battery to
line wire and offering compensation as before. In fact by this arrange-
ment there are only dots transmitted through the line wire, but they
will be received dots and dashes as forwarded from the transmitting end.
This arrangement may be applied with the moving contact or dead stops
of the ordinary relay or pecker, also if it is desired to translate from
one circuit to another this may be accomplished by connecting the two
circuits together, the receiving relay or pecker then being as it were in a
branch circuit, but its connections remaining as before described. A
recording instrument may be in a local circuit and manipulated by
armature and local stops on said relay or pecker or it may be in main
line circuit.

page_text: Our sixth improvement consists of connections with two relays or
peckers to translate or retranslate telegraph signals from a land line to
a cable without sending land line current through cable, or vice versa.
We accomplish this by having the relays wound differentially. To
illustrate this we shall assume one coil of left hand relay or pecker to be:
connected to cable, the opposite terminal of said coil being connected to
armature of said relay or pecker, the stops of relay or pecker are con-
nected to the opposite poles of a battery, the centre of said battery being.
put to earth through one coil of right hand relay or pecker. The right
hand relay is connected to land line same as that of cable through left
hand relay and land line battery or connected through one coil of left
hand relay or pecker to earth. To translate or retranslate, say that both
armatures lay against the stops and are connected to the negative
or zinc poles of batteries, the printing current (or that which is
determined to be the printing current) moves said armature to opposite
stops connecting opposite poles of battery to line or cable, but in so
doing only connect the determined batteries through cable or land
linc, for the reason that the land line battery is through one coil of the
translating or retranslating relay or pecker, while the cable and stops of
said relay or pecker are connected to their battery through the other coil
and to earth through one coil of land line relay or pecker, the directions
of current through said coil of land line relay or pecker from cable
batteries coinciding in direction to the current which is transmitted
through the other coil of land line relay or pecker, or vice versa.
Our seventh improvement consists of two arms pivoted one on each
side of an armature or its equivalent, of a relay or pecker, or the
equivalent of a relay or pecker, the said arms being placed angularly or
otherwise in relation to the armature, but in the same plane. The free
ends of the said arms are connected together by a bar which passes
freely through a hole or slot in the armature. The ends of the said bar
serve for contact points. Below or above the said bar is another similar
bar which passes through the armature, and has the ends touching the
arms before described. Two stops are provided the same as on an
ordinary relay or pecker. Compensating springs are attached to tho
armature as previously described. The object of this part of our Inven-
tion is to ensure that when the instrument is adjusted to receive
electrical signals and a current is sent, the armature shall be attracted;
and shall force the end of the bar with contact point against one of the

page_text: stops, closing the local or other circuit but allowing the armature still to
move forward (the bars being loosely fitted and the arms loosely pivoted)
until the compensating spring balances the current verses magnetism
exerted upon the armature. When a fall of potential occurs in the
magnets of the relay or pecker, or their equivalent, the armature moves
back, breaking local contact, the friction of the bars which pass through
the armature being sufficient to accomplish this as the armature moves.
As soon as the contact on the end of the bar strikes the back stop, the
armature will continue to move back until the spring balances the
current, verses magnetism as before described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Allan and James Wallace Brown in the
Great Seal Patent Office on the 11th August 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
ALLAN, Civil Engineer, and JAMES WALLACE BROWN, Electrician, both
of 18, Leadenhall Street, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of February, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said George Allan and James
Wallace Brown, Her special licence that we, the said George Allan and
James Wallace Brown, our executors, administrators, and assigns, or
such others as we, the said George Allan and James Wallace Brown, our
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN ELECTRIC TELEGRAPHS," upon the condition (amongst
others) that we, the said George Allan and James Wallace Brown,
our executors or administrators, by an instrument in writing under
our, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what

page_text: 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 we, the said George Allan and James
Wallace Brown, do hereby declare the nature of our said Invention, and
in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, reference being had
to the accompanying Sheet of illustrative Drawings, and to the figures
and letters marked thereon, that is to say :-
The main objects of our Invention are,—
First. To record dots and dashes transmitted through a submarine cable
or other difficult circuit, it may be a land line, by closing and breaking
local circuit on any of the well known recorders, either chemical or
otherwise, at a superior rate of speed.
Second. To translate or retranslate electric telegraph signals from one
circuit to another at a superior rate of speed by a simple arrangement
of line and battery connections with a single relay or peckers.
Third. To relay or retranslate from land line to submarine or other
cable without sending land line current through the cable or cable
current through the land line.
I. As means for effecting the object first above mentioned we con-
struct a relay or pecker to act with a compound instead of a simple
motion, as heretofore, that is to say, the contact maker may of itself
have a compound motion, the receiver being stationary; or the contact
maker and receiver may each have a simple motion. By the above
means a fall of potential in the actuating current will serve as effectually
to make and break circuit as if the current were reversed.
The following amongst others are mechanical arrangements whereby
this first part of our Invention can be carried into effect.
A. First Part. Under this modification the contact maker and receiver
have each a simple motion, which may be obtained in a variety of ways.
The most approved is described below under Fig. 1.
Fig. 1. The receiver, or, as we call it, the movable contact, is con-
structed of two platina or metal bars a, a', insulated from each other by
the piece and supported in bearings c; d, d, contact discs, preferably of

page_text: platina. The said discs are in electrical contact with the bars a, a¹,
respectively. The movable contact a, a¹, is free to move longitudinally
in its bearings; e, local circuit wires; f, contact maker or armature free
to vibrate on the centre g, and kept in equilibrium by the springs h;
i, tension adjusting screws; j, magnets for actuating the armature f;
k, line wire; 1, earth wire; m, local wire. The wires e, m, are connected
to the recording instrument in any ordinary or convenient manner. In
practise when a current is transmitted through the line wire to give a
signal the armature f is moved over to make contact with one of the
discs, say d. If the armature is acted upon by a greater force than is
necessary to make contact it will cause the movable contact a, a¹, to
slide in its bearings until equilibrium is produced by the action of the
springs h. If now there is a diminution of potential in the current the
equilibrium springs cause a retrograde motion of the armature and
contact with d is at once broken. When the diminution of potential is
sufficient, or the current is reversed, not only is contact with d broken
but the armature is carried over against the disc ď, and the movable
contact a, a, is caused to slide in the direction of motion of the
armature.

page_text: Fig. 3 shows a modification of the apparatus illstrated by Fig. 2.
A soft iron relay is used. Like letters refer to the same parts, as in
Fig. 2.
Fig. 4. u, u¹, are the stops of the receiver; v, v', local wires. The
5 contact maker or armature is formed of two pieces wo, 20¹. The part w
vibrates on the fixed centre x, and the piece w' on the pivot x¹ secured
to toy, compensating springs; 2, electro-magnets; ¹, earth and line
wires. It will be seen that the piece w is free to vibrate the whole
distance allowed by the compensating or equilibrium springs y, whilst
O the piece w¹ never moves a greater distance than the space between the
stops u, u¹. The friction between w, w¹, is sufficient to ensure simul-
taneous movement, except when the piece w¹ is retained by one of the
stops u, u¹.
Fig. 4 shows a modification of mechanism acting in the same manner
as Fig. 4. Here u³, u³, are the stops; v³, 0³, local wires; 10³, 20³, contact
maker; a, centre secured to wo; y³, compensating springs; %, electro-
magnets; 3, earth and line wires; **, tension spring to adjust or regulato
the friction between the pin x³ and piece w³.
The sensibility of action of relay or pecker armatures is greatly
increased by the use of the compensating or equilibrium springs
described under parts A and B, first head. These springs are adjustable
as to tension and position.
It will be obvious that mechanism arranged to act under the above
first head may be almost indefinitely varied without departing from the
distinguishing features thereof, for instance, the mechanism having
compound motion may be supported by threads or be left to float on or
in a liquid.
II. As means for accomplishing the object second above mentioned,
wo arrange a single, say an ordinary, relay or pecker to do the work now
done by several relays or peckers. Two arrangements of apparatus
under the above second head are shown in Figs. 5 and 6.
A, Second part. In this modification a single relay or pecker translates
or retranslates from one circuit to another by a simple arrangement of
line and battery connections shown in Fig. 5. Fig. 5, 1, north wire;
2, south wire; 3, armature; 4 and 5, stops; 6 and 7, electro-magnets;
8, translating battery; 9, earth wire from centro_of battery.

page_text: It will be seen that if (say) a copper current arrives through north
wire to 3, such current will travel in the direction of the arrows to the
zinc end of the battery, thereby causing the armature to reverse, that is,
to make contact with stop 5. The copper current in 1 is therefore
brought into connection with the copper end of the battery 8 and put 5
out of action. The copper end of the battery is also put into connection
with the south wire and a current sent forward. If a zinc current be
now sent along 1 the reverse action takes place.
B, Second part. In this modification a single relay or pecker is
arranged to serve as a receiving instrument or as a translator or retrans- 1
lator from one circuit to another, as shown in Fig. 6. Fig. 6, 10, key of
instrument at transmitting station; 11, transmitting battery; 12, earth
wire; 13, line wire; 14, electro-magnets of relay; 15, armature; 16
and 17, stops; 18, battery; 19, earth wire from centre of battery.
The relay as shown in Fig. 7 is acting as a receiver. On making con- 1
nection by the key 10 with the copper end of the battery 11, a copper
current is sent through the wire 13, and electro-magnets 14, armature 15,
and stop 16 to the zinc end of the battery 18, thereby causing the
armature to be moved against the stop 17. The copper current through
13 is by this means connected to the copper end of the battery 18 and 2
put out of action. On causing the key 10 to send a zinc current through
13 the action is reversed.
It will be evident that as the armature 15 only moves with the key 10
dots or dashes can be transmitted by varying the length of time of
depression of the key, although the length of time of action of the a
current is the same. If a line wire is connected, as shown at 20, the
relay will act as a translator.
III. As means for ensuring the objects third above mentioned, we
employ in combination two differential relays or peckers.
Apparatus adapted to obtain the above results is shown in Fig. 7.
Fig. 7. The land line relay is provided with a powerful battery 21. The
cable or difficult circuit relay is provided with a weak battery 22. The
respective batteries are connected at their centres to the electro-magnets
of the opposite relays and thence to earth. 23, land line wire; 24, cable
or difficult circuit; 25, land relay electro-magnets; 26, cable electro-
magnets; 27, land relay armature; 28, cable relay armature. If now a
copper current is sent through the land line 23 such current passes in

page_text: the direction of the arrows through the electro-magnets 25 and arma-
ture 27, thence to the zinc end of the battery 21, thence through the
electro-magnets 26 and armature 28 to earth. By this means the
armatures 25 and 26 are reversed, the copper current of line being con-
nected to copper end of battery 21, and a copper current from battery 22
transmitted along the cable or difficult circuit 28. If a zinc current is
sent through 27 the reverse action takes place. A current sent through
the cable or difficult circuit acts similarly on the land line.
By the above arrangement the weak battery current is transmitted
through the cable, and the strong battery current through the land
line.
Having now described the nature of the said Invention, and par-
ticularized the same in such manner that others will be enabled to carry
our improvements into effect, we claim,―
Under Part I.- Constructing a relay or pecker to act with a compond
motion for the purposes set forth,―
A. Constructing a relay or pecker with the parts a, a¹, and f,
operating substantially as and for the purposes set forth in Fig. 1.
B. Constructing a relay or pecker with the parts o, q, and r,,
operating substantially as and for the purposes set forth in Figs. 2
and 3.
C. Constructing a relay or pecker with the parts u, u¹, and w, w²,
operating substantially as and for the purposes set forth in Figs. 4
and 4*.
D. The use of equilibrium and compensating springs in combination
with relays or peckers constructed under the above first part.
Under Part II. Arranging a relay or pecker to operate as and for
the purposes set forth.
A. Arranging a relay or pecker to act as a translator, substantially as
and for the purposes described under Fig. 5.
B. Arranging a relay or pecker to act as a translator or receiver, sub-
stantially as and for the purposes set forth under Fig. 6.
Under Part III.-1. Employing two differential relays or peckers,
arranged and combined substantially as and for the purposes set
forth.

page_text: B. Arranging a relay or pecker, substantially as and for the purposes
set forth under Fig. 7.
In witness whereof, we, the said George Allan and James
Wallace Brown, have herounto set our hands and seals, the
Ninth day of August, in the year of our Lord One thousand eight
hundred and seventy-five.
G. ALLAN.
(L.S.)
J. W. BROWN. (L.S.)