THROWN IN THETARIA TELEGRADES
Year: 1869

page_text: LETTERS PATENT to Sir Charles Tilston Bright, of No. 6, Westminster
Chambers, Victoria Street, in the County of Middlesex, Knight,
for the Invantion of "THROWN IN THETARIA TELEGRADES"
PROVISIONAL SPECIFICATION left by the said Sir Charles Tilston
Bright at the Office of the Commissioners of Patents, with his
Petition, on the 4th October 1869.
I, Sir CHARLES TILSTON BRIGHT, of No. 6, Westminster Chambers,
Victoria Street, in the County of Middlesex, Knight, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN ELECTRIC TELE-
GRAPHS," to be as follows:-
My Invention consists in transmitting electrical signals through
metallic conductors with a circuit so arranged that when it is connected
for the purpose of transmitting signals one of the poles of a galvanic
battery or other apparatus for producing electrical currents is connected
at the receiving station to one coil of a relay or of an indicating or

page_text: -
signalling instrument of any kind, the other end of which coil is con-
nected to the metallic conductor to be operated upon. The same pole
of the battery is also connected to another coil of the relay or instru-
ment, the other and of which is connected to one end of a resistance
coil or series of resistance coils. The other end of the resistance coil or
coils is connected to the other pole of the battery, which is also connected
to the earth. The coils of the relay or receiving instrument are so
wound that a current passing through the coil connected with the
conductor causes the moving part of the appartus to move towards zero,
and a current passing through the coil connected with the resistance
coils causes it to move in such manner as to make a signal. At the
sending end a commutator or key is employed, by which the metallic
conductor or line wire is connected to the earth during the intervals or
spaces between the signals, and a much greater resistance than that of
the resistance coils at the receiving end is inserted when a signal is to be
made. Or a series of relays or instruments may be used with different
resistances, in which the coils are so wound that on a current passing
through the circuit one or other of the relays may be brought to zero
by the currents passing through both of the coils being equal, the
resistance being varied at the sending station.
My Invention also consists in causing audible signals of two kinds to
be made by currents of electricity passing through a single metallio
conductor by means of electro-magnets without employing a relay or
auxiliary circuit. In this part of my Invention I employ two electro-
magnets so arranged as to influence two permanent magnets, one of which
is moved by a positive current, the other being moved by a negative
current. The magnets when no current is passing rest against adjustable
stops, against which they are retained by adjustable springs; or the
electro-magnets may be moveable and the permanent magnets fixed. A
hammer is attached to each magnet, by which when a current is passed
a sound is produced by contact with a bell or other apparatus for pro-
ducing sound. The bell or other sounder is fixed upon a moveable
frame capable of adjustment forming the stop of the magnet while the
current is passing, or the hammer attached to the magnet may be capable
pf adjustment.
The commutator or sending apparatus consists of two keys, by one of
19

page_text: current, the currents in each case passing through the line wire and the
coils of the receiving apparatus at the receiving end, but not through
the coils of the receiving apparatus at the sending end.
SPECIFICATION in pursuance of the conditions of the Letters Patent;
filed by the said Sir Charles Tilston Bright in the Great Seal
Patent Office on the 4th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Sir CHARLES
TILSTON BRIGHT, of No. 6, Westminster Chambers, Victoria Street, in
the County of Middlesex, Knight, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of October, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Sir Charles Tilston Bright, Her special
licence that I, the said Sir Charles Tilston Bright, my executors,
administrators, and assigns, or such others as I, the said Sir Charles
Tilston Bright, 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 ELECTRIC TELEGRAPHS," upon the condition (amongst
others) that I, the said Sir Charles Tilston Bright, 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 Sir Charles Tilston Bright, do
hereby declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement:-
My Invention consists in so arranging telegraphic circuits for the

page_text: transmission of electrical signals through metallic conductors that when
a wire is connected for the purpose of transmitting telegraphic signals
one of the poles of a galvanic battery or other apparatus for generating
electricity is connected to one coil of a relay or of an indicating or
signalling instrument of any kind, and the other end of such coil of the
relay or indicating apparatus is connected to the metallic conductor
through which the currents are passed. The same pole of the galvanic
battery or apparatus for generating electricity is also connected to another
coil of the relay or indicating instrument, and the other end of such coil
is connected to one end of a resistance coil or series of resistance coils
or tubes of water or other apparatus of low conducting power. The
other end of the resistance coil or coils or apparatus, as above mentioned,
is connected to the other pole of the galvanic battery or apparatus for
generating electricity, which is also connected to [the earth. The coils
of the relay or receiving instrument are so constructed that a current
passing through the coil connected with the conductor causes the
indicator or moving part of the apparatus to move to and rest against a
fixed stop, and a current passing through the coil connected with the
resistance coils or resisting medium causes it to move in such manner
as to produce a signal. At the sending end a commutator or key is
employed, by which the metallic conductor or line wire is kept in
connection with the earth during the intervals or spaces between the
signals, and a much greater resistance than that of the resistance coils
at the receiving end is inserted by the motion of the key or commutator
when a signal is to be made, or signals to each side may be given by a
relay or indicating instrument, which is kept at zero in the intervals
between the signals. The connections of the coils of the relay or
indicating instrument at the receiving station are the same in this case
as before described; but at the sending station a fixed resistance is kept
in circuit during the intervals between the signals, which is increased
io produce a movement at the receiving station in one direction, and
climinished or withdrawn to produce a movement in the other direction.
Thus if the resistance of the conductor or line wire amounts to ten
housand units of resistance, and the resistance of the coils or resisting
inedium at the receiving station is one hundred and ten thousand units,
then if a resistance of one hundred thousand units be kept in circuit at
the sending station in the intervals between the signals the currents
passing through the coils of the relay or receiving apparatus will balance
each other, and the indicator or arm of the relay will remain at zero.

page_text: By increasing the resistance at the sending station to, say, one million.
units a signal will be produced in one direction at the receiving end, or
by withdrawing or reducing the one hundred thousand units of resistance
at the sending station a signal will be produced at the receiving end in
the other direction. Or a series of relays or instruments may be used
with different resistances, in which the coils are so wound that on a
current passing through the circuit one or other of the relays may be
brought to zero by the currents passing through both of the coils being
equal, the resistance being varied at the sending station.
My Invention also consists in causing audible signals of two kinds to
be made by currents passing through a single metallic conductor by
means of electro-magnets without employing a relay or auxiliary
circuit. In this part of my Invention I employ two electro-magnets so
arranged as to influence two permanent magnets, one of which is moved
by a positive current, the other being moved by a negative current. The
magnets when no current is passing rest against adjustable stops,
against which they are retained by adjustable springs or by their own
weight; or the electro-magnets or their soft-iron cores may be moveable
and the permanent magnets fixed. A hammer is attached to each
magnet or to the electro-magnets or their soft iron cores when either
form the moving part of the apparatus, by which when a current is
passed a sound is produced by contact with a bell or other apparatus for
producing sound. The bell or other sounder is fixed upon a moveable
frame capable of adjustment, the bell or sounder forming the stop of the
hammer or magnet while the current is passing, or the hammer attached
to the magnet may be capable of adjustment.
The commutator or sending apparatus consists of two keys, by one of
which a positive current is transmitted, and by the other a negative
current, the currents in each case passing through the line wire and the
coils of the receiving apparatus at the receiving end, but not through the
coils of the receiving apparatus at the sending end.
Having now described the nature of my said Invention, and the
manner in which the same is to be performed, I would remark that I
do not restrict myself to any special forms of apparatus to be employed
in carrying out the objects described, as many arrangements may be
devised for such purposes; but what I claim and desire to be secured to

page_text: me by the herein in part recited Letters Patent are, the improved means
of transmitting electrical signals, audible or otherwise, through metallic
conductors, substantially as herein specified.
In witness whereof, I, the said Sir Charles Tilston Bright, have
hereunto set my hand and seal, this Eighteenth day of March,
in the year of our Lord One thousand eight hundred and
seventy.
Witness,
ALEX. PRINCE,
Office for Patents,
4, Trafalgar Square,
Charing Cross.
CHARLES T..BRIGHT. (L.S.)