An Improved System for Transmitting Electric Currents.
Year: 1893

page_text: Date of Application, 21st Mar., 1893-Accepted, 29th Apr., 1893
COMPLETE SPECIFICATION.
An Improved System for Transmitting Electric Currents.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23 Southampton Buildings, in the
County of Middlesex, Patent Agent, do hereby declare the nature of this invention,
(a communication to me from William Courtenay, of 14 Dey Street, New York,
in the United States of America, Manufacturer), and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
This invention relates to improvements in systems for transmitting electric
currents, and it consists in the novel arrangement of the parts hereinafter
described.
The drawing is a plan view illustrating the positions of the parts in this system.
In the drawing are shown two circuits, connected by having a common member
through part of their circuits. These circuits may be multiplied indefinitely and
still retain the common member and it is to be understood that only two circuits
for convenience merely are described.
In this Specification is described and shown the invention as it is to be used for
telegraphic purposes, and it is to be understood that the invention is applicable to
all systems which are to be used for the transmission of electric currents.
In. the drawing letters A and B designate non-insulated and separate members
of the system, and C the insulated member common to both A and B.
The common meinber C acts as a common metallic return to all of the circuits
and may consist of one wire or of many wires twisted together to form a cable.
Each of the separate members A and B is provided at either end with
batteries A and A³, and B1 and B2, which are located between the relays,
telephones or other instruments A³ and A', and B' and B, and the common
member C.
The batteries may be arranged in any desired manner, that is, currents of a like
name may be sent through A and B in the same direction, or a current may be
sent in one direction through one of the circuits while a current is passing in an
opposite direction through the other circuit.
To lay out this system for manipulation upon it, the insulated common metallic
return C is connected at either end to the electrodes emicating from the batteries
at the ends of the line wires A and B and is suspended between the batteries on
insulated poles, or placed in contact with the earth, in which case it is insulated
from end to end.
The line wires A and B are, upon issuing from the offices, placed in contact with
the earth and are not provided with any insulation; they are placed with no
particular care as to the distance one from the other, the only care exercised being
to prevent actual contact; when desired this system may be placed upon poles,
the return C being insulated and the line wires A and B being not insulated but
merely kept a suitable distance apart.
In the operating of this system, when the keys A³ or A° are manipulated, the
relays A and A' are operated without in any way affecting the relays B' and B*;
likewise, when the keys B' or Be are manipulated, the relays B and B are
operated without in any way affecting the relays on the other circuit A.
The currents in this system remain separate though connected by a common
return, as they will not pass through the intervening matter between the lines
owing to the greater resistance offered than by the wire.
The advantages gained by the use of this system are apparent, as by it the
necessity of insulating the line wires is overcome; also, the accidents by breakage

page_text: incident to the weather, such as pressure of the wind or weight of snow or ice,
are avoided.
When this system is used for multiple transmission on one wire, the generators
or batteries are removed from the positions shown in full lines to the positions
shown by dotted lines, the common member C becoming the multiple transmission
wire.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a system for transmitting electric currents, the combination of two or
more non-insulated line wires in contact with the earth, supplied with an electric
generator and transmitting and receiving instruments on each line, and an insulated
metallic return connected to all of the line wires, substantially as specified and
described.
2. In a system for transmitting electric currents, the combination of two or
more line wires, provided with an electric generator and transmitting and receiving
instruments on each line, the line wires being non-insulated and in connection with
the earth for a section or sections of their length and the remaining section or
sections being insulated, and an insulated common return connected to the
generators of all of the line wires, substantially as specified and described.
3. In a system for transmitting electric currents, the combination of two or
more non-insulated or partly insulated line wires, an insulated common return,
receiving and transmitting instruments and electric generators, all arranged and
combined in the manner shown and described.
Dated this 21st day of March 1893
B. J. B. MILLS,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.