Improvements in Submarine Telegraph Cables.
Year: 1892

page_text: Date of Application, 30th July, 1892
Complete Specification Left, 25th Apr., 1893-Accepted, 27th May, 1893
PROVISIONAL SPECIFICATION.
Improvements in Submarine Telegraph Cables.
I, WILLIAM HENRY PREECE of Gothic Lodge Wimbledon, Surrey, Electrician,
do hereby declare the nature of this invention to be as follows:-
In long submarine cables as at present constructed the speed of working, and
therefore the rate of flow of successive currents of electricity whether intermittent
or alternate is regulated by the electrostatic capacity, and the resistance of the
core. It follows a distinct and definite law which is expressed by the formula
Speed a KR
K, being the inductive capacity, and R. the electric resistance of the core.
I have found by experiment that the valve of K can be very materially modified
by the influence of mutual induction between two parts of the circuit when the
circuit is metallic and the core compound; in fact the geometrical relations
between the insulator and conductors can be so modified that K may be practically
eliminated.
In submarine cables 1 propose therefore according to my present invention to
avoid the use of the earth as a part of the circuit, and to make the circuit entirely
metallic, I propose to construct the core of two conductors either cylindrical and
parallel, or cylindrical and concentric, or rectangular and parallel; separated from
each other and from the water by insulating media, and so arranged as regards
geometrical form, that the effect of the mutual induction of the two conductors
shall oppose and neutralise the effect of their inductive capacity. In this way I
propose to materially expedite the speed of working by telegraph, to extend the
distance to which speech by telephone through submarine cables is possible, and to
eliminate from cable working many existing sources of trouble and difficulty owing
to the use of earth.
Dated this 30th day of July 1892.
ABEL & IMKAI,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Sub.narine Telegraph Cables.
1, WILLIAM HENRY PREECE, of Gothic Lodge, Wimbledon, Surrey, Electrician,
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
In long submarine cables as at present constructed, the speed of working and
therefore the rate of flow of successive currents of electricity, whether intermittent
or alternate, is regulated by the electrostatic capacity and the resistance of the
core. It follows a distinct and definite law which is expressed by the formula
Speed of waves a K R
K being the total inductive capacity, and R the total electric resistance of the core.
I have found by experiment that the value of K can be very materially modified
by the influence of mutual induction between two parts of the circuit when the
circuit is metallic and the core compound; in fact the geometrical relations
between the insulator and conductors can be so modified that K may be practically
eliminated.

page_text: In submarine cables I propose therefore according to my present invention to
avoid the use of the earth as a part of the circuit, and to make the circuit entirely
metallic; I propose to construct the core of two conductors either cylindrical and
parallel, or cylindrical and concentric. or rectangular and parallel, separated from
each other and from the water by insulating media, and so arranged as regards
geometrical form, that the effect of the mutual induction of the two conductors
shall oppose and neutralise the effect of their inductive capacity.
In this way I
propose to materially expedite the rate of working by telegraph, to extend the
distance to which speech by telephone through submarine cables is possible, and to
eliminate from cable working many existing sources of trouble and difficulty owing
to the use of earth.
The accompanying drawing shews by way of example sections of various forms
and arrangements of submarine cable cores having two conductors forming a
complete metallic circuit according to my above described invention.
In Fig. 1 the two flat rectangular conductors a and b forming the metallic circuit
are imbedded in one and the same insulating sheath e side by side and parallel to
each other at a suitable distance apart for insuring perfect insulation from each
other in Fig. 2 the one conductor a is cylindrical and the other flat; in Fig. 3
two flat conductors a bare placed edge to edge; in Fig. 4 there are two metallic
circuits formed by four flat rectangular conductors a, b, c d, any two of which may
together form a circuit.
Fig. 5 shews two conductors a and of a square section.
Fig. 6 shews a conductor a of circular section and one 6 of a square section.
Fig. 7 shews two conductors ab of a semicircular or are shaped section, placed
opposite each other so as to form a circle, with part of the insulating core intervening
between the meeting edges.
Fig. 8 shews two conductors of segment shaped section.
The current would be worked by any suitable known method in cables of the
above described construction.
The weight of the conductors would vary with the length of the cable. The
serving of the cable and its armouring would be the same as for ordinary cables.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I.
claim is
1. Constructing a submarine telegraph cable with two conductors insulated from
cach other within one and the same insulating sheath, properly formed and
arranged geometrically side by side so that the effect of the mutual induction of
the two conductors shall oppose and neutralise the effect of their separate inductive
capacities, substantially as described.
2. The employment of a submarine telegraph cable as a metallic circuit con-
stituted by two conductors contained within one and the same insulating sheath and
constructed and arranged substantially as hercin described with reference to the
drawing.
Dated this 25th day of April 1892
ABEL & IMRAY,
Agents for the Applicant.