IMPROVEMENTS IN SUBMARINE TELEGRAPHY, WHICH IMPROVEMENTS ARE ALSO APPLICABLE IN SOME CASES TO LAND TELEGRAPHY
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Isham Baggs at the Office of
the Commissioners of Patents, with his Petition, on the 3rd July
1865.
I, ISHAM BAGGS, of 54, Chancery Lane, in the County of Middlesex,
Electrical Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SUBMARINE TELEGRAPHY, WHICH IMPROVEMENTS ARE ALSO
APPLICABLE IN SOME CASES TO LAND TELEGRAPHY," to be as follows:-
This Invention consists of certain arrangements whereby the prejudicial
effects of induction and earth currents in working submarine telegraphs and
line wires or conductors for the purpose of telegraphing by sea or land are
avoided, counteracted, destroyed, or superseded, and whereby the disturbing
effects of atmospheric influences are also nullified or counteracted. In
accordance with this Invention submarine cables are protected or preserved
from the influence of induction by causing the centre of the length of the
cable to be as nearly as possible a central point in the phenomena of actual
electric discharge, or, in other words, two electrically opposite influences arò
excited and caused to operate therein in opposite directions at one and the
same time. To illustrate and explain this portion of the said Invention, let
it be supposed that the generator of electricity for the purposes of the trans-
mission of electricity through a submarine cable is a voltaic battery of a given
number of pairs of plates. One half of the pairs of plates employed are
placed in communication with one end of the cable, and the other half of the
pairs of plates at the other end thereof. Under these circumstances it is

page_text: obvious that the cable forms the connecting link between the two halves of
the battery, whereby the influence of induction is prevented. The same
principle holds good with regard to land telegraphs, where the wires are
exposed to analogous influences, and whether the cable or line wire is charged
by high tension electricity, or by electricity of low tension, as in the case of
thermo-electricity, the same principle will apply. In order to avoid the pre-
judicial effects of earth currents, and also the influence of the aurora and
atmospheric electricity, a duplex system of conductors, whether arranged as
wires, coils, or otherwise, may be employed. The first portion or division of
these means may be the conductors proper to telegraphic instruments and
communication; the second being for the transmission of the disturbing
influences alone in such way that the latter being opposed to the former they
are balanced and leave the battery or other source of electrical force which
is dependent upon the volition of the operator to act as is intended, and
undisturbed by any of the ordinary sources of error.
To illustrate and explain this portion of the said Invention let it be supposed
that the telegraphic instruments are worked by the magnetization and demag-
netization of an electro-magnet arranged in connection with coils for inducing
magnetism when required. The central conducting medium of the cable may be
considered as consisting of a strand of copper wires connected with the
inducing coils of the electro-magnet, as is well understood by persons acquainted
with electric telegraphy. Additional coils are placed in juxtaposition to the
inducing coils, for the purpose of balancing all spontaneous interfering causes.
The outer part of the cable being assumed to consist of steel wires placed
there to give strength and cohesion thereto, the same are used as conductors
of electricity in addition, being stripped at the termini and electrically con-
nected together. A conducting wire is attached to the steel wires and
connected at both stations with one end of the before-mentioned balancing
coils, the other end of such coils being in communication with the earth or
sea, as may be required. The said last-mentioned conducting wire is never
in communication with the battery or other source of electricity. By means
of this arrangement whatever earth current or other disturbing cause may
circulate through, the inducing coils will also (if the steel wires are intact
throughout their length) circulate through the balancing coils, and if these
currents are made to circulate in opposite directions they will tend to balance
each other. In order that they may do so exactly, as far as the requirements
of practice extend, the conducting wire lastly mentioned is caused to bifurcate,
and the two branches of such wire respectively to communicate with platina
plates, or other conductors immersed in dilute sulphuric acid; such plates

page_text: being made to communicate with the earth by means of a plate analogous to
an ordinary earth plate. The result of these arrangements is that whatever
influences the central conducting medium of the cable may be subjected to in
the nature of earth currents or other analogous disturbing causes, will also
affect in like manner the steel wires before mentioned in the order of their
conducting power, as for instance, as steel is to copper, and as sectional area
is to sectional area. The current passing from the steel wires through the
before-mentioned conducting wire is conveyed in about equal proportions
through the bifurcations, and as only one of such bifurcations is in communi-
cation with the balancing coils, only half such current, or a proportional part
thereof passes through the said last-mentioned coils.