IMPROVEMENTS IN ELECTRIC TELEGRAPHS, PART OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE CONSTRUCTION OF INDUCTION COILS."
Year: 1873

page_text: LETTERS PATENT to Henry Highton, M.A., of Putney, in the County
of Surrey, for the Invention of "IMPROVEMENTS IN ELECTRIC TELEGRAPHS,
PART OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE CONSTRUCTION OF
INDUCTION COILS."
PROVISIONAL SPECIFICATION left by the said Henry Highton at the
Office of the Commissioners of Patents, with his Petition, on the
29th March 1873.
I, HENRY HIGHTON, M.A., of Putney, in the County of Surrey, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
ELECTRIC TELEGRAPHS, PART OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE
CONSTRUCTION OF INDUCTION COILS," to be as follows:-
:―
The object of this Invention is mainly to increase the force of the
current acting on the relay or receiving instrument of electric telegraphs.
For this purpose I use an induction coil or other instrument producing
similar effects in conjunction with the receiving instrument.

page_text: By properly apportioning the length and resistance of the primary
and secondary coils respectively, according to the resistance offered by
the relay or receiving instrument itself, and according to the insulation
and resistance of the line wire, the force of the current acting on the relay
or receiving instrument may be multiplied to any extent.
I employ for this purpose a core wound with numerous fine insulated
wires, and the ends of each wire are brought out and connected to
studs which can be coupled together in any order. Thus a number of
the wires may be coupled together in series to carry the primary current,
whilst others are coupled in series to carry the secondary current, and
so any desired length may be given either to the primary or to the
secondary coils according to the character of the circuit. Or the wires
either primary or secondary may be coupled so that the current may be
divided between different wires, and thus a number of thin wires may be
made to act with the same effect as a single thick wire.
An induction coil thus constructed is capable of being adjusted with
facility to suit the peculiarities of any telegraphic line and any receiving
instrument.
I am aware that induction coils have been used in connection with
receiving instruments for other purposes, but not heretofore with a due
apportionment of the length and resistance of the primary and secondary
coils for the purpose of multiplying or largely increasing the force of
the current acting on the relay or receiving instrument.
Horse-shoe magnets of varied construction acting alone or on each
other may advantageously be used instead of induction coils of the
ordinary kind.
These arrangements enable me to use smaller battery currents, thinner
wires, and lower insulation than have hitherto been practicable in over-
land telegraphs and in submarine and subterranean cables.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 30
filed by the said Henry Highton in the Great Seal Patent Office on
the 29th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
HIGHTON, M.A., of Putney, in the County of Surrey, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of March, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Henry Highton, Her special license that
I, the said Henry Highton, my executors, administrators, and assigns,
or such others as I, the said Henry Highton, my executors, adminis-
trators, 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,
PART OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE CONSTRUCTION OF INDUCTION
COLLS," upon the condition (amongst others) that I, the said Henry
Highton, 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 Henry Highton, do hereby declare the
nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
The object of this Invention is mainly to increase the force of the
current acting on the relay or receiving instrument of electric telegraphs.
For this purpose I use an induction coil or other instrument producing
similar effects in conjunction with the receiving instrument.
By properly apportioning the length and resistance of the primary and
secondary coils respectively, according to the resistance offered by the
relay or receiving instrument itself, and according to the insulation and
resistance of the line wire the force of the current acting on the relay
or receiving instrument may be multiplied to any extent.
I am aware that induction coils have been used in connection with
3 receiving instruments for other purposes, but not heretofore with a due
apportionment of the length and resistance of the primary and secondary

page_text: coils for the purpose of multiplying or largely increasing the force of the
current acting on the relay or receiving instrument.
In order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the arrangement of
apparatus which I prefer to employ.
I prepare a considerable number of electro-magnets of a horse-shoe
shape (that is, with the poles brought near to each other) each magnet
may consist conveniently (see Figures 1) of two cores of boiler plate
three quarters of an inch thick, eight inches wide, and ten inches long,
united together at one end, and each wound with about six or more
layers of No. 16 copper wire well insulated with silk. Where the resis-
tance of the line wire or receiving instrument is very great thinner wire
may be used. Having made, say, two dozen or more of such magnets I
arrange them in pairs, resting the one on the other (see Figure 2). The
magnets being thus arranged in two sets, upper and lower, one set is con-
nected so that its coils from part of the cable or line circuit, that is to say,
the primary circuit, and the other set is connected with the receiving
relay or other instrument so that its coils together with the instrument
form a secondary circuit (or each magnet may be wound with a primary
and secondary wire, in which case it will not be necessary to arrange
them in pairs). Then as is well understood every variation of the current
in the primary circuit will cause a current to pass in the secondary
circuit.
The wires of either set may be so joined as to act together in the
same manner as if they were one thick wire with the current divided
through all, or as if they were two, three, or more thinner wires through
which the current passes in succession so as to lessen or increase the
resistance to any extent within the limits imposed by the size of the
instruments. The way in which they should be joined in each case must
depend on the resistances respectively of the line wire and of the receiving
instrument and the state of insulation of the line wire so as to give under
each varying circumstance the best effect and multiply most largely the
current,
All I can do here is to state the rules on which the amount of current
passing through the receiving instrument will depend.
The first rule is that the potential of the secondary wire will, cæteris
paribus, be as the amount of variation of the current passing through

page_text: the primary wire multiplied by the length of the primary wire and also
by the length of the secondary wire, and that the actual current passing
through the relay or receiving instrument will be as this potential
divided by the resistance of the secondary wire added to that of the relay
or receiving instrument, therefore it will be necessary in each case to
calculate what manner of joining up the wires will give the best results.
Or the proper method of coupling may be ascertained experimentally,
first by trial, that arrangement of the couplings of the primary set is
found which gives the maximum magnetization of the iron cores, and
then (this arrangement of the primary connections having been made) by
a second similar trial, the arrangement of the couplings of the secondary
set which gives the strongest signal upon the receiving instrument or
relay is also found. It is obvious that the particular form of the appa-
ratus constructed on these principles may be much varied. For instance
one very large electro-magnet might be used wound with several primary
and secondary wires, but it would be more cumbrous and less easily
moved from place to place.
These arrangements enable me to use smaller battery currents, thinner
wires, and lower insulation than have hitherto been practicable in long
overland telegraphs and in submarine and subterranean cables; what I
especially claim as my Invention is the manner of joining up or other-
wise regulating the length and resistance of the primary and secondary
wires respectively so as to get a secondary current acting on the relay
or receiving instrument more powerfully than the primary current itself
would if acting on it directly.
In witness whereof, I, the said Henry Highton, have hereunto set
my hand and seal, this Twenty-ninth day of September, in
the year of our Lord One thousand eight hundred and seventy-
three.