IMPROVEMENTS IN TELEGRAPH
Year: 1883

page_text: LETTERS PATENT to Alfred Julius Boult of 323 High Holborn in the County
"IMPROVEMENTS IN TELEGRAPH
of Middlesex Engineer for an Invention of
"
AND TELEPHONE WIRES a communication from Gorham Gray of Boston
Massachusetts United States of America.
PROVISIONAL SPECIFICATION left by the said Alfred Julius Boult at the
Office of the Commissioners of Patents on the 3rd December 1883.
ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex
"
WIRES
AND TELEPHONE
[a com-
Engineer "IMPROVEMENTS IN TELEGRAPH
munication from Gorham Gray of Boston Massachusetts United States of
America]
This invention relates to electrical conductors for telegraph and telephone lines;
and consists in an anti-inductive wire or conductor as hereinafter more fully
described.
In telephone wires or conductors great difficulty is experienced especially in long
lines in carrying on plain and intelligible conversation between two points
connected by the wire or conductor on account of induction from other wires in
proximity to the telephone wire or conductor and this improvement consists in
uninsulated wires or conductors of the form hereinafter described whereby the
induction is greatly lessened and the conversation carried on between the two
points at the opposite ends of the wire or conductor made very much plainer and
more intelligible owing to the anti-inductive properties of this improved wire or
conductor
In carrying this invention into practice I form the improved anti inductive
conductor or wire with a series of spiral grooves formed in the metal of the wire
body. These spirals may be formed in any desired manner. of any desired pitch
and by any suitable machinery

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred Julius Boult in the Patent Office on the 3rd June 1884.
ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex
Engineer "IMPROVEMENTS IN TELEGRAPH AND TELEPHONE WIRES
" A com-
munication from Gorham Gray of Boston Massachusetts, United States of
America.
This invention relates to Electrical Conductors for Telegraph and Telephone
lines and consists in an anti-inductive wire or conductor as hereinafter more fully
described.
In telephone wires or conductors as now ordinarily constructed, great difficulty is
experienced especially in long lines in carrying on plain and intelligible
conversation between two points connected by the wire or conductor on account of
induction from other wires in proximity to the telephone wire or conductor and
this improvement consists in uninsulated wires or conductors of the form herein-
after described whereby the induction is greatly lessened and the conversation
carried on between the two points at the opposite ends of the wire or conductor
made very much plainer and more intelligible, owing to the anti-inductive
properties of this improved wire or conductor
In the accompanying drawing Figs. 1 and 2 represent perspective
piece of this improved wire, showing different modifications of form.
cross-section on an enlarged scale, of the wire shown in Fig. 1; and
cross-section of the wire shown in Fig. 2
views of a
Fig 3 is a
Fig. 4 is a
By reference to these figures it will be seen that the improved anti-inductive
conductor or wire is formed with a series of spiral grooves B, formed in the metal
of the wire body A. These spirals may be formed in any desired manner, of any
desired pitch, and by any suitable machinery care being taken so to proceed in the
manufacture as to compress the solid central part of the wire whilst leaving the
ribs or flutings produced thereon uncompressed. When this is done the result
will be that the central part or body (which is compressed) is of a much closer
grain or texture than the spirals or flutings
It is obvious that by this means the conductivity of the central portion is
increased and greatly exceeds that of the outer portion which is relatively a bad
conductor the wire used being by preference originally very soft.
Having now described the nature of the said invention and how the same is be
performed as communicated to me by my foreign correspondent.
I claim (1) the anti inductive wire substantially as set forth the central core of
which is of closer grain or texture than the outer portion
(2) The method of compressing the central portion or core of the wire by spirally
grooving the wire substantially as described
(3) Lessening the relative conductivity of the outer portion or shell of the wire by
increasing the density of the central portion or core and interrupting the continuity
of the shell by spirally grooving the same substantially as described
In witness whereof I the said Alfred Julius Boult have hereunto set my hand
and seal this third day of June in the year of our Lord One thousand eight
hundred and eighty four.