Year: 1899

page_text: We, GUGLIELMO MARCONI, Electrician, and THE WIRELESS TELEGRAPH AND SIGNAL
COMPANY, LIMITED, both of 28, Park Lane, in the City of London, do hereby declare
the nature of this invention to be as follows:-
This invention relates to the induction coils employed as described in the Specifica-
tion No. 12,326 of 1898.
In place of winding both the primary and secondary in single layers as claimed in
that Specification the coils are now either made very short (not much exceeding two
centimetres in length) or else are wound in sections. The number of turns in the
successive layers of the secondary. (and sometimes of the primary also) preferably
diminish as the distance from the centre increases. It is also found desirable to
connect direct to the sensitive tube or imperfect contact (not through the condenser)
the end of the secondary which is furthest away from the nucleus.
Figures 1 to 6 are diagrams of coils which have been successfully used-P is the
primary and-S the secondary. The primary-is-to distinguish it from the secondary
shown as a thick line although usually the wires of both are of exactly the same
diameter.
The diagrams are greatly enlarged half longitudinal sections but are not strictly to
scale. In place also of showing the section of each coil or layer of wire as a longitudinal
row of dots or small circles as it would actually appear it is for simplicity shown as a
single continuous longitudinal straight line. A is the end of the primary which is
connected to the aerial conductor and E is the end connected to earth or a capacity.
J is the end of the secondary which is directly connected to the sensitive tube or
imperfect contact and C is the end which is connected to it through the condenser.
G is a glass tube on which the coils are wound.
The wires are insulated by a single covering of silk.
The following table gives particulars of these coils.
1

page_text: The method in which the sections of the coil are connected is found to be
.important.
:
Improvements in Apparatus employed in Wireless Telegraphy.
We, GUGLIELMO MARCONI, Electrician, and THE WIreless Telegraph and Signal
COMPANY, LIMITED, both of 28, Mark Lane, in the City of London, 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:-
This invention relates to certain forms of induction coils employed as described in
the Specification No 12326 of 1898.
The coils are most effective either when made very short (not much exceeding two
centimetres in length) or when they are wound in sections. . The number of turns in
the successive layers of the secondary (and sometimes of the primary also) should
diminish as the distance from the centre increases but this although desirable is not
essential. It is also found desirable to connect direct to the sensitive tube or
imperfect contact (not through the condenser) the end of the secondary which is
furthest away from the nucleus.
Figures 1 to 6 of the drawings lodged with the Provisional Specification are
diagrams of various forms of induction coil which have been successfully used. P is
the primary and S the secondary. The primary is to distinguish it from the
secondary, shown as a thick line although usually the wires of both are of exactly the
same diameter.
-
The diagrams are greatly enlarged half longitudinal sections but are not strictly to
scale. In place also of showing the section of each coil or layer of wire as a
longitudinal row of dots or small circles as it would actually appear it is for simplicity
shown as a single continuous longitudinal straight line. A is the end of the primary
which is connected to the aerial conductor and E is the end connected to earth or a
capacity. J is the end of the secondary which is directly connected to the sensitive
tube or imperfect contact and C is the end which is connected to it through the
condenser. G may be a glass tube on which the coils are wound..
The wires are preferably insulated by a single covering of silk.
The following table gives particulars of coils which have been successfully used.

page_text: The method in which the sections of the coil are connected is found to be
important and the general arrangements have been described in the said Specification
12326 of 1898.
When using the above described induction coils or transformers there is usually
employed as the vertical wire at each station a conductor formed of seven strands of
about 1 millimetre diameter copper wire 140 feet long, the top of the conductor being
about 100 feet from the ground.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed, we declare that what we claim
is:-
1. Constructing induction coils for use in combination with sensitive tubes or
similar forms of sensitive or imperfect conductors for the purpose of indicating the
passage of Hertzian waves with the secondary of several layers the number of turns
in the outer layers being less than in those next the primary.
2. Constructing induction coils for use in combination with sensitive. tubes or
similar forms of sensitive or imperfect conductors for the purpose of indicating the
passage of Hertzian waves with the secondary of the coil in two or more sections.
3. Constructing induction coils for use in combination with sensitive tubes or
similar forms of sensitive or imperfect conductors for the purpose of indicating the
waves substantially as described and illustrated
passage of Hertzian
Figures 1, 2, 3, 4, 5 and 6.
in