Year: 1899

page_text: Date of Application, 26th Jan., 1899
Complete Specification Left, 23rd Oct., 1899-Accepted, 6th Jan., 1900
I, FERDINAND BRAUN, of No. 1, Universität Strasse at Strassburg in the Province
of Alsace, German Empire, Professor and Doctor of Philosophy, do hereby declare
the nature of this invention to be as follows:-
My invention relates to the transmission of electric signals without connecting
wires.
Hitherto the transmission of electric signals, as above mentioned, usually
termed "wireless telegraphy" has been based on the propagation of electric
waves in space, and various difficulties have been encountered which have
prevented such methods being satisfactory.
According to my invention, I avoid these difficulties by utilizing the surfaces
of conducting bodies as a medium for the transmission of the electric waves.
My invention is based on the fact, now well-known to electricians, that when
alternating currents of high frequency are supplied to cylindrical conductors,
the outer surface of the conductor is the important factor in transmitting the
energy, and the inner portions of the conductor are of very little use; this fact,
which is true for conducting bodies is also true for semi-conductors such as water
and earth, as experiments on a large scale have conclusively shewn.
According to my invention I take advantage of the tendency above mentioned
for electric current waves to press toward the outer surface of a conductor or
semi-conductor, by applying to two plates buried in the earth at a short distance
apart an alternating current of very high intensity and frequency. The lines of
flow of the current from one plate to the other will no longer take the shortest
path but will pass from their sources in large arcs covering a considerable area
Within this area the current vibrations may be collected and utilized to give
signals by devices of any suitable description.
The application of alternating current to the earth plates can be arranged
in various ways, for example, currents of high frequency may be created in a
complete system by means of condensers for instance, and these currents can be
then supplied to the wires which lead to the earth plates, or by means of rotary
machines a very high frequency may be forcibly obtained which is independent
of the self-induction and capacity of the earth plates; with these details my
present invention is not particularly concerned, as various methods of supply may
be adopted.
The collection of the electric disturbances may be effected in the usual manner.
Two earth plates inserted at points of different potential, and connected with
each other by means of wire, will serve for the purpose, a coherer being inserted
in its circuit as a delicate receiving element. The same purpose may be arrived
at by protecting one of the points in the usual way by means of metallic shields
against disturbance of potential or by connecting two points whose potential
is different in phase.
The advantages of my improved system are, first, the suppression of aerial wires

page_text: with all their attendant evils and inconveniences, second, that the energy expended
remaining upon the surface of the conductor, it follows that the energy will not be
diminished according to the square of the distance, as is the case when radiating
freely through the space, but in a much less degree being limited to surface
extension, third, an uneven or a wooded surface will present no obstacle to the
transmission.
Dotadi. 9741,
[1 1
1000
I, FERDINAND BRAUN, Professor and Doctor of Philosophy, of No. 1, Universität
Strasse, Strassburg, in the Province of Alsace, German Empire, 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 the transmission of electric signals without connecting
wires.
"
Hitherto the transmission of electrical signals, as above mentioned, usually
termed wireless telegraphy" has been based on the propagation of electric
waves in space, and various difficulties have been encountered which have
prevented such methods being satisfactory.
According to my invention, I avoid these difficulties by utilizing the surfaces
of conducting bodies as a medium for the transmission of the electric waves.
My invention is based on the fact, now well-known to electricians, that when
alternating currents of high frequency are supplied to cylindrical conductors,
the outer surface of the conductor is the important factor in transmitting the
energy, and the inner portions of the conductor are of very little use, this fact,
which is true for conducting bodies is also true for semi-conductors such as water
and earth, as experiments on a large scale have conclusively shewn.
According to my invention I take advantage of the tendency above mentioned
for electric current waves to press toward the outer surface of a conductor or
semi-conductor, by applying to two plates buried in the earth at a short distance
apart an alternating current of very high intensity and frequency. The lines of
flow of the current from one plate to the other will no longer take the shortest
path but will pass from their sources in large arcs covering a considerable area.
Within this area the current vibrations may be collected and utilized to give
signals by devices of way suitable description.
The application of the alternating current to the earth plates can be arranged
in various ways, for example, currents of high frequency may be created in a
complete system by means of condensers for instance, and these currents can be
then supplied to the wires which lead to the earth plates, or by means of rotary
machines a very high frequency may be forcibly obtained which is independent
of the self-induction and capacity of the earth plates; with these details my
present invention is not particularly concerned as various methods of supply may
be adopted. In order, however, that my invention may be clearly understood, I
have shewn in the accompanying diagrams various arrangements for supplying
current to the earth plates. In Figures 1 to 4 R represents a Ruhmkorff's induc-
tion-coil or a Holz's influence machine, and a a' the spark gaps in the air or in oil;
PP are the earth plates. This is the well known apparatus used by Hertz in

page_text: which, as shown for example in Figure 2, condensors may be interposed between
the two pairs of balls or, as shewn in Figure 3, between one pair of balls and the
earth plates.
In Figure 4 the earth plates are connected with the spark circuit through
the medium of an induction coil.
Figures 5 and 6 shew condensers joined in cascade, in Figure 5 with primary
coils interposed between the successive condensers so as to act inductively on the
circuit containing the earth plates P1, P2, and in Figure 6 without any induc-
tion coil.
Figure shews another arrangement in which two spark gaps are provided in
circuit with the earth plates, in which the combined action of capacity and induc-
tion is used. The evident purpose of this arrangement is to retard the vibrations,
whose frequence depends in a well known manner upon the product 'VLC
in which L signifies the self-induction C the capacity. Various other arrange-
ments of apparatus may be used.
The collection of the electric disturbances may be effected in the usual manner.
Two earth plates inserted at points of different potential, and connected with each
other by means of wire, will serve for the purpose, a coherer being inserted in its
circuit as a delicate receiving element. The same purpose may be arrived at by
protecting one of the points in the usual way by means of metallic shields against
disturbance of potential or by connecting two points whose potential is different
in phase..
A diagrammatical illustration of the manner of carrying out both the trans-
mitting and receiving stations is shown in Figure 8.
R means a Ruhmkorff's induction apparatus with the air gap a. C₁, C₂ con-
densers, P, P the earth plates as mentioned above. All these are parts of the
transmitting station. In the receiving station P, P are the recollecting earth
plates, F the well known coherer or the like, M is a Morse apparatus with the
battery B, and earth plate P₁. In the moment of action a local circuit will be
closed, comprising battery, Morse apparatus, coherer and earth plates as the
line coming from the battery is connected to the middle of the coherer.
All these connections may be varied in the manner now well known by elec-
tricians well up in what has been done already in wireless telegraphy.
The advantages of my improved system are, first, the suppression of aerial
wires with all their attendant evils and inconveniences, second, that the energy
expended remaining upon the surface of the conductor, it follows that the energy
will not be diminished according to the square of the distance, as in the case
when radiating freely through space, but in a much less degree being limited to
surface extension, third, an uneven or a wooded surface will present no obstacle
to the transmission.
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:-
The method of transmitting signals electrically from one station to another
without the use of connecting wires, consisting in supplying alternating electric
currents of high potential and frequency to earth plates at the transmitting
station, and collecting the impulses by earth plates at the receiving station,
substantially as and for the purpose described.
Dated the 23rd day of October 1809
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester and Birmingham.