The Saint Paul globe., 1898-07-03

newspaper prints an Illustration made
from the first photograph taken of the
wireless telegraph station, showing the
apparatus from whence messages are
made to fly 'shrough space a distance
OF four.een miles without the aid Of
any connecting wires, or any medium
Of communication save the atmosphere.
of which science makes such wonderful
use.
The principle of telegraphlng across
space without the aid of Intervening
wires finds an apt illustration in the
responsive action of two tuning forks
Ii we place a couple of tuning forks
which are tuned to exactly the same
note, short distance from ore anoth-
er, and then by drawing a Vi bow,
or by striking one of them, ,ause 1t
to sound a note-which is another way
OF saying that we cause it to emit
sound-the second tuning fork will
catch UP these Vibrations and begin
itself to vibrate sympatheticaIIy. 1t
will give evidence of it's vibration by
echoing the sound of the first tuning
fork. Within certain limits, and WITH
slight differences in practice, this is
the way in which electric waves by
being sent by one electric instrument
and being received on another transmit
first vibrations and thence messages
through space.
This was a method of signaling
which was known and experimental
with by Prof. Nikola Tesla, of New
York; by Prof. Oliver Lodge. in Eng-
land, by DR.. Swaby, in Berlin, and by
DR.. Brownies, in France, before Prof.
Marconi-who up to a recent period
used Brownlee's coherer to aid him
in getting distinctness of messages
was heard of. u
VERY SENSITIVE INSTRUMENTS
Prof. Marconi, however, claims to
have been more successful in the prac-
teal transmission of messages than
any of his fOrerunnerS. One of the
great difficulties in sending messages
Is, of course, the difficulty of getting
instruments sufficiently sensitive to re-
cord the Her. Zian waves when they
are sent. If the two tuning forks
winch have been suggested as an illu-
stration of electrical methods. were
placed half mile apart, the instru-
ments which would detect sympathetic
vibrations in the receiving tuning fork
would have to be extremely sensitive
and some difficulty would be found in
distinguishing sympathetic vibrations
from those due to eXtranaous causes.
SO it is with the electric tuning forks
11ertZlan electric waves, like light
waves or sound waves, do not run in
parallel lines straight from the START
ing point; they radiate in all directions
like fragments of a bursting shell
Prof. Nikola Tesla, therefore. suggest
ed some years ago that an electric,
screen should be added TO the apparat-
Us of the receiving station in order to
catch as many of the waves as possible
Thls suggestion Prof. Marconi has
adopted and adapted. H99hH y
In the case of the instrument At
6ournemouth, he has supplemented tha-
receivers by the addition of a mast 100
feet high. and from a ring near the
top a narrow strip of wire netting runs
to the receiving instrument and acts
as collector OF the vibrations from
Alum Bay, where the second station is
located. This mast and netting are
shown in the accompanying illustra-
tion.
So satisfactory have been the expert
ments conducted by Prof. Marconi that
he is about to extend the distance be-
tween his stations. carrying the second
one to Cherbourg, sixty miles away.
The experiments are at present in a
very elementary stage. 1t has been
found that the sound waves travel
much faster and better in foggy, rainy
or windy weather than when the air
is clear and the weather fine and still.
AS the clever man who can telegraph
without wires cannot make weather to
order, 1T is necessary to overcome the
atmospheric conditions that influence
the system, and Prof. Marc0ni Is bend
ing ell his energies to bring this about
Broadly speaking the success Of the ex-
periments is assured, inasmuch as m s.
sages are sent and clearly interpreted
without the aid of wires. Though
much remains to be done, wireless tele-
graphy will surely be in general use
before long, and people who marvel at
the idea of sending messages between
widely separated points without inter-
vening wires will then look upon it as
a matter Of course as they now do the
telephone.