Indiana daily times. [volume] (Indianapolis [Ind.]) 1914-1922, 1922-05-15

All world progress rests upon inter-
change Of intelligence. With the growth
and spread of radio. Even into isolated
communities, humanitarian, educational
and social possibilities come into view
hitherto envisioned through no other
agency. But to approximate the future
of radio, we must understand the record
of its past.
Radio on the ocean forced its way into
popular Imagination when the first cah OF
distress was flashed by wireless oper-
ator from a sinking ship.
Radio as a means of international COM
munication already ha proved itself not
only by service rendered to the general
public, but by the service Ii has rem
dered to Government, to industry and to
trade. And now radio in the home is
bringing entertainment and instruction
to millions OF people who are just be-
ginning TO glimpse the possibilities Of the
net art.
But the greater radio, the radio Of the
future, with its manifold ramifcations in
> the transmission of intelligence. this is
yet faint upon the horizon.
EARLY
HISTORY.
The origin Of radio lies In the expert
ments of Hertz, a German scientist. At
the time of his discovery he was using
among various laboratory devices, an ap-
paratus known as an induction co,I-an
electrical device which causes a spark.
Its operation begins at low voltage, or
electrical pressure which it then steps up
to SO high a point that the electric dis
charge or spark flashes across between
the spark points. Hertz found in. e1-
perimenting with the spark coil that he
had set into electrical vibration metallic
bodies and various electrical devices.
Knowing that there was no connection
between these and his sending appar
tus. he realized that he faced new
phenomenon, and by careful analysis
of the effect of the current, he came to
this conclusion: That ether" which per-
vades everything, is capable Of carrying
electric waves Tor, as later defined, .'elec-
tro-magnetic waves'D. and that these
waves travel outward through the air in
all directions.
MARCoSrs
INVENTION.
This discovery was widely published.
1t meant nothing. at that moment, how
ever, TO the general public, or the lay
mind-jCs. as the Einstein theory, for
example, means very little to US today
Yet, ii registered with a deep under
standing on the mind of an 1S-year-oId
youth then studying in Italy, GugIiemlo
Marconi- He reasoned that Il Ii were
true that rhe ether carried these electro
magnetic waves, IL By this medium, elec-
trio energy could be carried, Il would
lie desirable to break these waves III. into
a series 0, dots and dashes correpond-
ing To the Morse alphabet used In or
binary telegraphy. Having done that, the
ether gould be employed to do the work
hitherto done by wire teIegraphy.
With this definite objective he began
his task lie experimental. extensively
and found that. in order TO send out the
electric waves efficiently, it was neces-
sary to connect up an insulated wire
suspended In the air with one side Of the
induction coil--and in this simple form
came into being the first type OF wireless
sending apparatus ever used IN the
world. A definite return path was de-
sirable for the electrical circuit, so he
used the ground; connecting 1t by wire
to the other side OF the coik. still ut;liz-
ing, OF course, his connection to an aerial
Tor antenna, as 1t Is technically Called
he wires one sees suspended over so
many housetops now are these antenrfae
Having found the means of sending
electro ma gnetic waves through the air
the next question was how to receive
them To accomplish this, he developed
Il
action OF which was very simple. 1t con-
sisted of = small glass tube within which
were number Of filings: wire from one
side connected Ii to the aerial; another
wire from the other tide went to the
ground, through various coils or other
apparatus. When the electric wave
emitted from the sending station i'm
pinged on the receiving aerial. an electric
current passed through the little coherer
tube and acted upon those metallic filings.
Electrically speaking, it changed their
resistance In ordinary langua &c. this
means simply that the character Of the
filings changed: and every time that
change took place, something happened;
either the> telegraph relay closed, or a
noise was made In the receiving tele-
phones, or an ink recorder operated That
is, the feeble action on the tiny metallic
filings was used TO do specific job-to
make Ineligible by sound or by mark
the dots and dashes OF the telegraph
code. This was the original radio sys-
tenn; a transmitting instrument which
shot out dots and dashes by breaking up
at intervals Of short and long duration
the electro Magnetic waves sent out into
the ether. These electrical impulses
travelling through the air found their
way to any aerial wire Suspended in the
air. they would then go through the little
coherer device. and be made Ineligible
either by sound or by record on paper.
PRINCIPLES
OF TUNING
The next problem presenting itself
was to arrange matters so that if more
than one emission of electro magnetic
waves was carrying dots and dashes
through the air, the receiving apparatus
would not get the conflicting and stimuli
taneous messages IN tie form Of jun
Bile Of signals; In other words, there
arose, the problem of interference The
answer to that was, tuning. Implied by
that single word are many of the ia
miiiar terms appearing in the daily press
such as wave lengths. tuning apparatus
and tuning coils. yariometers, conden-
sers. and many other pieces of electrical
apparatus that resolve themselves into
associated devices to accomplish the end
Yet the principle of tuning is simple.
Consider-by way of analogy-the effect
of resonance in music. II Us common
knowledge, for example, that using a
violin, when one string Is tuned to a
certain pitch and played upon. another
string attuned to the same pitch will be
set into sympathetic and powerful VI
bration: that 1t will of itself respond
and give music, or a single note Of
music. In music, this effect is known as
symphony, or resonance We call It the
same thing in radio. The receiving ap-
paratus is electrically tuned to the send
dition of resonance is set up between
the two circuits Only then 10 we get
q response.
Tho elact opatir xra-aa ~ radio