The Winslow mail., 1925-10-30

Trying to figure out what made
his radio set work was beginning
to furnish Smith with as much en-
joyment as the programs. What
puzzled him most was that radio
waves could penetrate the brick
walls Of the house Nor could he
understand why, granting that the
waves did get inside the house, re-
ception should not be just as strong
with the loop as with an inside
aerial which he had strung around
the picture molding.
Besides" he continued, "how
can all these concerts be on the
air at the same time without inter
ferring with each other and pro-
ducing a tumble of noise? And
why can't we hear this without
the aid of set?'
You'd better stop right there"
I cautioned him. when the Op-
orator of your automobile engine
puzzled you l suggested following
drop of gasoline from the tank
to the exhaust. Now with radio
you've got to follow some such pro-
cedure, only this time we'll start
with a radio wave.
"The trouble is that even after
you visualize radio waves as very
much like the ripples that passed
to the distant shores when, as a
boy, you dropped stones in the lake
you cannot pin too much faith on
this explanation. The waves you
created in the lake passed through
the medium of water, whereas
those set up by the brOadcasting
stations are supposed to travel
through that hypothetical substance
known as ether. But Einstein, the
German physicist, upset the ether
theory, and so, more or less, up
set the radio wave idea.
However, it is obvious that some
kind of electromagnetic energy
must pass from the brOadcasting
station to your receiving set and
that it must pass through some
kind of medium on a certain wave
length, otherwise there would be
no radio communication, but just
a jubled reception, in the event
that uncontrolled energy were
transmitted. The wave idea seems
to offer something to stand on.
"You probably noticed when
dropping stones into the lake that
their size and the frequency with
which you dropped them had much
to do with the character of the
waves created. Big stones caused
deep waves Dropping stones in
quick succession set up trains of
! waves. Most of the waves, whether
created by big or little stones,
seemed to reach the shore, al
though sometimes you could detect
those from the smaller stones only
by the almost imperceptible move
ment of a floating leaf All this
is true of radio when you substi-
tute for the stones electrical erer-
gy and ether for the water. Sta
tions broadcast with varyin G
strength and on different wave
lengths which are determined by
the frequency of the electrical dis
charges. The more sensitive your
set is the more likely it is to pick
up the energy Of the waves at a
distance from the station"
Smith was following closely, but
! interrupted to ask how music and
| speeches were transmitted when I
was describing the whole business
in terms of electricity.
That's the surest part about it, ."
l explained. Sound is vibration.
At the brOadcasting station they
send a controlling current through
what is, in reality. a telephone
mouthpiece. The vibrations of the
! speakers voice varies this current
which, in turn, varies the carrier
waves passing out into the air.
When you tune your set you bring
it into resonance with the original
vibrations carried on the particular
carrier waves.
"The sort of waves sent out by
the broadca sting s atoms are
known as undamped, or continu-
Gus waves, just as though you
created a continuous train of wa
| ter waves by dropping stones with
perfect regularity. A thing you
probably will be surprised to
know, however, is that the energy
| that goes out over the air and
back through the ground complete
! ly reyerses it's direction anywhere
/ from $4,000 to 1,000, 600 times per
second. The house current for