Manchester Democrat. [volume] (Manchester, Iowa) 1875-1930, 1904-12-07

the scientific world were turned upon
this man, who Is but 30 years of age
and had never been heard of before.
Naturally any man following the in
dividual whose name has become iden-
titled with a certain Invention must
have something new, some improve
ment, to offer. Otherwise there is no
excuse for his presence in the field.
What made the Marconi apparatus
possible was the ''coherer." 1t is as
serted that this was Invented in 1890
by Branley. The coherer consists of
n glass tube, Into the opposite ends of
which electrodes are introduced. Be-
tween the inner ends of these cleo
trodes, which do not quite touch, are
placed metal filings. When the cleo
trical or Hertzian impulse is given,
these filings are magnetized and close
the circuit, thus half way actuating
the receiving apparatus. But right here
is where the troubles comes in with
the coherer; there is nothing to break
the circuit and produce the other half
OF the sound necessary to complete the,
Geographic character. Marconi breaks
this circuit by sort Of hammer blow,
which, us 1t were, shakes the filings
loose. AS matter of fact, this blow
is administered by an instrument OPP
Grated by little circuit. But, never
.theless, the coherer was and is an
objection, as it markedly limits the ca
pacity Of the receiver. Marconi is said
to have admitted MS much and is even
reported to have devised plan for
overcoming the necessity for the use
of the coherer by means of something
which he calls magnetic detector."
But Lee DE Forest when lie began
his experimentation with wireless
telegraphy was shrewd enough to see
that the mechanical phases of the In
struMents must be reduced to min
imuD,. Accordingly he put the idea of
the coherer out of his mind. In his In
strunent Responder" is employed.
The operator sits with pair of or
binary telephone receivers at his ears,
and the potentiality of the Hertzian
impulse passing down the wires ut
taclied to the antennae on the pole reg
listers in this receiver and is immedi-
ately written into message form. There
is nothing to watch, nothing to handle;
simply TO record what comes of itself
into your ears. And this, by the way,
may come as rapidly as the operator is
able to send 1t.
The simplicity of all wireless tele-
graph instruments is almost startling.
To the layman the impression is given
that it is impossible for the primitive
looking apparatus to do the work for
which 1t is made, and which, by the
way, it does In n remarkably thorough
manner. The De Forest is even more
simple and uncomplicated than most
of its competitors. The power for this
comes from dynamo. In the De For
est experimental quarters a direct cur
Trent of 10 volts operates n motor,
which III turn actuates dynamo pro-
ductng the necessary alternating cur
rent. By an ingenious Arrangement
this is stepped UP" to voltage of
| 10000.
Messages are sent by IN ordinary
Morse key, with resulting noise that
would put the average Fourth of July
celebration to the blush. The size of
the sparks thus brought into being and
their businesslilse Swapping about the
spark balls" are usually sufficient to
convince the layman that he is looking
upon something decidedly out of the
ordinary. The sender after getting his
message off simply pulls down n
switch and awaits his answer. Then he
again raises the switch and sends an
other message. -