The progressive farmer. [volume] (Winston, N.C.) 1886-1904, 1902-02-25
THE TRANSMISSION OF MESSAGES BY
TIE MARCONI SYSTEM.

10 one of the polished brass balls
a wire is attached, which runs up a
high mast, OF hangs from a kite,
The electric pulsations, set up when
a spark leaps from one ball to the
other, run along the wire and ares
thence radiated off into space. Just
how large a role this suspended wire
plays in the sending is not yet very
clear. Maybe some day it will not
be needed. The sending instrument
might be located in the cellar, for,
these electric waves seem to CO.
through brick and some, and almost
every thing, save the metals. :.
Is Is clear enough that if the send
ing operator can open and CLOSE his
circuit as he likes, he can make the
series of sparks long or short as he
likes. So you have a long or short
series of waves flying through space
at the speed of light. While Senior
Marooni waited in Newfoundland
with the telephone at his ear, this 1s
what his operator in Cornwall was
doing. In Newfoundland was an
arrangement of a little diferentsort.
Here we're batteries, and a circuit,
just the same. But instead of the
transformer and the polished bress +,
balls, a liGt'o glass tube makes a part
Of the circuit. Into this runs the
two ends of the wires from the bat
teries. In the gap between the two
are some niokel-silver filings. Ordi-
narily, these will not let the current
from the battery pass. The path fs
blocked.
But if this little tube, about as big
as a quill toothpick, be attached at
the same time to the receiving wire,
which runs out through the window
and up the mast, a curious effect h
observed. When the waves strike
the high wire, and are absorbed,
they come running down in a way Go
make the nickel filings stand up in a
hurry. The little particles seem TO
cohere, and in such a way as to let
the other current, from the batteries
on the floor, flow through. Why,
nobody knows. Give the tube a lit
tie tap, and they fall apart again. It
is the oldest sort of a performance,
and was quite unheard of until Prof.
Branly's discovery, ten years ago
When Prof. Lodge heard of the
Brandy experiments, he fixed up a
little automatic taper. It worked
on the same principle as an electric
door-hell q wonder how many people
ever stopped to think how gwen that
simple every day affair operates).
The effect of this tapping arrange.
ment was to give the slender tube
Of filings a smart jog every time the
electric waves made them cohere. Il
was a decoherer.
The rest was simple. If the bat
terry on the floor could be made to
operate the tanper, it could also set
a common Morse printing instru-
ment going. According as the series
IF waves coming down the receiving
wire was short or long, the machine
prints a dot or a dash. These you
read off on the tape, just as you
read the quotations m a stock ticker,
only you have to know the Morse
alphabet 80 understand.
Ordinarily the waves are strong
enough and their effect clear enough,
40 that no telephone attachment is
needed. The clicks can be read of
by ear just as in ordinary telegraphy.
But the waves to weaken with
the distance, and those which had
travelled 1000 miles, from Cornwall
to Newfoundland, we're faint, indeed.
That was why SignOr Marooni held
an instrument to his ear.-From
"Wireless Telegraphy and Signor
Marooni's Triumph" by Carl Sny-
derI in the American Monthly Re-
view Of Reviews for February.