Wheeling register. [volume] (Wheeling, W. Va.) 1878-1935, 1899-10-05
THE MARCONI SYSTEM.
a Brief But Easily Understood Description
of the Wireless Telegraph.

A Brief But Easily Understood Description
OF the Wireless Telegraph.
The Marconi system of wireless tel
egraphy, used by the New York Herald
to furnish bulletins of Tuesdays yacht
race, proved quite successful, and bull
letins at critical points were much more
accurate and early than those secured
by men with glasses on shore.
w. B. Bradfeld. assistant ITO Signor
Marconi, describes the working of the
Marconi system in the following article,
which can be understood by persons
having but a slight knowledge of cleo
trical science:
AS is well known, the Marconi system
is worked by means of "Hertzian
waves" so called after the late emil
nent German professor, Heinrich Hertz,
who first experimentally proved their
existence 80 years or so after Clerk
Maxwell had automatically predicted
them. These waves pass through the
ether.
Mr.. Marconi employs the following
apparatus to generate and collect these
waves: The first thing that is a2Dar-
ent to the observer is a tall mast. $50
feet high, from the top Of which is
suspended a wire-it is actually an
ordinary insulated copper wire, such
as is used for electric lighting pur-
poses. This passes through a window
of the operating room and is joined up
inside with the apparatus. There is
nothing strange in the appearance of
the mast itself, and no effort is made
to clothe this part of the apparatus in
mystery.
With regard to apparatus within the
room, simplicity is the most amazing
part Of it. The whole apparatus is fixed
on a small table about four feet long
and two feet wide, anc the battery for
supplying the power is packed under
meath il.
This battery consists Of SO dry cells,
which are connected UP IA in series
and Z in derivation, and is Joined up
in parallel with 8 accumulator cells to
give a steady current of 6 amperes. The
actual generator of the waves is an or
binary inductor or Ruhmkorff coil, such
as is used for the production of X rays,
and is capable of given a 10-inch spark.
Each end of the secondary winding OF
this coil is fitted with a sparkling rod,
to which is attached a brass ball one
and a half inches in diameter.
To n of these balls is connected the
vertical wire; the other is Joined to
earth. With the single addition of a
Morse key in the primary circuit the
transmitting apparatus is complete.
SENDING AND RECEIVING.
Consider for a moment what happens
when this key is depressed. The i'm
mediate and apparent result is q loud,
cracking spark discharge between the
two brass balls. The more important
result is that the vertical wire ct the
moment the spark passes emits waves
which go out into space in all direc-
tons, and continue to do so as long as
the key is depressed. 1t is easy to un-
derstand, therefore, that by depressing
the key for a short or a long period
short and long series of waves or oscIl-
lations are emitted, and the Morse al
phabet, which is used in ordinary tele-9
graphy, may be employed.
The only thing that remains is to
get something that will pick up and
indicate the presence of these oscilla-
tons.
The apparatus which Marconi en-
ploys to do this is what is commonly
known as a "coherer," a name which is
due to Prof. Oliver Lodge. of Liver
pool. An Italian named Calzecchi was
the first to discover the sensibility Of
coherers and filings tubes to Hertz
waves. He found that metallic filings
in a loose state Of contact offered an
appreciate resistance to the passage of
a current. He found also. however,
that on exposing these filings to the
action Of Hertzian waves the resist
ance fell enormously, burt that on shak-
ing them up the resistance was in
creased again to its original value.
Marconi's coherer works on the same
principle. but is vastly more sensitive