The silver state. [volume] (Unionville, Nev.) 1870-1903, 1902-06-05
THE MARCONI SYSTEM.
How Wireless Telegraph Messages Are Sent
and Received

How Wireless Telegraph Messages Are Sent
and Received.
In view of the claim made by Marconi.
TO the effect that he had received a sig.
nal at st. Johns, Newfoundland, from the
Lizard, Cornwall. 1880 miles away, by
means of his wireless telegraphy system,
a brief account of his methods of trans
hitting and receiving wireless messages
is timely.
In the Marconi system of wireless tele-
graphy the sending apparatus consists of
a mast carrying a wire. The wire is
carefully insulated by supension clear
of contact, and 1t is left disconnected
electrically at the top. The height Of
the mast. and consequently the length of
the wire. varies with the distance t.
which transmission is desired, and the
distance increases with the height. An
ordinary signaling mast Is about $50 feet
high. The lower end Of the insulated
wire is connected to . powerful spark
coil. and when a message Is sent pow
erful sparks are drawn from the
electrical generator under the control of a
hand key, operated In the same way as
an ordinary Morse wire telegraph. These
powerful sparks, producing to the rhythm
of the dots and dashes, simultaneously
electrify the vertical wire supported by
the mast, and cause the emission from
II of a corresponding sequence of invisi.
BILE electric waves These waves radiate
out over the surrounding land or sea In
all directions with enormous velocity, and
wherever in their advance they strike a
similar vertical wire they produce in II a
feeble electric disturbance, which can bt
made manifest by a suitable apparatus
The receiving instrument is connected TO
the receiving vertical wire at any posi-
ton in distance within the range of trans
mission. The principal part of the re
ceiying appartus is the coherer 1t con-
sists essentially of a small glass tube with
small gap between the wires inside. This
gap is filed with metallic filings which
have the property of opposing flow
slectricity in the normal condition of the
filings. On the passage of an electro
wave. however through the coherer the
filings are brought into better contact, as
though electrically welded, and they can
alloy an electric current to pass. BY a
suitable device the filings are then shaken
apart the practical result being that the
dots and dashes come out just as they
were transmitted. and are so recorded.
When messages are being sent the coh-
erer is disconnected: it is only used for
receiving.
About forty ships in the British navy
have so far been equipped with this APP
paratus. and the range of signaling is
about sixty miles. The longest distanc
yet covered with a message by the Mar
conf system previous to that claimed
recently had been from st. Cath
ines on the Isle of Wright. TO the Lizard,
Cornwall, a distance of 1s6 miles.
Electricians generally seem to regard
the late performance somewhat skep-
tically. DIR. A. E. Kennedy, in speaking
of the matter yesterday, said that with
most of the Philadelphia electricians, he
considered the reports so far published
about the alleged wireless signal sent
xcross 1900 miles of ocean. from Corn
wall to Newfoundland. as too indefinite
to warrant any trustworthy conclusions
and that not until an actual message
had been transmitted between the two
points will it be possible to say that the
hitherto existing record of 1So miles has
been increased to 1900. But he thought
1t quite reasonable to expect that sig
Mailing over l,S00 miles would be possible
at some future time. even supposing the
present results to be premature.
Beware of OiEtments for Catarrh That Con-
tain Mercury