Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1901-12-26
THE WIRELESS TELEGRAPH.
Marconi Explains the Operation
of His Wonderful System.
tances-vertical Wires Used Sys-
tenn That was Used for Queen
Victoria.

Ir a paper read before the Institution OF
Electrical Engineers Gueliellno Maroon
explains his system of wireless telegraph
as ft lows. says the New York journal:
When [ wish to bridge distances ana 1t
is net necessary that signals be sent in
enc definite direction, | use an ordinary
transmitter. 1t is made of two small
spheres. connected by wire. one with the
earth and the other with vertical coli
ductor of some height, called the aerlai
CONDUCTOR" When | wish to direct
beam of rays in given dirrcticn, use
cylindrical parabclic reflector placed In the
proper focal line. IKE system of opera
ton is simple.
The key is pressed. and the electrical
current is discharged through the spark
gap between the spheres. This discharge
is an oscillatng one. The spheres and
conductor become u radiator Of electrical
waves. BY pressing the ordinary tec-
graph key at long CT short intervals long,
or short waves are made. These affect
the distant recei,or at long or SHIRT inter-
walls producing the Morse alphabet of dots
and da shes.
One Of the most important parts of the
rcceiN er is the sensitive tube which is
called "A Coheie or radio conductor. The
only form # cotcrer | lave found to be-
rellablc Tor long ulSI aTCe "Drk IL IL SHi90
tube Of small diarlcter and four cent?
meters long. Two metal pole pieces are
tightly fitted into it, The space between
them is partly filled with a mixture of
nickel and silver filings. This coherer is
part of IA circuit which contains a local
cell and a sensitive telegraph relay. the
relay works another circuit operating a
"trcnber," Taper" or "1ecohcrer' and
a recording instrument.
Normally the resistance of the tilir rs is
great. but under the waves they cohcre
and become comparati> ely good conduo-
tor This allows the current from the 10
cal cell to operate the relay. One end of
the tube is connected With the earth, the
other with a vertical conductor
If a reflector for special direction
transmission is being used at the Sending
station, {. short strir of copper is fixed to
each end of the glass tube in the receiver.
These strips must be exactly proper
length, otherwise they will not be in tune
or SNntony, with the transmitted waves.
All of the electro magnetic apparatus in
the receiver is shunted by noninductive re-
sistancos in such a way that there is no
sparkling at contacts ard no jerks caused
10y the local battery, or cell. near the CO.
hercr.
The "tapper' and Geographic :nstru
nont, if not properly shuntsd. produce lis
turhirE effects. Small Choking coils are
put between the CCie rer and the relay
Ih'N force the waves to traverse the COS
hcrer. The oscillations or waves on the
copper strips cause the metal filings to CO.
here and become condlCtcr. The tap
Ter" shakes the filings apart. breakine;
the circuit. The practical result of this is
that the dots and das shes come just ms
they are transmitted ana are so recorded
by the mixer in something 81 the same
fashion in which Geographic instruments
wears used to print lDOD Il paDor pc.