The record-union., 1898-08-07
MESSAGES WITHOUT WIRES.
Marconian System of Wireless Tel
eEraphy Nearing COMPLETION.

When MarcOni'S somewhat sensation
al achievements in wireless telegraphy
were first made public q little more
than q year ago, it was suggested that
his system might prove serviceable for
communications between land stations
and lightships, merchant vessels or
warshipS off the coast. Since that
time it has been shown that such a
practice is feasible under certain con-
ditiOnS.
On the coast of Italy messages have
been sent to naval vessels at a distance
of ten miles. Correspondence has been
maintained for several months past,
with regularity, between Bournemouth
and the Isle of Wight. more than four
teen miles apart. On single occasions
messages have been already sent about
thirty miles. And Marconi is now en-
deavOring to arrange for signaling be-
tween the English coast and Cher
bourg, sixty miles away. One is thus
led to ask himself whether or not this
method of signaling possesses any ad-
vantages which are not inherent in
others now in vogue.
| If the weather is fine flags can be
seen for fifteen miles. and the hello
graph will send beam of sunlight
much farther. The latter apparatus
has been worked, in exceptional in
stances, for a distance exceeding 100
miles. But fog, rain, smoke and haze
will occasionally make all of these sys-
TENS practically worthless, and will in
terfere more or less with the success of
| lanterns at night The electro-ma
netic waves which Hertz did SO much
to investigate, but which Marconi was
the first to utilize, travel equally well
| by night and by day, through cloud
and through sunshine.
The man who operates a heliograph
must be able to find by telescope or
compass. or both, the station with
which he wishes to communicate, and
must carefully train his reflected sun
beam on that point. The HertZian wave
| finds the person whom it is designed to
reach without any such trouble. 1t
does not spread with the same power in
all directions to be sure, but it re-
quires no special aim.
1t has been objected that for an army
on the march balloon, to sustain that
portion Of the Marconi apparatus which
is usually supported on a pole, would
be required, and that this would involve
taking along cumbrous making
machinery The point has little force.
An elevation Of 100 or 200 feet is neces-
sary A kite would do the business if
there was a breeze. If not, a very
small gas bag would serve, and COM
pressed hydrogen from a storage cylin-
der would quickly fill it. Still, even if
it should be found inconvenent to en-
ploy wireless telegraphy in the field
it might nevertheless be available in
the navy. Improvements in the de-
tails of the system recently made on
this side of the Atlantic certainly seem
to increase its Serviceability in the
hands Of ordinary telegraph operators.
AS yet it is uncertain whether signal
ing with HertZian waves can be con-
Quoted with absolute secrecy or not
Marconi thought at one time that his
receiving instrument must be tuned
to respond to the particular rate of the
transmitter's vibration, and that only
receiver so adjusted could pick up
message. Professor Pupin, Mr.. Clarke
and others have expressed doubt
whether any very wide range of fire.
uuency in the electromagnetic vibra-
tions is possible with efficient appar-
atus But even should "selective sig
naling' be found impracticable, the
other merits of the system may pos
sibly be considered sufficient to justify
it's adoption at least experimentally.-
New York Tribune.