The Indianapolis journal., 1902-01-27
MARCONI AND THE CABLE SYSTEM.
Professor Herdt's Opinion Upon the
Relative Value.
New York Evening Post.


L. A. Herdt, professor of electricity in
McGin University, Canada, in speaking on
the Marconi wireless telegraph, said in
part:
From work lately published in France
by NM. Boulanger and Ferrier, officers in
the French army engineers, and comments
thereon by a distinguished scientist of La
val University, from whom we borrow in
part, we are led to conclude that the posi-
bility of the systems interference with
cable lines is entirely unfounded. The au-
thors of the work we allude to are known
throughout Europe as savants' and ex-
perts in the application of electricity in all
its branches. And that which adds especial
value to the opinions they express is their
utter disinterestedness. After experiment
ing in wireless telegraphy themselves on
different occasions, they were present last
September at Mr.. Marconi's experiments
between Toulon and Corsica Consequently
they speak after seeing for themselves, and
enlightened with their special knowledge
of the subject.
covered by the Marconi experiments in his
autumn trials, after alluding TO the i'm
provements successfully made in his ap-
paratus, especially in the matter of Syn
thonie,' which allows, when the distance
to be covered is sufficiently great, the
sending of several messages simultaneous
ly in different directions, the authors add
Notwithstanding these improvements,
the principal objections to wireless tele-
graphy still subsist:
81. Insecurity of communications.
80. Necessity of constructing very
high supports for the antennae, from the
moment that the distance to be covered
is at all great
L" g. CumberSomeneSS and SenSitiveneSs
of the apparatus.
'The first of these objections is the most
serious, and, unfortunately, so far. it does
not appear to be possible to remove it en-
tirely If the fact that messages can be in
tercepted is not very important objection,
owing to the possibility of using cipher
codes the same cannot be said about the
fact that the reception of message can be
interfered with by a transmitter even
placed at a considerable distance off. More
over, in warm climates (and why not in
warm weather anywhere0 the reception of
kilograms can be very much disturbed by
atmospheric perturbations.'
4" The necessity of employing very high
supports for the antennae is no great OBJ
lection on shipboard, where, moreover,
there is no occasion generally OF cOrre-
spending at great distances. But such is
not the case when working from land.
LAS a rule, communications are more
difficult over land than where the stations
are separated by water. 1t was thus that
the trials made in the Transvaal gave no
practical results. Good communications
can, however, be had on land with suffi-
ciently elevated antennae. But, beyond
fifty TO sixty meters in height, the construc-
ton of supports presents great difficulties
Recourse must, then. be had to captive bal
looms; but these are at the mercy of the
winds.
1T follows, therefore, that the progress
obtained by Mr.. Marconi, though impor-
tant does not yet allow wireless teleg-
raphy to supersede the processes hitherto
in use. Whenever possible, it will always
be preferable 10 employ existing methods,
which possess the great advantage of sim
plicity. Nevertheless, in many cases, wire
less telegraphy will be a precious compile
ment to the other, and ought not, therefore.
to be neglected. At sea, for instance it
would often be the only means of communi-
cation. and it is easy to imagine circum-
stances when even on land no other means
Of telegraphing would be available, espe-
cialy in military operations.
- 1t is in this field that the practical use
of wireless telegraphy must be sought and
the progress accomplished since its incep-
adopts may soon be attained
THE only possible inference from NM
Boulanger and Terriers observations is
that valuable as Mr.. Marconis work may
be. there is no prospect of wireless teleg-
raphy replacing the systems now in use:
its usefulness being alongside of and as an
adjunct to the latter but not al all in an
tagonism thereto