Evening star., 1899-04-15
Effect of Marconi's Work on the
Science Of Telegraphy.
SENDING MESSAGES WITHOUT WIRES
There Were All Sorts of Difficulties
to Overcome.
IDEA IS NOT A NEW ONE
From the New York Times.

of wires has astounded the world, but wire
less telegraphy. like most other new things,
had been known for some time before any
practical application Of it was possible. The
theory and The law had both been carefully
worked out before Marconi Logan dream
ing of practical methods for utilizing cleo
tric waves. To the constructive genius of
the young Italian, however, belongs the full
credit for applying these laws and theories,
while other scientists were still testing them
to ascertain whether or not they had been
really discovered and accurately classified
The science of wireless teIcgraphy. for it
has become practically new science. dates
its birth from Michael Faraday. who first
recognized the nature of the electric waves,
or rather the true movement and play of
electricity. although the waves" were not
known to him as such Faraday said that
electricity W2S the result of the play of
atoms and molecules. This suggested to
James Clerk-Maxwell. the great Scotch
physicist, who died in 1879, the similarity OF
light waves and electric waves. After ex-
perimenting, he came to the conclusion that
they were OF the same species and governed
by similar laws He concluded that the I'M
dulations or waves of electricity could be
transmitted through the air in the same
manner as light, and with about the same
rapidity, as the electric waves differed from
luminous waves only in force.
The German scientist Heinrich Hertz who
died in 1884, was able to prove beyond gues-
uon the correctness of the theory ANNOUNCE
ed by Clerk-MaxweH. The verifcation of
this theory. and the advances he made upon
the laws discovered by CleTk-Maxwell have
warranted scientists in naming the electric
undulations after him, as the "Hertzian
waves"
Where Mnreoni's Work Began.
II is with these waves that Marconi has
been experimenting so successfully. The
Eay had been blazed out. but scientist
had followed it far enough to justify the
conclusion that the waves would ever be
used for the practical transmission of mes
sages without the aid of wire. Marconi
took up the study where Clerk Maxwell
Hertz, Righi, PopOf, Sarasin. Branly and
dozen others had left off or had just
rived. H. acted upon the example of
Hdeckel who when he became believer
in evolution said that he would not make
1t the conclusion of his life study, but the
starting point. Marconi saw where the
study of the undulations had come to a
stand. and he took up the Investigations
exactly at that point, and soon had perfect
Ell u system by which actual messages
could be transmitted. The hypothesis be-
came practical a matter of commerce
and daily life as the ordinary telegraph line
OF the submarine cable The theory and
the law had been established by others: he
utilized it for the benefit of mankind. Hertz
had measured the waves. Brahly and Du-
Cretet had invented receivers for registering
them, and the Russian savant POpoff had
successfully sent messages by means of
them early 1899, but it had not been
thoroughly demonstrated that the waves
could be transmitted for considerable dis
tauce. registered with ease and easily read.
In nearly all discoveries of the present
day il is remarkable that some scientist in
the capacity Of prophet, had already an
nOunCed in advance just what would be ac-
cumplished LegerrleI Indicated the place
fl the heavens where Neptune would be
found by a telescope sufficiently powerful;
Haeckel announced that some day the skel-
eton Of the rea! ancestor OF mG,n-the miss
ing link-wOuid be unearthed years before
It was found in Java, and Clerk Maxwell
and Sir William Thompson announced, in
turn, the laws by which the electric waves
would act when their discovery and utfliza-
ton were accomplished Clerk-Maxwell
Showed that the light waves and the cleo
trio waves were subject TO similar laws
and both could be transmitted through nd
BY means Of the air or ether. Sir William
Thompson showed that when condenser
was discharged by dead wire oscillations
OF lcSSeniHg intensity were produced each
series OF oscillations being followed by a
period Of rest. This proved that the dis
charge was OsciRatory, and il was by this
1act that the waves were accurately meas
ured and brought within practical use. Fed
0ersen verified this theory.
Measuring the Waves.
Sir William Thompson. while he had indi-
Gated the way 20 measure the waves did
hot succeed in measuring them himself.
The short period of the waves was so IN
fntesimally short that il defied measure
ment. In this they differed from light
waves in that their period could not be
measured i'll centimeters. but in millionths
Df milHmeters- But another characteristic
Or the electric waves was used for the pur-
pose OF arriving at an accurate measure
meHt OF their short period. This was the
Tact tndt after each series of oscillations
or uuiulatiOnS there was a period of rest
r form of 81
IallOTs was determined Il was comparative
Iy easy TO determine when a series of a
given number Of oscillations would end
series or undulations was produced by
every interruption of the induction SPOOL
II the oscillations were short. the period of
res would be cOrreSpOndingly short; and in
th!S way froI A Righi of Bologna, Itaiy,
under whom MarcOni studied, was able to
measure more exactly the duration ot the
electric UDdulations
After the waves had been measured and
their character determined as nearly as
possible, the next step was the receiving
and regis Iering of them. Hertz and Saras-
IL. IN their experiments, made use of large
metallic plates. on which the electric waves
Were reflected. as light waves are ref .r.e1
IN mirror 1t was estimated that the 0s-
CfhauOrs were high as 100 900 nD a SEQ
ond. The results Of these experiments
showed tfe accuracy of previous calcula-
tons They showed also that the phenon1.-
ma were propagated with about the swift
n.Ss OF light, and that they were transmits
means.
The First Messages
In lS6 Popof had succeeded in sending
ano IN registering a message Righi had
In proved on his methods and Marconi. in
turn. improved upon the methods of R.ehi
H. introduced the use OF the mast for in
o1easing the length OF the conductor. hav-
ing discovered that the distance to which
signals may be sent varies according TO the
square Of the length of the conductor. His
nrst notable success was in 1s.sj or one
year after Popon had demonstrated the
pracUcabliity of transmitting messages
without the use of wires
The French scientists claim precedence
over Marconi in the practical use of the
electEic waves for trans mitting messages
NJ Risaut. in an article in La Science Fran
caiSe Of February "a says:
We have claimed for Mr.. Branly the
paternity of the essential feature in the
re- ewing instrument-the 'coherer.'"
The French office OF telegraphy is now
engaged in making experiments with the
apparatus of NM Brandy and Ducretet NJ.
fISaut, in the article referred to, describes
fnfln