The Scranton tribune. [volume] (Scranton, Pa.) 1891-1910, 1899-04-22

|
| that the discharge was oscillatory
and 1t was by this fact that the waves
were accurately measured and brought
within practical use. Feddersen veri-
| fed this theory.
| MEASURING THE WAVES.
| Sir William Thompson, while he had
indicated the way to measure the
waves, did not succeed in measuring
them himself. The short period of the
waves was so infinitesimally short that
II defled measurement. In this they
differed from light waves In that their
period could not be measured in cent?
meters. but in millionths of millimet-
| ers. But another characteristic of the
electric waves was used for the pur-
pose of arriving at an accurate meas
urement Of their short period. This
was the fact that after each series oil
oscillations or undulations there was
a period of rest. When once the geo.
metric form of the undulations was
determined 1t was comparatively easy
to determine when q series of given
number of oscillations would end. a
series of undulations was produced py
every interruption of the induction
spool. If the oscillations were snort,
the period of rest would be correspond
ingly short: and in this way Professor
a. Right of Bologna, Italy, under
whom Marconi studied, was able to
measure more exactly the duration of
the electric undulations.
| After the waves had been measured
and their character determined as
nearly as possible, the next step was
the receiving ana registering of them.
Hertz and Sarasin, in their expert
ments, made use of large metallic
plates, on which the electric waves
were reflected, as light waves are re-
nected in a mirror. 1t was estimated
that the oscillations were as high as
100 000 900 a second. The results OF
these experiments showed ..ie accuracy
of previous calculations. They showed
also that the phenomena were propa-
gated with about the swiftness of
light, and that they were transmissible
in the same way and by the same
means.
THE FIRST MESSAGES.
In 1895 Popoff had succeeded in send
ing and in registering a message. Rig
hi had improved on his methods, and
Marconi, in turn, improved upon the
methods of Righi. He introduced the
use of the mast for increasing the
length of the conductor, having dis
covered that the distance to which sig
nails may be sent varies according to
the square of the length Of the conduc-
tor. His first notable success was in
1896 or one year after Popoff had de-
monstrated the practicability of trans
hitting messages without the use OF
| wires.
The French scientists claim preced-
ence over Marconi in the practical use
of the electric waves for transmitting
messages NJ. Rigaut, in an article in
La Science Franchise of Feb. "a says:
I'VE have claimed for Mr.. Branly
the paternity of the essential feature
in the receiving instrument-the CO.
here-.'"
; The French office of telegraphy is
now engaged in making experiments
with the apparatus of NM. Branly and
Ducretet. Y. nlgaut, in the article re-
ferred to, \scribes the apparatus as
follows:
The mast Imports one end of an in.
sulated como Stor that floats in the
air, while the other end communicates
. with the pole of an induction coil and
other pole of the coil is connected with
the other sphere and then with the
earth. II the electric current passes
through a coil, discharge takes place
between the two spheres, which con.
stitutes what is known as the 'oscil.
, lator. Thus we have a discontinuous
, and oscillatory. electric discharge, or q
source of electric waves.
ha Of hl In.
sulated conductor fixed on the mast
the waves radiate. This extremity
! may be terminated by metallic sur.
face, that furnishes, with the conduc.
tor, the requisite electric capacity. This
radiating conductor is, then, the trans.
mitter. A spring key, as in the Morse
transmitter, enables the operator e
, make the discharge short or long.
The receiver consists of cohn"sl
+ or tube filed with metallic iilings
called by Branly a 'radioconductor,' 81
model invented by NJ. Ducretet Thi.
is put in communication on one sid
with an insulated conductor of a SEE.
ond tall mast, and on the other side
, with the earth. The end Of the insu
lated conductor is the collector of thC
! electric waves. On the other hand
4 tHt tOUCIllls luDe Is pldCcu III lne CIT
, cult of Il battery and a very seng.tiy'
| telegraphic relay. The battery cur
: | rent passes in the cleCtro-magnat o
. the relay only when the electric waves
coming through space, traverse the co,
: hcrer causing it to become "A conduc,
tor.
. "As i'm all kinds of telegraphy, eacl
! | station must have both transmitting
, and a receiving instrument. A port,
able receiving instrument sulIices fol
the reading of the Hertzian waves sig,
mails; and by connecting 1t with a reg
istering apparatus the message may
be printed on a band Of paper"
In February the French scientist.
were experimenting with sending &
message over a distance Of about nine
teen miles. MarcOni hal already trans
mitted a message over distance O.
thirty-One miles.
THE EARTH'S CURVATURE.
When Marconi began working at hi
| experiments there were number o
difficulties to overcome. One was tn
transmission of the message througl
| damp air, clouds, etc, another wa
the transmission of the waves owe
such a distance as made the curva
ture of the earth a barrier TO the cours
Of the waves. He surmounted bot
difficulties, and succeeded in sendinj
messages through clouds and fog, an,
in transmitting them at distances o
thirty-two miles and more, provin
that, to a considerable extent, at least