The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1902-10-19

Prof. Ernest Runner has won ma
tional fame by sending messages for
several miles over a telephone without
the aid of a wire. What Marconi has
done in the field of telegraphy he has
done in another field, and those ex-
pertS in Europe who are best qualified
to speak with authority on the subject
say that his achievement is as notable
and will produce as far-reaching re-
suits as the distinguished Italians.
Prof. RUNNER has for several years
heen-known as an indefatigable physi-
cist, and some time ago he gave proof
that his labor had not been in vain by
inventing the instrument known as the
photographophone. Consequently the
leading electricians and other experts
of Germany were not surprised when
he informed them recently that he had
discovered a method of sending wire
less messages by telephone and that he
intended to give practical proof
thereof, which he would like them to
witness.
Many accepted the invitation, among
them being Herr Won Rudiger, a promi-
nent government official, and Profess
sors Kalisch and Kapp, of the Techni-
cal High school, of Charlottenburg, as
well as representatives of the Berlin
and Vienna press.
The experiments were held on the
Wannsee, near Berlin, and were most
successful in spite of the facts that
heavy rain was falling and the air was
frequently disturbed by noise from
nearby vessels. The inventor sent
wireless messages by telephone for a
distance first of two and a half and
then OF four and quarter miles,
Follows Prof. Bell.
"How did Prof RUNNER happen to
invent such wonderful thing?" many
persons are now asking, and scientists
reply that he has achieved success
by following faithfully in the line of
Prof. Alexander Graham Bells expert
ment with light. In 1880 Prof. Bell
proposed that the radiophone be used
for utilizing radiant energy, such as
light or radiant heat, for the trans
mission of sound
The radiophOne, which was then at
tracing much attention, was an appa-
ratus founded Oh the discovery made
by Mr.. May while carrying out expert
ments on selenium-that when selen-
ium is exposed to light it's electrical re-
siStance differs greatly from what it is
in the dark.
While pondering over this discovery
Prof Bell conceived the idea that if
ray Of light issuing from one station
could be made to fall on q selenium
tensity could be varied by the voice
of a speaker, then, if a telephone and a
battery in circuit with the Selenium
plate were connected the words spoken
in the distant station would be heard
in the telephone.
Tests which were made proved that
this theory was correct.
Since then Prof. Simon, the inventor
OF the Singing lamp" and Mr.. w. Du-
dell, the English scientist, have shown
clearly that light can be used for the
transmission of sound, and that their
experiments in this direction have been
of signal service to Prof. Runner while
perfecting his method of wireless tel
ephony is thought by experts to be
very probable.
New Use of Selenum.
Nevertheless Prof. RUNNER has made
one distinct and most important dis
coyery, and therefore, no matter how
much he may be indebted to the work
OF others who have experimental with
light, he is well entitled to all the
praise which he is now receiving, for if
ne had not made this discovery he
could not have perfected his system Of
wireless telephony. He was first to
discover how to make the utmost pos
sible use of that curious metal selen-
1ulM.
hitherto Selen1um was supposed to
be color-blind, or, in other words, to be
only sensitive to red and yellow rays
Now, however, Prof, Ruhnier has dis
covered, through many chemical tests,
that selenium is also sensitive to blue.
VIOLET and ultra violet, or invisible rays.
TO show the Importance Of this discov-
cry ii is only necessary to point out
that if selenium were only sensitive to
red and yellow rays it would be i'm
possible to telephone without wires
whenever the sun was shining.
The more selenium is exposed to
light the better it acts as conductor of
electricity, and on this principle Prof.
Runners invention is mainly based.
His experiments at the Wannsee
were surprisingly simple. At the trans
uniting station person spoke into the
diaphragm Of the ordinary telephone.
The sound waves then acted upon the
electrical current by which the light
was produced, and this light was car
iied to the receiving station. There
the light acted upon the selenium,
which, as has been said, conducts the
current better or worse. according as
the light is strong or weak, and
through the aid of the current, which
was successfully weak and strong, the
same sounds as those generated in the
transmitting station were exactly re-
produced in the receiving station.
Moreover, the diaphragm vibrated in
the same manner in each station, and
the sounds sent forth from one point
were distinctly heard at the other. The
selenium used on this occasion was in