The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1896-10-12

these are called actinic rays, and then
again there is another class of which
the world has heard a great deal of late
the so-called x rays, which Prof. Roen-
| tgen made use of in seeing the bones of
| the human body.
The peculiar quality of the invisible
| rays Is that they will pass through
| substances which visible rays of light
will not pass through, and this is just
what happened when Prof. Bell thrust
| this piece of India rubber into the sun
beam path in his experiment. The
phenomenon showed that 1t was these
invisible rays which really took UP the
| sound vibrations and carried them
| along. And so from this Prof. Bell
| was led to change the name of his de-
| vice from a photophone to radio
phone. BY this new phrase the in
ventor was able to give a clearer and
more accurately descriptive name to his
invention.
But Prof. Bells researches were only
begun. The invention of the radio
phone was due to his discovery of the
peculiar properties possessed by sell
enium This is an eXceeding~ rare
| metal, so closely resembling tellurium
that the man who found it first gave
1t name which would indicate it's
relationship; as tellurium comes from
tellus, the earth, he took it's name
from selene, the moon. 1t is as ex-
| pensive as it is rare, and in his lab
oratory last spring, Prof Bell showed
the writer little glass jar which con-
tains probably the largest amount of
selenium in the world. Furthermore,
aside from it's expense, it was a trouble
some metal to deal with, and many a
long night did Prof. Bell spend-all
his work is done at night-over ways
and means for it's practical use.
1t happened one day when Prof. Bell
wished to make some experiments that
the selenium was all gone, and just by
way of hazard number of other sub
stances were tried to see if they would
act in anything like the same way.
| 1t was just from this chance expert
! ment that it was found that there are
great many substances that will do
almost as we'll. One of these was or
binary black wool. And just to show
how large a part mere chance plays
even in matters of pure science, Prof.
Bell goes on to tell of how one day he
was out of black wool, as well as
selenium. There was white wool, how
ever, and, nothing daunted, the inven-
tor proceeded to bedaub this with or
binary lampblack. And this worked
better than ever. 1t was only a little
further to experiment with lampblack
itself, and finally with just plain SCOT.
And the last it was found was the
best of all.
another Prof. Bell devised a talking
| machine, literally, out of a sunbeam
and a small phial of SCOT. At first all
the experiments were conducted in the
laboratory between one room and an
other. One day Prof. Bells coworker,
Sumner fainter, climbed up with a
radiophone transmitter into cupola Of
a school house a considerable distance
away. Prof. Bell was at the receiver
| by one of the laboratory windows,
wondering, like Darius Green, "wheth-
er the fool thing would work" Into
the transmitter Mr.. fainter cried:
prof. Bell. If you hear what | say
| come to the window and wave your
hat!''
Prof Bell did not walt for his hat.
With all the enthusiasm of a schoolboy
he jumped to the window and waved
his arms as frantically as he knew
how
Later came the experiments Of talk
ing through a distance of a mile and
half. And here the progress of the
invention stopped There were other
things to engage the attention of the in
vertor, and not until the announcement
RCentgen was able to do with his x
rays did the instrument receive further
attention. Now, however, with the
rapid progress which investigators
have made in this direction, Prof. Bell
has again taken up the work, with a
view to making the radiophone a prac-
teal and commercial invention. 1t
| would never do to have an instrument
which has to depend entirely upon sun
IferI,f 1li1 11ra
time it looked as if the radiophone
would be of no use to any one save
men of science. But it is possible that
with the advance Of electric lighting
and means of generating the X-rays,
a simple and practicable way will be
found to produce light that will rival
the sunbeam, at least for this purpose.
The conditions are that 1t shall be
sufficiently powerful, and at the same
time steady. If it does not possess the
quality of steadiness, in trying to talk
over ray of light you would exper-
fence the same sort of confusion as
when you try to telephone over wire
that is vibrating at the same time from
some ether source.
The writer asked Prof Bell what
would be the limit as to distance
through which the radiophone might op-
crate, and If it. would be possible to talk
with Telegraph. He replied that he
saw no reason why, If the right sort Of
light were found, it would not be posi-
BILE to establish a series Of rejecting
mirrors at convenient distances apart
and reflect the ray to any desired di-
rection. Provided the lenses employed
are perfectly acurate, the light would
not lose it's power, nor would the sound
vibrations be disturbed by any number
of such reflections.
theoretically 1t is entirely conceivable
that If series of mirrors were set up
at regular intervals, sufficient to over
come the curvature of the earth, it
would be possible to talk across the con-
tinent, or for that matter, were the way
clear, all around the world, with this
single original beam of light The only
condition would be that there should be
nothing in the way of an obstruction to
cross the beam in its travels.
AS to the practical use of the radio
phone, it is easy to see that with it's
simple construction 1t could be cheaply
built and might be employed for long
distances, where the cost of copper wire
would be prohibitive. It is likewise
easy to see it's utility In times of war,
when it would be impossible to string a
wire, or when wire might be cut by
the enemy. BY its means free commu-
nication could be established between
armies considerably distant from each
other or from a lookout to the head