The Scranton tribune. [volume] (Scranton, Pa.) 1891-1910, 1896-06-04
rESLA'S PHOSPnORESCENT LIGHT.
What He Has Accomplished in the
Way of Vacuum Tube Lighting.

A photograph made with light pro-
duced by the latest form Of Nikola Tes-
las apparatus for vacuum tube light
Ing has been reproduced recently In a
number Of technical and other papers,
and in some cases says the Sum-, has
been accompanied by remarkable as
sertlons regarding the new light. That
the Telsa system Of vacuum tube light
ing contains wonderful possibilities
there is no reason to doubt. but 1t Is
a mistake to assert that 1t Is going to
revolutionize the lighting systems Of
the world suddenly, and no one Is more
anxious to prevent any such misun-
derstanding than Mr. Tesla.
What ne has really accomplished Is
wonderful enough. Five years ago he
pointed out the possibility Of getting
light from the electrical effect Of pas
sing current through a tube of glass
from which the air had been exhausted.
With currents Of electricity interrupted
by the commutator Of Ruhmkoff coil,
such tubes were made to glow with
pale blue phosphorescent light, and by
introducing certain gases into the tube
the color Of the light was found to vary.
The electricity from an ordinary al
ternating current dynamo passed
through one Of the tubes would also
make 1t glow. These currents are
usually interrupted about 100 times a
second.
Experiment developed the fact that
light from these tubes from such q
source and Of such low frequency of
interruption in the current was enor-
inously more expensive than that pro-
duced in the incan'escent lamp. For
equal amounts of llgnt the vacuum
| tube glow cost ten times as much.
This was discouraging enough, but
there was also another hard problem to
| solve. There was at that time no
| known way in which this new light
| could be made intense. Big tubes, or
| a lot Of them, would give volume of
light, but only with the same pale char
| acter.
Since that time Mr.. Tesla has kept
| constantly at the problem Of develop
ing his theory and improving his ap-
paratus for proving it with the light
itself. He found that with an increase
in the frequency of electrical vibrations
the intensity Of the light increased and
its cost diminished. Ills needs soon,
however took him beyond the possi-
bilities in the way of producing vibra-
tions OF the current by mechanical
means, and his next step was to invent
purely electrical oscillator. His I'D
vance Of late has been great, he says,
but 1t is all along the line OF making
this device simpler and more econo-
mical in its parts and operation. No
material change has been made in the
lighting tubes.
With this electrical oscllator Mr..
Tesla has succeeded in producing cs
many Interruptions In the current as
f00,000,000 a second. Under such an
electrical influence, tubes. exposed only
by induction and not in any mechani-
cal way connected with the source of
electrical energy, burst into brilliant
light. The picture Of which reference
has been made was photographed with
the light of tube thus excited, but
under an influence Of only 6,00O 900 VI
brations a second. The tube, mounted
like an ordinary electrical stand lamp,
but free from wires or other visible or
tangible connections, was placed under
the influence of the oscillator. Mr..
Tesla sat between the light and its
source. and the picture shows him with
the great spider.web-lllie oscillator FOR
a background
In few weeks more, Mr.. Tesla says
he hopes that he will have reached
such q point OF success ap to warrant