The morning call. [volume] (San Francisco [Calif.]) 1878-1895, 1891-12-26
MASSES OF ELECTRIC FIRE.
Brilliant Experiments With High Power
Electric Currents.

Brilliant Experiments With High Power
Electric Currents.
An account OF interesting experiments
made by the Sienens Brothers Of London
with electric currents at the tremendous
pressure Of 10000 volts appears in Engineer
ing. The power OF the current will be
understood when it is remembered that DULY
1900 volts were used TO kill the condemned
murderers at Sing Sing, and it is generally
believed that 500 volts is fatal. Following
isS description of a few Of the experiments:
On table was an eectrode some three
inches in length, connected TO one terminal
of a transformer Over it was mounted
large sheet of glass three milimeters thick,
and above the glass was a second eectrOde
terminating IN sharp point. the distance
between the electrodes being three cent?
meters When the current was turned
on to the primary coil of the transformer
there first appeared a purple haze al the
upper electrode streaming toward the glass.
As the current increased this haze grew
in iullness and definition, and began to
throw out feelers, which darted outward,
and as quickly withdrew. As the electro
motive force augmented still further, these
feelers gathered power until they beat
themselves on the glass as If they would
force themselves through it in their mad
desire to reach the other eectrode. The
whole space below the pointed conductor
became alive with them, and exhibited
mass of leaving, cracking threads of pur-
pie fire, which writhed and twisted in i'm
potent attempts to burst through the bar
rier, and, falling that. spread themselves
along its surface, endeavoring to rush over
its edges and so reach their goal by cir
cuitous route.
But this was beyond their strength until
the electrOmOtve force approached 5000
volts. when suddenly the entire appearance
was changed. The current overIcaped the
edges of the plate and flowed completely
around it in all directions. At that moment
the intense purple color of the spark disap-
peared, and was replaced by white light
of the greatest brilliancy, which surged and
scintillated in way that produced fatigue
of the eyes in an extraordinarily short time.
Although steadier than before the discharge
still kept up its sparklike character enfold-
ing the glass plates in cleaning corrusca-
tions, which glistened and flashed until the
spectators had 10 turn away their bedazZled
gaze.
A change in the arrangement was then
made. The upper pointed eectrode was
replaced By brass disk three inches in
diameter. This was laid over the surface
of the glass plate with three very thin
washers of yulcanite intervening between
the two. The current was then turned on
in the same gradual manner as before
The space between the two disks immed-
ately filed with purple light, which had
sufficient motion in 1t to recall the flame
of q Bunsen burner spread out under the
bottom of beaker. Sparks then began
to appear at the edges and, as they gath
cred strength to radiate little beyond
them. Gradually they became streamers,
stretching out along the surface of the plate
in curved, fanciful forms which twined and
twisted and weaved themselves into a
glistening tilagree. compared by an imagin-
alive spectator to an agOniZed Japanese
chrysanthemum.
This experiment had not the brilliant re-
fulgence of the one that preceded it, but was
characterized by Quiverng irradiaton,
which wreathed and tossed like bird beat
ing itself at the bars OF its cage. In spite of
its less formidable appearance, however, it
proved destructive tn the glass. which pres
emily flew In pieces with a crash. Several
sheets were tried in succession, but each
was pierced and broken and allowed the
current to attain its object of flowing d.
rectly from one electrode to the other.