Martinsburg independent. [volume] (Martinsburg, W. Va.) 1875-1900, 1891-12-19
IEg0l IDS OF VOLTS.
sTARTLiA1 EFFECTS or SOME iIidil
TElsslOM CURRENTS.

Wonderful What May Bn Done with a
Current of 10, 900 Volts Can Hardly Be
Tmasiaed-.-lsemarlsa6i sights.
Several tests have been made with
alternating currents Of electricity at very
high pressures. AS only / 800 volts were
needed to kill the condemned nurderers
in Sing Sing prison, the effect of $1,000
and $4,000 volts on animate and imam
innate objects can hardly be imagined.
The difficulty of insulating the enormous
force is very serious, as an arc will flash
across four or five inches of space be-
tween the electrodes, and high tension
currents have not been used much. The
current for the lights and power at the
electro-technical exhibition at Frank
fort-on-the-Main was transmitted from
Lauffen, where it was generated by
water power, at a pressure of 10000
volts. After the close of the exhibition
experiments were made with the wire
and insnlators at high pressures. and
they We're among the most interesting of
the electrical experiments.
The distance between the cities is
about 1903 miles, and the wire. one
eighth of an inch in diameter, weighed
10000 pounds. The insulators were
able to preserve the intensity of the cur
rent. Each was composed of three sec
tons. The porcelain top was fat, with
a deep groove for the wire. Underneath
was saucer shaped receptacle, and be-
meath that were two more, one Of larger
breadth and depth than the other, and
all were filled with oil. The binding
wires ran through the oil, which is
good nonconductor. st Frankfort a
commutator changed the alternating
current to continuous current for light
and power. In the experiments the
pressure was increased to 10000, 10000
and As, 900 volts.
Beyond 27,000 volts the porcelain in
sulators were puuctGred frequently. In
producing an arc between two carbons
at 10000 volts u plate Of glass was
pierced very quickly. At $4,000 volts
the intensity was so great that the light
was not SO brilliant as it was at 10000
volts. It is believed that $4,000 volts
can be reached with conductors pro-
tectel from the effects Of weather.
CURRENTS or 10000 VOLTS.
Almost at the same time the Siemens
Bros, OF London, were experimenting
with high tension currents, having had
at the Naval exhibition an apparatus
capable of delivering current at pres
sure of 5000 volts This description of
a private exhibition of the apparatus
with 10000 volts is from Engineering:
son d table was al eleetrode some
three inches in length, connected to one
terminal of transformer. Over it was
mounted large sheet Of glass three mil
lmeters thick, and above the glass was
a second electroae terminating in sharp
point, the distance between the cleo
trodes being three centimeters. When
the current was turned on to the primary
coil of the transformer there first ap-
peared purple haze at the upper cleo
trode streaming toward the glass. AS
the current increased this haze grew in
fullness and definition, and began to
throw out feelers, which darted outward
and as quickly withdrew As the cleo
tromotiye 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 cleo
trode. The whole space below the point
ed conductor became alive with them,
and exhibited mass of leaping, crack
ling threads of purple fire, which writhed
and twisted in impotent attempts to
burst through the barrier, and failing
that, spread themselves along its surface,
endeavoring to rush over its edges, and
so reach their goal by a circuitous route.
''But this was beyond their strength
until the electro-motive force approached
$4,000 volts, when suddenly the entire
appearance was changed. The current
overleaped the edges of the plate and
flowed completely around it in all d.
rections. al that moment the intense
purple color of the spark disappeared,
and was replaced by white light of the
greatest brilliancy, which glistened and
flashed until the spectators had to turn
away their bedazzled gaze.
REMARKABLE EXPERIMENTS.
ga change in the arrangement was
then made. The upper pointed electrode
was replaced by a brass disk, three
inches in diameter. This was laid over
the surface Of the glass plate with three
very thin washers of vulcanite, inter
vening between the two The current
was then turned on in the same gradual
manner as before. The space between
the two disks Immediately filed with
purple light, which had sufficient motion