The Pickens sentinel-journal. (Pickens, S.C.) 1903-1906, 1904-12-07
DANGEROUS gLEcrRlclrY.
Occasions When High yoltages Do LIttI
Harm.

A great sensation was produced ten
OF twelve years ago, when prominent
| American electrician, Nikola Tesla, eX.
posed himself to the effects of a cur
rent whose pressure was said to be
| million volts. Well, there may lave
been some eXaggeration in that state
| ment, but there seems to be no queS-
tion that the voltage was far beyond
what was then regarded the limit OF
safety. A trolley current has Il pres
sure Of between 500 and 600 volts.
and, while it cannot we'll prove fatal.
it is thing to be treated respect
fully. For the execution of the death
penalty, at Sing Sing and Auburn prls-
ons, it is customary to employ only
about 1000 or 1900 volts.
Now, there are two things about les
las experiment which, in combination.
afforded comparative immunity. One
was that he did not use the continu-
Gus, or direct, current, but an alternat-
ing current. That is to say, the cleo.
tricity first flowed in one direction and
then in the opposite, the changes oc-
curing with extraordinary frequpn-
cy. If they had been produced at the
rate of only one or two or twenty-five
or thirty per second, serious harm
would have resulted. The alternations
which Tesla secured numbered many
neutrality-suspicious. a million per sec
ond. What he showed, therefore, was
that if the frequency was high enough
almost any voltage could be handled
with impunity. The feat was spec
tDpniop htIt ~
because for such things as lighting
low frequency is preferable. Never
theleSs, the revelation set scientific
men to speculating over the cause of
Mr.. TeSla's immunity. a favorite the
ory at that time was that the action
of the current was confined to the skin
and did not get below the latter.
Professor Nernst, inventor of an
electric lamp that has proved more
popular in Europe than America, now
questions that conclusion. In com
municatiOn to the Bunsen Society, he
expressed the opinion that high fire.
quency currents do penetrate the soft
cellular tissues beneath the skin, but
that they do not have time to work
any change in it because the reversal
OF direction comes so soon. OF course,
the correctness of either explanation
is of less Importance than the main
fact but the human mind is so con-
Stituted that it always wants to know
the reason for strange things. AS yet
other scientists have not publicly pro-
nounced upon the accuracy Of Profes-
sor Nernst's views, but will doubtless
do so in time.
With direct and low frequency al
ternating currents accidents some
times happen which are not followed
by the consequences which might nate
uralIy be expected. One often readS
an account of what seems to be, and
probably is. Il narrow escape. A per.
son is exposed to n current of high
voltage and receives IL painful shock,
but is practically unhurt. For such
incidents there are Il variety OF cA-
plantations. If bare wire is touched
with perfectly dry hands or with
greasy hands, the effect is trlhing. A
good electrical contact between metal
and flesh is obtained only when the lat
ter is moist. Grease acts as an insu-
iator. Dry clothing does, too. More
over, there is no likelihood that cleo
tricity will bother Il person unless he
makes two good contacts and the cur
rent can flow through him. 1t must
he able to get oft as wei! as to get in
y man might bend over and touch IL
third rail, used to operate an electric
railway, but he would not feel any
effect unless some other part OF his
body simultaneously roStpn on II SOC.
ond metallic object, which formed
part of the circuit One contact is not
enough. New York Tribune.