Shepherdstown register. [volume] (Shepherdstown, Va. [W. Va.]) 1849-1955, 1888-04-13
LIGHTNING.

gives and exhaustive treatment of the
above subject Among other state
ments it say that friction of water par
ticles has been known to generate
electricity since the days of Arm
strong's electrical machine, in>which
a jet of steam escaping from a narrow
pipe was found to be electrified. There
is reason to believe that the particles
striking against each other, or against
the atoms of the air, may also give
rise to electricity.
A charge of electricity may induce
another charge of electricity of DIN OPP
posite kind from itself on any conduct
ing matter near it. Now as the earth
is composed of what may be called
conducting matter, it is evident that
charged cloud sailing over the sur
face of the earth induces an opposite
charge on the ground below.
By well-known law of electricity,
two bodies containing opposite
charges have tendency to rush to-
wards each other, combine and neu'
tralize This action is illustrated in
an ordinary thunder shower, as when
they are able to overcome the resist
ance of the air between them, the
opposing charges of electricity leap
together with flash and a report
l.. h. &C al
near together, one of them may take
the place of the earth, and the ex
change of electricity take place be-
tween them. Lightning of this kind
does not pass to the earth, but this
phenomenon gives rise to what is
known as the back stroke"
This back stroke is not due to the
direct flash and discharge. 1t is caused
by the reaction from a discharge
which has taken place elsewhere. III
a large area of country were covered
by "a thunderstorm which induces q
charge OF electricity in a cloud, the
electricity will naturally gather
upon the most prominent objects
of the landscape, namely, the build
building and hills of the district.
In this case the whole atmosphere
of the region is in state of tension,
and it may be called suspense. The
charge of electricity is almost strong
enough to leap across the space be-
tween the cloud and the nearest OBJ
ject of the landscape. Presently there
is flash and the tension relieved.
The discharge has taken place at the
point which offers the path of the
least resistance through the air, and
the place at which the electric tension
was the most critical. When this dis
charge takes place and suddenly neu-
tralizes the opposing tensions of cleo
tricity, the change so suddenly made
is sometimes almost as fatal as direct
discharge, owing to the sudden fall OF
electrical potential, or collapse to its
old condition, being what is called
return stroke
The article further states that there
is no real safety during a thunder
storm except within the area properly
protected by a lightning conductor,
or i'll building which, being built Of
iron, for instance, is itself conductor.
A lightning rod may be a small affair,
example, two or three twisted lengths
of telegraph wire, but should only be
applied TO the building by person
who perfectly understands his bust
ness. Otherwise it may prove source
of danger instead of safety.
Chimneys are often struck, owing
to their creating currents of warm
smoke, and by their lining of conduct
ing SCOT, thus rendering them very
dangerous parts of house.
Many times fire balls seem to be dis
charged during the lightning display,
and they seem often to play queer an
ties. The true nature of fire balls is
not well-known. 1t may be possible
that they are the luminous end of a
gentle discharge of current electricity
passing between a charged cloud and
the earth.
Engineering states also that light
ming rods should be periodically in
spected and tested by competent per
sons. In order to do this, circuit is
completed by means of wire from
the top or point of the rod to the
earth, and the whole circuit is then
tested by current of electricity