The Newberry herald. [volume] (Newberry, S.C.) 1865-1884, 1884-03-20
For The HERALD.
THE LIGHTNING ROD.

| FOX 1hS he hALO.
. THE LIGHTNING ROD.
In 1852, DR.. Franklin discovered
that frictional electricity and light
ming are. identical. Whatever is
true then of eIectricityis true oflight-
ming. These facts are known: 1st
Electricity exists in all bodies in a
| disguised state, consisting Of two
| kinds so opposed to each other that
they have been called the positive
| and the negative. I'd feither kind of
electricity is in a free state it at
tractsthe other kind, and ifthey meet,
they neutralize, just as fire and water
neutralize heat, when the one has
contact with the other. 3rdly. Some
bodies are very good conductors
of electricity, Others very poor con-
ductors,while some substancesrefuse
to conduct it under any circumstan-
ces. For example, copper and iron
are very good conductors, dry
wood a very poor conductor, and
glass, feathers, varnish and woolen
goods are non-conductors. Water,
in any form, is good conductor.
The gases which rise from a
chimney are good conductors.
4thly. If current Of electricity is
traversing any substance, and en-
counters even a slight resistance,
it will leap to any other object near
it, provided that object be a better
conductor than the one along which
it is flowing. Indeed, a good con-
ductor will rarely fail to attract
the current from poor conductor.
To increase the conductivity of any
substance, attach points of copper
highly polished. 5thly. The earth
! and the air are always charged with
electricity, the one kind existing in
the earth; the other kind existing in
the air. Between these two there is
always a communication going on,
whenever a conductor can be found
for their passage, 9Th. If fracture
exists, or variation Of density, in
the conductor, or if any cause in
terferes with the continuity of the
conductor, the current does not
| flow freely.
These facts are sufficient to en-
able US to determine (a) in
what way a lightning-rod protects
a building and d(b) in what manner the
rod should be joined to the build
ing. A lightning rod is Of much
J service during clear, warm, wealth
er by afording to the electricity OF
the earth and the air an opportuni,
ty of contact, thus preventing a
surcharge in either of the ele-
1 ments. lion a fair day, metallic
rod g. few feet in length, painted at
the top and insulated at the bot
tom, be elevated and its lower ex-
tremity be connected with an cleo
troscope, the presence of electricity
will be very satisfactorily indicated
by the divergence Of the gold-leaf.
Currents Of electricity are contin-
ually traversing the earth's surface,
seeking intercourse with the elec-
tricity of the air. If Q rod, well
connected, be attached to building;
the finds are brought into COM
munication and nentralized !; but if
there be no rod, the timbers, being
imperfectly jointed and poor con
ductors, prevent the neutralizing
which would otherwise occur, and a
large quantity Of electricity is thus
| left in free state. A cloud comes
over, and. by the process of precip-
itation, immense quantities of elec-
tricity are developed in the cloud
which attract the free electrici'
| ty of the opposite kind in the earth,
and fash Of lightning is the re-
suit. But, suppose. on the contra
~, that the building has been we'll
protected with rods, no charge pro.
badly exists in the earth, and that
of the cloud must pass on to some
other locality before it will be
drawn to the ground. If, however,
that of the cloud should happen to
find a sufficient quantity of the op-
posite kind in the vicinity of the
building, mutual attraction would
cause. the two fluids to rush togeth-
er by means of the rod, and their
energies be thus destroyed. If the
foregoing be correct, the proper
erection of lightning-rods becomes
a very simple process.
The material Of the rod ought to
be copper, but as iron is generally
used, it will be taken here. Take
an iron rod 64-100 so. In. cross
section, either square or foaad, care