Lexington weekly intelligencer. (Lexington, Mo.) 1871-1887, 1882-11-11
LIGHTNING CONDUCTORS.

The following excellent rules for
the construction and erection OF light
ming conductors are based on the
practical aud theoretical evidence
taken by the lightnlng-rod conference,
recently held in London, to deter
mine the best Kind of protectors to
place on buildings employed for the
manufacture and storage of exPlos-
ives:
l. Material of Rod-Copper, weigh
ing not less than six ounces per loot
run, the electrical conductivlty OF
which is not less than 60 per cent. OF
that Of pure copper, either the form
of rod, tape, or rope OF stout wires,
no individual wire being less than
No. ~ 3. w. &. (109 seconds.) Iron
may be used, but should not weigh
less than two aud one-quarter pounds
per foot run.
2. Joluts-Every JOINT, besides be-
ing we'll cleaned and screwed, scar
fed, or riveted, should be thoroughly
soldered.
8. Form of Points-The point of
the upper terminal of the conductor
should not have q sharper angle than
60 degrees. A foot below the extreme
point q copper ring should be screwed
and sOldered on to the upper termin-
al, in which ring should be fixed three
or four sharp copper points. each
about six inches long. 1t is desirable
that these points should be so platin-
lied, gilded, or nickel-plated as to
resist oxidation.
4. Number aud Height of Upper
Terminals-The number of conduc.
tors or upper terminals required will
depend upon the size of the building.
the material of which it is construct
ed, and the comparative height above
ground of the several parts. No gen.
eral rule can be given for this, except
that it may be assumed that the space
protected by a conductor is. as a rule,
a cone, the radius Of whose base is
equal to the height of the conductor
from the ground.
5. Curvature-The rod should not
be bent abruptly round sharp corners.
In no case should the length of q curve
be more than half as long again as its
chord. A hole should be drilled in
string courses or other projecting
masonry, when possible, to allow the
rod to pass freely through it.
6. Insulators-The conductor should
not be kept from the building by glass
or other iDsulators, but attached to it
| by %fasteniDgs of the same metal as
the conductor itself ia composed Of.
Z. Fixing-COnductors should pre-
ferentislly be taken down the side of
the building which is most exposed
to the rain. They should he held
firmly, but the holdfasts ehould lIot
he driven liz SO. tightly as to pinch
the conductor or prevent contraction
and expansion due to change of tenn
perature.
s. Other Metal Work-All metallic
spouts, cutters, irou doors, and other
masses of metal about the building
should be electrically connected with
the conductor.
6. Earth Connecfion-It is most de-
sirable that, whenever possible, the
lower extremity of the conductor
should be buried in permanently damp
soil. Hence proximity to railway
pipes and to drains or other water is
desirable. II is a very good plau to
bifurcate the conductor close below
the surface of the ground, and 10
adopt two of the following methods
for securing the escape Of the light
ming into the earth: () A strip of
copper taps may be led from the bot
tom of the rod to a gas or water main
quot merely to a leaden pipe) if such
exist near enough, and be soldered to
it; (2) a tape may lie soldered to q
sheet of copper 8 feet by 8 feet by
1-16 inches thick buried in permanent
ly wet earth and surrounded by
cinders or coke; (s) many yards of
copper tape may be laid IN a trench
filed with coke, having not less than
10 square feet of copper exposed.
10. Protection from Theft, etc.-In
cases where there is auy likelihood of
the copper being stolen or injured, it
should be protected by being inclosed
in An iron gas-pipe reaching ten feet
Cf there is room) above GROUND, aud
some distance into the ground.
IL. Painting-Iron conductors, gal
~vanized or not, should be painted. 1t
is optional with copper ones
IL. lnspection-When the conduc-
tor is finally fixed, it should in all
cases be examined aud tested by a
qualified person. and this should be
done in the case Of new buildings af-
ter all work Oh them is finished.
IS. Periodical examination aud test.
ing, should opportunities offer, are
also very desirable, especially when
iron Garth counnctiOue oro ON, lnro1