Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1914-07-21
The Truth about Lightning Rods,
GIVE PROTECTION, BUT ARE DANGEROUS
II NOT PROPERLY INSTALLED.

please publish in the News Letter, IN con
else and simple language, an article ol
lightning rods for farm buildings by
some one in authority and fully capable
to write on the subject?
This request can not be fully answered
in a short note in the News Letter, bu
the information given below seeks to an
swer in q definite and specific way tn,
most important questions involved.
/. Do lightning rods really protect
buildings? Answer: Yes; but the rod.
must be of proper character, proper
ly installed, and properly grounded in
relatively moist earth. Periodical in
spection and maintenance in good condi-
tion are indispensable to efficient pro-
lection.
2. Do lightning rods on building
increase the danger of it's being struck Z
Answer: Yes; but properly rOdded
house may be struck several times with
out injury, whereas a single stroke with
out the protection afforded by the rods
may cause disaster.
3. Should lightning rods be put up
with OF without insulatOrs? Answer
Without. Buildings with metal roofs
or wherein any metal construction en-
ployed is properly connected TO earth,
are already partly provided with light
ming protection. II rods are added to
such buildings the rods should be put in
direct metallic connection with the roof
and other metal work about the build
ing wherever practicable. All down
spouts should be led into metal pipes
going into the earth to give the proper
earth connection, or the spouts should
otherwise be well grounded by use OF
wires or cables. lnsulators are entirely
unue and it is proper to have ex-
tended metal work in buildings, like
heating and water pipes, all electrically
connected together and all we'll ground.
ed. This latter result is gained incl
dentally through connections made to
water pipes, since the latter usually pass
through the earth outside the building.
| 4 Are gilded or otherwise expensive
points of platinum or special metal or
fauciful construction necessary? An
swer: No; not in the least. Sharp
need lelike points are effective in dissi-
pating small sustained electrical charges,
but such electrical manifestations are
perfectly harmless. The imagined supe-
riority of such fanciful points is utterly
valueless when the rod is struck by a
real lightning flash. The useful quail
ties lightning rod points must possess
are iufusibility. mechanical strength and
security of installation, and permanence
and durability under prolonged exposure
to the weather. Stout bluntly- pointed
| iron rods three -eighths or one-half inch
in diameter rigidly and securely fasten-
ed 80 as to project l-2 or 2 feet above
the structure to which they are attached
satisfy all the requirements.
| s. What material Is best for conduct
ors or rods? This question can not be
answered fairly in single statement.
| Because of it's availability and cheap
ness, as we'll as its electrical properties,
/ iron Is one of the best materials for rods.
Iron, however, rusts and deteriorates
under prolonged exposure to the wealth
or. This is only partly overcome by
galvaniziug; hence galvanized'iron
| lightning rods should be OF ample size
| mot less than one-quarter inch IN diam
eter) carefully installed and subjected to
systematic inspection and repair.
| Two-strand cable galvanized-iron
fence wire of substantial size of the
same style as barbed wire but without
the barbs furnishes very good material
for cheap iron lightning rods. The pres
euce of the baIbs constitutes rather
serious Inconvenience in handling and
installing such conductor, and no ma
terial benefit is derived from their pres
ence.
Copper is better than iron not only on
account of its indestructibility but also
because of its softness and pliability
which make it easy to install. Scien-
fists are not in accord in regard to the
relative merits of the electrical proper
ties of copper and iron, but in any case
questions Of cost, durability, and the
| like far outweigh minor differences In
electrical properties.
Aluminium is a competitor for iron
and copper for lightning rods. Its dura-
bility under exposure to weather is in
It's favor, but its fusibility makes 1t In
ferior to iron for points.
IL low first cost is the controlling fac
tor, galvanized iron rods must DO chos-
en-. but subsequent inspections must be
made and repairs may become neces-
sary.
II higher first cost is not an obstacle,
the choice should 60 to copper first or
possibly aluminium.
8. Should lightning conductors be
made in the form of solid rods, fiat bars
or bands, stranded twisted cables, woven
stranded ribbons, or hollow twisted
cables? Answer: Any of the forms
may properly be employed, or two or
more forms may be employed in combi-
nation. Conductors should be put up in
long continuous pieces as far as possible.
Solid round wires one quarter TO one
half inch In diameter are best for this
purpose. Conductors OF size larger
than one-fourth inch, however, present
difficulties in handling and installation
IL the rods are solid. Ii then becomes
better to use stranded cables and other
similar forms. Long continuous
lengths, ample cross section combined
with fiexibility and the ease of its in
stallation over crooked courses render
stranded cables, in general, better than
apy other form of conductor available.
Substantial iron points In combina-
tiop with copper cables from ive-six-
tesnths inch in diameter, for small farm
buildings, to one-half inch in diameter
for large important structures form one
of the best possible systems Of conduct
ors for lightning-rod construction.
There is no good reason for purchas
ing other fanciful forms Of cable at ma
terially greater prices per pound than
are asked for standard makes OF cable OF
approximately the same cross section.
I. Must lightning rods be connected
10 the earth? Answer: Yes; BY all
means, and most effectively. Just q
few operators in the lightning rod pro-
fessiou have sought to impose upon the
uniformed q system Of ungrounded
ng btping rods. Such rods are menace
instead Of protection. 1t 10 impracti.
cable to fully discuss here methods OF
making connections to earth. In general
terms the conductor should DO carried
down into the earth and away from the
building in trench or other excavation,
90 a. to reach and imbed the conductor
itself or plates attached thereto into
permanently moist earth. Connections
with water pipes or other metal work 1t.
self conn ected to earth constitute good
grounds. >,
s. Are Goversmsnt buildings provid.
ed with lightning rodsp Answer: Yes;
many of them, but naturally not every
one.