Milford chronicle., 1914-07-24
ten QUESTIONS and ANSWERS
ABOUT LIGHTNING RODS

This request can not be fully answered
IN short note in the News Letter. but
the information given below seeks to an
swer in a definite and specific way the
most important questions involved
+ ~ Do lightning rods really protect
buildings? Answer Yes but the rod.
must be of proper character, properly
installed, and properly grounded in
relatively moist earth. Periodical in
| spection and maintenance in good condi-
ton are Indispensable to efficient protec-
ton.
~ Do lightning rods on building
increase the danger of its being struck
Answer: Yes but a 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
90 Should lightning rods be put up
with or without insulators? Answer :
Without. Buildings with metal roofs or
wherein any metal construction employed
is properly connected to earth are already
partly protected with lightning protec-
ton. If rods are added to such buildings
the rods should be put in direct metallic
connection with the roof and other metal
work about the building wherever prac-
ticable. 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. InsulatOrs are
entirely unnecessary and il is proper to
have extended metal work in buildings,
like heating and water pipes, all electri-
cally connected together and all well
grounded. This latter result is gained
incidentally through connections made
to water pipes, since the latter usually
pass through the earth outside the build
ing.
(4) Are gilded or otherwise expensive
points of platinum or special metal or of
fanciful construction necessary? Answer:
No; not in the least. Sharp needlelike
points are effective in dissipating small
sustained electrical charges, but such
electrical manifestations are perfectly
harmless. The imagined superiority of
such fanciful points is utterly valueless
when the rod is struck by real light
ming flash. The useful qualities light
ming rod points must possess are infusi-
bility, mechanical strength and security
of installation, and pernanence and dur
ability under prolonged exposure to the
weather. Stout, bluntly- pointed iron rods
three-eighths or one-half inch in diane
ter rigidly and securely fastened so as to
project one and a-half or two feet above
the structure to which they are attached
satisfy all the requirements,
Isl What material is best for conduc-
tors or rods?
This question can not be answered
fairly in single statement.
Because of its 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 wea-
Their. This is only partly overcome by
hence galvanized-iron light
ming rods should be of ample size mot
less than one-quarter inch in diameter
carefully installed and subjected to sys-
tematic 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 a very good material for cheap |
iron lightning rods. The presence of
the barbs constitutes a rather serious in
in handling and installing |
such a conductor, and no material bene
fit is derived from their presence.
Copper is b1tter than iron not only on
account of its indestructibility but also
because of its softness and pliability
which make it easy to install. Scientists
IRE not if accord in regard to the rela-
i've merits of the electrical properties OF
copper and iron, but in any case cues
ions of cost, durability, and the like far
outweigh minor differences III electrical
Aluminium is a competitor for iron and
copper for lightning rods. Its duTaml-
tv under exposure to weather IS IN us
avor, but its fusibility makes II inferior
o iron for points. If low first cost IS the
controlling factor, galvanized-iron rods
must be chosen, but subsequent inspec-
ions must be made and repairs may be-
ONE necessary.
If higher first cost is not an obstacle,
he choce should go to copper hrst or
,ossibly aluminium.
t6) Should lightning conductors be
made in the form of solid rods, fat bars
r bands. stranded twisted cables, woven
trauded ribbons, or hollow twisted cables;
answer: Anv of the forms may properly
e EMPLOYED. or two or more forms may
e GupiOyGu III NOAAbAAatASA-s
DIS should be put up in long continuous ]
ieces as far as possible. Solid round
Tres one-quarter to one-half inch IN d.
meter are best for this purpose. Con
uctors of a size larger than one-tourth
ich. however, present difficulties IN
andling and installation if the rods are
bid. It then becomes better to use
.rauded cables and other similar forms. g
ong continuous lengths, ample cross
ection combined with the fexibillty ana
lie ease of its installation over crooked !
purses render stranded cables, IN gen G
raj, better than any other form OF CON
uctor available.
Substantial iron points in combination
it'll copper cables from fve-sixteentns j
lch in diameter, for small farm build s
lgs. to one-half inch in diameter Tor
rye important structures form one OF
le best possible systems Of conductors
r lightning-rod construction.
There is no good reason for purchasing
her fanciful forms of cable at materially
eater prices per pound than are asked .
r standard makes of cable OF approx
atelv the same cross section.
ar Must lightning rods be connected
The earth7 Answer Yes by all means, u
ID most effectively. Just few opera ;
rs in the lightning rod profession have ?
upht TO impose upon the unintormedd 3
stem of ungrounded lightning rods.
= ut a. n