The times. (Owosso, Mich.) 1882-1897, 1883-08-10
Provide Your Own lightning Rodp

LIZ. NeO lHurDer gives mucn Valua-
bic information in an article on the
above practical question in the Ameri-
can AgriculturiSt for August.
First. AS to the rod itself. 1t is well
known that copper is a much better
conductor of electricity. than iron, but
it is so expensive that iron is most gen.
orally used, making the rod much larger
than would be necessary if it were of
copper. The shape is of no consequence
and the twists and grooves in some
patented" rods are merely to beguile
the ignorant. The rod may be of round
| 7-16-inch iron, or it may be fiat strip
an inch wide and SIG of an inch thick.
If more convenient to procure, larger
iron may be used, but it should not be
smaller than these sizes. 1t is very i'm
portant that the rods be continuous.
The pieces of round iron may be Joined
by couplings, which are cut with q
screw-thread on the inside, while the
ends of the rods are made to fit. The
portions are usually joined by welding.
Second. The manner of fastening to
the building. At one time it was GUS
tomary to pass the rod through glass
ring, which was fastened to the build
ing, and the rod thus kept from contact
with it. But insulators of this kind are
quite useless, for as soon as they are
wet they cease to insulate. The rod
may be attached by staples. There is
not the least danger that lightning will
leave the rod to pass into the house by
way of the staples. A fiat rod may be
fastened by strap of iron fashioned to
IL L.. l.
Some years ago there was an idea that
the conducting power of the rod would
be injured by painting it. This is not
true. Paint the rod of any color that
will make itas inconspicuous as possible.
Third. How far will a rod protect
The old rule was that a rod would pro-
tect an area with radius twice as
great as the hight of the rod. In prac-
tice little attention is paid to this rule,
it being customary to provide each
chimney with a rod, which, IN most
houses, will bring them much nearer
than the above rule requires. Each
chimney should have rod, connected
with the main rod, which runs along the
peaks of the roof and to the ground.
Upon all ordinary buildings but one
main rod is needed. If there is roof
Of tin or other metal, this, rs well as all
iron crestings and other ornaments,
should be connected with the rod
Fourth. The upper end of the rod.
Formerly much stress was placed upon
having the rod terminated above by a
very sharp point, which should be kept
gilded to protect it from rust, and later,
platinum points were used. At present
neither of these are regarded necessary.
The rod extends foot or two above the
top of the chimney, and is filed to point.
The various ornamental crossings much
used on buildings answer Us points. If
the chimney is long distance from the
gable-end of the roof, it is well to place
short upright piece of rod there, which
should, of course, be pointed.
Fifth. The lower end of the rod. The
mere placingof the lower end of the rod
in the ground, so that it will be out of
sight, will make the rod intended as q
protection source of danger, and the
building would he safer without it. The
whole object of the rod is to carry off
the electricity quietly. and its usefulness
depends upon proper termination in
the ground. Dry earth is a poor con-
ductor; moist or wet earth is good
conductor. The lower end Of the rod
should reach place where the earth,
in the dryest time, is always moist.
Some dig down to this point and then
surround the lower end of the rod for
few feet with coke, which absorbs
moisture and is an excellent conductor.
The ease of finding moist stratum for
the rod will differ with the locality, but
II should always be secured.