Wilmington daily commercial., 1872-09-12
rFroii Appleton's Journsll
PROTECTION FROM LIGHTNING.

w. l'n.yrrtheless true that the amount of dam
o,e 10 life and property, occasioned every
,1sr by lightning, is something appalling.
H. those who think of the subject for the
drst time it may perhaps appear that the
LANCER TO which we are exposed from light
nng is very slight; but those who have care
s',ll1 noted the number of persons injured by
Lining during the course of the year are
",,sre that the risk of accident from this
D,rrce is greater than that incurred by tray
,llers ON our railroads in other words, that
,he number of persons killed by lightning is
',rcatpr than that killed on our railroads
rims during the ten days succeeding July .,
~ no less than fifteen persons were killed
hv liphtning in the Northern and Eastern
STATES. A succession of three railroad acct
lpnts. in each of which five persons had been
l0lsd would have Mortified the community
Inf these fifteen deaths by lightning seem to
attract but very little attention. When we
cnme to extend our Investigations over q
Ionrer period, we find substantially the same
results. Poey, in 1855, found that. during
the preceding twelve years, there were re-
corded 2G2 cases of persons that had been
Killed. and 430 injured while, of course as
every one knows. the cases that escape the
notice of the statistician are generally quite
as numerous as those that are recorded. In
France, during twenty nine years, an average
If II persons lost their lives and 232 were
injured. per annum, as may be seen be refer
ring to the report of Boudin, presented TO the
Academy of Sciences, in 1864. The most
perfect records were kept in Mecklenburg,
where It was found that one person was killed
ont Of every 247, 200 inhabitants. Now, on
Enesh railroads, the death-rate Is one for
every $50, 80 passengers; and, in France,
the ,leath-TatC IS one for every ,955, sos pas
senscrs In short, statistics fully bear us out
in saving that, on our worst-managed roads,
the per centage of passengers killed is not as
great as the per centage of the whole popula-
lion that is killed by lightning. These melan-
choy facts should lead to an earnest consid-
Grafton of the best means of avoiding light.
nng-srOkes; and, fortunately, ii is the opin-
ion Of our most judicious and most tho
roughly Informed men that all danger from
this source may be avoided, at least in ships
aud houses. In the British navy, where the
very perfect system of protection, devised by
sir William Snow Harris, is in use, injury by
lightning has become a thing almost unknown;
while, previous to its adoption, the material
loss was valued at $250,000. The Cathedral
Of 81. Peter, in Geneva, although so elevated
as To be above all other buildings in the
ncighborhoOd, has for three centuries enjoyed
perfect immunity from damage by lightning;
while the tower of st. Geryaise, although
much lower, has been frequently struck.
This doubtless arises from the fact that all
the towers of st. Peter are accidently fur
nished with very perfect conductors The
great column of London, known as the Mon
umcnt, erected in 1871 in cOmmemoration of
the great fire, although over two hundred feet
in height, has never been struck while much
lower buildings in the vicinity have not es-
capped The Monument however, is prOtec-
ted by a most perfect conductor; the upper
end terminating in vase, from which pro-
coed numerous metal plates designed to imi-
tate the appearance of tongues of flame.
The vase communicates, by means of stout
bars of iron, with the metal staircase which
drscends through the middle of the column
aud terminates in the ground. A still more
striking instance of the value of lightning
rods is the church on the estate of Count
Orsni in Carinthia. This building was
placed upon an eminence and had been so
often struck by lightning that it was deemed
nolunger safe to celebrate divine service with
in It's walls. In 1880, single stroke of light
ngdcslroyed the entire steeple after it had
been rebuilt, it was struck, on an average,
four or five times a year, without counting
extraordinary storms, during which 1t was
struck from five to ten times in single day
In l77S, the building was reconstructed, and
furnished with conductor; and, according
to lichtenberg, up to l7S3-that is to say,
during the space of five years-the steeple
had been struck only once, and this stroke
had fallen upon the metallic point without
producing any damage. In short, no doubt
exists in the minds of intelligent and we'll
informed men in regard to the efficiency of
well-cOnslructed ligntning-rods of course,
in this, as in every other department of APP
Piled science, we find men who excaim against
them, and men who think that such appliances
are worthless, unless some particular notions
OF their own are embodied in their construc-
lon but, on the other hand we find that the
great bulk of our scientific men are unani-
nous in regard TO their efficiency, as well as
In respect to the best methods of construct
ing them; and ii is curious fact that the
rod which now receives the greatest favor
from those who are most competent TO form
an opinion in the matter is substantially the
Old rod described by Franklin. The country
+ at the present moment Overrun by so-called
llghtning-rod men, who palm off worthless
and expensive articles upon their customers,
and in many cases are, in addition to this,
guilty of downright swindling. 1t may be
wen, therefore, to say that, by attending to Il
lew essential points, any ordinary carpenter
or house-buider can easily erect a rod that
viii give perfect protection. The points to be
attended to are three: l. The rod should be of
sufficient size-a solid iron rod half an inch
square, or a copper rod, one inch wide and
one-tenth of an inch thick, are the sizes rec
commended by the best authorities. Thin
copper strip is not easily handled but a
copper wire, No. l or 0, may be more easily
procured, and will answer quite as well. The
light tubular and fancy rods sold by itinerant
vendors are almost always deficient in metal.
There is no advantage in tubular, star-shaped,
twisted, or other rods Harris, the great au-
torily, says: "Provided the quantity of
metal be present, the form under which we
place it is evidently of no consequence to its
conducting powers" Harris "On Thunder
storms" p. 100. Becquerel, Pouilett, Fara-
day, Noel, and every electrician of note that
We have consulted, agree with him.
?. In arranging the rod, carry it along the
ridge and along the corner of the gables.
Connect It with all the tin roofs, cutters, wa
tcr-spOuts, ETC.; and do not iaSutdte6. Points
are of comparatively small consequence, and
it is not best to disfigure house by row of
bayonets stuck ON il. The crossings and fin
ials of Mansard roofs are as good lightning
rod points as can be desired. The rod may
he painted the same color as the house, but
do not allow the paint to destroy the metallic
connection between the rod and the masses
Of metal that we have mentioned. The bes
mode of attaching the rod to the building il
by small staples for wires, and tacks or nall
Tor flat strips.
3. Beyond all question, the most import
ant point in the construction and erection Of
tFfNn L. Nla md fnn