The sun. [volume] (New York [N.Y.]) 1833-1916, 1907-07-21
LIGHTNING AND ITS DANGERS
LOSS OF LIFE GRE iTER THAN
COMMONLY SUPPOSED.
Trees ms conductors AMI How They Might
lie Made safer Itcrugcs-Best Kind
OF Rods -S0mc abandoned Notions
-TOurIsts' Experience an Mountain.

II mischief lone by lightning. In France
md Germany statistics on the subject
are systematically tabulated by the Govern
ment every year. If complete statistics
were accessible there can be little doubt
they would show that the annual loss OF
life and property il far greater than il
commonly supposed. In one respect the
damage is often greater than 1t need be.
oven apart from any consideration OF
lightning conductors
During five or six days i'm the summer OF
1891 il was estimated by u competent au-
thority that besides other mischief not
less than six hundred animals Of one sort
and another in England were killed by
lightning, most Of them being sheep and
cattle in the field. In all such casualties
il IL usual TO regard the Carcasses as unit
for human food. says the London Chronicle,
and they are ordinarily buried. MIR. Att
field. professor Of chemistry 10 he Pharma-
ceutical Society. has pointed out hat this
is often an unnecessary waste.
The carrasses are not in the slightest
degree affected ~ regards their whole-
someness as food by the electric discharge.
and If within a short time after being struck
down they were treated as in the ordinary
process Of slaughterinE and the veins
and arteries drained before the blood had
coagulated there COULD be no reasonable
objection to their hping eaten.
This summer has been especially dis
disastrous. In various parts Of the country
thunderstorm have been frequent. and
scarcely "A week has passed of late in which
the newspapers have not recorded the
destruction Of sheep and cattle.
But besides the killing of sheep n cattle
there have been several disasters fatal 20
human life. 10 say nothing of "A great deal of
mischief TO property. Of various kinds.
Here, again, the mischief is often quite
easily aVOidabl". IL Is, Of course, very
we'll known that a good lightning conductor
properly fixed is an absolutely reliable
safeguard against all injury; hut IA fact
which is not 80 well known is that an efi-
Cient lightning conductor might often be
set up at the cost 81 a few shillings by taxi
ing advantage of the conducting power
Of trees.
Everybody should be aware Ivy this
time that trees are IA source of peril IN times
of thunderstorm though from accidents
which every now and again occur it would
seem that there ~ still a great amount
of ignorance on the subject. Only a few
days ago n lightning flash struck "A poplar
tree near Winchester and Killed a man who
had taken shelter AT the foot Of il, no doubt
in ignorance OF his danger, Such fatal
tiles are exceedingly mno and IL has not
~infrequently occurred that cottages and
other buildings have been struck by light
ming in consequence of the vicinity Of some
tall tree.
IN casualties to animals are often due 10
the fact that with the commencement of a
thunder shower they are apt TO gather
.or shelter beneath the branches OF some
isolated tree. The explanation of the mis-
c:;ef is very well known. A tree il a con-
dGctor of lightning. but not a very good one.
lii the absence of a better Channe the
lightning will fash through it, but there is
always a nance of It's glancing aside TO
any medium that affords a reader passage.
Now the body Of "A man or an animal con-
%stitltes a much better due than a
tree does, and consequently the electricity
whenever il has an opportunity Of doing
So will leave the tree and flash through
the animal body. The same thing will
often occur when the lightning, passing
downward through the tree, reaches a
point at which a reader passage is pre-
scented by some adjacent building. The
full Volley is detected from the tree into
the building.
IL has been suggested that in all such
cases If n metal rod were carried from
the earth for a short distance up the tree
there would be no such detection. The
metal conductor would afford a reader
passage than the body of a man or the
materials OF "A house. and the tree, which
otherwise is "A source OF danger, would
become an absolute protection, even TO
persons or animals sheltering beneath il.
VI tOo'ty "oste eeb'o bAot Oil
trees should he thus dealt with, but il often
happens that from its special position q
tree during "A thunderstorm is not only a
source Of Some peril but is the occasion
Of much uneasinesS and anxiety.
According TO the lightning rod conference
appointed a few years ago by the Meteoro-
logical Society OF london to inquire into
the subject and report on the best form
Of the thing there is nothing much better
than a solid iron rod. On the newest Of
our public buildings. such as h new Law
Courts, where il may be assumed they
would act on the best professional advice,
they have adopted fiat bands OF copper.
These are made in sizes varying from
a sixteenth to an eighth Of an inch thick
and from three quarters of an inch to two
or three inches wide. The copper il a
somewhat better conductor than iron. and
the fat bands adapt themselves more
easily 10 the walls Of a building than a
thick rod. But the iron makes a very
satisfactory lightning rod, and provided
it is quite continuous and embedded we'll into
the earth, going down, If possible. into a
moist stratum Of soil. it affords perfect
security.
The cost Of such n rod up n house or
the main trunk Of "A tree TO a height a little
beyond that of surrounding objects is really
very trifing.
protective power of a good lightning rod are
not perhaps equally we'll aware tina it may
serve not only to direct harmlessly to earth
an actual discharge OF lightning, but may
also prevent the occurrence OF the nash by
conducting the electricity I'M silent stream
80 to speak. For this purpose electricians
now recognize the fact that it Is important
that the conductor shall terminate In a
sharp point, indeed the most approved
form OF lightning rod now has a corona
Of points, and a practical difficulty IL to Keep
these terminals sufficiently pointed by
preventing corrosion. When IL Ia prac-
ticable to do 10, they should be periodically
Examined, and should DO repointed when
they are found to have rusted away
The notion prevalent at n time that a
conductor should terminate In a ball Is
quite abandoned, and 80 also Ia the idea
that a tube IL better than q solid rod. IL
Used to be thought hat electricity passed
only by the surfaces Of the conductor, and
as a tube presented more surface thar a
solid rod the tube was for n while the fav-
orite form. This is now known to have
been a mistake.
1t is true that electricity at rest distributes
itself over the surfaces Of a conductor, but
when in motion IL passes through the whole
mass. and the efficiency of O metal rod Of
any given kim Ia TO be gagged by It's sec
tional area, only, a. IL has been said, that
sectional area must terminate in q point,
the finer the batter