The Somerset press. [volume] (Somerset, Ohio) 1873-1977, 1878-08-08
Danger From Lightning.

lightning possible, and what are the
means by which the risk may be lessened
or avoided7 An isolated tree, standing
either upon a wide plain or upon an en-
inence, is obviously likely to determine
lightning discharge, to "attract the
lightning" to use common expression.
The top of the tree is the nearest point
to the cloud, and since the tree is bet
ter conductor than the air, a line drawn
vertically through it to the cloud marks
the shortest and easiest course along
which the electricities may pass. If,
when the charged cloud arrives directly
over this point, the tension il sufficient
to overcome the resistance along tina:
line, a discharge will take place, and
the tree will be struck. But if the
tension be not sufficient, the cloud will
pass harmlessly over. Hence it appears
that person standing during a thun-
der-storm beneath tree so situated
is exposed to some risk. On
no account, therefore, should the
traveller take refuge under an is
olated tree; generally he will do we'll
to avoid its neighborhOod altogether !;
but should he be overtaken by the storm
when on plain with no shelter near,
the tree may still be made to afford him
some protection. If he take up posi-
tion near it, but not under its branches,
he will probably escape unhurt should
the lightning descend upon it. The
safest distance from the tree is that
which is equal to its height. To ap-
proach much nearer than this is to in
cur the risk of being within the in
fluence of the stroke; to remain at a
much greater distance away is to place
ones self in the same conditions of isola-
ton as the tree itself. 1t will have
been remarked by all observers of the
phenomenon that whenever tree has
been struck by lightning it has generally
occupied an isolated position. In scrib.
ing the position az one of isolation, how.
ever, it is not meant that the tree is nee
essarily standing alone, but that it is not
one of numerous group. When there
are many trees together. their collective
conductivity is often sufficient to cause
an indestructive discharge of the elec
tricity. This is especially likely to hap
pen when the trees are wet with rain
for then their surfaces are covered with
film of water, which is good condu-
tor. For this reason, the danger from
lightning is much less after rain has be
gun to fall, than before, when every
thing is dry.
1t appears, therefore, that the afes
situation during a thunderstorm is il
the midst of wood, particularly if tn,
neighborhood of the tallest trees b,
avoided. In such place of shelter tn,
traveller may take refuge in full assur
ance that he will there be effectuall,
| ch lad hor i
of injury from lightning is undoubt
edly incurred by persons travelin,
across wide and very fat plain. be
cause in such situation they are onl,
elevated objects. To lessen the risk
which may here be somewhat serious
, advantage should be taken of whateve
undulations of surface may exist t.
keep upon the lowest ground. N
, doubt the prostrate position would il
! these circumstances afford greater sc
, curity than the erect. 1t happens no
i unfrequently that animals are killed b
lightning under tree to which they ha
betaken themselves for shelter. L
these cases the tree is struck partly i
/ consequence of its isolation, and partl
3 on account of the presence of the an
mails beneath it. Usually there are sey
. eral, and often many of them assemble
r together, huddled probably by terro
into contact one with another. Tn
3 air, heated by their bodies, rises abov
3 them laden with moisture, derive
mainly from their breath. Who hs
E not noticed the cloud of vapor that i
D the early morning and in certain state
t of the weather hangs over flock {
n sheep or a herd of kine2 The colum
: of moist air ascending through til
8 branches of the tree toward the clou
8 offers, in consequence of the compa
atively high conductivity of water,
Q favorable passage for the electricity.
1 herd of cattler under an isolated tree
I thus exposed to a double risk; also it
/ evident that these animals are in tt
open country lesssecure from injury tina
t human beings, who can not affect the a
mosphere in like degree.