The new dominion. [volume] (Morgantown, W. Va.) 1876-1904, 1878-08-17
Danger From Lightning.

| Under what conditions is damage from
lightning possible, and what are the
means by which the risk may be lessened
or avoided? An isolated tree, standing
either upon 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, 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 ia 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 a person standing during a thun-
der-storm beneath a tree 80 situated
is exposed to some risk. On
no account, therefore, should the
traveller take refuge under an is
dated 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-.
ton 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 APP
proach much nearer than this is to in
cur the risk of being within the in
fluence of the stroke; to remain at
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 d scrib-
ing the position a. 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 cleo
tricity. This is especially likely to hap
pen when the trees are wet with rain,
for then their surfaces are covered with
a film of water, which is good conduc-
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 safest
situation during a thunderstorm is in
the midst of a wood, particularly if the
neighborhood of tbs tallest trees be
avoided. In such a place of shelter the
traveller may take refuge in full assur-
ance that he will there be effectually
shielded from harm. The greatest risk
of injury from lightning is undoubt-
eddy incurred by persons travelling
across a wide and very fiat plain, be-
cause in such situation they are only
elevated objects. To lessen the risk,
which may here be somewhat serious,
advantage should be taken of whatever
undulations of surface may exist to
keep upon the lowest ground. No
doubt the PROSTATE position would in
these circumstances afford greater Sc
curity than the erect. 1t happens not
unfrequently that animals are killed by
under tree to which they had
betaken themselves for shelter. In
these cases the tree is struck partly in
consequence of its isolation, and partly
on account of the presence of the ami
mails beneath it. Usually there are sew
eral, and often many of them assembled
together, huddled probably by terror
into contact one with another. The
air, heated by their bodies, rises above
them laden with moisture, derived
mainly from their breath. Who has
not noticed the cloud Of vapor that in
the early morning and in certain states
of the weather hangs over a flock of
sheep or herd of kline? The column
of moist air ascending through the
branches of the tree toward the cloud
offers, in consequence of the compar-
atively high conductivity of water, a
favorable passage for the electricity. A
herd of cattler under an isolated tree is
thus exposed to double risk also it is
evident that these animals are in the
open country lesssecure from injury than
human beings, who can not affect the at
mosphere in a like degree.