The Forest Republican. [volume] (Tionesta, Pa.) 1869-1952, 1886-05-26
DANGERS OF LIGHTNING
suRPRIsINa INCREASE IN STROKES
THE PAST FIFTY YEARS.


Atmosphere.
The researches Of Professor Won Pet
zold. Karsten Weber, and others have
proved that the number of damaging
strokes of lightning has considerably in
creased during the last fifty years, and
this increase cannot be explained by the
theory that, owing to the growing num-
Der of houses, factories, etc., the number
of lightning strokes increased proportion
ately; to the contrary, this number ought
to decrease, as every building, even when
not protected by lightning-rod, effects
an equilibrium of the opposite electric po
tentials, and, therefore, the number Of
lightning strokes ought relatively to de
crease with the growing number OF
buildings. This, indeed, is proved by
the fact that in the space of one year
among 100, 900 buildings there
occurred but thirteen cases Of
lightning strokes in cities,
against twenty-three strokes on
buildings in the country. We, therefore,
have to take this natural phenomenon
from another point of view, and to con
slider the ratio of damaging or other
strokes to the number of buildings in
certain district. This ratio, called by
the German naturalists blitzgefahr
danger from lghtning), increased in
the kingdom of Bavaria from 1914 to
1882 threefold (according to records o.
insurance companies even tvefold), and
other countries show the same increase.
AS in nature each phenomenon must have
its cause, the question arises: To what
cause is due the aforementioned facts2
And this question not only is of scien-
tific interest, but also of great practical
Importance. A great many theories have
already been advanced to explain this
phenomenon; among others, that, owing
to the decrease of the woodland, houses
are more and more made the projecting
points of a certain area, and, therefore,
attract the lightning; beside, this de-
crease effects greater rise of tempera.
ture in summer, and, in consequence,
more numerous thunder storms. Others
find the cause of it in the large increase
of such constructions as gas and
water works, weather-cocks, etc.
But this theory does not explain
why, especially, country houses, which
commonly lack these kind of construc-
tions, are mostly exposed to danger by
lightning. Admitting that these causes
may to some extent explain the increase
of danger from lightning, they are not
sufficient to fully show the surprising in
crease of strokes during so short period.
There must be more general and funda-
mental cause. Through what can the
electrical intensity during a thunder
storm be so strongly increased that a
larger number of lightning strokes pass
over to the earth than was the case here
tofore2 1t is not so much the increasing
number of thunder-storms as their greater
force which produces the increased
danger
AS the main cause we now point out
the enormous increase during the last fifty
years of factories, railroads, steamboats,
in short, of all constructions filling the
atmosphere with smoke, vapors and par
ticles of dust of every description. When
we consider that every day thousands o.
locomotives, thousands of steamers go
around the earth, that thousands Of
factories of all kinds daily emit enor-
nous quantities of smoke, vapor
and dust into the air, that, especially in
cities, the large number of houses pro-
duce immense quantities Of smoke and
dust, the assertion will not seem incre l.
ible, that there is certainly a hundred
times the smoke, dust and gases absorbed
in the atmosphere that was fifty years
ago Already with the NAKED dye the
impure state of the atmosphere may be
noticed. Go through the coal districts
of Manchester, England, through those
of Pennsylvania, through the cities OF
Essen, Germany, and Pittsburg, Penn,
and you will notice layer of vapor con-
stantly lowering over them; the air is
filed with foul gases, and every object is
more or less covered with the settling
particles of dust.
These conditions being established, we
have TO consider their relations to the
violence of thunder-storms. To give
the reader better conception of this re
lation we will briefly discuss the theory
of thunderstorm and the origin Of
electricity thereby developed. Friction
is now generally accepted to be the cause
of the electricity in a thunderstorm.
Friction between air and particles of ice
according to Luvine) or between air
and molecules of water (according to
Andries), is the main cause of that cleo
tricity. When beside these factors par
ticles of dust are filling the atmosphere
the development of electricity is highly
increased. 1t is the election of steam
anu usHcs coulnhoh 10 INC phenomenon
which causes the thunder-storms attend
ing TO it assume an exceedingly violent
character.
That the pyramid of Cheops is rem
dered electrical by the whirling dust of
the desert may here also be mentioned.
1t is nothing but the friction of the
grains of sand on the surface of the pyra-
mid that causes electricity to originate.
The author of this essay claims that
the rapid, enormous, and lasting devel-
opment of electricity during thunder
storms cannot be otherwise explained
than by purely mechanical cause, anaIo
gous to the mechanical force eff the hydro
electrical machine Now, as our atmos-
phere contains so much more dust than
in former years, the fact must be OF greet
influence regarding the intensity of cleo