Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1913-10-20
LIGHTNING.
Scientists Tell What Actually Hap
pens in Electric Storm.

| Lightning is violent discharge of
| electricity, either between one cloud
| and another, between a cloud and the
| earth, or between two strata of air
\ differently electrified The discharge
| is commonly assumed to be from
higher to lower level. although it
may be from either or both.
The potential between various air
strata, or between air strata and the
| earth is variable. and changes in it
may be sudden. Clear air is, as a
| rule. electrified positively and the
| same is true of air containing smoke,
| fog or falling snow. In rain the
liberalization ranges from high mega
| tive to high positive. but is more often
positive.
During single storm the air may
change back and forth several times
from a positive to a negative condition,
and the difference in potential be-
tween the earth and point 10 feet
| above it may amount to hundreds or
even thousands of volts. Considering
| the surface of the earth as datum,
| the potential increases with elevation
but the difference in potential per unit
of vertical distance decreases with al
| titude.
| Two principal kinds of lightning are
distinguished. linear and ball. The
effects of the first zInay he. peculiarly
destructive It's flashes are followed
by thunder and usually accompan MED
/ by a downpour of rain. When its light
! is seen from a great distance, often
through clouds near the horizon, it is
called diffused heat. or sheet light
ming. The same appearance may,
however, be due to actually diffused
and silent discharges at great alti-
tudes.
The same flash may strike and blast
a number of trees, and the results may
be quite as curious and ergatic as the
lightning itself. tree may be
scorched, it may be stripped OF lts
leaves, it may be cleft longitudinally
or, more rarely, severed horizontally
Pieces of bark or wood may be torn on
in strips. One-h half of a trees crown
may be withered, the other half re-
naming unframed. Sometimes the
bark is stripped from only one side
occasionally without a trace of burn
ling; at other times il may be riddled
as by worms, with multitude OF 1T
tie holes.
The lightning furrow on tree Is
usually single; but it may be double
usually in parallel lines. burrows
may be oblique or spiral. the curren
in such cases following the grain o
the new wood. If the tree is imam
mable or is rendered very dry by the
flash a fire may result. In other cases
the dry duff or humus at the base o
the tree is ignited by the flash.
A flash of lightning striking upwart
Through the tree from its base acts al
an explosive. The trees may then d.
torn into small fragments, and case
have been recorded where these ap
peared like a piece of hemp. Ii I'M
upward flash is less violent the tree
may be split radially. The tops o
trees have been torn off while TIT
Hover parts remained uninjured o.
the other hand, the lower portion OF
tree has been demolished. While TN
upper part fell to the ground intact.
Lightning often strikes twice
more than twice in the same place
Some trees favorably located for at
tracing the flash bear seven or eish
scars, all visible, and determined by
steam analysis of the trunk. IN
same is true regarding some rock
SUBMITS and buildings. Out OF 80
: cases recorded by one observer
. We're repeated strokes on trees an
buildings.
81 II hos heen held though not PROVED
that the big trees of California are re
lpeatedly struck by lightning, and tina
l although not killed, their leaders ar
broken and their tops stunted IN con
Isl sequence The form of their boles an
: 1.-the shape Of their crowns would seer
II to favor this belief. Although giant
their heights are much lower tina
= would be expected from the taper
: their holes.
ground is as remarkable as its effet
y upon trees. 1t may enter the groun
without disturbing it or heating !
= or it may tear large holes or melt tn
IS surface. Although lightning usual
s strikes the ground with vertiei
y stroke. it sometimes comes obliquel
II or almost horizontally, blowing lon
n burrows. Sometimes it tears a circt
i lar or funnelshaped hole, and, whe
lie striking sand, forms fulgurites. Thes
ii are hollow tubes, formed of the fuse
d materials, and may vary from one
IT half inch to six inches in diamete
d Fulgnrites may extend % feet into tn
earth, and be vitrified or CLASSY on tn