Wausau pilot. [volume] (Wausau, Wis.) 1896-1940, 1905-10-03
AURoRAs AND THUNDERsToRMs.
Both Due to Disturbances of the At.
mosphere's Electricity.

The aurora is an electrical phe
nomenon, and its seat is the atmcs-
phere. Possibly it may reach up to
an elevation of many miles. The
nickering character and the difficulty
OF securing simultaneous observations
Oh any one streamer at two or more
separate points make computation
or It's exact height difficult matter.
How the electricity is excited which
causes an auroral display is not yet
fully determined. A dozen different
theories are entertained on the sub
Ject, and scientific men have not yet
made final and unanimous choice
among them So, too, with the thun-
| derstorm. That this is electrical in
Its nature was proved by Franklin
with his kite a century and a half
ago; but the method by which the
electricity is generated in the cloud Is
not established beyond dispute.
If the wise men cannot yet decide
these questions of the origin of the
atmospheric electricity which gives
rise to the aurora and thunderstorm,
at least they are in harmony in re-
gard to the existence of some relation
ship between the two. Referring to
this fact, the United States Monthly
Weather Review remarked recently
that some auroras seem to lave a linn
tied extent, as may be inferred from
the fact that they are seen from but
few stations, although in the neigh
borhood of many stations reporting
thunderstorms, as though the electric
discharge forming the aurora is in
some way connected with the thun-
derstorm. On the other hand, there
are many extensive auroras that have
no apparent connection with local
thunderstorms, although they may be
associated with the numerous thun-
derstorms that prevail in the equator
ial regions. All auroras are supposed
to originate in disturbances Of the
earth's electric condition, and such
disturbances may be caused either by
local atmospheric phenomena or by
solar phenomena. In both cases there
are earth currents, and either light
ming or aurora, or both. In both
cases, also, there are magnetic dis
turbances, but there are very slight
during the ordinary thunderstorms.
1t is barely possible that all these
phenomena are essentially terrestrial,
and due to so-called tidal strains or
elastic strains in the interior of the
globe Such strains are known to
exist, and must be as periodic as the
tides. They must also have great ir-
regularities, due to the sudden relief
of strain that takes place during the
geologic process of faulting. 1t is also
possible that influences emanate from
the sun thak may affect the distribu-
ton of electricity in the earth's at
mosphere. Both solar and terrestrial
causes may therefore produce both
the local and the general auroras, and
it is not at present possible to state
which of these is most important,
either in any special case or in gen.
eral
The fact that there is a maximum
frequency of auroras in the early
evening of local time, between and
1 p. m, over the whole globe shows
that the local or terrestrial influences
are quite appreciable The other fact,
that a sudden increase in auroras,
earth currents and thunderstorms oc-
ours on the same day over a large
region, such as Europe, the Atlantic,
and North America, must be due to
either one of two causes; either this
represents an influence emanating
from the sun and affecting a large
part of the earth, or it represents a
very important widespread terrestrial
influence.