The morning news. [volume] (Savannah, Ga.) 1887-1900, 1900-02-11
WHAT CAUSES THUNDER
Theory Suggested for What Is Yet
an unexplained Phenomenon.

Letter to the Electrical Review.
What is the cause of thunder. meaning
the cause of the noise? We do not know.
The thunder, we know, is the result of the
phenomenon We call lightning" but just
what it is has not been as yet adequately
determined. The electric discharge pro-
duces a variety of effects, physiological,
luminous, calorifc, magnetic, mechanical,
and chemical, whose characteristics are
more or less well recognized. 1t is fair to
presume that we must hunt for the cause
of the noise in the calorific, mechanical or
chemical attributes.
Most OF the authorities in definition say
thunder is the noise Immediately follow
ing a flash of lightning, and is due to the
disturbances of the air caused along its
path by the discharge, and they let it go
at that.
1t may be that the real explanation win
be found partly in each of the calorific,
mechanical and chemical actions. A mere
disturbance of the air Is hardly an ade-
uuate reason. We have too little evil
dence to go upon. The heating effects, so
called, may have some bearing. We know
the spark will infiame ether, alcohol, and
some of the hydrocarbon gases: yet 1t
does not ignite gunpowder, except by the
help of wet string which becomes heat
ed A Leyden jar charged and discharged
several times in rapid succession becomes
heated All solid conductors become heat
ed by it. But does air? Mechanical eff
fects are numerous and usually disastrous
TO any solid body not a good conductor.
We are shown by kinnersley's thermom-
eter that some effect is produced on a
body of water, but IL Is asserted not to be
due to any increase of temperature in the
air.
The chemical effects are most varied
Priestly found a reduction of volume in
most air by passage of the spark (Which
NAV be significant), and that the air be-
came acid. Cavendish found this was due
to the formation of nitric acid by the
chemical action of the discharge. Com
pound gases are readily decomposed but
air is not compound gas; Il is merely D
mixture OF oxygen and nitrogen. and Meth
err of its constituents is combustible, while
the other is inert in that sense.
But we may get some light on the sub
ject yet from the interchangeable army of
electrical investigators. Possibly the re-
searches in the Lquefaction of gases may
help out. In a recent paper on the subject
ii Is stated that ozone liquefies at atmos-
pheric pressure at temperature of 1854
degrees Fahrenheit and that 1t is easily
exploded. Now, IL Is we'll known that
the electric discharge produces this So
called allotropic oxygen in great abund-
ance. According to Priestly the electric
discharge effects q reduction of volume
In moist air, which would indicate or
dinarily a fall of temperature. Moist Air
Is the usual atmospheric condition during
lightning flashes. Possibly the stream OF
innumerable sparks in a stroke OF light
ming produces cumulative or intensive
effect. first lowering the temperature. then
forming ozone, then causing it's liquefac-
ton, and finally it's explosion, or perhaps
defamation, which expresses more occur
ately the terrifying crash following or ac-
T4..1.4
hand. This is mere speculation, and
give II for what It Is WORTH