The San Juan County index. (Aztec, N.M.) 1890-19??, 1900-04-27
SCIENTIFIC TOPICS.
CURRENT NOTES OF DISCOVERY
AND INVENTION.
Cause Of Thunder q Mystsry-scisnce
Has Been Unable to Account for the
Phenomenon BARRIERS Scissors and
COmbs-Coach and Cradle.

What is the cause OF thunder, mean
ing the u Of the noise? We do not
know. The thunder, we know, is a
result Of the phenomenon we call
lightning" but just what 1t is has not
been as yet adequately determined.
The electric discharge produces a va
riety Of effects, physiological. lumin-
Gus, calorihc, magnetic, mechanical and
chemical, whose characteristics are
more OF less we'll recognized. 1t is fair
to presume that we must hunt for the
cause Of the noise in the calorihc, me-
chanical or chemical attributes. Most
Of the authorities in definition say
thunder is the noise Immediately fol-
lowing a fash 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. It may be that
the real explanation will be found part
ly In each Of the calorihc, mechanical
n chemical actions. A mere dis
turbance Of the air is hardly an ade-
quate reason. We have too little evil
dence to go upon. The heating eff
fects, so called, may have some bear
ing. We know the spark will inaame
ether, alcohol and some of the hydro
carbon gases; yet 1t does not ignite
gunpowder, except by the help Of a
wet string which becomes heated. A
Leyden Jar charged and discharged
several times In rapid succession be-
comes heated. But does air? Mechan-
c a effects are numerous and usually
disastrous to any solid body not a good
conductor. We are shown by Kinners-
ley's thermometer that some effect Is
produced on a body of water, but 1t is
asserted not to be due to any increase
Of temperature in the air. The chemi-
cal effects are most varied. Priestly
found a reduction of volume in moist
air by passage Of the spark (Which
may be Significantly and that the air
became acid. Cavendish found this
was due to the formation of nitric acid
by the chemical action Of the dis
charge. Compound gases are readily
d~ecomposed, but air is not a compound
gas; it is merely a mixture Of oxygen
and nitrogen, and neither Of its con-
stituents is c~ombustible. One assists
combustion of other bodies, while the
other is inert in that sense. But we
may get some light on the subject, yet
from the indefatigable army Of cleo
trical Investigators. Possibly the re-
searches in the liquefaction Of gases
may help out. In a recent paper on
the subject it is stated that ozone
%liQuefes at atmospheric pressure at a
temperature of 1854 degrees Fahren-
heit and that it is easily exploded.
Now, 1t is well known that the electric
discharge produces this so-called al
lotropic oxygen in great abundance.
According to Priestly the electric dis
charge effects a reduction of volume
IL 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 lightning produces a cumula-
tive or Intensive eject, Arst lowering
the temperature, then forming ozone,
then causing its liquefaction, and final
ly its explosion, or perhaps defamation,
which expresses more accurately the
terrifying crash following or accom-
panying a lightning stroke near al
hand. This is a mere speculation, and
/ give it for what 1t Is worth.-Electri-
cal Review.