The year 1753 is memorable in the
history of
electrical development. The experiments of the colonial philosopher with
lightning had awakened a general enthusiasm in the scientific
circles of Europe. In at least three capitals philosophers were pressing
hard after Franklin, and great activity was shown, when
suddenly there occurred in St. Petersburg a mishap which checked the
ardor of all investigators, and exerted an influence which
has lasted until to-day. During a thunder-storm, while stooping the
better to follow the indications of an electrical
“gnomon” (in modern
phrase, electrometer), Richman met instant death.
Coins in his pockets were fused, and
many of the
tearing and throwing effects associated with high potential,
oscillatory discharges were apparent. Richman’s companion,
standing
three feet away, was uninjured, although much damage was done to the
doors and woodwork of the room. This escape has been frequently
commented upon, but a systematic study of the conditions determining
immunity has never been made. The trend of investigation has been in
the other direction, and the fatality of lightning has been perhaps
unduly emphasized. Voltaire crystallized this general view by
caustically saying, apropos of Richman’s death:
“There are some great
lords whom it does not do to approach too closely, and lightning is one
of these.” The opinion expressed by Voltaire is to some
extent held
even at the present day, and this, joined with the fact that no
immediate practical use could be made of the electricity of the air,
has hampered investigators, and retarded the advance of knowledge in
this direction. Investigation must precede practical application, and
if we would successfully harness the electricity of the air, we must
first know something of its energy. Steadily, though slowly, this
measuring process has been carried on.
Repeating, in a way, the experiments of
Franklin and
Richman, we attempted in 1887, from the top of the Washington Monument,
then the highest edifice in the world, to measure the electrical
potential of the air during a thunder-storm. Potential values of
several thousand volts were indicated by the electrometer. The
crackling and hissing of the sparks, with the attendant phenomena, were
intensely exciting. With each flash there were marked electrical
manifestations, but at no time did the experimenter consider himself to
be in great danger. In 1891, at Blue Hill, during experiments in
kite-flying in a thunder-storm, the wired kite-string was led into the
observatory, connected with an electrometer, and an attempt made to
secure a record of the variations in the potential. Here, again, the
situation was seemingly critical. As the storm progressed, the
electrical phenomena were so marked that we wished ourselves well out
of the experiment. But beyond a rather severe shock, experienced while
making some necessary connections, there were no harmful results.
Not for a moment do we underestimate the
destructive
power of lightning. No one should attempt experiments like those
mentioned without taking every precaution; for positive danger lurks in
the charged cloud, and, as in the handling of explosives, a small
omission in details or an imprudence brings disaster. Yet the daily
handling of currents far deadlier than ordinary lightning-flashes is a
reassuring fact, and points to a coming mastery of the latter.
The keen suffering which many undergo
just in
advance of or during a thunder-storm is of a dual nature. The sense of
impending danger alarms and terrifies; but there is also a depression
of spirits which is physical and real, brought about by some as yet
unknown relation between the nervous system and conditions of
air-pressure, humidity, and purity. The suffering due to depression and
partial exhaustion requires, from those who are strong, sympathy rather
than ridicule. The suffering due to alarm and fright, however, is
unnecessary. It is largely the work of the imagination. To a nervous
nature there is something appalling in the wicked, spiteful gleam of
the lightning, and the crash and tumult of thunder. But such a one
should remember that the flash is almost always far distant, and that
thunder can do no more damage than the low notes of a church organ.
Counting all the deaths from all the storms during a year, we find that
the chance of being killed by lightning is less than one in a hundred
thousand. The risk in the city may be said to be five times less than
in the country. Dwellers in city houses may be startled by peals of
thunder, but owing to the great spread of tin roofing and fair ground
connections, there is very little danger. In the country, if buildings
are adequately protected, and the momentum of the flash provided for,
the occupants may feel secure. A good conductor well grounded is
necessary in all isolated and exposed buildings. Barns, especially when
filled with green crops, should have good lightning-conductors. The
question is often asked, “Do trees protect? “The
answer is that the
degree of protection will vary with the character of the tree and its
distance from a watercourse. An oak is more liable to lightning-stroke
than a beech. The character of the wood, the area of leafage, the
extent and depth of root, will determine the liability to stroke.
Another question which is often asked is whether there is danger aboard
a large steamship during a thunder-storm. On the contrary - there are
few safer places. Sufficient metal with proper superficial area is
interposed in the path of the lightning, and its electrical energy
converted into harmless heat and rapidly dissipated. Accidents occur
chiefly because the victims ignorantly place themselves in the line of
greatest strain, and thus form part of the path of discharge. For this
reason, it is not wise to stand under trees, near flag-poles or masts,
in doorways, on porches, close to fireplaces, or near barns. Those who
are not exposed in any of these ways may feel reasonably safe. It
should be remembered, in the event of accident, that lightning does not
always kill. It more often results in suspended animation than in
somatic death. Therefore, in case of accident, try to restore
animation, keep the body warm, and send for a physician without delay.
From: "Needless Alarm during Thunder-Storms," by Alexander
McAdie, The Century
Magazine, Vol. 58, No. 4, Aug
1899, The Century Company, New York, pages 604-606. (source)
See also:
Other articles
on meterology written by Alexander McAdie.
