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Allen, Grant, 1848-1899

"Falling in Love With Other Essays on More Exact Branches of Science"

It is a
flood-gate, not a moat: it carries away the electricity of the air
quietly to the ground, without allowing it to gather in sufficient
amount to produce a flash of lightning. It might thus be better called
a lightning-preventer than a lightning-conductor: it conducts
electricity, but it prevents lightning. At first, all lightning-rods
used to be made with knobs on the top, and then the electricity used to
collect at the surface until the electric force was sufficient to cause
a spark. In those happy days, you had the pleasure of seeing that the
lightning was actually being drawn off from your neighbourhood
piecemeal. Knobs, it was held, must be the best things, because you
could incontestably see the sparks striking them with your own eyes. But
as time went on, electricians discovered that if you fixed a fine metal
point to the conductor of an electric machine it was impossible to get
up any appreciable charge because the electricity kept always leaking
out by means of the point. Then it was seen that if you made your
lightning-rods pointed at the end, you would be able in the same way to
dissipate your electricity before it ever had time to come to a head in
the shape of lightning. From that moment the thunderbolt was safely dead
and buried. It was urged, indeed, that the attempt thus to rob Heaven of
its thunders was wicked and impious; but the common-sense of mankind
refused to believe that absolute omnipotence could be sensibly defied by
twenty yards of cylindrical iron tubing.


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