Franklin made these experiments or
trials with electricity and with thunder clouds in order to find out
what he could about them.]
[Footnote 17: Leyden: see map in paragraph 62.]
119. The electrical kite.--But Franklin's greatest experiment was
made one day in sober earnest with a kite. He believed that the
electricity in the bottle, or Leyden Jar, was the same thing as the
lightning we see in a thunder-storm. He knew well enough how to get
an electric spark from the jar, for he had once killed a turkey with
it for dinner; but how could he get a spark from a cloud in the sky?
He thought about it for a long time; then he made a kite out of a
silk handkerchief, and fastened a sharp iron point to the upright
stick of the kite. One day, when a thunder-storm was seen coming up,
Franklin and his son went out to the fields. The kite was raised;
then Franklin tied an iron key to the lower end of the string. After
waiting some time, he saw the little hair-like threads of the string
begin to stand up like the bristles of a brush. He felt certain that
the electricity was coming down the string. He put his knuckle close
to the key, and a spark flew out. Next, he took his Leyden Jar and
collected the electricity in that. He had made two great discoveries,
for he had found out that electricity and lightning are the same thing
and he had also found how to fill his bottle directly from the clouds:
that was something that no one had ever done before.
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