The Complete Works in Philosophy, Politics and Morals of the late Dr. Benjamin Franklin, Vol. 1 [of 3]

By Benjamin Franklin

Page 203

cork balls, electrified
by them, will sometimes close at the approach of excited glass; and
at other times be separated to a greater distance. And this change
I have known to happen five or six times in less than half an hour;
the balls coming together each time and remaining in contact a few
seconds, before they repel each other again. It may likewise easily
be discovered, by a charged phial, whether the electrical fire be
drawn out of the apparatus by a negative cloud, or forced into it
by a positive one: and by which soever it be electrified, should
that cloud either part with its overplus, or have its deficiency
supplied suddenly, the apparatus will lose its electricity: which
is frequently observed to be the case, immediately after a flash of
lightning. Yet when the air is very dry, the apparatus will continue
to be electrised for ten minutes, or a quarter of an hour, after
the clouds have passed the zenith; and sometimes till they appear
more than half-way towards the horizon. Rain, especially when the
drops are large, generally brings down the electrical fire: and
hail, in summer, I believe never fails. When the apparatus was last
electrified, it was by the fall of thawing snow, which happened so
lately, as on the 12th of November; that being the twenty-sixth
day, and sixty-first time it has been electrified, since it was
first set up; which was about the middle of May. And as Fahrenheit's
thermometer was but seven degrees above freezing, it is supposed the
winter will not entirely put a stop to observations of this sort.
At London, no more than two thunder-storms have happened during the
whole summer; and the apparatus was sometimes so strongly electrified
in one of them, that the bells, which have been frequently rung by
the clouds, so loud as to be heard in every room of the house (the
doors being open) were silenced by the almost constant stream of
dense electrical fire, between each bell and the brass ball, which
would not suffer it to strike.

I shall conclude this paper, already too long, with the following

1. May not air, suddenly rarefied, give electrical fire to, and air
suddenly condensed, receive electrical fire from, clouds and vapours
passing through it?

2. Is not the _aurora borealis_, the flashing of electrical fire from
positive, towards negative clouds at a great distance, through the
upper part of the atmosphere, where the resistance is least?


_Made in Pursuance of those made by Mr. Canton, dated December 6,
1753; with Explanations, by Mr. Benjamin Franklin._

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Text Comparison with The Complete Works in Philosophy, Politics and Morals of the late Dr. Benjamin Franklin, Vol. 1 [of 3]

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Among these papers some, we conceive, will be new to the English reader on this side of the Atlantic; particularly a series of essays entitled The Busy-Body, written, as Dr.
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I made besides so wretched a figure, that I was suspected to be some runaway servant.
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And thus, after having been saved from one rock concealed under water, upon which the vessel struck during our passage, I escaped another of a still more dangerous nature.
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Franklin attended here, as a commissioner from Pennsylvania, and produced a plan, which, from the place of meeting, has been usually termed, "The Albany plan of Union.
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But, notwithstanding this, a party of the same men shortly after marched to Lancaster, broke open the gaol, and inhumanly butchered the innocent Indians, who had been placed there for security.
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Considering the accidents to which all human affairs and projects are subject in such a length of time, I have, perhaps, too much flattered myself with a vain fancy, that these dispositions, if carried into execution, will be continued without interruption, and have the effects proposed: I hope, however, that if the inhabitants of the two cities should not think fit to undertake the execution, they will at least accept the offer of these donations, as a mark of my good will, token of my gratitude, and testimony of my desire to be useful to them even after my departure.
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A thin glass bubble, about an inch diameter, weighing only six grains, being half filled with water, partly gilt on the outside, and furnished with a wire hook, gives, when electrified, as great a shock as a man can well bear.
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For the electrical fire is never visible but when in motion, and leaping from body to body, or from particle to particle through the air.
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--For as whatever body can insinuate itself between the particles of metal, and overcome the attraction by which they cohere (as sundry menstrua can) will make the solid become a fluid, as well as fire, yet without heating it: so the electrical fire, or lightning, creating a violent repulsion between the particles of the metal it passes through, the metal is fused.
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in them.
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And this can only be done in glass that is thin; beyond a certain thickness we have yet no power that can make this change.
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that pointed rods erected on buildings, and communicating with the moist earth, would either _prevent_ a stroke, _or_, if not prevented, would _conduct_ it, so as that the building should suffer no damage.
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As to the needle of Captain Waddel's compass, if its polarity was reversed by the lightning, the effect of lightning and electricity, in regard of that, seems dissimilar; for a magnetic needle in a north and south situation (as the compass needle was) instead of having its power reversed, or even diminished, would have it confirmed or increased by the electric fire.
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If the Abbé's opinion be right, that the exterior surface, communicating with the coating, is charged, as well as the interior, communicating with the hook; how can I, who stand on wax, discharge both these phials, when it is well known I could not discharge one of them singly? Nay, suppose I have drawn the electric matter from both of them, what becomes of it? For I appear to have no additional quantity in me when the experiment is over, and I have not stirred off the wax: wherefore this experiment fully convinces me, that the exterior surface is not charged; and not only so, but that it wants as much electric matter as the inner has of excess: for by this supposition, which is a part of Mr.
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funnels to, what the best, 292, 295.