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

By Benjamin Franklin

Page 188

lightning, imagining its luminous appearance to be owing to
electric fire, produced by friction between the particles of water
and those of salt. Living far from the sea, I had then no opportunity
of making experiments on the sea-water, and so embraced this opinion
too hastily.

For in 1750, and 1751, being occasionally on the sea-coast, I found,
by experiments, that sea-water in a bottle, though at first it would
by agitation appear luminous, yet in a few hours it lost that virtue:
_hence and from this_, that I could not by agitating a solution of
sea-salt in water produce any light, I first began to doubt of my
former hypothesis, and to suspect that the luminous appearance in
sea-water must be owing to some other principles.

I then considered whether it were not possible, that the particles
of air, being electrics _per se_, might, in hard gales of wind,
by their friction against trees, hills, buildings, &c. as so many
minute electric globes, rubbing against non-electric cushions, draw
the electric fire from the earth, and that the rising vapours might
receive that fire from the air, and by such means the clouds become
electrified.

If this were so, I imagined that by forcing a constant violent stream
of air against my prime conductor, by bellows, I should electrify it
_negatively_; the rubbing particles of air, drawing from it part of
its natural quantity of the electric fluid. I accordingly made the
experiment, but it did not succeed.

In September 1752, I erected an iron rod to draw the lightning
down into my house, in order to make some experiments on it, with
two bells to give notice when the rod should be electrified: a
contrivance obvious to every electrician.

I found the bells rang sometimes when there was no lightning or
thunder, but only a dark cloud over the rod; that sometimes after
a flash of lightning they would suddenly stop; and at other times,
when they had not rang before, they would, after a flash, suddenly
begin to ring; that the electricity was sometimes very faint, so
that when a small spark was obtained, another could not be got for
some time after; at other times the sparks would follow extremely
quick, and once I had a continual stream from bell to bell, the size
of a crow-quill: even during the same gust there were considerable
variations.

In the winter following I conceived an experiment, to try whether the
clouds were electrified _positively_ or _negatively_; but my pointed
rod, with its apparatus, becoming out of order, I did not refit it
till towards the spring, when I expected the

Last Page Next Page

Text Comparison with Benjamin Franklin and the First Balloons

Page 0
The documents which I publish are copies of Franklin's letters, made on thin paper in a copying press (probably the rotary machine invented by Franklin), and all but one bear his signature in ink.
Page 1
It is supposed that not less than 50,000 People were assembled to see the Experiment.
Page 2
With great Respect, I am, Sir, Your most obedient and most humble Servant B.
Page 3
I just now learn, that some observers say, the Ball was 150 Seconds in rising, from the Cutting of the Cord till hid in the Clouds; that its height was then about 500 Toises, but, being moved out of the Perpendicular by the Wind, it had made a Slant so as to form a Triangle, whose Base on the Earth was about 200 Toises.
Page 4
Sir, The Publick were promised a printed particular Account of the Rise & Progress of the Balloon Invention, to be published about the End of last month.
Page 5
With great esteem and respect, for yourself and the Society; I have the honour to be, Sir, Your most obedient & most humble Servant, B.
Page 6
If those in the Gallery see it likely to descend in an improper Place, they can by throwing on more Straw, & renewing the Flame, make it rise again, and the Wind carries it farther.
Page 7
They say they have a contrivance which will enable them to descend at Pleasure.
Page 8
I wish I could see the same Emulation between the two Nations as I see between the two Parties here.
Page 9
Faujas's Book upon the Balloons, which I hope you have receiv'd.
Page 10
I am the more anxious for the Event, because I am not well inform'd of the Means provided for letting themselves gently down, and the Loss of these very ingenious Men would not only be a Discouragement to the Progress of the Art, but be a sensible Loss to Science and Society.
Page 11
Mr.
Page 12
" Part of the valedictory and the signature are omitted by Bigelow and Smyth, but the former gives an "Extract of the Proposals" for the balloon of which I have no copy.
Page 13
" Minor discrepancies between this and the other press-copies and the letters as printed by Bigelow and Smyth also occur.
Page 14
"; p.