Experiments and Observations on Electricity Made at Philadelphia in America

By Benjamin Franklin

Page 33

has the line A, E, for its basis. So the portion of atmosphere
included in H, A, B, I, has the line A, B, for its basis. And likewise the
portion included in K, B, C, L, has B, C, to rest on; and so on the other
side of the figure. Now if you would draw off this atmosphere with any
blunt smooth body, and approach the middle of the side A, B, you must come
very near before the force of your attracter exceeds the force or power
with which that side holds its atmosphere. But there is a small portion
between I, B, K, that has less of the surface to rest on, and to be
attracted by, than the neighbouring portions, while at the same time there
is a mutual repulsion between its particles and the particles of those
portions, therefore here you can get it with more ease or at a greater
distance. Between F, A, H, there is a larger portion that has yet a less
surface to rest on and to attract it; here therefore you can get it away
still more easily. But easiest of all between L, C, M, where the quantity
is largest, and the surface to attract and keep it back the least. When you
have drawn away one of these angular portions of the fluid, another
succeeds in its place, from the nature of fluidity and the mutual repulsion
beforementioned; and so the atmosphere continues flowing off at such angle,
like a stream, till no more is remaining. The extremities of the portions
of atmosphere over these angular parts are likewise at a greater distance
from the electrified body, as may be seen by the inspection of the above
figure; the point of the atmosphere of the angle C, being much farther from
C, than any other part of the atmosphere over the lines C, B, or B, A: And
besides the distance arising from the nature of the figure, where the
attraction is less, the particles will naturally expand to a greater
distance by their mutual repulsion. On these accounts we suppose
electrified bodies discharge their atmospheres upon unelectrified bodies
more easily and at a greater distance from their angles and points than
from their smooth sides.--Those points will also discharge into the air,
when the body has too great an electrical atmosphere, without bringing any
non-electric near, to receive what is thrown off: For the air, though an
electric _per se_, yet has always more or less water and other non-electric
matters mixed with it; and these attract

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Text Comparison with Benjamin Franklin and the First Balloons

Page 0
Smyth states that he printed one letter from my copy, and he noted how the other copies differed from the drafts in the University of Pennsylvania.
Page 1
Montgolfier, of Annonay, was repeated by M.
Page 2
No News was heard of it till the next Day, when Information was receiv'd, that it fell a little after 6 aClock, at Gonesse, a Place about 4 Leagues Distance, and that it was rent open, and some say had Ice in it.
Page 3
They say the filling of it in M.
Page 4
It was dismissed about One aClock in the Morning.
Page 5
) PASSY, Nov^r 21st, 1783 Dear Sir, I received your friendly Letter of the 7th Inst.
Page 6
_ When they were as high as they chose to be, they made less Flame and suffered the Machine to drive Horizontally with the Wind, of which however they felt very little, as they went with it, and as fast.
Page 7
But the Expence of this Machine, Filling included, will exceed, it is said, 10,000 Livres.
Page 8
Thus the great Bulk of one of these Machines, with the short duration of its Power, & the great Expence of filling the other will prevent the Inventions being of so much Use, as some may expect, till Chemistry can invent a cheaper light Air producible with more Expedition.
Page 9
I send you herewith a Paper in which you will see what was proposed by Mess^rs Robert who constructed the Machine; and some other Papers relative to the same Subject, the last of which is curious, as containing the Journal of the first Aerial Voyage performed by Man.
Page 10
I had a Pocket Glass, with which I follow'd it, till I lost Sight, first of the Men, then of the Car, and when I last saw the Balloon, it appear'd no bigger than a Walnut.
Page 11
Le Chevalier de Cubiere qui a suivi la marche du Globe est arrive chez M.
Page 12
_Letter of August 30.
Page 13
for "By the emulation," in Smyth, read "But the Emulation;" in paragraph fifteen for the phrase, in Smyth and Bigelow, beginning, "I wish I could see the same emulation," correct to end, "between the two Nations as I see between the two Parties here;" in paragraph sixteen, in both Bigelow and Smyth, for "Experiment," read "Experience;" and for the unintelligible phrase in both Bigelow and Smyth, "Beings of a frank and [sic] nature," read "Beings of a Rank and Nature.
Page 14
2d" corrected to "Sept.