can drive into it?
Is it not thus that the surface of this globe is continually heated by
such repeated vibrations in the day, and cooled by the escape of the
heat when those vibrations are discontinued in the night, or intercepted
and reflected by clouds?
Is it not thus that fire is amassed, and makes the greatest part of the
substance of combustible bodies?
Perhaps, when this globe was first formed, and its original particles
took their place at certain distances from the centre, in proportion to
their greater or less gravity, the fluid fire, attracted towards that
centre, might in great part be obliged, as lightest, to take place above
the rest, and thus form the sphere of fire above supposed, which would
afterward be continually diminishing by the substance it afforded to
organized bodies, and the quantity restored to it again by the burning
or other separating of the parts of those bodies?
Is not the natural heat of animals thus produced, by separating in
digestion the parts of food, and setting their fire at liberty?
Is it not this sphere of fire which kindles the wandering globes that
sometimes pass through it in our course round the sun, have their
surface kindled by it, and burst when their included air is greatly
rarefied by the heat on their burning surfaces?
May it not have been from such considerations that the ancient
philosophers supposed a sphere of fire to exist above the air of our
* * * * *
_Of Lightning; and the Methods now used in America for the securing
Buildings and Persons from its mischievous Effects._
Experiments made in electricity first gave philosophers a suspicion that
the matter of lightning was the same with the electric matter.
Experiments afterward made on lightning obtained from the clouds by
pointed rods, received into bottles, and subjected to every trial, have
since proved this suspicion to be perfectly well founded; and that,
whatever properties we find in electricity, are also the properties of
This matter of lightning or of electricity is an
Smyth, the editor of the last and most complete edition of Franklin's Works, who made careful search for the original documents.Page 1
view of the historic and scientific interest of these letters, they are now printed exactly according to the press-copies.Page 2
I am told it is constructed of Linen & Paper, and is to be filled with a different Air, not yet made Public, but cheaper than that produc'd by the Oil of Vitriol, of which 200 Paris Pints were consum'd in filling the other.Page 3
to forward the Transactions, as well as to the Council for so readily ordering them on Application.Page 4
The Duke de Crillon made a feast last week in the Bois de Boulogne, just by my habitation, on occasion of the Birth of two Spanish Princes; after the Fireworks we had a Balloon of about 5 feet Diameter filled with permanent inflammable Air.Page 5
Most is expected from the new one undertaken upon subscription by Messieurs Charles and Robert, who are Men of Science and mechanic Dexterity.Page 6
_Planant sur l'Horizon.Page 7
Charles propose to go up.Page 8
It may be attended with important Consequences that no one can foresee.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
" 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
"The Manuscript, containing some Particulars of the Experiment, which I enclose," mentioned in the Postscript, is a two-page account in French, in Franklin's handwriting, by an eye-witness of the voyage, M.Page 14
Pilatre du Rozier" should be "M.