The recent bi-centenary of Franklin's birth, which coincided with the
revival of interest in balloons, makes this a timely topic, especially
since Franklin's descriptions of the first balloon ascensions are
almost unknown and do not appear among his philosophical papers. The
five letters which I have the honor to present were written to Sir
Joseph Banks, President of the Royal Society of London, in 1783, when
Franklin was Minister to the Court of France and, with the collateral
documents, they give perhaps the most complete and accurate account
of the beginning of aerial navigation, enlivened with the humor and
speculation characteristic of the writer. It is certainly remarkable
that Franklin, in the midst of diplomatic and social duties, could have
found time to investigate personally this new invention of which he at
once appreciated the possibilities.
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. They have
corrections in the author's hand-writing and, except for a few words,
are quite legible. They were purchased by me from Dodd, Mead & Co.,
in December, 1905, and previously had belonged to G. M. Williamson,
of Grandview-on-the-Hudson, to whom they had come from Vienna. None
of the letters appear in Sparks' edition of Franklin's Works, and
while all but one are included in the collections compiled by Bigelow
and Smyth, there are numerous inaccuracies, some of which will be
specified hereafter. Drafts of three of the letters are deposited in
the University of Pennsylvania, but the existence of one letter and the
whereabouts of another were unknown to the late Mr. Smyth, the editor
of the last and most complete edition of Franklin's Works,[1] who made
careful search for the original documents. Although the American owners
of these copies did not allow them to be transcribed, Mr. 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. In
general it may be said that, whereas Bigelow gives the text without
paragraphs, capital letters or the old spelling,[2] Smyth follows the
originals more closely. In view of the historic and scientific interest
of these letters, they are now printed exactly according to the
press-copies. The letter dated November 30, appears never to have been
printed and whereas Smyth reproduced the letter of November 21 from the
University of Pennsylvania draft, this or another draft (or possibly
this copy) was in the possession of the French aeronaut, Gaston
Tissandier, about 1887.[3]
[1] The Writings of Benjamin Franklin, collected and edited by
Albert Henry Smyth, Volume IX, New York, 1906.
[2] Complete Works of Benjamin Franklin, compiled and edited by
John Bigelow, Volume VIII, New York, 1888.
[3] Histoire des Ballons, Paris, 1887, Volume I, page 29.
(THE FIRST HYDROGEN BALLOON.)
PASSY, Aug. 30, 1783.
Sir,
On Wednesday, the 27th Instant the new aerostatic Experiment, invented
by Mess^rs. Montgolfier, of Annonay, was repeated by M. Charles,
Professor of experimental Philosophy at Paris.
A hollow Globe 12 feet Diameter was formed of what is called in England
Oiled Silk, here _Taffetas gommé_, the Silk being impregnated with a
Solution of Gum elastic in Lintseed Oil, as is said. The Parts were
sewed together while wet with the Gum, and some of it was afterwards
passed over the Seams, to render it as tight as possible.
It was afterwards filled with the inflammable Air that is produced by
pouring Oil of Vitriol upon Filings of Iron, when it was found to have
a tendency upwards so strong as to be capable of lifting a Weight of 39
Pounds, exclusive of its own Weight which was 25 lbs. and the Weight of
the Air contain'd.
It was brought early in the morning to the _Champ de Mars_, a Field in
which Reviews are sometimes made, lying between the Military School and
the River. There it was held down by a Cord till 5 in the afternoon,
when it was to be let loose. Care was taken before the Hour to replace
what Portion had been lost, of the inflammable Air, or of its Force, by
injecting more.
It is supposed that not less than 50,000 People were assembled to see
the Experiment. The Champ de Mars being surrounded by Multitudes, and
vast Numbers on the opposite Side of the River.
At 5 aClock Notice was given to the Spectators by the Firing of two
Cannon, that the Cord was about to be cut. And presently the Globe was
seen to rise, and that as fast as a Body of 12 feet Diameter, with a
force only of 39 Pounds, could be suppos'd to move the resisting Air
out of its Way. There was some Wind, but not very strong. A little
Rain had wet it, so that it shone, and made an agreeable Appearance.
It diminished in Apparent Magnitude as it rose, till it enter'd the
Clouds, when it seem'd to me scarce bigger than an Orange, and soon
after became invisible, the Clouds concealing it.
The Multitude separated, all well satisfied and delighted with the
Success of the Experiment, and amusing one another with discourses of
the various uses it may possibly be apply'd to, among which many were
very extravagant. But possibly it may pave the Way to some Discoveries
in Natural Philosophy of which at present we have no Conception.
A Note secur'd from the Weather had been affix'd to the Globe,
signifying the Time & Place of its Departure, and praying those who
might happen to find it, to send an account of its State to certain
Persons at Paris. 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. It is suppos'd to have burst by the
Elasticity of the contain'd Air when no longer compress'd by so heavy
an Atmosphere.
One of 38 feet Diameter is preparing by Mr. Montgolfier himself, at the
Expence of the Academy, which is to go up in a few Days. 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.
It is said that for some Days after its being filled, the Ball was
found to lose an eighth Part of its Force of Levity in 24 Hours;
Whether this was from Imperfection in the Tightness of the Ball, or a
Change in the Nature of the Air, Experiments may easily discover.
I thought it my Duty, Sir, to send an early Account of this
extraordinary Fact, to the Society which does me the honour to reckon
me among its Members; and I will endeavour to make it more perfect, as
I receive farther Information.
With great Respect, I am, Sir,
Your most obedient
and most humble Servant
B. FRANKLIN
SIR JOSEPH BANKS, Bar^t.
P. S. Since writing the above, I am favour'd with your kind Letter
of the 25th. I am much obliged to you for the Care you have taken to
forward the Transactions, as well as to the Council for so readily
ordering them on Application. Please to accept and present my Thanks.
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. It is said
the Country People who saw it fall were frightned, conceiv'd from its
bounding a little, when it touched the Ground, that there was some
living Animal in it, and attack'd it with Stones and Knives, so that it
was much mangled; but it is now brought to Town and will be repaired.
The great one of M. Montgolfier, is to go up, as is said, from
Versailles, in about 8 or 10 Days; It is not a Globe but of a different
Form, more convenient for penetrating the Air. It contains 50,000
cubic Feet, and is supposed to have Force of Levity equal to 1500
pounds weight. A Philosopher here, M. Pilatre du Rozier has seriously
apply'd to the Academy for leave to go up with it, in order to make
some Experiments. He was complimented on his Zeal and Courage for
the Promotion of Science, but advis'd to wait till the management of
these Balls was made by Experience more certain & safe. They say the
filling of it in M. Montgolfier's Way will not cost more than half
a Crown. One is talk'd of to be 110 feet Diameter. Several Gentlemen
have ordered small ones to be made for their Amusement. One has ordered
four of 15 feet Diameter each; I know not with what Purpose; But such
is the present Enthusiasm for promoting and improving this Discovery,
that probably we shall soon make considerable Progress in the art of
constructing and using the Machines.
Among the Pleasanteries Conversation produces on this Subject, some
suppose Flying to be now invented, and that since Men may be supported
in the Air, nothing is wanted but some light handy Instruments to
give and direct Motion. Some think Progressive Motion on the Earth
may be advanc'd by it, and that a Running Footman or a Horse slung and
suspended under such a Globe so as to have no more of Weight pressing
the Earth with their Feet, than Perhaps 8 or 10 Pounds, might with a
fair Wind run in a straight Line across Countries as fast as that Wind,
and over Hedges, Ditches & even Waters. It has been even fancied that
in time People will keep such Globes anchored in the Air, to which by
Pullies they may draw up Game to be preserved in the Cool & Water to be
frozen when Ice is wanted. And that to get Money, it will be contrived
to give People an extensive View of the Country, by running them up in
an Elbow Chair a Mile high for a Guinea &c. &c.