Benjamin Franklin Papers

From Benjamin Franklin to Joseph Banks, 27 July 1783

To Joseph Banks

ALS: British Library; copy: Library of Congress

In this letter, prompted by Banks’s overture of May 28, Franklin rejoices in the peace, muses on the folly of war, and reclaims his place in the British scientific community, as he had long wished to do.6 Erasing eight years of estrangement, he notes with pleasure the recent discoveries made by “our” Society. By way of reciprocation, he adds a postscript alluding to an experiment that no one in Paris had yet witnessed but all were discussing: the “vast Globe sent up into the Air” in the village of Annonay. The age of flight had begun, and in the months to come Franklin would be its chief chronicler to the Royal Society.

The idea for the hot-air balloon came from Joseph Montgolfier, a scion of the great papermaking family of Annonay with whom Franklin had corresponded and whose paper he greatly admired.7 Unsuited to business (he had failed at several ventures) but fascinated by mathematics, chemistry and mechanics, subjects in which he was entirely self-taught, the 42-year-old was observing particles rising up the flue in his fireplace on a cold day in November, 1782, when he realized that he might be able to harness the power of heated air. His first experiment consisted of levitating a four-foot-high box made from taffeta stretched around a thin wooden frame. Rushing home to the papermill in Vidalon, he engaged his brother Etienne to collaborate on further experiments. Etienne, five years his junior and the youngest of Pierre Montgolfier’s sons, had been in charge of the Vidalon mill since 1772, when their father had called him home from his architecture studies in Paris to manage the family business. While in Paris, Etienne had received formal instruction in science, which would now prove invaluable, and had also met several people who would play key roles in the story of the balloons (not to mention papermaking), most notably Nicolas Desmarest and Jean-Baptiste Réveillon.8

Joseph and Etienne experimented with ever-larger “machines” in the confines of the Vidalon compound, careful to keep their trials secret. In mid-December, after a huge box filled with hot air burst its retaining cords and sailed into a neighboring field, Etienne wrote a long letter to Desmarest in Paris, begging him to announce their discovery to the Académie des sciences and establish their priority. Details would follow, he promised. The academician declined to take any further action until Etienne sent a good drawing and a detailed description.9 The brothers, meanwhile, continued their experiments throughout the spring: calculating forces, modifying designs, and constructing larger vehicles capable of lifting heavier loads. Eventually, with the help of their family, they fabricated a balloon 35 feet in diameter, its four segments made from cloth lined with paper (to prevent leakage) and fastened by 1,800 buttons. This was the “machine aérostatique” that they demonstrated before the Etats particuliers, the diocesan assembly of the Vivarais region, on a rainy June 4, 1783.1 The globe, to which they had at the last minute attached a brazier holding the source of heat—straw and shredded wool, set aflame—bobbed to a height of 3,000 feet and remained aloft for about 10 minutes, gently landing in a vineyard more than one and a half miles away.

The following morning, at the brothers’ request, the Etats wrote an official account (procès-verbal) of the trial they had witnessed, establishing the Montgolfier brothers of Annonay as the globe’s inventors. By June 28 that report was in the hands of Lefèvre d’Ormesson, controller general of finances, who forwarded it to Condorcet, secretary of the Académie des sciences, requesting a response. At its next meeting, July 2, the academy appointed a five-man commission to examine the invention. Three members were well known to Franklin: Lavoisier, Desmarest, and Le Roy. They were joined by mathematicians Gaspard Monge and the abbé Charles Bossut.2 The following day, July 3, the commission reviewed the procès-verbal and a set of observations by the Montgolfiers.3 Two weeks later, Condorcet reported to d’Ormesson that since Etienne Montgolfier had proposed to come to Paris to repeat his experiment before the commission, they would await his arrival.4

News of the Annonay experiment spread quickly in the scientific community. Charles Blagden learned of it almost immediately from members of the Académie des sciences.5 Franklin was given the procès-verbal and “Observations” to read, and had his secretary make copies.6 His opinion, expressed to Blagden some weeks later, was that the balloon should have been constructed of “fine oil’d Silk,”7 as indeed the next balloon was.

It would be another several weeks before the general public would read an accurate description of the experiment. In the meantime, what purported to be an eyewitness account was published on July 10 in the Affiches, annonces, et avis divers. The anonymous letter, written by an Annonay landowner with no love for the Montgolfiers, portrayed the experiment as a harebrained scheme concocted by a pair of reckless brothers who were determined to go up in the sky and would not stop until one of their necks was broken. Their contraption was shaped like a house, measured 16 × 16 × 36 feet, and had burst into flames upon landing, terrifying the peasantry into believing that the moon had detached itself from the sky, signaling the Last Judgment. A variant of this letter was reprinted on July 26 in the Mercure de France, a prominent weekly news journal.8

Everything changed once Etienne Montgolfier made his presence known to the academy.9 Le Roy informed Franklin of his arrival on July 27, the date of the present letter.1 That same day, the Journal de Paris printed a factual account, obviously written by an academician, of both the Annonay experiment and how the academy had learned of it. It included calculations of the balloon’s weight, volume, and lifting force taken from the “Observations.” Acknowledging Montgolfier’s reputation for making the finest paper in France (a subject the academy had investigated in 1781),2 the article also observed that if he had only been able to fill the balloon with “l’air inflammable” extracted from iron (a technique only recently demonstrated by Lavoisier), it might have achieved greater height.

A team of scientists outside the Académie des sciences immediately formed to do just that. Having studied the procès-verbal and “Observations,” and having heard rumors that Montgolfier planned to launch a balloon 100 feet in diameter,3 they knew that whatever gas he would use (the secret was closely guarded) would be the same as what he had used in Annonay, which was only slightly lighter than air. “Inflammable air” was 10 times as light, but was extremely expensive to produce and had so far been generated only in small quantities. On July 28, Barthélemy Faujas de Saint-Fond installed himself at a table in the Café du Caveau in the Palais-Royal,4 soliciting contributions to repeat Montgolfier’s experiment, this time with inflammable air and under the expert direction of the popular lecturer in physics Jacques-Alexandre-César Charles. Advertising only by word of mouth, as Faujas would boast in the book he published later that year, the subscription was soon filled by wealthy patrons.5 Long before Etienne Montgolfier would stage his demonstration, Franklin would witness the spectacular ascension of a 12-foot-wide hydrogen balloon.6

Passy, July 27. 1783.

Dear Sir,

I received your very kind Letter by Dr Blagden, and esteem myself much honour’d by your Friendly Remembrance. I have been too much and too closely engag’d in public Affairs since his being here, to enjoy all the Benefit of his Conversation you were so good as to intend me.7 I hope soon to have more Leisure, and to spend a Part of it in those Studies that are much more agreable to me than political Operations.—

I join with you most cordially in rejoicing at the Return of Peace. I hope it will be lasting, & that Mankind will at length, as they call themselves reasonable Creatures, have Reason and Sense enough to settle their Differences without cutting Throats: For in my Opinion there never was a good War, or a bad Peace.8 What vast Additions to the Conveniences and Comforts of Living might Mankind have acquired, if the Money spent in Wars had been employ’d in Works of public Utility. What an Extention of Agriculture even to the Tops of our Mountains; What Rivers render’d navigable, or join’d by Canals; what Bridges, Acqueducts, new Roads & other public Works, Edifices & Improvements, rendering England a compleat Paradise, might not have been obtain’d by spending those Millions in doing Good which in the last War have been spent in doing Mischief! in bringing Misery into thousands of Families, and destroying the Lives of so many Thousands of working People who might have perform’d the useful Labour.—

I am pleas’d with the late astronomical Discoveries made by our Society. Furnish’d as all Europe now is with Academies of Science, with nice Instruments and the Spirit of Experiment, the Progress of human Knowledge will be rapid, and Discoveries made of which we have at present no Conception. I begin to be almost sorry I was born so soon, since I cannot have the Happiness of knowing what will be known 100 Years hence.—9

I wish continu’d Success to the Labours of the Royal Society, and that you may long adorn their Chair, being with the highest Esteem, Dear Sir, Your most obedient & most humble Servant

B Franklin

Dr Blagden will acquaint you with the Experiment of a vast Globe sent up into the Air, much talk’d of here at present, & which if prosecuted may furnish Means of new Knowledge.

Sir Jos. Banks.

[Note numbering follows the Franklin Papers source.]

6See BF’s previous letter of Sept. 9, 1782: XXXVIII, 84–5.

7XXXVI, 384–5, 486–7.

8The best account of the Montgolfiers and the history of the first balloons is Gillispie, Montgolfier Brothers; the information in this paragraph is drawn from pp. 10–17. Our understanding of the story, which will occupy this edition for several volumes, is based on Gillispie’s work and the contemporary MSS and imprints that informed it, many of which (the Montgolfier papers, in particular) were deposited by the author in the Princeton University Library.

9Gillispie, Montgolfier Brothers, pp. 21–2.

1See Gillispie, Montgolfier Brothers, pp. 3–4. The experiment is often cited as taking place on June 5, a date that appeared in contemporary newspapers beginning with the Jour. de Paris, July 27, 1783. The confusion stemmed from an ambiguity in the assembly’s hastily written account. The actual date is clarified by the Montgolfier brothers’ petition to the Etats particuliers, published and discussed in Auguste Le Sourd, Essai sur les Etats du Vivarais depuis leurs origines (Paris, 1926), pp. 150–2; see also Comte de La Vaulx and Paul Tissandier, Joseph et Etienne de Montgolfier (Annonay, 1926). The Montgolfiers’ draft petition is illustrated in Gillispie, Montgolfier Brothers, facing p. 7. Faujas de Saint-Fond also attributed the experiment to June 5 in his widely read Description des expériences de la machine aérostatique de MM. de Montgolfier, published in November, 1783, based on an undated letter he claimed to have received from Etienne Montgolfier, quoted on pp. 3–4.

2The minutes of the July 2 meeting include the text of d’Ormesson’s June 28 letter to Condorcet as well as the names of the commissioners: Académie des sciences, Procès-verbaux, CII, 149. Monge (1746–1818) and Bossut (1730–1814) are listed in the Index biographique des membres et correspondants de l’Académie des sciences … (Paris, 1954), pp. 363–4, 63–4. For Monge, see also Dictionary of Scientific Biography. Bossut, assistant director of the Académie des sciences, is identified in the DBF. Condorcet served on the commission ex officio. During the fall, Monge left the commission and Tillet, Brisson, and Cadet were added: “Rapport Fait à l’Académie des Sciences, sur la Machine aérostatique, de Mrs. de Montgolfier …,” Histoire de l’Académie royale des sciences for 1783, p. 5.

3The “Observations” refer explicity to the procès-verbal and correct certain points. The MS version that circulated in July (BF’s copy of which is discussed below) was unsigned. The authors were commonly known, however (see Neil Chambers, ed., Scientific Correspondence of Sir Joseph Banks, 1765–1820 (6 vols., London, 2007), II, 113), and were identified when the “Observations” were published alongside related documents and commentary in Jour. historique et politique, no. 33 [mid-August], pp. 359–63.

4Condorcet to d’Ormesson, July 19, 1783, described in Gillispie, Montgolfier Brothers, p. 25, and reproduced in Comte de La Vaulx and Paul Tissandier, Joseph et Etienne de Montgolfier (Annonay, 1926), p. 35. In an undated letter to Desmarest written during this period, Etienne Montgolfier described the capabilities of the invention, explained the brothers’ need for financial assistance for further development, asked Desmarest to intercede with the academy to have a commission named, and expressed his desire to demonstrate the machine before that commission “during [his] visit to Paris.” The Montgolfier family decided that Etienne would make the trip alone: Gillispie, Montgolfier Brothers, pp. 22–4.

5Blagden reported these general conversations to Joseph Banks on July 4, 1783: Chambers, ed., Scientific Correspondence of Sir Joseph Banks, II, 101–2.

6Those copies, which include a July 3 notation made by the commission, are in the hand of L’Air de Lamotte (University of Pa. Library).

7Charles Blagden’s Journal, entry of July 25, 1783, where Blagden called the balloon a “flying Sack.” Yale University Library.

8The first letter, dated June 21, has so many factual errors that the author’s claim to having been present at the launch cannot be believed. It does not mention the presence of the Etats particuliers. It does, however, point out that the Montgolfiers’ neighbor (and rival) Mathieu Johannot remained productively engaged in manufacturing what might be the most beautiful paper in France: Affiches, annonces, et avis divers (also known as Feuille hebdomadaire), July 10, 1783, p. 112; described in Gillispie, Montgolfier Brothers, p. 25. The second version, also from an anonymous source in Annonay but dated June 26, dropped the final section about Johannot: Mercure de France (Jour. politique de Bruxelles) for July 26, 1783, pp. 176–7.

9Etienne had left Annonay on July 11, but spent his first days in Paris lodging quietly with an uncle. The newly fabricated balloon he intended to demonstrate was shipped separately, on July 12, but was never used: Gillispie, Montgolfier Brothers, pp. 24–5.

1See the postscript of Le Roy’s letter of July 27. That letter mentions the previous day’s meeting of the Académie des sciences; Le Roy must have learned the news then.

2XXXVI, 384.

3Faujas de Saint-Fond to Joseph Banks, July 28, 1783. He enclosed copies of the procès-verbal and “Observations” and reported on Montgolfier’s plans: Chambers, ed., Scientific Correspondence of Sir Joseph Banks, II, 113. The rumor of a 100-foot-wide balloon was still circulating a month later: Mercure de France (Jour. politique de Bruxelles) of Aug. 23, pp. 177–8.

4Planche XXII, La Vaulx and Tissandier, Joseph et Etienne de Montgolfier, pp. 35–6.

5Faujas de Saint-Fond, Description des expériences de la machine aérostatique de MM. de Montgolfier … (Paris, 1783), pp. 8–9. The list of subscribers has never been located.

6See BF to Banks, Aug. 30[– Sept. 2].

7Blagden carried Banks’s letter of May 28. During almost two months in Paris, he visited BF only three times; see the annotation of that letter and BF to Blagden, July 29.

8For BF’s earlier uses of this phrase see XXXI, 437; XXXVII, 457.

9BF had voiced a similar regret in his letter to Joseph Priestley of Feb. 8, 1780. Among the discoveries that he anticipated within the next thousand years was an invention “to deprive large Masses of their Gravity & give them absolute Levity, for the sake of easy Transport”: XXXI, 455–6.

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