by Bill Bryson
Blagden also gleefully reported the open war in Paris between supporters of hot air and those of hydrogen, quoting an unacademic phrase of Dr Alexander Charles: ‘La belle cacade que Faujas et Montgolfier ont fait.’ He then added primly: ‘I know no decent English translation of this term [cacade].’ Banks (a product of Eton and Oxford) knew of course that cacade meant a heap of shit. Blagden concluded sententiously: ‘Every thing that occurs relative to this business makes me rejoice that during all the Heat & Enthusiasm of our Neighbours we retained in this country a true Philosophical Tranquillity.’
A year later, in September 1784, he was happy to pass on the opinion of his friend, the distinguished French chemist Claude Berthollet. ‘Aerostatic globes and Animal Magnetism have, during the whole of this past year, so filled people’s heads in this country that useful research has been utterly neglected.’ Blagden added pointedly that this now expressed the view of ‘the soberer part’ of the French Academy.
French ballooning certainly generated the most powerful outpouring of popular feeling. It also assembled enormous crowds in Paris, full of dangerous utopian dreams and heady aspirations. The kind of eyewitness account of such balloon launches which would have alarmed Banks is well illustrated by Le Tableau de Paris, 1 December 1783:
The swarm of people was itself an incomparable sight, so varied was it, so vast and so changing. Two hundred thousand men, lifting their hands in wonder, admiring, glad, astonished; some in tears for the intrepid philosophers should they come to harm; some on their knees overcome with emotion; but all following the aeronauts in spirit, while these latter, unmoved, saluted, dipping their flags above our heads. What with the novelty, the dignity of the experiment; the unclouded sun, welcoming as it were the travellers to his own element; the attitude of the two men themselves sailing into the blue, while below their fellow-citizens prayed and feared for their safety; and lastly the balloon itself, superb in the sunlight, soaring aloft like a planet, or the chariot of some weather-god! It was a moment which can never be repeated, the most astounding achievement the science of physics has yet given to the world.
Yet such wild enthusiasm could strongly appeal to a British physician and inventor like Dr Erasmus Darwin. Though Darwin was a Fellow of the Royal Society (elected in 1761), he was also part of a radical and nonconformist network of provincial philosophers, and a leading light of the Lunar Society based in Birmingham and Derby. Moreover he was a poet.
Darwin saw the Montgolfiers as the pioneers of a new age, and was untroubled by Banks’ scientific reservations or patriotic anxieties. He celebrated the Montgolfiers’ early flights in a long, ecstatic passage from his poem The Loves of the Plants (eventually published in 1789). A botanical description of a flying thistle-seed from Canto 2, ‘Air’, was suddenly transformed into an image of an airborne French balloon:
…Soon the shoreless air the intrepid Gaul
Launch’d the vast concave of his buoyant ball,
Journeying on high, the silken castle glides
Bright as a meteor through the azure tides;
O’er towns, and towers, and temples wins its way,
Or mounts sublime, and gilds the vault of day …
Darwin presents the Montgolfier balloon’s ascent first as seen from below, as the watching crowd gaze upwards, torn between rapture and terror:
Silent with upturn’d eye unbreathing crowds
Pursue the floating wonder to the clouds;
And flush’d with transport, or benumb’d with fear
Watch, as it rises, the diminish’d sphere.
Now less and less – and now a speck is seen –
And now the fleeting rack obtrudes between!
Then Darwin ascends to the imagined view from above, looking out from the aeronaut’s basket, at the very edge of the stratosphere. The aeronaut gazes down upon the Earth, but also upwards at the stars revealed above him. He observes the clouds and the weather systems. He even sees (like the future astronauts) the curvature of the planet itself, in the blue horizon-line of the ocean:
The calm Philosopher in ether sails,
Views broader stars and breathes in purer gales;
Sees like a map in many a waving line,
Round earth’s blue plains her lucid waters shine;
Sees at his feet the forky lightning glow
And hears innocuous thunder roar below …
Finally, in a quite extraordinary passage, Darwin sends the balloon on a fantasy voyage right through the solar system. Here science is frankly abandoned for science fiction. ‘Rise, great Montgolfier! Urge thy venturous flight / High o’er the moon’s pale ice-reflected light.’ He sails past ‘the red eye’ of Mars, floats round Jupiter, and surges beyond Saturn with its ‘crystal rings’ and Herschel’s newly discovered ‘Georgian’ planet of Uranus. He elevates magnificently through the Milky Way, and the glittering constellations of the zodiac. He becomes a new North star, ‘to blaze eternal round the wondering pole’, a beckoning light to all future space ‘mariners’. (The Loves of the Plants, 1789, Canto 2, lines 27–66.)
British journalists, though more sceptical than poets, were not entirely immune to such fantasy journeys either. They also saw the immense possibilities of balloon flight, and responded to the first reports of the French experiments. A long article on ballooning in the Monthly Review at the end of 1783 concluded:
We found our imaginations warmed by the gigantic idea of our penetrating some day into the wildest and most inhospitable regions of Africa, Arabia, and America, of our crossing chains of mountains hitherto impervious, and ascending their loftiest summits, of our reaching either of the two poles and in short, of our extending our dominion over the creation beyond any thing which we now have conception.
REPORTS
It was exactly this kind of ballomania and unscientific speculation that Joseph Banks is reputed to have dismissed out of hand. Yet the recent publication of Banks’ Scientific Correspondence,1 and a re-examination of the Royal Society archives suggests a more complex and intriguing state of affairs.
First, it turns out that no fewer than fifty letters on the subject of ballooning were exchanged between Banks and his scientific correspondents between 1783 and 1786. Not only Banks himself, but several other Fellows of the Royal Society (besides Darwin) were evidently fascinated by ballooning, and became far more closely involved than has been previously assumed.
It is also clear that the latest balloon news, including extensive cuttings from the French newspapers, and many ‘a parcel of pamphlets and journals’, was regularly supplied to Banks not only by Charles Blagden, but also by Banks’ personal assistant and librarian at Soho Square, the Swedish botanist Jonas Dryander.
This began in September 1783 when Dryander excitedly passed on a package from Paris: ‘Journal de Paris from August to September 17 is just come. I have only had time to turn over some of the last numbers to hunt for information about the great aerostatique experiment. I’ll copy here the description of the machine…’
Banks continued to receive such detailed reports of all the French balloon ascents throughout the rest of 1783 and 1784. He was informed that the French Academy of Sciences, under his opposite number the Marquis de Condorcet, had appointed an official commission to investigate ‘aerostation’, and were funding further ascents by Pilâtre de Rozier. He also received various communications from Barthélemy Faujas de Saint-Fond, a geologist and official from the Jardin du Roi, who had set himself up as a commercial promoter of ballooning in France. Saint-Fond published one of the earliest books on the subject, Descriptions des Experiences des Machines Aerostatiques de MM Montgolfier; Banks had obtained his own copy by the end of November 1783.
Apart from Blagden, Dryander and Saint-Fond, Banks’ most important source of balloon information was Benjamin Franklin, by then in his seventies and wise in the ways of both men and machines. It has not been appreciated how significant this contact was. Franklin’s ‘two papers’, submitted to the Society in Novemb
er 1783, were in reality just part of an extensive exchange of confidential letters and ballooning documents between him and Banks, amounting to no fewer than sixteen items, which continued virtually unbroken from July 1783 to April 1785.
Banks’ fascination with ballooning is expressed much more openly to Franklin than to anyone else. In September 1783 he wrote: ‘Most agreeable are the hopes you give me … I consider the present day which has opened a Road in the Air, as an Epoch … the more immediate Effect it will have upon the concerns of mankind, [is] greater than anything since the invention of Shipping …’
It was to Franklin, rather than to Blagden, that Banks wrote so warmly on 28 November 1783, immediately after the Montgolfiers’ first manned flight.
The Experiment now becomes interesting in no small degree. I laughed when Balloons of scarce more importance than soap bubbles occupied the attention of France. But when men can with safety pass, and do pass, more than 5 miles in the first Experiment I begin to fancy that I espy the hand of the Master in the education of the Infant Knowledge, who so speedily attains such a degree of maturity …
If not a ‘ballomaniac’, Franklin was certainly in favour of balloons. He had interviewed Joseph Montgolfier and the Marquis d’Arlandes at the American Embassy, the evening after that first manned flight. He had also witnessed Dr Charles’s first ascent by hydrogen balloon from the Tuilleries on 1 December, and sent Banks a most eloquent account. ‘All Paris was out, either about the Tuilleries, on the quays and bridges, in the fields, the streets, at the windows, or on the tops of houses …’
It was after this flight that Franklin was reported to have made his famous remark, when asked what was the use of a balloon: ‘I replied – what’s the use of a newborn baby?’ Perhaps he was inspired by Banks’ earlier reference to ‘the Infant Knowledge’.
Banks again wrote enthusiastically to Franklin on 9 December:
The new Art of Flying … makes such rapid advances in the country you now inhabit … Charles’s Experiment seems decisive, and must be performed here in its full extent. I have hitherto been of the Opinion that it is unwise to struggle for the honour of an invention that is about to be Effected. Practical flying we must allow to our rivals, Theoretical flying we claim ourselves … When our Friends on your side of the water are cooled a little … they shall see that we will visit the repositories of the Stars and Meteors.
The question now became, what were the realistic applications of ‘Practical flying’, as opposed to theories and fantasies?
PRACTICAL FLYING
Indeed it was not at first clear, either to the Royal Society or the French Academy of Sciences, what the true purpose or possibilities of ballooning really were. In fact ‘flight’ was itself a novel and surprisingly unexplored concept, despite an extensive literary tradition from Icarus and Pegasus onwards. What, in practice, could balloons actually do for mankind, except provide a hazardous journey interspersed with fine aerial ‘Prospects’?2
According to Saint-Fond they might, for example, provide observation platforms: for military reconnaissance, for sailors at sea, for chemists analysing the Earth’s upper atmosphere, or for astronomers with their telescopes. It is notable that most of these applications were based on the notion of a tethered balloon. In fact many of the Montgolfiers’ early experiments were made with tethered aerostats, held to the ground by various ingenious forms of harness, guy ropes or winches.
Despite his poetical effusions, Erasmus Darwin’s first practical idea of balloon-power was paradoxically that of shifting payloads along the ground. He suggested to his friend Richard Edgeworth that a small hydrogen balloon might be tethered to an adapted garden wheel-barrow, and used for transporting heavy loads of garden manure up the steep hills of his Irish estate. This convenient aerial skip would allow one man to shift ten times his normal weight. Indeed it might revolutionise manual labour.
Similarly, Banks himself had the initial idea that balloons could increase the effectiveness of earth-bound transport, by adding to its conventional horsepower. He saw the balloon as ‘a counterpoise to Absolute Gravity’: that is, as a flotation device to be attached to traditional forms of coach or cart, making them easier to move over the ground. So ‘a broad-wheeled wagon’ normally requiring eight horses to pull it, might only need two horses with a Montgolfier attached. This aptly suggests how difficult it was, even for a trained scientific mind like Banks’, to imagine the true possibilities of flight in these early days.
Franklin, ‘the old fox’ as Blagden called him, was quick to suggest various menacing military applications, perhaps deliberately intended to fix Banks’ attention. ‘Five thousand balloons capable of raising two men each’ could easily transport an effective invasion army often thousand marines across the Channel, in the course of a single morning. The only question was, Franklin implied, which direction would the wind be blowing from?
His other speculations were more light-hearted. What about a ‘running Footman’? Such a man might be suspended under a small hydrogen balloon, so his body weight was reduced to ‘perhaps 8 or 10 Pounds’, and thus made capable of running in a straight line in leaps and bounds ‘across Countries as fast as the Wind, and over Hedges, Ditches & even Water…’ Or there was the balloon ‘Elbow Chair’, placed in a beauty spot, and winching the picturesque spectator ‘a Mile high for a Guinea’ to see the view. Then there was Franklin’s patent balloon icebox. ‘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.’ This contraption would surely have appealed to that twentieth-century illustrator Heath Robinson.
Many other ingenious suggestions were made, including the use of balloons as buoyancy tanks for ships, as aerial river-ferries, and for air mail between towns. The latter merely required that the recipients were always precisely downwind of the sender. Indeed, Erasmus Darwin attempted to pioneer balloon-post by sending a Christmas letter in December 1783, attached to a small hydrogen balloon. It was meant to fly northwards carrying seasonal greetings from the Philosophical Society in Derby to Matthew Boulton’s garden in Birmingham. In the event it overshot by fifteen miles when ‘the wicked wind carried it to Sir Edward Littleton’s’.3
Thomas Martyn, a Professor of Botany at Cambridge, published an illustrated pamphlet appealing directly to the Royal Society, Hints of Important Uses for Aerostatic Globes, 1784. Martyn’s big idea was high-speed visual communications by tethered balloon. He urged the use of balloons as signal platforms, invaluable for directing armies on land or fleets at sea. A day-time system of flag semaphore could be replaced by fireworks at night – a rather more problematic suggestion. ‘These Experiments … might be beyond measure enlarged and extended under the direction of a public body, such as our Royal Society.’
Finally even Professor Martyn succumbed to aerostatic fantasy, by fixing an astonishing frontispiece to his pamphlet. It showed a huge, beautiful dream-balloon soaring magnificently amidst the clouds, carrying beneath it a solid, wooden ocean-going ‘air-ship’, with square-rigged sails, large sea-going rudder and elegant anchor on a chain, evidently ready to circumnavigate the entire globe.
NAVIGATION
The great emerging scientific question became this: could an aerostat be navigated? Was it truly an ‘air-ship’? Could a balloon be steered against the prevailing air current, to a previously chosen destination? Could it ever, quite simply, provide a sure method of getting from A to B? Throughout 1784 Banks closely followed the British balloon flights of Lunardi and Blanchard with this navigation question in mind. Several distinguished Fellows of the Royal Society were sent to observe them. Blagden and Cavendish, together with the astronomers Herschel and Aubert, stationed themselves at various rooftop vantage points in London, equipped with telescopes and quadrants. They carefully sent back their data to Banks, and made a special point of observing the effects of wings, oars and rudders on the balloon’s horizontal flight-path. Could it be diverted agai
nst or across the wind, however marginally? Lunardi favoured simple wooden oars for this task, while Blanchard proclaimed his faith in silken wings, cotton rudders and a complex propeller-type device known as a moulinette (‘a sort of ventilator that could be turned by means of a handle’). Despite their repeated claims, none of this equipment produced the least observable effect.
These negative observations were significant, because aeronauts in France had been claiming that they could produce a slightly diverted flight-path across the line of the wind, using sails and rudders. During an impressive 150-mile flight made from Paris to Artois on 19 September 1784, the Roberts brothers, who had helped design Dr Charles’ original balloon, stated with pseudo-scientific precision that they had achieved a ‘deflection of 22 degrees’, and ‘might have obtained 80 degrees’. This, they argued, was almost as efficient as a close-hauled sailing ship moving through the comparable medium of water. Banks now had reason to believe that they were deluded.
The one scientific instrument which proved effective in balloon navigation was the mercury barometer. It was already established that air pressure dropped with an increase in altitude. In some sense, not entirely understood, the air got ‘thinner’ the higher one went. So as a balloon rose, an onboard barometer would give a steadily lower reading; and conversely, as the balloon descended, the barometric reading would rise. So an appropriately calibrated barometer (with an adjustable scale set at zero immediately before launching) could act as an altimeter, indicating a balloon’s changing height above the ground.