Many a revolutionary technology has grown beyond its original, intended use; the Internet, the steam engine, and the spiral-cut glazed ham, to name a few. This week's excerpt looks at some of the more...unconventional...uses of the 18th century's newly-developed "balloon."
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'? 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.
[Benajmin] 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 of ten 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'. 
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.
1 Barthelemy 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.
2 Erasmus Darwin was an early ballooning enthusiast
3 Joeseph Banks, botanist and newly-elected President of the Royal Society
4 The supremely impractical suggestion of balloon mail was to be strangely vindicated by the French some ninety years later. During the Prussian siege of Paris in 1870–71, no fewer than sixty-six hydrogen balloons, each carrying 125 kilos of domestic mail and government despatches, sailed successfully over the Prussian lines, landing as far aﬁeld as unoccupied Brittany, whereupon the mail was rapidly distributed by horse across the nation. The ﬁrst balloon, the Neptune, carried a letter from the photographer Felix Nadar to The Times. Subsequent balloons, with that touch of French genius, teased the Prussians by having patriotic names emblazoned on their canopies in huge letters – the Victor Hugo, the George Sand, the Armand Barbès.
Biographer Richard Holmes was born in London, England and educated at Cambridge. His first book was published in 1974 and won a Somerset Maugham Award. The first volume of his biography of the poet Samuel Taylor Coleridge, Coleridge: Early Visions, was published in 1989 and won the Whitbread Book of the Year award. Dr Johnson & Mr Savage (1993), an account of Johnson's undocumented friendship with the notorious poet Richard Savage, won the James Tait Black Memorial Prize (for biography) in 1993. The second volume of his study of Coleridge, Coleridge: Darker Reflections, was published in 1998. It won the Duff Cooper Prize, the Heinemann Award and was shortlisted for the first Samuel Johnson Prize awarded in 1999.
Seeing Further: The Story of Science, Discovery, and the Genius of The Royal Society is available at Amazon.com