Seeing Further

by Bill Bryson

  Banks was therefore particularly scathing when he learned that Lunardi had forgotten to take a barometer on his first historic ascent in September 1784, and had pretended to calculate his maximum altitude from the length of the icicles formed on the lower edge of the balloon canopy. He concluded that the pilot was a brilliant charlatan. Banks feared that Lunardi, having entranced the fashionable and susceptible Duchess of Devonshire, would go on to ensnare the gullible Prince of Wales, and even King George III (already rather less than stable) with his ‘balloon madness’.

  But there was an alternative to Lunardi: the Frenchman Jean-Pierre Blanchard. In the autumn of 1784, two Fellows of the Royal Society decided to purchase private passages aboard Blanchard’s hydrogen balloon, making proper observations and taking appropriate equipment with them. The first was John Sheldon, Professor of Anatomy at the Royal Academy, who flew from Chelsea in October 1784.

  Despite much anticipation, Sheldon’s flight was largely abortive from a scientific point of view. ‘The balloon was so loaded at first,’ recorded Blagden dryly, ‘that it fell down in a neighbour’s garden.’ Alarmed by the whole experience, Sheldon broke his barometer shortly before take-off, while Blanchard threw overboard the rest of his equipment immediately after. Blanchard mercifully off-loaded the terrified Sheldon at Sunbury, in Middlesex. He then claimed that he had successfully navigated with his wings and rudder some seventy-five miles into Hampshire.

  But the first half-hour of the ascent was observed by Blagden and Cavendish from the roof of a house at Putney Heath ‘with instruments’, triangulating their observations with another observer from a house in Earls Court. Their meticulous calculations showed that the balloon ‘floated along with the wind uniformly and regularly, seeming to pay no regard to the operation of the machinery they had taken up’. There was still no indication that a balloon could be navigated.

  Blagden estimated that Sheldon had spent £500 on the ascent, and concluded that he had ‘made himself so ridiculous in this business, as to reflect little credit on the Royal Society’. Banks noted, with perhaps pardonable ambiguity, that ‘Mr Sheldon and Mr Blanchard have probably fallen out, as I have not heard a word from them for some time.’

  The next philosopher to purchase a flight with Blanchard was the American physician Dr John Jeffries, in November 1784, ascending from Grosvenor Square. In fact, Jeffries was not yet a Fellow of the Royal Society, but hoped to be elected on the strength of his ballooning experiments. Accordingly, he carefully prepared a suite of scientific instruments to take with him: a mercury barometer, a thermometer, a hygrometer and an electrometer, to measure the much-feared electrical charges in clouds. In addition he packed maps, a compass and special note-making equipment. He also strapped aboard special air flasks, to sample the upper atmosphere at different altitudes, which he promised to give to Cavendish for analysis.

  Jeffries drew up a memorandum for the Royal Society before they left, stating the main scientific objectives of the ascents, to be achieved by ‘a variety of experiments’ and ‘not for mere amusement’. He was quite precise:

  Four points need to be more clearly determined. First, the power of ascending or descending at pleasure, while suspended or floating in the air. Secondly, the effect which oars or wings might be made to produce towards this purpose, and in directing the course of the Balloon. Thirdly, the state and temperature of the atmosphere at different heights above the earth. And fourthly, by observing the varying course of the currents of air, or winds, at certain elevations, to throw some new light on the theory of winds in general.

  On this trip, going across the Thames into Kent, Jeffries made the first truly scientific record of a balloon ascent. He meticulously recorded a mass of data – height, direction, air temperature, electrical charges, appearance of clouds, horizon line – at regular time intervals. One of the details which emerged was a ‘profile’ of the characteristic flight-path of a hydrogen balloon: not a single smooth parabola, as had been supposed, but a series of looping ascents and descents, as the balloon moved above and below its ‘equilibrium point’. It was also clear to Jeffries that wind directions often changed at different altitudes. But on the crucial question of navigation, Jeffries could observe no controlled alteration of flight-path, for all Blanchard’s ‘heroic’ rowing and flapping and spinning.

  Jeffries went on to take part in the most significant of all the early balloon ascents in Britain, the first crossing of the English Channel with Blanchard on 5 January 1785. He wrote an outstanding account, which exists in at least three versions. The first was sent as a private letter to Banks from Paris shortly after the flight on 13 January 1785, the second as a formal paper published by the Royal Society in the Philosophical Transactions for January 1786, and the third as a retrospective diary.

  Despite its apparent triumph, both sporting and diplomatic, the main scientific significance of this flight was that it proved conclusively that a balloon was not navigable, either over land or sea. As Jeffries expressed it privately in his diary, he could only ‘thank God’ and a favourable wind for his survival. He never flew again.

  By the end of 1785, Banks too was rapidly losing interest in ballooning. His correspondence with Franklin tailed off into a courteous exchange of medals and compliments. His doubts could be summed up succinctly: balloons were not navigable, and – as he had originally thought – they should be left to the French. Yet at the last Banks may have encouraged a book by a younger Fellow of the Royal Society that would inspire a new generation of aeronauts.

  RETROSPECTIVE

  In 1785 Tiberius Cavallo FRS published A Treatise on the History and Practice of Aerostation. Cavallo was a brilliant Italian physicist who had moved to London at the age of twenty-two, and had already written extensively on magnetism and electrical phenomena. Elected a Fellow in 1779, he quickly turned his attention to ballooning. He had some claims to be one of the first to inflate soap bubbles with hydrogen as early as 1782. Although a handsome portrait is held by the National Portrait Gallery in London, he is now largely and unjustly forgotten. Yet his study emerges as the most authoritative early treatise on the subject, either in English or French. The copy of Cavallo’s book held by the British Library is personally inscribed ‘To Sir Joseph Banks from the Author’ – in firm, black, racy ink.

  Cavallo adopted a considered and even sceptical tone, well calculated to appeal to Banks. Of his fellow-countryman Lunardi’s historic flight he noted:

  Besides the Romantic observations which might be naturally suggested by the Prospect seen from that elevated situation, and by the agreeable calm he felt after the fatigue, the anxiety, and the accomplishment of his Experiment, Mr Lunardi seems to have made no particular philosophical observation, or such as may either tend to improve the subject of aerostation, or to throw light on any operation in Nature.

  He analysed and dismissed most claims to navigate balloons, except by the use of different air currents at different altitudes. He emphasised the aeronaut’s vulnerability to unpredictable atmospheric phenomena, such as downdraughts, lightning strikes and ice formation. He deliberately included the alarming account of those who survived when a French balloon was caught in a thunderstorm, during an ascent from St Cloud in July 1784, and dragged helplessly upwards by a thermal:

  Three minutes after ascending, the balloon was lost in the clouds, and the aerial voyagers lost sight of the earth, being involved in dense vapour. Here an unusual agitation of the air, somewhat like a whirlwind, in a moment turned the machine three times from the right to the left. The violent shocks, which they suffered prevented their using any of the means proposed for the direction of the balloon, and they even tore away the silk stuff of which the helm was made. Never, said they, a more dreadful scene presented itself to any eye, than that in which they were involved. A unbounded ocean of shapeless clouds rolled one upon another beneath, and seemed to forbid their return to earth, which was still invisible. The agitation of the balloon became greater every moment …
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  Yet for all this, Cavallo was a passionate balloon enthusiast. He recorded and analysed all the significant flights, both French and English, made from the Montgolfiers’ first balloon at Annonay in June 1783 to Blanchard and Jeffries’ crossing of the Channel in January 1785. He distinguished carefully between hot-air and hydrogen balloons, and their quite different flight characteristics. He looked in detail at methods of preparing hydrogen gas, noting that Priestley had come up with one that used steam rather than sulphuric acid. He also examined the different ways of constructing balloon canopies from rubber (‘cauchouc’), waxed silk, varnished linen and taffeta.

  In a longer perspective, he stressed the astonishing speed of aerial travel over the ground – ‘often between 40 and 50 miles per hour’ – combined with its incredible ‘stillness and tranquillity’ in most normal conditions. This he thought must eventually revolutionise transport and communications, even if the moment had not yet arrived. He pointed out that in achieving altitudes of over two miles, balloons opened a whole new dimension to mankind’s observations of the Earth beneath. Man’s growing impact on the surface of the planet became visible from the air for the first time, as did the vast tracts of the Earth – mountains, forests, deserts – yet to be traversed. Above all he stressed that the full potential of flight had not yet been remotely explored.

  Cavallo considered the whole range of possible balloon applications. But he finally and presciently championed its relevance to the infant science of meteorology:

  The philosophical uses to which these machines may be subservient are numerous indeed; and it may be sufficient to say, that hardly anything of what passes in the atmosphere is known with precision, and that principally for want of a method of ascending into the atmosphere. The formation of rain, of thunder-storms, of vapours, hail, snow and meteors in general, require to be attentively examined and ascertained.

  The action of the barometer, the refraction and temperature of air in various regions, the descent of bodies, the propagation of sound etc are subjects which all require a long series of observations and experiments, the performance of which could never have been properly expected, before the discovery of these machines. We may therefore conclude with a wish that the learned, and the encouragers of useful knowledge, may unanimously concur in endeavouring to promote the subject of aerostation, and to render it useful as possible to mankind.

  It was largely due to Cavallo’s book that, a decade later, ballooning received a signal acknowledgment and consecration. The third edition of the hugely influential Encyclopaedia Britannica, published in 1797, for the first time recognised the existence of ‘Aerostation’. It described it with all due formality as ‘a science newly introduced to the Encyclopaedia’, and gave it a comprehensive article of fourteen pages. This included two full spreads of diagrammatic illustrations, showing every known kind of aerostats that would actually fly. Almost all the material was drawn, unacknowledged, from Tiberius Cavallo.

  The editors of the great Encyclopaedia made one symbolic gesture. They placed as the frontispiece to the opening volume of the new edition a prophetic engraving. It showed a traditional gathering of ‘natural philosophers’ in a Roman forum, arrayed in classical togas and surrounded by pillared Doric temples. (Could they have intended a sly reference to the Royal Society?) They then introduced one striking anachronism. High overhead, a hydrogen balloon (complete with wings) sails imperiously into some unknown future.

  Such prophetic dreams would soon be taken up by a new generation of British aeronauts, such as James Sadler and Charles Green. But as for Sir Joseph Banks PRS, now perhaps made more earth-bound by his knighthood, aerostation virtually disappears from his letters after 1790. When in January 1800 he received a charming inquiry from Ireland suggesting a scheme to build a balloon railway beneath a ‘mile-long covered gallery’ at Greenwich, he replied with barely a sigh: ‘The Royal Society have no Funds destined for the Execution of Projects so Expensive as yours must be; nor indeed have they in any one instance interfered in the business of Aerostation.’

  1 See the wonderful new edition, The Scientific Correspondence of Joseph Banks 1765–1820, edited by Neil Chambers, 6 vols (London, Pickering & Chatto Ltd, 2007). Further sources are given in my bibliography on page 486.

  2 The idea that the ‘Prospect’ itself – the free ascent, the magnificent views, the whole ‘aerial experience’ – was the real point of ballooning, only truly arrived with the sporting, propane-powered hot-air balloons of the late twentieth century. However, one early pioneer of this existential attitude was Thomas Baldwin, whose remarkable Aeropaedia (1786) was an entire book dedicated to a single flight, made from Chester on 8 September 1785. It contained the first ever paintings of the view from a balloon-basket; an analytic diagram of the corkscrew flight path projected over a land map; and a whole chapter simply given up to describing the astonishing colours and structures of cloud-formations. One typical observation reads: ‘The river Dee appeared of a red colour; the city [Chester] very diminutive; and the town [Warrington] entirely blue. The whole appeared a perfect plane, the highest buildings having no apparent height, but reduced all to the same level, and the whole terrestrial prospect appeared like a coloured map.’ [p. 204].

  3 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.

  8 RICHARD FORTEY

  ARCHIVES OF LIFE: SCIENCE AND COLLECTIONS

  Richard Fortey FRS is a geologist and palaeontologist and spent his career in research at London’s Natural History Museum from where he retired in 2006. His widely acclaimed books include The Hidden Landscape, Life: An Unauthorised Biography, Trilobite!: Eyewitness to Evolution, Fossils: The Key to the Past and The Earth: An Intimate History. His latest book, Dry Store Room No. 1, is a portrait of the Natural History Museum.

  OBSERVATION WAS A CRUCIAL FOUNDATION FOR THE NEW SCIENCE. IN BIOLOGY, THAT MEANT THE CLOSEST EXAMINATION OF SPECIMENS. KEEPING THEM, SO OTHERS COULD REFINE THE OBSERVATIONS YEARS, DECADES, OR EVEN CENTURIES LATER, PROVED TO BE JUST AS IMPORTANT, AS RICHARD FORTEY EXPLAINS.

  Safely stored behind the scenes at the Natural History Museum in South Kensington is a slightly twisted vertebrate skeleton preserved on a slab of creamy white limestone. This particular specimen was discovered in quarries near Solnhofen in southern Germany in 1861. The fine limestones of Solnhofen are ideally suited to making lithographic stones, and in the nineteenth century lithographs provided one of the most important means of book illustration – indeed lithographic stones of this quality are still in demand by artists today. Vast quantities of this lithographic limestone of Jurassic age – about 150 million years old – have been taken out of opencast workings, where the rocks can be split into convenient slabs a centimetre or two thick; the German word plattenkalk appropriately describes their lithological character. On many of these flat-surfaced pieces of rock, fossils are laid out like gifts on a salver.

  Some Solnhofen fossils are rather common, such as those of delicate little sea lilies. Others are both rare and more spectacular. There are a great variety of fish species known nowhere else, for example. The fossil horseshoe crab Mesolimulus provides evidence that its living relatives breeding each year along the Atlantic coast of America have changed little over tens of millions of years. Delicate flying reptiles – half a dozen species or so of pterodactyl – testify by contrast to creatures that have vanished from the Earth
for ever. A few species of dinosaur are known, of the most delicate sort (Compsognathus), and quite unlike the monsters of popular imagination. Insects include dragonflies (Aeschnogomphus) whose every wing-vein is visible as delicate tracery. All these creatures are preserved in rocks which originated as tacky muds flooring a lagoon that lay offshore from a richly biodiverse habitat. Such special circumstances sampled and preserved a much wider variety of organisms than the usual fossil locality, and the wide range of fossils provides a rare window into an entire habitat from a very different world. Yet if the remains were not kept carefully in museums all this evidence of past life would perish, and new generations of children and scholars could not interrogate the past. Local museums at Eichstätt and Solnhofen fulfil that function for those who would come to Bavaria and marvel at its geological treasures. But some of the specimens from the Solnhofen limestone have a relevance that extends far beyond the reconstruction of the late Jurassic scene, and these specimens are treasures in the collections of museums around the world. None more so than that specimen – a mere 35 cm at its longest – safely curated in the Natural History Museum in London.

  For this is the first example ever discovered of the early bird Archaeopteryx. It remains one of the most important specimens in the British national collections. The next complete fossil bird of the same species – the so-called Berlin specimen – was found sixteen years later. It would be difficult to overstate the importance of this London specimen of Archaeopteryx in the history of biology.

  First, the date of its discovery is only two years after the publication of The Origin of Species, the sesquicentenary of which we celebrated in 2009. Charles Darwin famously described what he called ‘difficulties on theory’ in that work, where he anticipated a number of criticisms that he expected his great idea to encounter. Prime among these was ‘the rarity or absence of intermediate forms’ in the fossil record. Second, the detailed scientific description of Archaeopteryx was an accomplishment of Richard Owen in 1863; he was later to become first director of the Natural History Museum. Owen was no Darwinian, but he was an able anatomist. It must have proved anathema to him when Archaeopteryx was recruited as probably the best example of an ‘intermediate form’ and one that had turned up with the impeccable timing usually associated with a good piece of theatre. Its amalgam of reptilian and bird features (feathers and wishbone among them) was a striking vindication of the notion of descent with modification, and a rebuttal to those who might wonder how it was possible for animals to make the transition from earth to the skies.