Falling upwards, p.20
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       Falling Upwards, p.20

           Richard Holmes
 

  At first Glaisher defined his view of the balloon, with deliberate dry British understatement, as ‘an instrument of Vertical Exploration’.13 Yet he later found himself expanding on this utilitarian view. The scientific hopes of the great French balloon enthusiasts, François Arago and Antoine Lavoisier, might yet be fulfilled. Balloon experiments, he became convinced, would begin to give us a completely new conception of the planetary envelope within which we all live. This atmospheric envelope was ‘the great laboratory of changes which contain the germ of future discoveries’.

  Such experiments, if boldly pursued, would throw light on ‘the physical relation to animal life of different heights, and the form of death which at certain elevations waits to accompany its destruction’. In short, the balloon, properly placed in the hands of empirical British scientists, could become nothing less than ‘a philosophical instrument’ of enquiry.

  In fact Glaisher began to see infinite perspectives opening up: ‘Do not the waves of the aerial ocean contain, within their nameless shores, a thousand discoveries destined to be developed in the hands of chemists, meteorologists, and physicists? Have we not to study the manner in which the vital functions are accomplished at different heights, and the way in which death takes possession of the creatures whom we transport to these remote regions?’

  This idea of an aerial ocean, with its ‘nameless shores’, its crucial boundaries of life and death ‘at different heights’, was effectively new and would have immense implications.14

  3

  How had James Glaisher come to this visionary viewpoint? Born in 1809, he was the son of a watchmaker from Rotherhithe, and had grown up with a keen interest in precision instruments and an almost religious respect for meticulous accuracy. As a young man he had worked for the British Trigonometrical Survey, and been sent to learn his craft in Ireland. Tramping over the mountains of Donegal in every kind of weather, he had become fascinated by that most imprecise and indefinable phenomenon – clouds. How, he wondered, could such infinitely changeable and complex things be precisely measured, and their subtle influence accurately and mathematically calculated?

  On returning to England, he was appointed assistant at the Cambridge University observatory, where his skill and dedication were quickly noticed by Sir George Airy. At the age of twenty-nine he was recruited by Airy to head the newly opened Department of Magnetism and Meteorology at the Royal Observatory, Greenwich. He would hold this post for the next thirty-six years (1838–1874).15

  Glaisher had an almost Platonic commitment to the power of mathematics. He was passionate about measurement, and believed that there was nothing in Nature that would not yield to it. He began to consider how the kind of precise mathematical and statistical observations essential to astronomy might be applied to the still-infant science of meteorology, concluding that the crucial requirement was accurate and systematic data – lots of it. Like Professor Joseph Henry at the Smithsonian, he soon realised that the key to gathering such data was the new telegraph system. For the first time the electric telegraph made national weather reporting a genuine possibility.

  Within a decade Glaisher had established his own amateur network of some sixty local volunteers, using properly calibrated instruments, right across England. His dedicated team of weathermen were mostly doctors and clergymen, men tied to their particular parishes, who could be relied upon to take regular readings of temperature, barometric pressure, wind speed and atmospheric conditions (cloud, rain, sunshine) at precisely nine o’clock every morning.

  The results were telegraphed to Glaisher at the Royal Observatory before noon. He could now command a daily picture of the evolution of weather systems right across the country. In August 1848 he began to contribute a national weather report to the Daily News. He was elected a Fellow of the Royal Society in June 1849, and became the Secretary of the Meteorological Society in 1850. His weather charts were shown at the Great Exhibition in 1851. He could track the weather, but still he did not attempt to forecast it.16

  In the autumn of 1852, Glaisher followed four of Charles Green’s ‘last’ ascents from Vauxhall, using a telescope, from the roof of the Greenwich observatory. Perhaps in response to Barral and Bixio, Green was deliberately going for height, and claimed to have reached nearly 22,930 feet. It struck Glaisher that high-altitude ballooning might be a possible way of radically extending meteorological research. But for the moment he was kept too busy by Airy to do anything about it.17

  As he entered his fifties, Glaisher’s meteorological career seemed distinguished and settled, but unlikely to go much further – or higher. He diverted himself with some exquisite studies of the formation of snowflakes, each one a perfect demonstration of mathematical symmetries in Nature. Yet, once asked to organise the BAAS balloon project with Coxwell, for the first time he admitted ‘the desire which I had always felt for observations at high altitudes’.18 Perhaps the spirit of his youth, or the spirit of the Donegal hills, breathed back into the whiskery face of the paterfamilias.

  Glaisher’s moment came when one of the younger meteorologists from Greenwich, chosen to accompany Coxwell on a training flight, ‘declined’ to ascend. There was nothing else for it – Glaisher would simply have to go up himself. He put it to the BAAS, and perhaps to Mrs Glaisher, as a matter of reluctant necessity: ‘I found that in spite of myself I was pledged both in the eyes of the public and the British Association to produce some results in return for the money expended. I therefore offered to make the observations myself.’19 But there can be little doubt that James Glaisher FRS, in his own quiet way, was truly delighted at the heady prospect.

  Glaisher came to regard the clouds and the upper atmosphere – ‘the great laboratory of changes’ – as the natural extension of all his previous, ground-based work. Deciding that the balloon basket must become a miniature laboratory in the air, he assembled a remarkable array of twenty-four instruments designed for high-altitude research. Mounted on a large, tilted wooden control board fixed across the centre of the basket, they included five different types of aneroid and mercurial barometers (to indicate altitude), four types of thermometer, and two types of hygrometer. He also had a compass, a chronometer, a magnet, a pair of opera glasses, and ‘scissors for cutting string’.20

  He set himself the primary task of recording and comparing the readings from all his instruments, continuously for the entire duration of the flight, and logging them accurately against a chronometer. This required extraordinary speed and self-discipline. Indeed, once Glaisher teamed up with Henry Coxwell in the air, he would prove an exceptionally dauntless and phlegmatic observer.

  At one hectic moment during a flight in July 1863, Glaisher logged in the space of sixty seconds seven readings from his aneroid barometers, accurate to the hundredth of an inch, and twelve readings of the thermometer, accurate to a tenth of a degree: an average of one reading every three seconds. In another flight, over an extended period of approximately ninety minutes, he logged the flight time on 165 separate occasions, and recorded on average one instrument reading every nine seconds.21 From this mass of meticulous data he would compile detailed reports for the BAAS committee, which subsequently became the basis for his contribution to the most celebrated study of Victorian ballooning, Travels in the Air.22 Not the least remarkable part of this data was individual flight ‘profiles’, in the form of illustrated graphs of hitherto unrivalled accuracy.

  Speed and concentration were not the only requirements. Safeguarding his instruments under all conditions in the air was also paramount. As they were mostly glass, the great problem was to prevent them breaking during the impact of landing. Glaisher devised an ingenious method of securing each instrument to the board by a system of string laces. These provided a simple but highly effective quick-release mechanism, as they could be cut by scissors. If a landing promised to be rough, Glaisher could cut and dismount his entire instrumentation set in less than a minute, sliding each instrument into one of a series of flat, cushioned drawers enc
losed in a heavily padded crash-box securely fixed in the centre of the basket. (In a sense this was a forerunner of the aircraft ‘black box’.)

  Glaisher and Coxwell would make twenty-eight experimental ascents between 1862 and 1866, usually from the small industrial town of Wolverhampton, but later over London.23 Wolverhampton particularly suited their purposes, as it was close to the geographic centre of England, and thus prudently furthest from a sea coast in any direction. It also had a highly efficient and economical municipal gas company, whose chief engineer, Mr Proud, became one of Glaisher’s warmest supporters.24

  Their first ascent was made from Wolverhampton on 17 July 1862, and reached a little over twenty-two thousand feet in the space of two hours. Immediately on their descent, Glaisher wrote up a remarkable description of the physical conditions experienced in a balloon at high altitude. Although this was his first time aloft, the coolness and precision of his account is already characteristic. It is striking that he records instrumental and bodily measurements with equal objectivity.

  At the height of 18,844 feet, eighteen vibrations of a horizontal magnet occupied 26.8 seconds, and my pulse beat at the rate of 100 pulsations a minute. At 19,415 feet palpitation of the heart became perceptible, the beating of the chronometer seemed very loud, and my breathing became affected. At 19,435 feet … the hands and lips assumed a dark bluish colour, but not the face. At 21,792 feet I experienced a feeling analogous to seasickness, though there was neither pitching nor rolling of the balloon, and through this illness I was unable to watch the instruments long enough to get a dew point [reading]. The sky at this elevation was a very deep blue colour, and the clouds were far below us. At 22,357 feet I endeavoured to make the magnet vibrate, but could not … Our descent began a little after 11 a.m., Mr Coxwell experiencing considerable uneasiness at our close vicinity to the Wash.25

  4

  Information about the nature of the upper atmosphere was astonishingly vague until Glaisher’s ascents of the 1860s. There was no clear idea of how high the respirable atmosphere reached, or whether the air would grow hotter or colder as an aeronaut got ‘nearer’ to the sun. In the legend of Icarus, of course, it got hotter. No one knew therefore how high a man (or indeed a bird) could safely fly before he was either asphyxiated, frozen, burnt or even electrocuted by static electricity in high clouds. Nor was it known how much warning you would get about the imminent arrival of any of these lethal conditions.

  Certainly ballooning anywhere above four miles, or twenty-one thousand feet, was regarded as perilous, and entering upon unknown territory, the terra incognita of the upper air. Gay-Lussac, Barral and Bixio, and Charles Green had each flown somewhere in the 22–23,000-feet zone, though their barometric altimeters were nowhere near as accurate as Glaisher’s, and their claims probably exaggerated. Most crucially of all, before Glaisher and Coxwell there was no clear identification of what we would now call the stratosphere, starting about six miles up, or thirty-two thousand feet. This is the critical point where the air can no longer be breathed, and human life cannot be sustained. Almost the only certain thing that aeronauts knew about the upper atmosphere was that the barometric air pressure dropped steadily as you got higher.

  Information about the life of weather systems was equally sketchy. Up till now, the approach to weather had been strictly earthbound and empirical. Weather records had been built up over centuries by local observers, notably in England by country clergymen and squires such as Gilbert White in Hampshire or James Woodforde in Norfolk. But such ‘meteorology’ amounted to little more than the simplest, daily records of temperature, air pressure, wind speed and rainfall. The instruments to measure these had been widely available in England since the seventeenth century.26

  The first mercury barometer, using a thin column of mercury sealed into a calibrated glass tube, was invented by Evangelista Torricelli in 1644. Robert Hooke at the Royal Society invented the aneroid or ‘clock-faced’ barometer, based on a coiled metal spring rather than on mercury, in the 1670s, together with an improved type of thermometer and hygrometer. Regular readings with such instruments could suggest broad seasonal trends and averages, over long periods of time. But this was purely empirical data. It implied no theory of weather formation, no concept of what forces or systems actually generated weather, and, crucially, no idea of prediction or ‘forecasting’. So up to now the foretelling of weather had been essentially a local affair, the province of local expertise and memory, of folklore and tradition, of proverbial sayings and immemorial superstitions.fn28

  Theoretical developments had been very slow. The philosopher and mathematician René Descartes had published an essay on La Météorologie in 1637. His word ‘meteorology’ was derived from Aristotle’s Greek term, meteor, simply meaning anything ‘high up’. So Descartes’ meteorology was partly astronomy, including meteors, comets and shooting stars, as well as speculations on the nature of clouds, fog, sunshine, the formation of ice and the cause of storms. In 1686 the British astronomer and mathematician Edmund Halley drew on maritime records to construct an early chart of global weather systems, suggesting tropical and subtropical airflows over the major oceans and land masses.28

  In the 1730s George Hadley, like Halley a Fellow of the Royal Society, developed the theory of trade winds, which took account of global rotation and thermal convection. Some hundred years later a Polish scientist, Heinrich Wilhelm Dove, a future director of the Prussian Meteorological Institute, suggested in a series of papers that storms were the result of warm-weather systems colliding with cold ones. Thus the idea of mobile weather ‘fronts’ (partly drawing their imagery from Napoleonic warfare) began to emerge. But all these observations still lacked any more general, unifying theory of meteorology.29

  Even so, a growing fascination with the mystery and beauty of weather was becoming evident in the Romantic writers and painters of the time. John Ruskin, the future champion of the great atmospheric cloud paintings of J.M.W. Turner, was one unexpected enthusiast. At seventeen, while still an undergraduate at Oxford, the young Ruskin joined the newly formed London Meteorological Society. The following year, in 1838, he composed an elegant essay on the general problem of finding an empirical basis for true, predictive meteorology. He contributed it to the Society’s Journal:

  A Galileo or a Newton, by the unassisted working of his solitary mind, may discover the secrets of the heavens and form a new system of astronomy. A Davy in his lonely meditations on the crags of Cornwall or in his solitary laboratory, might discover the most sublime mysteries of nature … But the meteorologist is impotent if alone; his observations are useless, for they are made upon a point, while the speculations to be derived from them must be [extended] in space.30

  Ruskin’s central argument was that genuine ‘forecasting’ required a much broader understanding of weather ‘systems’, and multiple observers. It must depend on the collation of data simultaneously from many points over the land – and ultimately over the sea. He imagined whole teams of volunteer observers – in the European Alps, on the Atlantic Ocean, in the American prairies – recording weather information at agreed times. He would eventually be proved right by Glaisher, Fitzroy, Henry and others.

  But until the 1860s, foretelling weather even one day ahead still depended on the supposed ‘weather eye’ of farmers, foresters, hunters, fishermen and sailors. Indeed, at a local level – where such people genuinely knew their own patch, a particular valley or harbour or line of hills – such short-term predictions could be impressively reliable (and still are, for example for modern yachtsmen). But there now appeared a professional race of Victorian weather prophets, who claimed to be able to do this scientifically, and who achieved national followings. Here the equilibrium between science and superstition – or plain mumbo-jumbo – was finely balanced.

  On the north-east coast at Whitby, the curator of the Whitby Museum, Dr George Merryweather, became nationally famous throughout the 1850s for his Patent Tempest Prognosticator. It was shown at t
he Great Exhibition of 1851, at the same time as Glaisher’s weather reports, and submitted to the Board of Trade for testing. It was not adopted, for reasons that soon became clear.

  The Prognosticator was based on an idea current all along the stormy east coast of England, which was mentioned a generation earlier by the depressive poet (and temperamental balloonophile) William Cowper – himself extremely sensitive to atmosphere – while staying in East Anglia. It was based on the well-known response of leeches to sudden changes in barometric pressure. Their soft, gelatinous bodies were squeezed and made drowsy and inactive by normal air pressure, but low pressure refreshed and awoke them. As Cowper wrote: ‘I have a leech in a bottle that foretells all these prodigies and convulsions of Nature. No change in the weather surprises him … he is worth all the barometers in the world.’31

  Dr Merryweather’s Prognosticator was in fact an ingenious form of multiple leech barometer. It consisted of a circular display of twelve glass flasks, each containing a prize leech partially immersed in rainwater. The flasks were cunningly enclosed at the top with a system of whalebone springs, and these in turn were linked to a set of counterweights connected to metal hammers arranged to strike against an impressive brass bell mounted in the centre of the apparatus. It was another arrangement that would have delighted Heath Robinson.

 
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