by Sarah Dry
Thanks to the power of technology and bureaucracy, distance, once a foe to be vanquished, became something rather more interesting and much more valuable to the British Empire. Rather than a challenge to the exercise of power, it came to be seen as a mark of that very power. A tiny post office on an Indian tea plantation, set beside a stream in which an elephant might peacefully bathe, could reveal itself to be, on closer inspection and by dint of a small wire emerging from it, a node in a global network of imperial connection and control. As a result of scenes such as this, often reproduced in imperial gazettes and albums, distance became the leitmotif of the Empire, an expanse on which the sun famously was given no opportunity to set.
Distance wasn’t just symbolic of the great power of the Empire, it also created value where none had existed before. Reliably fast steamships that muscled their way across the seas meant that English citizens could eat bread made from Indian grain grown year-round (or nearly so) at a comfortable and safe distance from the land in which it was grown, from both the sunlight and the rains upon which it depended. India became both Britain’s bread box and its money box. By 1904, it was Britain’s greatest source of imported goods and the largest market for Britain’s own exported goods.20 India’s value to the Empire arose not in spite of, but because of, its distance from London.
Distance was what made the Empire work. It was as much a part of the logic of its success as any local control. In many ways, it was inevitable that Walker’s greatest achievement would be the discovery of something he called world weather. The greatest distances the world could offer were available to Walker, and he took them and put all his skills to bear in meeting the correspondingly enormous challenge that had brought him from the peace of Cambridge to the monsoon wars.
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The very meteorological facts that made India such a challenging place to govern made it singularly ripe for meteorological investment and study. India offered a fantasy geography for the meteorologist. This was partly a matter of scale. Everything in India was oversized. Conceptually separated from its neighbors in the region by dint of its special relationship to Britain, it was also physically separated by the extreme vertical boundaries of the Himalayas at its northern edge, by the coasts on its east and west sides, and by a southern tip that, reaching to the equator, tapered into nothingness. Straddling a quarter of the earth’s latitude, India demonstrated an enviable range of climatological phenomena. Its scale and climatological features meant that unlike Britain, where weather varied from day to day, in India the weather conspired to generate longer-term patterns: months, rather than days, formed convenient units of measurement. This made calculation vastly more manageable. As a result, India was a place where the patterns of the weather could make themselves more legible than almost anywhere else on the planet. Walker’s predecessor Henry Blanford wrote without irony of India that “Order and regularity are as prominent characteristics of our atmospheric phenomena, as are caprice and uncertainty those of their European counterparts.”21 This was partly a matter of geographical extent. India was a place where “general laws have a sufficient space to produce general results,” and so-called “disturbing influences are regular and well-ascertained.”22 For anyone who had ever grown first irritated and then maddened by the changeability of English weather, India presented a compellingly bold picture. Inundations were almost normal in parts of the country, while desert conditions prevailed elsewhere. More than 460 inches of rain fell in an average year on the village of Cherrapunji in the Assam hills, while parts of the Upper Sind garnered less than three inches. Impossible things seemed to happen frequently in India. In the wettest regions, it wasn’t uncommon for twenty-five inches of rain to fall in a single day—the same amount that normally fell on London in a year.23 During extremely hot weather, instruments recorded negative readings for humidity in some places. It was common for cyclones to hit the Indian coasts that were stronger than any which had ever been experienced in Europe.
This meteorological profusion took many and complex forms, but the most dominant was that of the monsoon, an alternating pattern of dry land winds that persisted for half the year and high humidity, cloud, and heavy rainfall that lasted for the other half. During the cold season, from October to April, the winds blew in dry and cold from the northeast. They reversed direction from May, bringing from over the oceans the wetter air that bore the heavy rains that fell from June to September or October.
The monsoon was a perfect example of the paradoxes of India. The very thing that caused so much suffering—the unpredictability of the monsoons—might turn out to be the key that could unlock the secrets of the weather more generally. The monsoon was as strong a signal as a meteorologist could ask for, writ as it was in the suffering or prosperity of millions, dutifully reported by those thousands of rain gauges and the busy barometers and thermometers whose readings were also faithfully recorded. And strong signals were the best chance that meteorology had of transforming itself into a more reassuringly predictive science. Norman Lockyer made it seem almost self-evident: “surely in meteorology, as in astronomy,” he urged his fellow scientists, “the thing to hunt down is a cycle.” Geography should be no obstacle, and indeed need not be, given the great reach of the British Empire. If a cycle is “not to be found in the temperate zone, then go to the frigid zones, or the torrid zones, and look for it,” urged Lockyer, “and if found, then above all things, and in whatever manner, lay hold of, study it, record it, and see what it means.”24
If the monsoon’s variable cycle was about as hard to miss as an elephant at close range, it was a more difficult matter to determine what caused the rains to come when they did. The starting point was the sun, the only thing more visible than the Indian monsoons. It had already offered up a well-characterized cycle of its own, during which its spots waxed and waned. These black spots, first noticed by Galileo, had been studied since by scientists seeking to understand what effect they might have on the earth. In the eighteenth century, astronomer William Herschel compared the historical index of grain prices in Adam Smith’s Wealth of Nations with sunspot data, looking for correlations. In the 1830s, the Magnetic Crusade to map the magnetic currents of the earth had sent observers with magnetic instruments to the four corners of the globe. They’d hit the jackpot when they discovered that the earth’s magnetic field fluctuated in time with the sun’s. Interest in sunspots took off further in 1850, when Heinrich Schwabe published nearly twenty-five years’ worth of daily records he’d made of sunspots —the best data set so far—which he used to identify a ten-year cycle of waxing and waning spots. That figure was soon revised to eleven years, and the sunspot cycle seemed even more likely to have definitive impacts on Earth. More grist was added to the mill in 1859, when a very strong solar flare had caused magnetic instruments to go haywire, sent telegraph communications offline (and even set some telegraph stations on fire), and generated visible aurora even by the equator. Thanks to the sense of urgency occasioned by such events, funds were made available to build a series of special observatories that were meant specifically to observe the sun and to collect and analyze data about possibly related phenomena on earth (on Piazzi Smyth’s expedition to Tenerife, he carried many requests from leading scientists to make solar observations). Caught up in the sense that certain natural mysteries were on the cusp of being revealed, physicists sought, and to a certain extent found, links between sunspots and magnetism, sunspots and temperature, sunspots and wind, and sunspots and rainfall. That these relationships could often be summed up in almost disarmingly simple terms was part of their allure. The links seemed obvious. Charles Meldrum, the government astronomer at the official observatory in Mauritius, summarized his own findings thus: “many sunspots, many hurricanes; few sunspots, few hurricanes.”25
But despite the energy that went into solar physics, by the early twentieth century no further direct physical connections had been discovered between the earth and the sun to rival the find
ings of the Magnetic Crusade. Interest gradually waned. Sunspottery, as detractors called it, came to look dangerously like a dark art, its practitioners finding patterns where none rightly existed, in a morass of confusing detail.
Among scientists, a small group remained faithful to the search for links between the sun and the earth. These cosmic physicists were less interested in cracking a secret code of nature than they were with understanding the fundamental physical connections between phenomena. Unlike most physicists, who concerned themselves with the behavior of electricity, magnetism, and heat at very small scales, these physicists probed nature at the very largest of scales, that of the solar system and beyond, on the assumption that “a force not less universal than gravity itself, but with whose mode of action we are as yet unacquainted, pervades the universe, and forms, it might be said, an intangible bond of sympathy between its parts.”26 It was undeniable that the sun affected some aspects of earthly phenomena. The hunt was on to figure out what precisely was the nature of the force “not less universal than gravity” which was responsible for such effects. They were convinced that physical connections between the earth and the sun (among other celestial objects) were profoundly important to the unfolding of meteorological, magnetic, and electrical phenomena on earth. Though the distances they worked with were great, they thought in surprisingly sensuous terms. Like lovers, the sun and the earth were exquisitely attuned to each other. “Mutual relations of a mathematical nature we were aware of before,” wrote two leading cosmic physicists, “but the connexion seems to be much more intimate than this—they feel, they throb together, they are pervaded by a principle of delicacy even as we are ourselves.”27 Tiny, ramifying perturbations could arise anywhere in the solar system, not just on the sun itself. Like the trigger of a gun, small changes in the gravitational fields of other planets in the solar system could cause sunspots that could themselves have huge effects on earthly weather. The sun was therefore able to produce incredible variation in earthly weather “by falling at different times on different points of the aerial and aqueous envelopes of our planet, thereby producing ocean and air currents, while, by acting upon the various forms of water which exist in those envelopes, it is the fruitful parent of rain, and cloud, and mist.”28 Such a passionate belief in these connections gave cosmic physicists patience and hope in spite of the lack of results to date. The seemingly impenetrable variability of the weather was a measure “not of its freedom from law,” wrote Lockyer and Hunter, “but of our ignorance.”29 All natural things, including that most fickle of phenomena, rainfall, would eventually be shown to obey the laws of nature. Only more time was needed.
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And data, lots and lots of data. Of that, at least, Walker had as much as, if not more than, he could have hoped for. Walker was not a cosmic physicist, by training or inclination, nor was he (anymore) susceptible to the fever for cycle-hunting. He was, instead, a man for whom numbers were tools that could be put to particular uses. The disciplining of numbers was essential. Just as Walker had put himself to the ultimate test of disciplined study as a student at Cambridge, so he submitted his numbers to the test of reliability and meaningfulness.
He’d inherited the concerns of those who’d come before him, and he would be conscientious in addressing those concerns. It would be wrong to say he wasn’t guided by the past. In many ways, the questions he asked of his numbers were questions others had already raised, about the relationship between distant phenomena, about the way in which things that are very far apart can, indeed, be linked. This characteristically imperial notion was both enabled and promoted by all the structures—the railways and telegraphs, and bureaucratic structures—which made the empire possible. Walker was, like anyone, influenced by the world around him, by what had come before, and by what he was hired to do in the moment.
First, he needed to gather the numbers themselves. That in itself was not difficult. He was in charge of the most advanced meteorological network in the world. Numbers—corresponding to facts about the weather—streamed into his office day after day, month after month. No data monsoon or failure thereof afflicted the Director-General of Observatories. In 1907, for example, his office in Simla received the records of rainfall from 2,677 rain gauges across India. He also received readings from several dozen meteorological observatories of pressure, temperature, and wind speed taken at eight-hourly intervals and, in some locations, recorded continuously by automatic instruments. He knew he needed data from the oceans if he was to crack the monsoons, and so he sent two full-time clerks to Calcutta and Bombay whose sole job was to visit ships as they came into harbor for the purpose of copying their meteorological logbooks and calibrating their barometers. The atmosphere—that ocean of air—wasn’t as easy to access, but it was critical to create a three-dimensional map, if possible, of the air currents that brought rain or dryness. By 1904, when Walker took up his job, it was generally agreed that more information on the middle and upper atmosphere was urgently needed, and should be acquired by any means—kites, balloons—necessary.30 Walker sent balloons and kites up from Belgium, and over the Bay of Bengal and the Arabian Sea. They flew as high as 2.5 miles into the atmosphere. From Simla, he sent up gutta-percha observation balloons that carried ultra-light instruments. These had to be recovered for their data to be useful, and he attached cards to the balloons, promising a reward for their safe return. The previous Director-General of Observatories, Henry Blanford, had pointed to snowfall in the Himalayas as an important factor in the monsoons, so Walker arranged for large-scale photographs to be taken of the snowfall visible from Simla, which could be compared year on year.31
And he corresponded. He set up telegraphic and postal correspondences with fellow observers around the world. The office in Simla, with its characteristic telegraph wire leading out of its windows, received weekly telegraphs keeping Walker informed of weather conditions at the Royal Alfred Observatory in Mauritius, a key location from which monsoon winds blew. Departmental observatories in Zanzibar and the Seychelles provided much-needed data on the Indian Ocean. For the southwest monsoon, he corresponded with Zomba, Entebbe, Dar es Salaam, Cairo, and Durban in Africa; with Perth, Adelaide, and Sydney in Australia; and with Buenos Aires and Santiago in South America.
All this data was promising, and seemed necessary. It was also potentially fatal to the dream of solving the monsoon mystery. Too much data could easily prove incapacitating. This was the dilemma. To understand the phenomenon, it needed to be observed. But it wasn’t clear precisely what the boundaries of the monsoon were. Where it started and where it ended was part of the answer Walker was seeking. So he needed, as had others before him, to cast his net wide. But the wider he cast, the more numbers he caught, the harder it would be to find the elusive signal amid all that noise.
“There are undoubtedly too many observations,” noted John Eliot, “and too little serious discussion of observations.” Instead of accumulating observations without consideration of how they might be used, the time had come for investigation of causes to “direct and suggest the task of observation.” A natural feature of a more thoughtful observing regime would be to consider allied sciences alongside that of meteorology—“there are undoubtedly definite relations between certain classes of solar phenomena and phenomena of terrestrial magnetism” and who knew what other links might be uncovered.32 What Eliot suggested was the creation of a central organization where observations taken throughout the British Empire could be compared.
As Arnold Schuster, a prominent cosmic physicist, put it, “observations are essential, but though you may never be able to observe enough, I think you can observe too much . . . It would not be a great exaggeration to say that meteorology has advanced in spite of the observations and not because of them.” There was always the danger that data collection would become an end in itself and science would become nothing more than “a museum for the storage of disconnected facts and the amusement of the collecting enthusias
t.”33
Before the matter of the proper place of observation in meteorology could be settled, the nature of meteorology itself needed to be resolved. What meteorology was, exactly, was up for grabs. Should it consist of prediction? Of observation? Of theorizing? Or, as seems reasonable, a mix of the three? But if a mix of the three, in what sort of hierarchy should these different approaches to the atmosphere be ordered? The question of whether prediction could precede theorizing was a potentially explosive one, as the cancellation of weather forecasts in response to FitzRoy’s death makes clear. Some felt strongly that prediction without proper theory was a dangerous undertaking—for both the public who might be provided with faulty forecasts and, just as concerning, for the scientists who were wary of exposing what they saw as the weakness (or immaturity) of their discipline. American meteorologist Cleveland Abbe spoke for this point of view when he wrote in 1890 that “hitherto, the professional meteorologist has too frequently been only an observer, a statistician, an empiricist—rather than a mechanician, mathematician, and physicist.”34 Others felt just as strongly that theories based on too few observations were as useless as observations unleavened (as one commentator put it) by theory. As noticeable as the differences between what might be called theory- versus data-led meteorology might have seemed, there was not as much separation between these attitudes as might be thought. Indeed, depending on the problem at hand, the same person might advocate first a data-driven, and then a theoretical approach. Julius Hann, for example, did more than anyone to establish the descriptive, empirical tradition of climatology, but he also applied thermodynamics—a highly theoretical field—to problems of atmospheric phenomena.35
