3
SEE-THROUGH CLOUDS
The peak of the island of Tenerife appeared for only a moment as the RMS Titania eased into harbor, but Charles Piazzi Smyth was ready for it. He caught the clouds “unveiling for a moment the chief glory of the island, showing it for an instant as a reward after the toil of the voyage.” He knew that his next vision of the peak would come only following a hard climb up the mountain. For the time being, he exulted in the chance to see “a higher and purer sphere.”1
Though it felt serendipitous, the vision of the peak was far from an accident of cloud and wind. Instead, it was a direct consequence of what Piazzi Smyth called a “certain,” as in definite, “line of separation between the land-cloud and the sea-cloud.” Whatever caused that line may have remained uncertain, but the line itself was not. The line was, in fact, a stable and even celebrated feature of the landscape. When the great Prussian explorer Alexander von Humboldt had stopped at the island in 1799 at the beginning of what would become his epic five-year journey to South America, he too had noticed the curious phenomenon by which the clouds parted to reveal the top of the peak.2 Some thirty years later, Charles Darwin had witnessed the same meteorological unveiling when he visited the island in January 1832 at the beginning of his own voyage to South America. He mentioned it in his Naturalist’s Voyage, remarking how “we saw the sun rise behind the rugged outline of the Grand Canary Island, and suddenly illuminate the Peak of Teneriffe, whilst the lower parts were veiled in fleecy clouds.”3
FIG. 3.1. The peak of La Palma seen above the cloud line in a drawing by Charles Piazzi Smyth in 1856. Alexander von Humboldt and Charles Darwin had observed and written about the same meteorological feature. Credit: Royal Observatory Edinburgh.
In his own narrative describing his journey to test the possibilities of mountaintop astronomy, Piazzi Smyth mentioned the existence of a scientific explanation for the delineated cloud lines before remarking that at the moment he caught sight of the peak through the clouds, “the effect on the feelings was such, that there could have been few persons with whom the leading idea would have been the physical explanation.” Clouds and their motions evoked feelings more readily than thoughts, suggested Piazzi Smyth. Or did they? Piazzi Smyth was coy about whether he was one of the people for whom physical explanations did in fact dominate. He claimed that awe and wonder preceded scientific understanding, but in the telling, Piazzi Smyth is scientist first, wonderer second.
That the clouds, as the most visible and visibly changeable aspect of the weather, might produce strong emotions had the self-evident truthfulness of cliché for Piazzi Smyth. In the early decades of the century, the English painter John Constable had offered a newly prominent role for the sky—formerly mere backdrop—as “the keynote, the standard of scale, and the key organ of sentiment” in landscape painting.4 By sky, he really meant clouds. In his finished paintings and in his remarkable series of cloud studies, he single-handedly transformed clouds into the primary pictorial mechanism for delivering emotional impact. This did not mean banishing the techniques of science from art. On the contrary, scientific techniques for Constable worked in the service of emotional veracity. He believed that a large portion of the “artistic” quality of a work he painted lay in the authenticity of the emotions it provoked. Did it make the viewer feel as if she were standing in a field, watching the scene unfold before her? If scientific tools and practices could increase the emotional impact of a painting, this was all to the good.
Constable, the consummate artist, had learned to see the clouds partly through the eyes of Luke Howard. When in 1803, Howard had offered a newly standardized nomenclature for clouds, he provided a new set of tools for capturing the felt reality of clouds, in words and pictures. For Constable and the painters he influenced, scientific understanding of the clouds could be utilized to generate a convincing subjective experience. For scientists, the trick was to devise methods for describing clouds that captured not the feelings produced by clouds but their changing nature. As important as Howard’s imposition of order on what had previously seemed impossibly disordered was his insight into the ways in which clouds were transformed into other clouds. The study of changing types, rather than fixed forms, was written into his project from the start. The role of emotion in the service of Howard’s science was less certain. What was clear, instead, was how difficult it was to separate the two. Clouds were interesting, useful, and important precisely because of the ways they elided—glided across—the boundary between objectivity and subjectivity, between science and art, between fact and feeling.
In the same way that Tyndall and Forbes’s dispute over glacier motion hinged not on who had the better explanation but on what counted as an explanation, so the men who wished to study clouds scientifically were at pains, in 1856, to define what exactly that might mean. In 1804, Howard had provided one explanation—to know a cloud meant to identify it and to name it. This natural historical approach treated clouds as specimens of nature that could be observed and collected in much the same way as butterflies. And just as biologists could tell a great deal about butterflies by their taxonomic descriptions, so would it be possible to learn much about the geography of clouds by this technique. Though Howard emphasized how important it was to attend to the modifications of clouds, he made no suggestions about the physics of cloud transformation, nor about the role of clouds in the generation of storms.
By 1856, clouds were increasingly subject to a new sort of scrutiny and to new ways of being known. A new government office for weather, called the Meteorological Department, was established in 1854 with the intention of increasing knowledge about the weather for both practical and scientific benefit. The doubled mission of the office was evident in the choice of an Admiralty captain as its first head. Admiral Robert FitzRoy, who had captained the Beagle, the ship upon which Darwin had served as naturalist (and from which he had observed the clouds at Tenerife), was a practical navy man whose interest in clouds was to protect the sailors who served under him, and, by extension, any Briton who might come to harm during a powerful and unexpected storm. While government bureaucrats and scientists both agreed that reliable predictions of coming weather were far off, FitzRoy took a pragmatic approach to the matter. He thought that it was more important to use knowledge of the weather to save lives than to wait until a “mature” science could be established on the basis of statistics. This would lead to both pathbreaking and highly controversial action on his part.
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Piazzi Smyth was thirty-seven when he arrived at Tenerife.5 It was an expedition toward which his whole life had led him. He had been born under a Neapolitan sky and christened with a name like a prophecy: Charles Piazzi Smyth. Sandwiched between solid Scottish nomenclature nestled the surname of Giuseppe Piazzi, a great Italian astronomer and friend of his father. The exoticism and ambition, of both his Italian namesake and his own father, himself an accomplished naval officer, both took root in the child. By the age of sixteen, he was well on his way, literally and metaphorically, as he departed the Bedfordshire school where he’d been studying and sailed along the west coast of Africa until he reached the farthest point of the continent. He landed at the Cape of Good Hope in 1835 where, by prior arrangement, he was to spend the next ten years as an apprentice to the Royal Astronomer at the Cape, Thomas Maclear.
He learned how to locate and precisely map the stars—vastly more of them visible in the dry air of the Cape than in Britain. He worked hard in helping measure the length of an arc of the meridian. He spent parts of five winters surveying the land in the pursuit of geodetic precision, enduring cold mist and icy winds in the mountains of the western Cape. He traced the faint, dusty glow of the zodiacal light, scattered by dust held in the plane of the solar system, a delicate, elusive phenomenon that hovered on the edge of visibility.
Seeing required training, and so did recording what he saw. He sketched from an early age and developed a fluent, veridical style. He drew the view from his room at the school in Bedford, the people on board the ship that carried him to the Cape, and the buildings that he encountered once there. He sketched Halley’s Comet as it passed in 1835–1836. He was the first person to make photographs in Africa, experimenting with making rudimentary images of plants even before he had learned which chemicals to use. As early as 1843 he was able to take images that survive today—people and buildings in southern Africa, including one of the Cape Observatory (possibly the oldest photograph of any observatory).
He returned to Britain to become Astronomer Royal for Scotland at the age of twenty-seven. It was a precocious appointment, but he soon realized that the grandest thing about the post was the title. He had scant funds, and the observatory was chronically understaffed. The skies of Edinburgh were smeared with hazy coal smoke, layered over with low cloud, gray as the stones on the houses of New Town. It was hard to see anything like what he had seen in the Cape. Nevertheless, he set himself to fulfilling the demands of his office.
His moment of inspiration arrived at the same time as a wife. He decided to embark upon a journey to Tenerife, to see if he could bring precision instruments to the top of the mountain and establish an observatory there. No longer precocious, by this time Piazzi Smyth was thirty-six, and his bride, Jessie, a surprising forty. They married on Christmas 1855, and by the following June they were sailing to Tenerife. In the hold of an expensive yacht that transported them were the following instruments: an actinometer, magnetometer, thermometers, electrometers, spectrum apparatus, and polarimeter, loaned by none other than the Astronomer Royal, George Airy. Barometers and more thermometers were loaned by Admiral FitzRoy, head of the Met Office. The hydrographer loaned him four chronometers. And Robert Stephenson trumped them all by lending him an entire yacht, the RMS Titania, with a crew of sixteen men for the return journey.
It was a classic voyage of imperial reckoning, made possible by the well-engineered tools of the industrial revolution, the instruments he’d been loaned by the greatest scientists of the day, the expensive sailing ship, and the well-trained crew he had the run of. What Piazzi Smyth was doing was attempting to verify an old hypothesis with an enviable pedigree. Isaac Newton had proposed in his Opticks of 1704 that astronomical observations would be greatly improved by removing the “injurious portion of the atmosphere.” Since then, many had concurred but no one had attempted to prove the point. Tenerife was closer to London than the Cape, and so more convenient, but it also presented potentially insurmountable obstacles to scientific observation. It was possible that the instruments would prove impossible to transport to the peak, fail to operate once there, or that perpetual cloud would surround the summit. If, on the other hand, those obstacles could be overcome, then more science and more scientific vision could be had.
FIG. 3.2. The crew of the Titania en route to Tenerife, photographed by Charles Piazzi Smyth in 1856. Credit: Royal Observatory Edinburgh.
The mountain could be a machine for making facts out of theories, as Piazzi Smyth put it. And so, by implication, could the astronomer himself. But doing so required balancing between worlds in a manner that brought to mind a man teetering atop a peak. A Scot who had been born in Naples, trained in southern Africa, and professionally employed in Edinburgh (a proud capital that was simultaneously an outpost of London), Piazzi Smyth was a creature of the periphery. As such, Piazzi Smyth was uniquely qualified to make the attempt.
His success depended on maintaining the standards of metropolitan astronomical science on a mountaintop several thousand miles from Britain. His own excitement, and the appetite for exploration it fed, had brought him first to the Cape and now to Tenerife. It was a necessary precondition for an explorer-scientist in the middle decades of the nineteenth century. But the spirit of exploration sometimes sat uneasily with the sort of self-restraint insisted upon by the men who stayed in London. For while the requests of the London scientists who had loaned him the instruments (and given him the money) were many, and varied, they were also quite firm—even rigid—about the extent of the domain to which they felt Piazzi Smyth had earned access. Even on an expedition designed to go further, astronomically speaking, than had ever been gone before, it was possible to go too far. That went for the types of observations Piazzi Smyth could make—geology and biology were not welcomed—and it also went for the forms of expression Piazzi Smyth used to describe his discoveries. Piazzi Smyth knew this, and this knowledge helps explain the defensive note that crept into his writing about the moment of first contact between him and the mountain. He knew that he had to suppress his own emotional response in favor of the instrumental readings he’d been empowered to make. If he worked hard and got lucky, he might manage to render the mountain a suitable outpost for British astronomy, a new sort of colony: a temporary, provisional, but potentially bounteous source of new knowledge. This goes some way toward explaining Piazzi Smyth’s curious locution and defensive recounting of his dramatic arrival at Tenerife. He was trying to abide simultaneously by two norms for watching the skies—the one based on emotion, the other on what he called “physical explanation.” What is interesting about Piazzi Smyth is not only that he felt himself to be caught between—or spread across—these two ways of looking at clouds, but that he shared the experience of a doubled response with his readers.
The need to eliminate the personal from scientific observation took on a special urgency in the case of mid-nineteenth-century astronomy, when it became apparent that differences in the reaction times of observers could become a significant source of error when it came to making extremely precise observations of celestial movements. There was a phrase for this problem, the “personal equation,” which suggested the desirability of reducing human differences to a numerical factor, a handicap that could then be subtracted from the results, giving a true number. Astronomers became professionally paranoid, on guard against any and every source of error. “Vigilance can never sleep; patience can never tire,” wrote one popular writer at the end of the century. “Variable as well as constant sources of error must be anxiously heeded; one infinitesimal inaccuracy must be weighed against another; all the forces and vicissitudes of nature—frosts, dews, winds, the interchanges of heat, the disturbing effects of gravity, the shiverings of the air, the tremors of the earth, the weight and vital warmth of the observer’s own body, nay, the rate at which his brain receives and transmits its impressions, must all enter his calculations and be sifted out from his results.”6
Even taking such extreme precautions, it was impossible to eliminate personal differences between observers—specifically, the reaction times that varied between observers trying to determine with extreme accuracy the time at which a star crossed a certain location in the sky. The more precisely astronomers were able to map the stars, the more the personal equation mattered, since small differences in the reaction times of observers made a big difference when tiny units of time were being measured. One way around this problem was to establish hierarchies of observers, each of whom was himself observed by the managers of observatories, men such as George Airy, head of the Royal Observatory at Greenwich.7 Piazzi Smyth was not alone on the mountaintop, but from the perspective of astronomers like Airy, he might as well have been. There was no one to watch Piazzi Smyth, no one against whose observations his own could be checked, no one observing him making his observations.
When Piazzi Smyth mentioned that for most people, looking up at a sublime bit of meteorology—the shifting of clouds to reveal a monumental peak—was an emotional experience, he was, in a somewhat oblique way, making reference to a perennial astronomical bugbear. Though astronomers used the term personal equation in hopes of eliminating differences between observers, Piazzi Smyth was here drawing attention to the ineffability of personal observation, to the way it could not be reduced to numbers. By rendering the subjectivity of the observer into a commonplace to be acknowledged rather than a troublesome anomaly to be eliminated, Piazzi Smyth was suggesting the possibility that scientists could be simultaneously objective and subjective, impersonal and personal.
If the problem of precision was significant in astronomy, it was partly because the astronomy that Piazzi Smyth and most of his contemporaries were doing was, above all, a cartographic exercise. The vast energies and expenditure poured into astronomy in the first decades of the nineteenth century by the French and the British were a form of scientific colonization. Nearly a century after Newton had shown it was possible to predict the motions of heavenly bodies according to a set of physical laws, astronomers were mostly still preoccupied with working out what this meant in practice. Mapping the position of the stars, the sun, the moon, and the planets—called positional astronomy—was a continuation of the research program that Newton had first set out in 1687 with the first edition of his Principia. For this, long hours of observation, with the most precise instruments, used by the best-trained observers overseen by the most demanding supervisors, were necessary to produce a map sufficiently refined to demonstrate both the theoretical potential of the Newtonian system and, just as important, to wring from it the practical benefits of improvements in navigation and surveying. Knowing the heavens made it possible, in a direct and practical way, for nations to know the earth, and in knowing the earth, to control an ever-greater part of it.8 It also made it possible to predict with extraordinary accuracy the movements of celestial objects, an accomplishment which brought considerable prestige to the discipline of astronomy and served as a beacon for the ambitions of many other physical sciences.
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As powerful a tool as positional astronomy could be, astronomers always hoped for more. Piazzi Smyth had come of age in the 1830s, when astronomers felt increasingly emboldened to hope that it might be possible to say not only where but also what the stars were. Once astronomers saw the prospect of moving beyond celestial mechanics—once seen as the ultimate “perfect” system—an exciting but newly confounding world opened up before them. Newton’s cosmos had been sterile—a clean clockwork universe in which God made intermittent appearances to keep the planets on their eternal orbits but little else occurred. The new cosmos was filled with energy that bombarded the planet, bathing it in a relentlessly dynamic flux of light and magnetism. The smooth and singular orbits predicted by Newton’s mathematics were replaced by complex and messy traces of thousands of barometers, thermometers, magnetometers, and a host of other instruments that sought to catch the cosmic fluxes of the universe.
There was no more influential proponent of the idea that nature could be made to yield her secret laws than Alexander von Humboldt, the Prussian explorer and naturalist. When he stopped at Tenerife, he laid his anchor in mist “so thick, that we could scarcely distinguish objects at a few cables’ distance.” Like Piazzi Smyth, he feared that the mountain would remain out of sight, but “at the moment we began to salute the place, the fog was instantly dispelled. The Peak of Teyde appeared in a break above the clouds, and the first rays of the sun, which had not yet risen on us, illuminated the summit of the volcano.”9 Despite the mist, Humboldt noted the effects of the transparency of the atmosphere, “one of the chief causes of the beauty of the landscape under the torrid zone.” Not only did it heighten colors, harmonizing and contrasting them, but it changed the very “moral sensibilities” of the inhabitants of southern realms, leaving them with a “lucid clearness in the conceptions, a serenity of mind, correspond[ing] with the transparency of the atmosphere.”10 Clear skies, then, could lead to clear minds.
Humboldt never stopped thinking about both how natural environments affected human beings and how humans could understand the physical nature of those environments. Decades later, as he sat down to write a book that was the culmination of a lifetime of travel and contemplation, he returned to the question of how different landscapes affect people differently, or the “different degrees of enjoyment presented to us in the contemplation of nature.” Thinking back on the many places he’d been, a few leapt out. In addition to the “deep valleys of the Cordilleras,” where tall palms had created a forest above the forest, he returned once again to Tenerife, remembering
when a horizontal layer of clouds, dazzling in whiteness, has separated the cone of cinders from the plain below, and suddenly the ascending current pierces the cloudy veil, so that the eye of the traveler may range from the brink of the crater, along the vine-clad slopes of Orotava, to the orange gardens and banana groves that skirt the shore.
What was it that gave scenes like these the ability to move a man’s heart, to spark the “creative powers of [a man’s] imagination”? Part of their potency lay in their changing aspects, in the way moving clouds or water dramatized the flux of forces that was ever present but not always so visible. Humboldt called this the “peculiar physiognomy and conformation of the land, the features of the landscape, the ever varying outline of the clouds, and their blending with the horizon of the sea.” The result of all this change was that he, like Tyndall, had the eerie sense that nature was imbued with emotion—his own emotion. “Impressions change with the varying movements of the mind,” wrote Humboldt, “and we are led by a happy illusion to believe that we receive from the external world that with which we have ourselves invested in it.”11
FIG. 3.3. Alexander von Humboldt, painted by Julius Schrader in 1859, with Mount Chimborazo and Mount Cotopaxi in the background.
This happy illusion was in large part due to the unity of Nature. “The powerful effect exercised by Nature springs, as it were,” wrote Humboldt, “from the connection and unity of the impressions and emotions produced.” Unity was the feature that caught the attention. To achieve true understanding, it was necessary to go deeper. As humankind developed intellectually, it became possible to move beyond the primordial feelings of unity and arrive at an even more powerful method for apprehending the world.
By degrees, as man, after having passed through the different gradations of intellectual development, arrives at the free enjoyment of the regulating power of reflection, and learns by gradual progress, as it were, to separate the world of ideas from that of sensations, he no longer rests satisfied merely with a vague presentiment of the harmonious unity of natural forces; thought begins to fulfill its noble mission; and observation, aided by reason, endeavors to trace phenomena to the causes from which they spring. [emphasis added]12
By separating thought and emotion, Humboldt thought it would eventually be possible to disentangle the many threads of differing phenomena—magnetic, astronomical, and meteorological—and assign them to their respective origins, or, in other words, “to trace phenomena to the causes from which they spring.” Only by regulating emotion could mankind surpass the powerful first impression of unity. Humboldt’s vision was both gradual and bold. It would take time, but in the end a much deeper understanding of the multiple forces of nature at work could be achieved. The way to turn “mere” natural history into a physics of the earth (Physik der Erde) was to “track the great and constant laws of nature manifested in the rapid flux of phenomena, and to trace the reciprocal interaction, the struggle, as it were, of the divided physical forces.”13 Taken together, these readings would reveal the true and truly singular face of the earth.14
Just as it became increasingly possible and attractive to determine the effect of physical forces on earth, so it became almost irresistible to look for the invisible but powerful threads that linked the earth and the heavens. Humboldt did not distinguish between the forces present on earth and those that prevailed throughout the universe. His approach encompassed nothing less than the entire cosmos. The “harmonious unity of nature” necessarily knit together the heavens and the earth. In the same way, it constituted a sort of undulating tapestry of physical forces that could be discerned in the isolines of temperature and pressure, and in the corresponding bio-geographical continuities that Humboldt so painstakingly reconstructed.
Humboldt’s vision was shared by John Herschel, the son of the great astronomer William Herschel, discoverer of Uranus, and himself an accomplished scientist. John Herschel helped organize the so-called Magnetic Crusade of the 1830s, an ambitious attempt to simultaneously map changes in the earth’s magnetic field at different places around the globe.15 The results of this multi-year expedition were stunning, revealing that Earth’s magnetic field changed in response to that of the eleven-year cycle of sunspots. No better example of Humboldt’s belief that beneath flux lay order could have been hoped for. Here was a powerful justification both for the gathering of multiple sorts of data—on sunspots, solar spectra, gravity, radiation, and much besides—and for the effort needed to disaggregate those phenomena from each other. Knowledge, in this sense, would be as much subtractive as additive. To understand both the emotional power of a place like Tenerife, and the physical phenomena made manifest, required tools for working backwards from the powerful impression of unity to the underlying causes which together operated to create the traces recorded by the many instruments Piazzi Smyth took with him to the island.
For Piazzi Smyth and his peers, separating the effects of the terrestrial atmosphere from that of the solar atmosphere was a prerequisite for understanding the true nature of either. In this sense, it was not possible to do solar physics without doing terrestrial physics or vice versa. This new physical way of doing astronomy firmly knit together the earth and the cosmos, to create, as one writer put it, “a science by which the nature of the stars can be studied upon the earth, and the nature of the earth can be made better known by study of the stars—a science, in a word, which is, or aims at being, one and universal, even as Nature—the visible reflection of the invisible highest Unity—is one and universal.”16
Earth’s atmosphere played a peculiar role in this search for unity. In its shifting movements, the atmosphere and the clouds which floated in it represented the difficulty of seeing to the essence of things, as well as the need to always be vigilant about the objective of observation. Clouds were sometimes obstructions to the visions that lay beyond—of stars, of peaks. But they were also aspects of the natural world and therefore worthy of study in themselves. They represented a particular variety of the fullness of nature, the way in which the veils that she drew across herself were themselves part of nature. The objects that obscure vision are themselves worth looking at. In this way, the atmosphere was a doubled object, both an impediment to science and an object of it.
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How did Piazzi Smyth, in practice, set out to disentangle the myriad forces that together made up the unity of Nature? The first, elusive glimpse of the peak, revealed through the clouds, pointed the way. His objective was to get as high up the mountain as was possible and locate a place on which an observatory could be built. A crew of twenty porters and twenty mules helped him get there, once the cumbersome boxes he’d brought on the ship had been broken down into parcels more suitable for carrying up a jagged volcano than stowing on a ship. By one o’clock on the first day of climbing, the expedition reached over 7,000 feet. “Light and heat revel everywhere,” marveled Piazzi Smyth. “There is no need of volcanic assistance.”17 They reached the top of the mountain’s intermediate peak, Guajara, as day fell. The porters hastily stashed their loads and sped back down the mountain to spend the night at a more reasonable altitude. Piazzi Smyth and the rest of the small party of foreigners stayed at the summit. Piazzi Smyth exulted that he was, “within twenty-four days of leaving England, bivouacking at a height of nearly 9000 feet, on a mountain only 28 degrees from the Equator.”18
On the way up the mountain, they hiked through the discrete layer of clouds he’d seen from below on the ship. The layer floated like an atmospheric sea, above which the peaks of Tenerife and nearby La Palma jutted, secondary islands emerging not from the liquid water of the ocean but from the condensed water droplets that formed the cloudscape. Those clouds were persistent and uniform, and they stretched as far as the eye could see. They were a literal and a metaphorical boundary. Piazzi Smyth called it “that great plain of vapour floating in mid-air at a height of 4000 feet.” It was a “separator of many things. Beneath were a moist atmosphere, fruits, and gardens, and the abodes of men; above, an air inconceivably dry, in which the bare bones of the great mountain lay oxidizing in all variety of brilliant colours, in the light of the sun by day, and stars unnumerable at night.”19 Above, too, was the realm in which lay the astronomical justification for his trip, the vindication of Newton and a sharpness of celestial vision otherwise inconceivable.
What clouds were and to which landscapes they belonged was an open question. Howard had altered the form and content of meteorology when he had suggested that clouds were neither endlessly variable nor unclassifiable. But many questions remained, not least whether clouds were, like living species, indigenous to certain places or whether they were more general, universal features to be found throughout the globe. When Piazzi Smyth went up the mountain, the clouds at Tenerife were noteworthy for their difference from English clouds, but they were also, it was to be hoped, potentially able to be reduced to universal laws just as the changing magnetic readings taken during the Magnetic Crusade had been.
The intensity of the light changed the nature of time on the mountain. Piazzi Smyth could see so much more in a single day or night than he could ever see in lower realms that he was able to achieve an astonishing amount of observing. “The day wears apace,” explained Piazzi Smyth, “and most luxuriantly in so pellucid an atmosphere, lit up by the rays of a vertical sun, undiminished by any aerial impurity. Each moment on a day of this sort is worth hours on any other; we look at everything far and near, see it as it were face to face, and gain a higher idea of the glorious creation in which we live.” Color acquired extraordinary depth: “glorious cadmium,” “the richest tint of red-orange,” “lemon-yellow,” “powerful rose-pink” and, finally, the “deep blue sky above.”20
Much work was needed to transform the light into a useable scientific tool. Piazzi Smyth spent about a month camped at 9,000 feet before frustration with persistent dust sent him higher, to the appropriately named Alta Vista, at 10,700 feet. He set about doing what he had avoided doing at Guajara, transporting the “great Pattinson equatorial telescope,” which required “straining every nerve to accomplish the main feature of the expedition—viz. to place the largest telescope on the highest available part of the mountain.”21 Around the inner “telescope square,” a group of local men and some crew members from Stephenson’s ship labored to create a group of five rooms (with roofs, Piazzi Smyth noted proudly) and a veranda which offered some protection from the elements.
Down to its bones, the place was hybrid. The walls were built of rocks from the summit, to which were added felt wall coverings and supporting timbers made by young poles of fir brought from Tenerife and glass plates, shutters, and door hinges brought all the way from Edinburgh. Plain nails were plentiful on the island, but “good screw nails,” noted Piazzi Smyth, “seem to be bound up with the march of Anglo-Saxon civilization.”22 It was a joke that showed how much the success of the astronomical experiment depended on reproducing conditions back in Britain, down to the screws used to fix the instruments together.
It wasn’t easy. Most of the more than 500 pages of Piazzi Smyth’s book on the subject were spent describing just how hard it was. His tone was not querulous but full of amazement. “Some part or other of our photographical apparatus, for picturing the sun’s image,” he explained, “would every now and then begin to smoke and burn.” The eyepieces to the telescopes became dangerously heated, so they periodically had to stop in order to keep from burning themselves.23
It was worth it, though, and he knew it from the start. The difficulties were not avoidable. In fact, they were necessary. His first effortless, instantaneous gaze depended not only on the absence of vapor from the atmosphere but on an unbroken chain of labor and supervision (of men and materials) stretching from the summit back to Edinburgh and London. All of this hard work—the packing and portaging, the building and the training—become as transparent as the atmosphere the moment Piazzi Smyth put his eye to the telescope’s eyepiece. That is the magic trick behind this kind of scientific work—behind, in a sense, all scientific work: a great amount of work is applied to making a small bit of nature visible in a way it has never been visible before.
FIG. 3.4. Jessie Piazzi Smyth with telescope and sun hat at the peak of Alta Vista. Credit: Royal Observatory Edinburgh.
When Piazzi Smyth aimed his telescope at the sky and set his eye against the eyepiece, a singular line of vision stretched from there to the farthest star. He could see farther, much farther, than he (or anyone) had ever seen before. This is worth repeating: From his vantage on the mountaintop, armed with a powerful telescope, with the clear air stretching above him to the emptiness of space, Charles Piazzi Smyth could see farther into the heavens than anyone had ever seen before. In the first night of observing on the summit, he transcended the viewing records of a lifetime. Pairs of stars, normally blurred and indistinct, leapt out at him. Even the faintest stars, of sixteenth magnitude, were easily visible. He quickly ran out of astronomical tests with which to gauge the extent of the vision he’d acquired.24
Having proven the practicality and desirability of mountaintop astronomy, Piazzi Smyth set about taking observations that would contribute to the exciting developments in physical astronomy, in showing what the stars and the planets were, rather than just where. The instruments he’d so laboriously transported offered the potential to do what Humboldt had urged and begin to tease apart the physical phenomena that together made up our impressions of both heaven and earth. What caused the spots on the sun to change, and by what cycle did they do so? What were the red prominences that shot out from the sun, visible during eclipses but presumably present all the time? What was the nature of the double stars, and how did their rotation change over time? What patterns controlled the tides, the earth’s weather, its magnetic field?
There were so many questions. It was impossible to answer them all. But the fact that they were being asked at all indicated how much had changed in the way people thought about the heavens and the earth. New and improved instruments made it possible to “see” invisible physical phenomena for the first time. Increasingly powerful telescopes were able to gather more light and resolve finer detail. Photography was put to astronomical uses almost as soon as it was invented, when Louis Daguerre pointed a camera at the moon in 1839, a feat repeated with more success the next year by John William Draper, who devised a way to track the moon during the long exposure. Images of the sun followed in the 1840s, and the first star, Vega, submitted to photography in 1850. Most influential of all was the spectroscope, a device that made light an experimental tool capable of diagnosing the contents of distant atmospheres. It provided yet more evidence for the unity of nature, proving that the same elements were present on earth and in the heavens.
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The distinctive array of colors produced by the diffraction of light had been observed for centuries. Leonardo da Vinci had noted “rainbow colors” around the edges of air bubbles in a glass of water. Isaac Newton had introduced himself to scientific society when he’d demonstrated that the oblong of light produced by a prism of sufficiently clear glass was made up of colors that could not be further modified. He coined the term spectrum—playing on its double meaning as both a ghostly image and something which is seen—to describe the rainbow of colors which were refracted to different degrees by the prism. It was Newton who divided the spectrum into the seven colors, a system which dominated the way people saw the spectrum throughout the eighteenth century. It was only in 1802 that William Hyde Wollaston, a physician with an interest in light, observed the spectrum through a very narrow slit and noticed for the first time that atop the spray of colors lay a series of black lines. He made an initial attempt to map these lines, identifying the five most prominent, and labeled them with the corresponding capital letters A through E. Acting independently, in 1824 Joseph von Fraunhofer, a German glassmaker working with high-quality prisms (and consequently more interested in what the spectrum could reveal about the purity of the glass than vice versa), added considerably to the map, assigning unique numbers to more than 500 lines.
Seeing the spectrum was no simple matter. No one knew how many lines there might be. The closer anyone looked, the more seemed to appear. Still less certain was what caused them. This made it that much harder to know when to trust one’s eyes. A further complication was the difficulty of translating what was seen into something that could be represented graphically. Piazzi Smyth, trained from an early age in just these skills, was exquisitely attuned to just how much skill was required to accurately represent astronomical phenomena with techniques such as John Herschel’s use of “a fine camel’s hair brush” and successive washes of varnish to draw stars. A faithful imitation of such tricky phenomena to record as the Aurora Borealis, a cloud of nebular gas, or the tail of a comet could only be obtained by “correctness of eye, facility of hand, and a due appreciation of the subject.”25 The spectrum, with its spray of lines of varying strength, which seemed to come and go, was especially hard to capture.
FIG. 3.5. Spectra of the sun observed at various altitudes and times of day from Charles Piazzi Smyth’s report on the Tenerife expedition. The bottom reading was taken when the sun was setting.
Charles Babbage, impresario of science and decrier of British decline in relation to the French and the Germans, not only recognized that vision was a skill that had to be acquired, but saw that it had national repercussions. In his Reflexions on the Decline of Science in England, he recounted how Herschel had warned him how difficult it was to see spectral lines of the sun. He could sit in front of a spectroscope through which the solar lines were visible, said Herschel, but Babbage would not be able to see them until he had been told “how to see them,” at which point, and only at which point, he would then be able to see them. After having seen them, Herschel told Babbage, you will wonder how you could have missed them and will never be able to look at a spectrum again without seeing them. And so it was.26 Without good systems for training observers, Babbage concluded, British astronomy could not compete on the international stage.
The drive initially was to map more and more lines. Soon, it became clear that the number of lines visible depended not only on the size of the telescope or the clarity of the prism, but on the time of day and direction in which the telescope was pointed. In 1833, the physicist David Brewster announced the results of a multi-year project. Not only had he observed the spectrum at a resolution some four times greater than what Fraunhofer had achieved, but he had observed the spectrum at different times of the year, under different meteorological conditions, and with the sun at varying angles in the sky. With his observations, Brewster was able to move toward the Humboldtian dream of disaggregating phenomena in order to understand them better. In 1856, when Piazzi Smyth embarked for Tenerife, it still remained very unclear what the cause of these lines were and where they originated.
And so, in addition to his nighttime observations of the stars, Piazzi Smyth used the spectroscopes he’d brought to study the characteristic lines that appeared when sunlight was observed passing first through a slit and then through a prism. The metropolitan scientists, tethered to their urban observatories, wanted to know if lines appeared or disappeared when Piazzi Smyth looked through the spectrum on the mountaintop. Did they look different at sunset or sunrise?
Here the mountain came into its own as a tool for separating the earth’s atmosphere from the sun’s. Atop the peak, observing sunlight with his spectroscopic apparatus, itself a hybrid of telescope, prism, and a slit that spread the spectrum and thereby revealed the lines, Piazzi Smyth was uniquely positioned to help solve the question. Pointing the spectroscope at the sun at midday, he was closer to the sun’s atmosphere than any other similarly equipped observer on the planet. So too, as he tracked the sun on its ascent and descent, at dawn and sunset, when it hovered just at the horizon, he had access to a thicker portion of the atmosphere than anyone else on the planet.
As with the distant stars, so with the sun, what Piazzi Smyth saw from his privileged position seemed effortlessly dispositive, unmistakably clear. As he watched the setting sun through the apparatus, he saw the number of lines grow visibly before his eyes. This was evidence that at least some of the lines were earthly in origin, a visible marker of some invisible substance which increased as the section of the earth’s atmosphere he was looking through thickened. This meant that the spectrum revealed by any spectroscopic apparatus pointed at the sky was always a hybrid, a representation of the atmospheric contents of both the sun and the earth. This complicated the quest to identify the contents of something so distant as the sun with little more than a special piece of glass. But Piazzi Smyth’s observations on Tenerife also showed that the spectroscope, used in the right location and with the right techniques, could be a tool for revealing the differences between those contents and for plumbing the atmospheric reaches of the earth itself.
What caused the lines that grew before his eyes, Piazzi Smyth did not hazard to guess. Nor did he wonder, at that moment, about the precise details of their variation, whether the lines ebbed and grew solely due to the amount of atmosphere through which he was observing or whether the internal changes of the earth’s atmosphere itself affected the pattern he saw. Those thoughts would come later. At the time, the observations formed just one part of the dozens he was making, using every waking moment on the mountain.
We know how Piazzi Smyth felt as he craned his neck to look up at the summit of Tenerife because he wrote a book about his experience. His great subject was the act of observation itself, and hidden in every record of the outside world that he made over a lifetime of watching was a record of Piazzi Smyth, the observer. Convinced of the advantages of photography for scientific observation, Piazzi Smyth spent “all spare moments” on the mountain with a camera he had gotten at the last minute, making images of the surrounding landscape, the unusual flora, and the work of scientific observation itself. The description I have recounted takes up about five pages in Teneriffe, An Astronomer’s Experiment: Or, Specialities of a Residence Above the Clouds, which Piazzi Smyth published in 1858. That book provides a lengthy description of the whole voyage in language that is colorful without being florid. It also contains a set of twenty stereo-photographs taken by Piazzi Smyth on the expedition, the first time such a set of photographs had been included in a printed volume.
In his preface to the book, Piazzi Smyth explained the reason he had taken such care and effort to make and print his doubled photographs: They possessed what he called a “necessary faithfulness.” While single photographs may contain smudges or artifacts, the stereo-photograph can serve as its own correction. A comparison of the two images will reveal what is real, and what is merely accidental. A further degree of veracity is achieved when the images are combined stereoscopically to produce the impression of distance or solidity, normally the purview only of great painters. The doubled images themselves do a double duty, producing scientific accuracy and the kind of aesthetic “effects” normally produced by artists.
Piazzi Smyth was always doing science and watching himself (and others) do science. He recorded natural phenomena and the process of recording natural phenomena with the same level of interest. This meant that he sketched the boat (itself a scientific instrument of exploration) upon which he traveled and even took photographs of the crew in the difficult setting. It meant that he kept a detailed journal of the expedition (a long-standing dual form of registration—both of the natural world and of the perceptions of the observer of the natural world). It meant that he carefully observed the sailors from his ship who had transformed themselves (with his help) into disciplined observers themselves. He included a photograph of the second mate of the ship in the act of taking a temperature measurement. In one hand is the chronometer he used to time the observation; in the other is the notebook in which he recorded it. The image, like the others in the book, appears in stereo—a further doubling of an already doubled act of observation: Piazzi Smyth watching the second mate watching the temperature. Similarly, the act of scientific observation was itself carefully watched here, not only by Piazzi Smyth but also by the readers of his popular and his official accounts. Science, an act of observation, required observation itself to be regulated.
FIG. 3.6. Stereo-photograph image of ship’s mate making observations, taken by Charles Piazzi Smyth. Credit: Royal Observatory Edinburgh.
FIG. 3.7. Title page to Charles Piazzi Smyth’s official report of his expedition to Tenerife, with a stereo-photograph by him of a model of the peak by James Nasmyth.
FIG. 3.8. The Alta Vista Observatory, where a series of rough buildings formed a “telescope square,” in a stereo-photograph by Charles Piazzi Smyth. Credit: Royal Observatory Edinburgh.
The two photographs Piazzi Smyth chose to include in his official report were both images of the summit of the mountain. The first was a stereoscopic portrait of something no one had seen, including Piazzi Smyth himself. It was a double photograph of a model of the summit made by the engineer and talented amateur astronomer James Nasmyth. Piazzi Smyth photographed the model, based on data collected by the expedition, from above, and printed it in stereo view, providing a pure image of what the crater would look like to those with perfect vision and a perfect, God’s-eye vantage point. The second photograph was a single image (made from an enlarged camera-copy) of the Alta Vista Observatory, also taken from above. This view was a “real” view in the sense that Piazzi Smyth had climbed up a nearby peak from which he was able to look down on the observatory. The image shows the arm of the great telescope emerging from the “telegraph square,” the protected area around which the rudimentary observatory buildings had been erected. A flag can be seen extended in the wind.
This is an image of observation turned back on itself, a bold reminder to the Royal Society of just who had made the journey to the top of the mountain, and what he had accomplished there. If the purpose of the expedition had been to subtract the atmosphere from celestial observations, Piazzi Smyth had surely accomplished that. He’d also shown that every observation of even the most distant celestial objects was also an observation of the earth’s atmosphere. Finally, he’d understood that every outward observation was also, inevitably, an inwardly turned observation of the observer himself, of the self at the telescope’s eye.
* * *
Everyone agreed that the expedition had been successful in proving the merit of mountaintop astronomy. Still, Piazzi Smyth managed somehow to wring defeat from the jaws of victory. A group of referees contacted by the Royal Society to judge the work before publication considered that Piazzi Smyth had strayed too far from his area of expertise in his geological and botanical observations, and refused to print the photographs which he had gone to such effort to take, citing cost of publication. Piazzi Smyth responded with a characteristic mixture of petulance and defiance. Within months he and Jessie had published their own account, including all of their photographs and observations. (Piazzi Smyth noted acerbically that his wife had managed to single-handedly print all three hundred photographs needed for the publication.) It was the first indication of what would prove a persistent problem for Piazzi Smyth—transgressing disciplinary boundaries in scientific circles and ruffling scientific feathers.
Piazzi Smyth’s restless mind made it hard for him to sit still, and within a few years of his return, he had found a new fascination that would prove even more troublesome. No longer was he fixated on proving the feasibility of observing the stars on top of a mountain. It was to another kind of mountain, a man-made one, to which he now turned his interest. Still fascinated with matters of visibility, the question he now posed was: Is it possible to see God if one looks hard—and measures carefully—enough?
The man-made mountain was the great Pyramid at Giza. It had long been the subject of polite European curiosity. Ever since Napoleon had visited at the end of the eighteenth century, Europeans had wondered how the pyramids had been built and by whom. The ratio between the perimeter of the base of the pyramid and its height, for example, was the same as that between the circumference of a circle and its radius, suggesting, to those who wished to believe it, that the ancient builders had understood pi. More intriguingly, but more complicatedly, in the 1850s a man called John Taylor suggested that the basic unit of construction of the pyramid was a cubit of twenty-five British inches long. The British inch, according to Taylor’s assessment, had an ancient pedigree. Not only that, Taylor inferred that this ancient British inch was also a sacred British inch, having formed the basis for the cubit which Noah had used to build his Ark and Moses his Tabernacle.
Piazzi Smyth read Taylor’s work and was so taken with his ideas that he applied his considerable writing skills to transforming Taylor’s obscure pamphlet into an exciting narrative dramatizing the Pyramid’s divine origins and the correspondingly divine lineage of the British inch. His book Our Inheritance in the Great Pyramid was the product of just six months of intense work, but it immediately found a large and enthusiastic audience of readers.27 In the light of competition with the French over the metric system, many were happy to look at the Pyramid along with Piazzi Smyth and see evidence for the divinity and antiquity of British metrical values. Soon, he and Jessie embarked for a self-financed journey to visit the Pyramids and measure them for themselves. If anyone could look hard enough and see well enough to find evidence of divinity stamped upon the stones, it was Piazzi Smyth.
FIG. 3.9. Charles Piazzi Smyth wearing an Egyptian fez. Credit: Royal Observatory Edinburgh.
The result of Charles and Jessie Piazzi Smyth’s stay at the Pyramid was thousands of measurements, made with, among other things, a “well-seasoned” rod from a pipe organ dating from the time of Queen Anne which would be less likely to warp in the intense heat, along with more modern mahogany sliding rods and ivory scales. The Piazzi Smyths observed the Pyramid as carefully as anyone, measuring its dimensions in as many directions and with as much precision as possible. At the same time, they made meteorological and astronomical observations much as they had atop the mountain at Tenerife. Piazzi Smyth proudly presented their results to the Royal Society in April 1866, a year after their return. He was rewarded for his efforts with a prize from the Society recognizing the “energy, self-sacrifice and skill” with which he had undertaken the work.28 It would seem that Piazzi Smyth had managed to bring the Pyramid into the realm of precise and incisive observations that he had triumphantly entered on top of Tenerife, and in so doing to read God’s intervention in the form of the structure. But while the quality of Piazzi Smyth’s measurements was never in doubt, his inferences from them ultimately went too far. Though it did not happen immediately, Piazzi Smyth’s reputation among his scientific peers was irredeemably damaged by his commitment to the idea of a sacred origin for the British inch.
The matter came to a head some ten years after his trip to the Pyramids, when Piazzi Smyth submitted a paper on the topic to the Royal Society in which he accused the renowned physicist James Clerk Maxwell of “serious error in an Egyptian allusion” Maxwell had made in a lecture to the British Association for the Advancement of Science.29 Piazzi Smyth’s paper was rejected as unsuitable, since it constituted what was viewed as an ad hominem attack on Maxwell. Piazzi Smyth’s ill-judged response was to resign his fellowship from the Royal Society. He did not expect his hasty offer to be accepted. Much to his surprise—and chagrin—it was. At the age of fifty-five, Piazzi Smyth had managed to exile himself from the Society that arbitrated the scientific world in which he had lived his entire life.
Though Piazzi Smyth’s friends were sympathetic, most felt he had brought the sad state of affairs upon himself. This poignant self-exile from the scientific community was perhaps one reason his next passionate engagement was with an instrument that freed him completely from the need to coordinate, communicate, or calibrate with others. The rainband spectroscope, as it was called, allowed him to do science alone. With it, he could look to the skies as an isolated individual and diagnose the entire contents of the atmosphere. What Piazzi Smyth hoped the spectroscope could do was something far more radical even than freeing him from the restricting embrace of the parliament of science. He hoped it could do nothing less than help transform meteorology into a predictive, rather than a descriptive, science.
Keeping in mind that astronomy had long provided the template for a successful predictive science (even as a new emphasis on physical speculation had crept into it), anyone wishing to predict the weather on scientific lines was faced with the challenge of matching astronomy’s predictive power. This was, to put it mildly, not easy. In the 1870s, weather forecasting was within scientific circles possibly even more controversial than mystical theories of the Great Pyramid.
* * *
Beginning in 1859, Admiral FitzRoy embarked upon what he called an experiment in weather forecasting. Using a telegraphic network that had been established merely to gather weather data into a system for generating and communicating weather forecasts, FitzRoy fashioned himself as a one-man meteorological band. He based his forecasts on observations of barometric pressure, temperature, and observed wind speed taken at a dozen locations around the country and transmitted to him via telegraph. Applying rules of thumb and his sailor’s intuition, within thirty minutes of receiving the information each morning he sent his forecasts back out over the network. The forecasts were immensely popular with local fishermen and sailors, as well as holiday-goers seeking sunshine. They were also controversial because they were so often incorrect. What good was a government science office, critics queried, that sent out erroneous predictions? Surely it did no good for the science of meteorology to be tainted by such inaccurate forecasts. Much to the discomfort of those scientists who winced at every inaccurate forecast, FitzRoy’s program received a great deal of attention from pundits and commentators who called him a “weather prophet” and made much of the humorous concatenation of scientific intent with the kind of fairground prognostications made by fortune-tellers. Things came to a sudden halt in 1865, when FitzRoy committed suicide for unknown reasons.
Following FitzRoy’s death, a committee formed of fellows of the Royal Society had been appointed to oversee the activity of the Met Office. They were unhappy to discover that the government office had been run as a personal meteorological fiefdom. FitzRoy had delegated little, and written down less. He used no scientific laws or mathematical equations, relying on his sailor’s intuition to produce forecasts by himself that he saw as augmenting rather than supplanting the weather wisdom of self-sufficient sailors. The Royal Committee members disapproved of what they considered government sponsorship of an act of individual prognostication akin to fortune-telling. Fearing liability for deaths at sea should the warnings be incorrect, and concerned to protect the reputation of the infant science of meteorology from charges of amateurism, they shut the storm warning program down.
Ten years later, the project of government-sponsored storm warnings in Britain remained locked in a stalemate. The fishermen and sailors along the coast missed the forecasts and wanted them reinstated. The committee of scientists still resisted, suggesting instead a round of internal, private forecasts. In the meantime, the Times had decided to go ahead and publish a weather map, the first of its kind, in the daily newspaper, beginning on April 1, 1875. Piazzi Smyth, for one, saw the resemblance between the government storm warnings and the folksy weather wisdom of old, but unlike the Royal Society fellows, it didn’t bother him in the least. He despaired of the bureaucracy and what he considered the unnecessary punctiliousness of the Royal Society committee members. He bemoaned those scientists who wanted to keep science for themselves, to claim a higher knowledge of phenomena—the movements of clouds, vapor, heat, and cold—which remained as unruly as the crowds that jostled on railway platforms on their way to seaside recreations. Excited by the novel technology of the rainband spectroscope, he saw an opportunity to circumvent the Royal Society committee and to bring weather forecasting back to the people. He recognized that the spectroscope could also sort out the links between terrestrial and heavenly phenomena at the same time, clarifying the unity of nature as well as the specific properties of earthly weather. Piazzi Smyth’s plan was to use a descendent of the spectroscopes that he had carried up the mountain at Tenerife, and deployed in a variety of exotic locations ever since; it would enable him to diagnose perhaps the most changeable, fluctatory phenomena on Earth—the skies above Britain. The weather embodied a deep paradox. It was made up of uniform molecules, and yet it was eternally in flux.
Spectroscopy had developed rapidly in the years following his Tenerife expedition. In 1859 Gustav Kirchhoff and Robert Bunsen had shown that the lines in the solar spectrum corresponded to chemical contents of the atmosphere of the sun, and Kirchhoff had gone further to correlate many of the Fraunhofer lines with specific metals. But there was still much confusion over what exactly caused the lines, whether some were the result of absorption in the sun’s atmosphere, some of absorption in the earth’s atmosphere, and some, possibly, owed their presence to a substance present in both. In 1860, David Brewster published a long paper, coauthored with J. H. Gladstone, in which he “majestically mapped the separation” between solar and terrestrial lines. The capstone of nearly three decades of work was the publication of a five-foot-long map of the solar spectrum in which he clearly distinguished between solar and atmospheric lines (without making any guess as to what might cause the lines). In it, Brewster and Gladstone referred to Piazzi Smyth’s Tenerife observations, noting that he “had an opportunity of analyzing the light of the sun when seen through a smaller amount of atmosphere than has fallen to the lot of any other investigator.”30 Despite their success in mapping the lines, an experiment designed by Brewster and Gladstone to reproduce the bands in the laboratory had failed and the origin of the atmospheric lines remained unexplained.
It took a Frenchman to clarify the matter. In 1865, Jules Janssen had stood on the balcony of his house on rue Labat in Montmartre, Paris, and aimed a spectroscope at the sky. Janssen was poor, and the earth’s atmosphere was a ready and free laboratory. Following up on the curious phenomena already identified by Brewster in 1833, he wanted to investigate the same lines that Piazzi Smyth had seen on the Tenerife mountain, and to try to pinpoint their origins to the earth or the sun’s atmosphere. Using a very good prism, he could see something that no one else had seen—the so-called dark bands were in fact crowds of dark lines, similar in structure to the more familiar, less variable lines of the spectrum that had been initially identified by Fraunhofer, some of which had been determined to be solar in origin. Janssen observed the lines at all times of day and noticed something further. The lines were especially strong when he observed sunlight at sunrise or sunset, but they never disappeared, even when he looked at the sun at high noon (a finding that contradicted Brewster’s earlier work). They must, he reasoned, be caused by something ever present in the earth’s atmosphere. (The effect at sunrise and sunset would be greater because sunlight had to pass through more of the earth’s atmosphere to reach him.)
He set out to figure out what it might be. First he traveled to a Swiss mountaintop, to see if the lines were diminished when viewed through a smaller portion of atmosphere. They were. Then he made his way to Lake Geneva, where he observed a large bonfire on the pier at Nyon. When viewed from close by through the spectroscope, he saw no dark bands, only the normal spectrum. But when viewed from the top of the tower in Geneva, a dozen miles across the lake, the spectrum was crossed by the same dark lines that Piazzi Smyth had observed on Tenerife and that Janssen had observed over Paris. He was by now almost certain that they were caused by water vapor that was suspended in the air above Lake Geneva. With the cooperation of a Parisian gasworks, he set about making an artificial atmosphere to confirm his guess. A span of metal tubing stood in for the breadth of the entire atmosphere. Buried in a box of sawdust and enclosed at either end with panes of glass, the tube was filled with water vapor under pressure. At one end of the tube, an array of gas jets sent a beam of strong light through the tube, while Janssen observed at the other end of the tube with his spectroscope. He saw the same dark bands he’d seen over Paris, which had first been noticed by Brewster in 1833 and which Piazzi Smyth had seen wax and wane on top of the mountain in Tenerife in 1856. The more the pressure was raised, the darker the bands appeared. The greater the length of tubing, the darker they appeared. Janssen was now certain that the dark bands were caused by water vapor in the earth’s atmosphere. He wasted no time in concluding that the lines could also be used to search for water vapor in the atmospheres of other celestial objects. He asserted immediately, for example, that there was no water vapor present in the atmosphere of the sun, a remarkably assured statement.
* * *
Piazzi Smyth’s own interest in spectroscopy, which had waned after his Tenerife expedition, was reignited by the news that Janssen had managed to observe the solar prominences for the first time during a total solar eclipse in India in 1868. Soon after the Indian eclipse, Piazzi Smyth bought himself a new spectroscope. It was a small wooden device just four inches long and less than an inch in diameter, with an eyepiece at one end and a diffraction slit at the other. Inside lay a series of alternating prisms, cleverly arranged so that the light that passed through them emerged from the spectroscope at the same angle at which it had entered. While not a poor man’s device (costing some two pounds), the pocket spectroscope was the province solely of neither professional meteorologists nor astronomers.
The instrument made it possible to do solar physics at a moment’s warning, anywhere the fervent observer happened to be, liberating him or her from surveillance. Skill was required, a delicate habit of minute adjustments, to get good results. The instrument should be aimed low down near the horizon so as to subtend as thick a portion of the atmosphere as possible. A break in the clouds was ideal, but the sun should not interfere too directly, lest it overpower the delicate observation. Sunrise and sunset were also not recommended for this reason. Fogs, mist, and dense coal smoke could also obscure the readings.
For Piazzi Smyth, all this adjusting was enjoyable, part of the fun of looking at the skies. The convenient little tool found its way to his eye many times a day. Fifty times was easily possible when he had his “enthusiasm-fit” upon him.31 Every situation was different, every cloud break, every confluence of pressure, temperature, and wind bearing variously on the transformations of the weather. He didn’t know exactly what, if anything, he was looking for. He didn’t really need to be looking for anything, at any particular moment. He looked first, almost before thinking.
In 1875, Piazzi Smyth made a trip to Paris, where he visited the Astronomer Royal Urbain Leverrier (he found him exceedingly rude, leaving him and Jessie to find their way home alone through a thunderstorm). That storm followed the Piazzi Smyths back to London and, observing it carefully with his spectroscope, Piazzi Smyth noticed a hazy and indistinct—but nevertheless present—“dark broad band” crossing the spectrum between the red and orange sections. The band was darker than the areas surrounding it, and was fuzzy rather than distinct. It faded as he moved the spectroscope to another part of the horizon. When he took his eye away from the instrument and looked with plain sight at the sky, he could see nothing in particular that looked different in that region than in any other. Piazzi Smyth continued to observe as he traveled north to York, where he noticed the strong presence of a blurry dark band in the spectroscope one sunny morning when rain seemed unlikely. Rain did indeed ensue, and observing it fall, Piazzi Smyth felt vindicated in his hunch that the pocket spectroscope was a special new kind of tool for predicting the weather.
He set out to share the news of what he’d come to call the “rainband.” Unlike the hard-edged lines of the solar spectrum, which were understood to be caused by the absorption of light waves by different substances in the solar atmosphere, the rainband was blurry, indistinct, and dynamic. Just what caused it, Piazzi Smyth did not say, though his identification of it with the coming of rain was a strong indication that he thought it most likely to be the signature of water vapor in the atmosphere. He announced his discovery in a letter to the journal Nature, founded just months earlier, under the title “Spectroscopic prevision of rain with a high barometer.” The title made it clear that Piazzi Smyth was modifying what had previously stood as the most basic of meteorological assumptions—that a high barometer, and therefore high pressure, implied good weather.
FIG. 3.10. Solar spectra recorded under different weather conditions showing the position of the rainband at r.
In fact, Piazzi Smyth had revealed precious little about the rainband. He did not offer an opinion on what caused it, and did not even mention the phrase water vapor in his article. More than a new bit of scientific knowledge, what Piazzi Smyth was so eager to announce was a new tool for doing science. Spectroscopy—recently identified as a tool for diagnosing the contents of the earth’s atmosphere—could also be a device for measuring the changing amounts of those elements in the earth’s atmosphere. This made it a tool of practical meteorology, what he called the “prediction of weather for the common purposes of life.”
Despite Piazzi Smyth’s excitement, there was reason to be very cautious about the possibility that the “rainband” spectroscope might transform weather prediction. The blurry bands of the so-called rainband were even harder to learn to see than the fixed solar lines, since they were variable. They changed because the thing they represented—water vapor in the atmosphere—was itself constantly shifting. The allegedly convenient and easy-to-use rainband spectroscope was in fact an instrument for diagnosing variability of a very complex and very particular sort. While spectra contained an enormous amount of information about the entire breadth of the atmosphere at a glance, they were also snapshots, representing just an instant in time. To be useful, they had to be interpreted in relation to snapshots that came before and those that came later. Even the darkness of the bands was only useful when compared with preceding rainbands. Comparing the intensity of successive rainbands was an intensely subjective task, which only relatively few could master sufficiently to render it a consistent practice. F. W. Cory, writing in the Quarterly Journal of the Royal Meteorological Society, argued that the spectroscope was simply too difficult to use, requiring two or three months of “patience and perseverance” (this admitted by one of its most ardent supporters) to be mastered easily by unsupervised individuals.32
Piazzi Smyth persevered. He wrote a series of letters to popular journals in which he tried to reframe the problem of prediction within meteorology, a problem that had always been knotty but had become particularly so ever since FitzRoy’s sensational forecasts and their cancellation following his sensational death. For Piazzi Smyth, prognostication was not a bad word, and the pocket spectroscope no better or worse than existing methods for predicting the weather. It was merely one more tool for energetic, self-motivated people who couldn’t wait for a “perfect” meteorology (akin to astronomy) to rise from the ashes of Admiral FitzRoy’s storm warning project. “We need not after all be offended at the mere name of ‘prognostic,’” Piazzi Smyth reassured the public, pointing out that even the stalwart barometer could only go so far in predicting the coming weather. The boundary between folk wisdom and science, which the Royal Society committee was desperate to police, was a mere illusion, according to Piazzi Smyth. Knowledge was knowledge, however it was gained, and in relation to as complex a thing as the weather remained necessarily provisional, dependent on skill, judgment, and the individual perspective of a single observer whether it was generated by the most rustic fisherman or the most well-trained astronomical observer. “For are there not prognostics and prognostics in meteorology! What are not the risings and fallings of the wind-compelling barometer itself, but a weather prognostic for those who can interpret them.”33
In the face of the almost unimaginable complexity of the weather, Piazzi Smyth was both pragmatic and optimistic. Rather than limiting the sources of data or its applications, he thought it made sense to increase both. He imagined legions of independent observers across the country, “many, very many people,” the natural acuity of whose eyes was enhanced by the pocket rainband spectroscope to render them an army of proto-Supermen, able to see through the clearest of skies to the vapor that lurked within. Thus outfitted, they could “observe and speculate on the weather for themselves at their own places of abode, supplementary to any forecasts that may be issued once a day from London.” The best part about the spectroscope was its portability and ease of use. It enabled any individual to penetrate his solitude and immobility to reach, quite literally, beyond the confines of terrestrial domesticity and into the vastness of space itself. A glance of just two seconds was enough to “tell an experienced observer the general condition of the whole atmosphere.”34 It gave a feeling of security, Piazzi Smyth explained, to know that even in the most cramped and confined space, “with no more than a few cubic feet of peculiar, and for science-purposes, vitiated, air about it,” he could nonetheless still be “nobly looking through the whole atmosphere from the surface of the earth right through to space outside, and analyzing its condition as to watery vapour (the raw material of rain, as the Times phrased it) in one instantaneous, integrating glance.”35
The information the spectroscope gave to the observer was not merely fast but all-encompassing. It penetrated the entire atmosphere at the speed of light and made a single human being the diagnostician of the globe. This was a global science of the atmosphere practiced by individuals. Unsupervised, untethered, unabashedly personal—the pocket rainband spectroscope fulfilled Piazzi Smyth’s fantasy of how science should be. Here was a tool with practical benefit to the sailors, farmers, and holidaymakers of Britain and beyond, a tool which could deliver immediately on its promise, rather than coyly holding out the hope for future understanding of the laws which drove the weather. With it, every man could become an observatory, twitching the skies above.
But what Piazzi Smyth considered the very best qualities of the spectroscope—the way it facilitated a multitude of quick and calibrating glances, its constant availability to those who found themselves gripped by it—proved to be its undoing. Instead of bringing meteorological observing to the people, as Piazzi Smyth had hoped it would, the miniaturized, portable rainband spectroscope revealed just how ill suited most people were to the practice of science. The craze for rainband spectroscopy faded as quickly as a summer storm, leaving the public to rely on their own eyes, their familiar barometers, and the unfamiliar new weather maps when it came to making decisions about the weather.
While Piazzi Smyth was promoting the benefits of individualized vision, the scientific winds were blowing the other way. A Parliamentary investigation into the Met Office was begun in October 1876. In the wake of FitzRoy’s death, the Met Office had embraced so-called self-registering instruments that could automatically trace the changes in the weather. These fantastical devices were like instrumental chimeras, combining the normally separate actions of measurement and registration in one object. The bedeviling influence of friction, which had foiled attempts to design self-registering instruments in the past, met its match in the form of photography. One of the first applications of photography was to the challenge of automatically registering the weather. In 1845, just six years after Louis Daguerre had pioneered the photographic process, two meteorologists (Francis Ronalds at Kew Observatory and Charles Brooke at Greenwich) set about designing a series of self-registering instruments (including a magnetometer, electrometer, barometer, and thermometer) which could deflect a beam of light against a photographic place. Other self-registering instruments used the simpler method of connecting an inked pen to the measurement device.36
These traces were to be used not for weather forecasts—which FitzRoy’s death had revealed as dangerously subjective—but for the long-term project of deducing the physical laws that underpinned the movements of the atmosphere. In the eyes of Robert Scott, FitzRoy’s replacement as head of the Met Office, the values of comparison and continuity completely trumped those of independence and skill. In 1875, he quoted approvingly from the 1840 report of the Committee of Physics and Meteorology of the Royal Society: “Systematic cooperation is the essential point to which at present everything else must be sacrificed; and cooperation on almost any plan would most certainly be followed by more beneficial results than any number of independent observations, however perfect they might be in themselves.” The contributions of those who the committee referred to as “amateurs of science” were welcomed only as long as they conformed to the rules, “even,” it was noted, “at the temporary sacrifice of their own views and convenience.”37
Exactly how the ever more numerous traces of pressure, temperature, and other weather-related phenomena could be transformed into a science of the weather was an open question. British meteorologists in the 1870s felt themselves to be stalled in a stage of early development. What astronomers had once achieved—the ability to make predictions that were accurate far into the future—seemed an ever-receding goal. Meanwhile, astronomy itself had forfeited the self-confidence it had assumed in the wake of Newton’s great achievement. Men such as William Herschel, Edward Sabine, John Herschel, David Brewster, Jules Janssen and, last but not least, Charles Piazzi Smyth had shown that astronomy could be a physical as well as a positional science, but in so doing they had exposed new sources of ignorance and uncertainty. The mature science of astronomy was young again, while meteorology, ever the “infant” science, sought new sources of confidence.
The scandal of FitzRoy’s death did not help matters in Britain. The promise of automatic observatories was a decidedly mixed one—offering the chance of fulfilling Humboldt’s dream of disaggregating the signals of a pluripotent Cosmos but challenging the ability of scientists to manage ever greater amounts of data. Data had long threatened to overwhelm singular astronomers as they faithfully recorded the skies in a single location, night after night. Once armies of self-registering instruments were unloosed on the observatories of the globe, it was hard to see how it would ever be possible to catch up.
New techniques for reducing the traces of such instruments were urgently required. Humboldt had understood this back in the 1830s and had urged Heinrich Berghaus to publish a graphical companion to his Cosmos in the form of a Physikalischer Atlas, which used diagrams to represent the way climate, plants, animals, and geological features changed across the globe. In Britain, Francis Galton came up with a strikingly visual way of finding the mean values for meteorological traces that involved superimposing a series of traces and graphically determining the average line. As innovative as these visual methods were, they could only go so far in the absence of data. In exchange for the personal judgments of forecasters, self-registering instruments promised objective knowledge and produced reams of data. How to wring meaningful understanding from the proliferating traces of the atmosphere was less than obvious. Not all data was created equal. One could have simultaneously too much data of one kind and not enough of another.38
One problem was that the atmosphere was three-dimensional but observers had been largely limited to data from the surface of the earth. This was part of the reason that Piazzi Smyth had been so taken with the spectroscope. It enabled anyone who used it to soar high overhead, traversing unimaginable distances in the process. This was its great advantage, but it was also a disadvantage, as the spectroscope was unable to distinguish the absorptive capacities of different parts of the atmosphere. Every molecule that lay in the line of vision was included in its gaze. It flattened the heterogeneity of the atmosphere even as it provided a way to diagnose its changes. This was a paradox that Piazzi Smyth, for one, was willing to accept, considering the benefits of this kind of vision accumulated to outweigh the losses.
But there were many ways to see the skies. One of the challenges was to get up into the atmosphere and observe it in situ. From the 1850s onward, a series of daring and popular balloon journeys up into the atmosphere took place. These sensational flights were undertaken in the service both of meteorological knowledge and with the spirit of adventure that characterized polar expeditions. They were, as far as they went, immensely successful in raising the profile (literally) of meteorology and capturing the imagination of the public. But balloons were expensive, and the journeys dangerous. At best, they provided a single set of observations recording the conditions in one particular column of air over the course of several hours. Generating systematic knowledge out of these singular adventures would be almost impossible.
Another way to get up into the skies, figuratively, rather than literally, was to pay close attention to clouds. Clouds rode the air currents that determined weather and climate. Noting their sizes, their shapes, and their movements was a way to map the invisible ocean of air above. Clouds were like flags in the upper atmosphere, telling an observer which way the wind was blowing and in which direction, as well as giving an indication of how much water vapor was present in the air. If that were the case, then clouds could be a way to see deeper into the mysteries of the atmosphere. Rather than obscuring the heavens, or frustrating astronomers, clouds could reveal the patterns of atmospheric movement and the laws that drove air around the planet.39
The first step was to classify the clouds. When Luke Howard had introduced his pioneering cloud nomenclature at the beginning of the nineteenth century, he had helped regularize the study of clouds. What he had not been able to say with confidence was whether his tripartite system of clouds would apply throughout the world. Were clouds globally uniform, or were certain clouds only to be found in certain parts of the world? The century had almost ended before anyone had seriously attempted to answer this question. In 1885, an amateur meteorologist with deep pockets named Ralph Abercromby decided to try. He set out on a self-financed circumnavigation of the globe with the explicit aim of determining how universally applicable Howard’s system was. He determined that while the same type of cloud could signify different kinds of coming weather in different places, the essential cloud types were indeed universal.40
Abercromby described his clouds with words, but his discovery inspired the search for more methods of faithfully capturing clouds. If clouds were universal, they could unlock the mysteries not only of the local weather but of what it seemed increasingly reasonable to assume were planetary weather patterns. But in contrast to temperature, pressure, or even rainfall, clouds resisted instrumental registration—they belonged to that “extensive class of phenomena which cannot be recorded instrumentally, but of which it is necessary to take careful notice owing to their importance as indicating changes which are in progress in the atmosphere.” Clouds were almost impossible to observe with the kind of objectivity that instruments promised, but they were too important to ignore. “It is very difficult,” noted C. H. Ley in the preface to his father’s contribution to cloud classification, Cloudland, “to treat of a vague and complicated subject in any but a vague and complicated manner.”41 What was needed was an instrument that could register the clouds in the same way that the barometer registered pressure and the thermometer temperature—instantly, faithfully, and reliably. By the 1870s, exposure times were fast enough that the photographic camera presented itself as a potential solution to this problem.
It comes as no surprise, given Piazzi Smyth’s lifelong commitment to watching the skies, that he was an early advocate for what he called cloud-capturing photography, a new technology to feed his endlessly voracious visual appetite. He’d grown up learning to use whatever tool suited the task of observation before him: Watercolors, pen and ink, pencil, and paints were his early tools. As a youth in the Cape of Good Hope, he had also recognized that photography had the potential to transform scientific observation. Throughout his life, he’d experimented with it, making photographs on board ships, atop mountains, and in the gloom of Egyptian pyramid tombs, developing stereo-photography and even the photography of plaster models. In the 1870s, he designed a new camera specifically for taking photographs of clouds. It incorporated a special corrector to counteract the spherical aberration otherwise introduced by a portrait lens, enabling the full aperture of the lens to be used without distortion.42 He exhibited it at the Edinburgh Photographic Society’s 1876 Exhibition, alongside some cloud photographs, and was awarded a silver medal for it.
He then abandoned the project to undertake one last, intense piece of spectroscopic research, seeking clear rather than cloudy skies in which to probe the nature of the solar spectrum as deeply as possible. Instead of Tenerife, he traveled to the more accessible Portugal and there found that he was able to almost eliminate the so-called telluric, or earthly, lines associated with water vapor. There Piazzi Smyth was finally able to separate the true solar spectrum from both the dry atmospheric spectral lines and those corresponding to moisture in the atmosphere, the culmination of the project he’d begun atop Tenerife some twenty years earlier. As proud as he may have been of the fruits of his observational labor, Piazzi Smyth was not alone in his quest to subtract earthly from solar phenomena.43 At the 1882 meeting of the British Association for the Advancement of Science, several others claimed priority in the matter of separating the solar from the dry and wet atmospheric lines. The related question of whether the oxygen bands had their origins partly in the sun also remained unanswered well into the 1890s. In 1893, an elderly Jules Janssen decided to try to settle the matter himself. At age sixty-nine, he made his way to the top of Mont Blanc in an attempt to observe solar oxygen from there. His observations of the absence of oxygen lines in the solar spectrum as viewed from the top of the mountain were taken as evidence for the absence of oxygen on the sun. The spectroscope continued to amaze with its ability to penetrate deep into the atmospheres of distant objects.
While the scientific community continued to seek evidence for new substances in the atmospheres of the earth, the sun, the planets, and even such remote phenomena as the Zodiacal light, Piazzi Smyth himself receded ever further from public view. His last undertaking was almost entirely solitary. He had both embraced the pleasures of independence and tasted the bitterness of exclusion during his lifetime. His commitment to pyramidology had resulted in his self-imposed retreat from the Royal Society and the community of scientists it represented. His spectroscopic work continued to be of excellent quality, but his insistence on using the British inch as the unit of length had severely limited the usefulness of his maps. In the end, he found himself almost alone. He had time, the luxury of retirement. He had his instruments and a few assistants to help him. And he had the clouds. They passed by the high windows of his home in Ripon, Yorkshire. He grasped them with his camera, angling it up to exclude all but the tops of the tallest trees.
FIG. 3.11. Charles Piazzi Smyth in old age with a grand-niece. Credit: Royal Observatory Edinburgh.
FIG. 3.12. Photograph from Cloud Forms That Have Been at Clova, Ripon, taken from his library window by Charles Piazzi Smyth on June 30, 1892. Credit: Royal Society.
FIG. 3.13. “The wrecks of a summer squall,” Smyth notes on the cloud photograph taken on June 30, 1892, along with observations of barometric pressure, temperature, rain- and sunband, and wind speed. Credit: Royal Society.
He returned to cloud photography, the subject he had investigated some twenty years earlier, looking for a way to standardize the observation of the clouds just as the spectroscope had standardized the observation of light. But while his earlier project had been undertaken in the acknowledgment of a wider community of observers, this final project, undertaken in 1892 and 1893, was an impossible, almost lunatic attempt to record the face of the skies alone. He himself gently mocked his project, calling it a “labour of love and meteorologic research, in days of old age and failing faculties.” At the heart of his project was a set of photographs which, without intention or ambition to extend beyond their tiny window of the world, served as a powerful renunciation of the communal approach to knowledge. Of the hundreds of images he took, he printed 144 of the best in three massive volumes, bound in leather and prefaced with a manuscript copied out in a clear hand, detailing the nature of his project. These tomes represented the work of thousands of hours, but they were read by almost no one. Never published or widely shared, they stand as a monument to life spent in intensely personal observation.44
Piazzi Smyth’s timing was, in a certain sense, excellent. At the very moment that he was devoting himself in solitude to his “labour of love,” the scientific community had begun its own project in cloud photography. Inspired in part by Abercromby’s discovery that cloud types were universal, in 1891 the attendees of an international conference of thirty-one meteorological directors from around the world launched an international project to map the clouds. Their plan encompassed not merely a single location but, in theory (if not in practice), the entire globe. The projected International Cloud Atlas would improve upon Howard’s classification system and put flesh on Abercromby’s anecdotal assertions about the universality of clouds. Headed by a Swede, Hugo Hildebrandsson, and a Frenchman, Léon Teisserenc de Bort, the atlas had the crisp mark of imperial power on it, the confidence to mark the skies with order as the railways and telegraph wires had marked the land. The plan was explicitly both global and synchronized, aiming to promote what its authors described as “inquiries into the forms and motions of clouds by means of concerted observations at the various institutes and observatories of the globe.”45 It was, in other words, everything that Piazzi Smyth’s solitary project was not.
Clouds became, through the classificatory magic of the International Cloud Atlas, standardized objects that could be identified reliably on the basis of images that served much the same purpose as the sketches of birds in a naturalist’s guide. Clouds were, the atlas declared, universal types that could be identified at any point on the planet. To aid in such identification, the atlas made stunning use of color photographs. It proved impossible, however, to capture images of all the sixteen basic types of clouds described in the atlas this way. Certain clouds, such as the alto-stratus, the nimbus, and the stratus, were too difficult to catch. Lithographic representations of painted pictures—an older technology for representing ideal types—of these cloud types appear in the completed atlas alongside color photographs, as do black-and-white photographic images. Perfect scientific vision, these different kinds of images seem to suggest, was impossible. Instead, the act of looking was an active and dynamic process. Seeing clouds well—which included seeing them as universal types—required seeing them in different ways and from different locations. This way of looking proved resilient. The International Cloud Atlas has remained in print ever since. Photography remains the standard technology for representing the clouds and, just as important, the atlas is a compendium of global knowledge, generated by observers positioned all over the planet just as Hildebrandsson and Teisserenc de Bort had suggested back in 1896. The projected future of meteorology that they envisioned has, in many important respects, come to pass.
In another, and perhaps more important sense, meteorology has changed dramatically since then. No longer is taxonomy enough. Once a system for classification had been established—not by a solitary looker like Piazzi Smyth but by a committee representing the international community—the next step was to apply it to the deeper, and much knottier, problem of explaining why the clouds appeared where they did, of explaining what drove the weather and the clouds with it. For all its confidence, the Cloud Atlas was little more than a down payment on a future piece of work whose success was far from certain.
Piazzi Smyth offered no help with that project either. His life and his considerable energies had been expended in the belief that looking was an end in itself, an activity that was both morally and scientifically productive. Looking at things that were difficult to see—the distant stars, the ever-changing spectrum, the clouds—was a way to exercise mental faculties and spiritual sense at the same time. Piazzi Smyth left to others the task of seeing through clouds to the physics of the solar system or looking at a fuzzy, shifting rainband to crack the code of the weather, or capturing clouds that shifted with dizzying rapidity. He was ready to look not for explanation but for something deeper still—the mark of the divine. “Up to this time, whatever science can or cannot say in scholastic explanation,” Piazzi Smyth reasoned, “or however far behind she may be in reducing either the minute beauties of calm summer skies or the majestic agglomerations of threatening thunder . . . to nothing but a few mechanical processes throughout their whole extent and bearing, yet the forms of beauty exhibited so frequently and prodigally before our neglectful eyes in Clouds, can only be reverentially looked upon by us.” In the final consideration, clouds were noteworthy to Piazzi Smyth not because they made elusive, difficult objects for scientific study, but because they made it easy to see God. Able to be witnessed by all of us, they were testaments to divine order, bearing the “visible impress of the greater invisible Intelligence which arranges all we see.”46 At the end of a busy and tumultuous life, Piazzi Smyth took a full measure of solace from the order he found in the wildness of the sky.