[907] While progress in all branches of knowledge has been rapid beyond precedent during the past sixty years, in at least two directions this knowledge has been so unexpected and novel in character that two new sciences may be said to have arisen: the new medicine, with which the names of Lister and of Pasteur will remain associated; and the new astronomy, of the birth and early growth of which I have now to speak.

The new astronomy, unlike the old astronomy to which we are indebted for skill in the navigation of the seas, the calculation of the tides, and the daily regulation of time, can lay no claim to afford us material help in the routine of daily life. Her sphere lies outside the earth. Is she less fair? Shall we pay her less court because it is to mental culture in its highest form, to our purely intellectual joys that she contributes? For surely in no part of Nature are the noblest and most profound conceptions of the human spirit more directly called forth than in the study of the heavens and the host thereof.

May we not rather greet her in the words of Horace: ‘O matre pulchra filia pulchrior’?

With each passing year, Huggins became increasingly involved in observations requiring assistance. Until the untimely death in 1870 of his neighbour, chemist William Allen Miller, Huggins relied on him to confirm important telescopic observations and assist in spectroscopic comparisons. On occasion, he invited others to work with him at Tulse Hill. But he could not long continue as a solitary observer if he wished to maintain his position on the cutting edge of research in astronomical physics.

By the mid-1870s, he faced a growing field of able competitors in London and abroad, who vied with him for the same prize discoveries: to decipher the spectral code of the nebulae, to reduce the varieties of stellar spectra to a seemly and sensible order, to bring the full potential of the spectroscope's analytic power to bear on the solar surface and its immediate environs, and/or to be the first to observe some new as yet unimagined celestial phenomenon. He had already experienced a loss of priority to Lockyer's and Janssen's independent claims to have found a spectroscopic method for viewing solar prominences without an eclipse. He would have to work hard to ensure that he did not lose such an opportunity again.

Another difficulty gradually arose as astronomical photography became an accepted, even expected, part of the serious amateur's toolkit.

In April 1892, three ‘lady candidates’ failed to receive sufficient votes to be elected to fellowship in the all-male RAS. Before the ballots were cast, the chair urged each Fellow to vote as he saw fit, with the caveat that admitting women as full members might violate the Society's Charter. One Fellow threatened to ‘protest against the legality of the election in case the women should be elected’. Another cautioned that a vote for women was a vote for introducing a ‘social element’ into the RAS's normally ‘dull meetings’. It would require ‘a piano and a fiddle’, and laying down a ‘parquet flooring’ so all could ‘dance through most of the papers’.

But change was afoot in the Society at the dawn of the twentieth century. On 8 May 1903, the RAS Council elected Margaret Huggins and her friend, historian of astronomy Agnes Clerke, as Honorary Members. Only three other women had received such an honour: Caroline Lucretia Herschel (1750–1848) and Mary Somerville (1780–1872) in 1835, and Anne Sheepshanks (1789–1876) in 1862. Over the next eleven years two more women, both Americans, joined their ranks: Scottish-born Williamina Paton Stevens Fleming (1857–1911) in May 1906 and Annie Jump Cannon (1863–1941) in March 1914. The RAS finally amended its Charter to include women in February 1915. That November, five women were among the nine individuals nominated for election. In January 1916, all were elected.

On 4 April 1868, at about the same time Huggins was completing his paper on stellar motion in the line of sight, he received a visit from Howard Grubb (1844–1931). Son – and now partner – of engineer and telescope maker Thomas Grubb, young Howard had spent the last two years supervising the construction of the Great Melbourne telescope, a state-of-the-art instrument for studying nebulae in the southern sky. Its construction had been commissioned by the Royal Society on behalf of, and with funds provided by, the state of Victoria, Australia. Recently completed, the monumental 4-ft Cassegrain would soon be bound for Melbourne.

Accompanying Grubb on his visit was astronomer Albert Adolphus Adalbert LeSueur (1849–1906), who had observed the figuring of the mirrors and would be assisting in the instrument's operation at the University of Melbourne's observatory. Huggins took great pride in showing his observatory to guests like these, who knew and appreciated not only the fine quality of his instruments, but the skill required to put them to good use.

In 1897 The Nineteenth Century, a popular magazine, published an essay by William Huggins on ‘The new astronomy’ and his role in its development. In it, Huggins imposed an artificial order and rationale upon his programmatic decisions by enumerating a neat sequence of pioneering projects that began with his first efforts in stellar spectroscopy and ended with his design of a spectroscopic method to determine stellar motion in the line of sight. He fleshed out the story with vivid descriptions of the career risks he took, the instrumental and methodological challenges he faced, as well as the rewards he gained throughout his long and illustrious career in consequence of his decision to devote his observing programme to the spectroscopic study of celestial bodies. The captivating eyewitness account carried readers behind the scenes of scientific discovery in a very personal and dramatic way.

Huggins and his wife, Margaret, later reprinted extended excerpts from it in both their Atlas (1899) and Scientific Papers (1909) thus making its passages readily available to interested scientists and laymen alike. Indeed, after his death in 1910, ‘The new astronomy’ was the reference of choice for obituarists and biographers who lacked the time and energy required to read Huggins's many published papers, let alone the access necessary to examine his unpublished correspondence and notebook records.

Huggins could have set himself the arduous task of examining the spectrum of every known nebular object, or systematically cataloguing the spectra of northern hemisphere stars. Instead, he pursued a varied and opportunistic research programme like many other amateur astronomers of his day, devoting considerable time and serious attention to research problems generated by others, and to the exotic rather than the mundane. As an independent observer he was free of the obligations and commitments that restricted his institution-bound contemporaries. Driven by broad interests and an insatiable curiosity, he explored a number of different subjects in innovative and often technically demanding ways. His challenge was to maximise his exposure to opportunities for new discoveries without becoming identified as a speculative or impulsive dilettante.

It was a challenge his years as an entrepreneur had prepared him well to meet. He developed a reputation for care in making observations and caution in suggesting explanations for the phenomena he observed. His successes led to more opportunities for success, and he became recognised as one upon whom colleagues could rely for advice on spectroscopic matters.

Cultivating advantageous alliances

In June 1865, the Royal Society called on Huggins to verify a discovery recently announced by Father Angelo Secchi, director of the Vatican observatory.

In 1718, after comparing contemporary records of stellar positions with those of ancient times, Edmond Halley determined that the bright stars Palilicium (Aldebaran), Sirius and Arcturus had undergone a greater displacement on the two-dimensional sky than could be accounted for by precession alone. He postulated that these stars possess a ‘particular Motion of their own … which in so long a time as 1800 Years may shew it self by the alteration of their places, though it be utterly imperceptible in the space of a single Century of Years’. Halley's ‘particular’ stellar motion is what today's astronomers call ‘proper’ motion. It constitutes one component of a star's ‘space velocity’, or motion in space relative to the Sun. The other is its ‘radial velocity’, or motion in the line of sight.

Since Halley's day, astronomers have measured the proper motion of many stars. But even the nearest of our Sun's stellar neighbours is too distant to exhibit any of the visual cues (e.g. changes in apparent brightness or size) we normally rely on as evidence of motion in the line of sight. Indeed, the ability to detect, let alone measure, a star's radial velocity eluded earthbound observers until the late 1860s when William Huggins brought the new instruments and methods of celestial spectroscopy to bear on the matter. It proved to be the most influential of his contributions to modern day astronomical practice.

The introduction of spectrum analysis into astronomical research in the mid-nineteenth century was synchronous with William Huggins's rise to prominence as an amateur astronomer. After his death in May 1910, eulogisers were effusive in their praise of his vision and imagination, which American astronomer George Ellery Hale suggested allowed Huggins ‘to divine some of the less obvious applications of the spectroscope’. Appreciation of his willingness to break new ground was tempered by admiration for what the Astronomer Royal for Scotland, Frank Watson Dyson (1868–1939), termed Huggins's ‘characteristic thoroughness’ and ‘care’, and what maverick American astronomer Thomas Jefferson Jackson See characterised as his ‘judicious habits of weighing evidence’, ‘wise selection of subjects of research’, and ‘strict conscientiousness and calm deliberation’. How did so cautious and measured a man come to lead a movement that ultimately revolutionised the theory, technique and practice of astronomy by the turn of the twentieth century?

The question's paradoxical premise, I argue, is founded on a well-crafted and convincing illusion, namely the sturdy façade of Huggins's public persona. Like a precious egg preserved in situ, the real stuff of another's life remains undisturbed until we, the curious, penetrate its protective shell. Once inside we may find only dust and musty memories. Not so in the case of William Huggins.

In ‘The new astronomy’ Huggins tells us: ‘I was fortunate in the early autumn of the … year, 1864, to begin some observations in a region hitherto unexplored’ namely, the nebulae. He could indeed feel ‘fortunate’ to have turned his spectroscope on this class of celestial objects. They are among the faintest on the sky. It had been over thirty years since he caught his first glimpse of a nebula's spectrum. Even so, Huggins recounted the experience in riveting detail as if it were only yesterday. Readers could only imagine the diligent care with which he must have recorded the event in real time.

In 1914, Huggins's widow, Margaret, shipped six bound notebooks containing the records of nearly a half century of work done at their Tulse Hill observatory off to Wellesley College near Boston, Massachusetts. When the notebooks arrived at the private school for women, Professor of Astronomy Sarah Frances Whiting (1846–1927) was the first to examine them. She found what she believed to be the notes from his early observations of nebular spectra. ‘In 1864’, she wrote, ‘[Huggins] records his observations of the green lines in the nebulae, and scores of nights were spent trying to match these lines with magnesium, lead, iron, what-not.’ Entries fitting Whiting's description can be found in Notebook 1. However, they are clearly dated 1889 and 1890, and they are written in Margaret Huggins's hand.

It has long been accepted by historians of astronomy that William Huggins underwent a dramatic change in his research interests and methods in the early 1860s. And no wonder, for he has told us so himself in ‘The new astronomy’:

The restless mix of ambition and curiosity that had spurred William Huggins down so many unexplored paths in the past would not let him sit quietly upon the laurels he had earned. The discovery of terrestrial helium and the puzzle of radium's spontaneous glow brought him new brinks to teeter on, fresh risks to calculate, and undreamt-of wonders to reveal. Because the published record of his research in these areas is scant and unrelated to his more familiar astronomical investigations, Huggins's creative work, particularly on the question of the nature of radium glow, has been ignored by historians of science. In this chapter, that oversight will be rectified. The public record augmented by his unpublished correspondence with fellow investigators bring to light how eagerly and ardently he and his wife, Margaret, applied their spectroscopic and photographic expertise to these new and tantalising problems.

The previous chapter introduced the young American astronomer George Ellery Hale, and discussed the foundation of Huggins's alliance with him. In this chapter, we will follow the growth and development of their close relationship as Hale launched his career in astrophysics and pursued his ambitious plan to erect and direct the world's largest refracting telescope. Huggins nurtured his friendship with Hale, and developed a similar association with Irish mathematician and physicist Joseph Larmor.

William Huggins's work on solar prominences, and his expedition's failure to observe the eclipse of 1870, encouraged him to attempt a bold plan for photographing the solar corona without an eclipse. His initial impression of success in this project led him to pursue it for many years with great interest and drive. The inconclusiveness of his results tested the strength of his persuasive power and encouraged him to try to build an international network of confirmatory witnesses. The evidence Huggins believed he needed to argue successfully for the validity of his method was not forthcoming. Nevertheless, his correspondence contains the details of the verbal and visual rhetorical process by which he was able, as a relative outsider to solar observation, to shape the development of methods of observation in the emerging discipline of solar research, the types of questions being asked about the solar atmosphere, the kind and form of observation that counted as real and conclusive evidence, and finally the direction in which solar observation was taken by the growing network of solar observers up to the turn of the century.

The Egyptian eclipse

Despite growing threats of local unrest in Egypt, Arthur Schuster travelled to that country in May 1882 to observe a total solar eclipse.

By 1890, William Huggins had acquired considerable renown and prestige. He also faced serious threats from all sides: refutations and criticisms from Lockyer, reports that old problems were being conquered with improved instrumentation at other observatories, and lack of recognition from men too young to remember his pioneering role in the development of observational techniques they took for granted.

How did he manage to keep himself on the forefront of discovery and hold his detractors at bay? One way he did this, as we shall see in this chapter, was by cultivating and nurturing personal alliances with prominent American astronomers. He had discerned early on that the locus of cutting-edge astronomical research was shifting from the Old World to the New. Visionary plans were being drawn up and executed on the other side of the Atlantic thanks to eccentric tycoons like James Lick and Charles Yerkes (1837–1905) with egos and fortunes large enough to cover the cost of erecting monumental observatories equipped to face the challenges of the new astronomy. It is emblematic of the eclectic and dynamic nature of Huggins's investigative interests and methods that he embraced the work of these new American observatories and made use of their resources to further his own research goals.