[BITList] Star qualities

[John Feltham]

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Huggins, Sir  William  (1824-1910), astronomer, was born on 7 February  
1824 in the parish of St Peter, Cornhill, London, the only child of  
William Thomas Huggins (1780?-1856), a silk mercer and linen draper,  
and his wife, Lucy Miller (1786?-1868), a native of Peterborough. He  
attended the City of London School from 1837 to 1839, then until 1842  
was tutored privately.

In 1843 Huggins acquired a small telescope. He formalized his interest  
in scientific matters in 1852 by becoming a fellow of the Royal  
Microscopical Society. In 1853 he purchased a 5 inch Dollond  
equatorial, and in 1854 he was elected a fellow of the Royal  
Astronomical Society (RAS). Soon afterwards he sold the family  
business and moved to Tulse Hill, a London suburb where he found both  
the time and the darkened skies necessary to pursue astronomy. Huggins  
had a substantial observatory building constructed at his home, and in  
1856 acquired a notebook in which to record his observations. Although  
his first brief and sporadic entries described subjects common to  
casual observers, he soon undertook more systematic research through  
the guidance and encouragement of expert amateurs, notably William  
Rutter Dawes (1799-1868) of Haddenham, from whom, in 1858, he  
purchased an 8 inch object glass made by Alvan Clark of Cambridge,  
Massachusetts; this he had mounted in an equatorial, clock-driven  
instrument by Thomas Cooke of York.

Pioneering celestial spectroscopy

Huggins's rise to prominence coincided with the successful adaptation  
of the spectroscope to new astronomical purposes following the  
announcement in 1859 by the German scientists Gustav Kirchhoff  
(1828-1887) and Robert Bunsen (1811-1899) of their interpretation of  
Fraunhofer's lines. Their suggestion that these perplexing dark  
interruptions in the otherwise continuous solar spectrum betrayed the  
sun's terrestrial chemical make-up stimulated much interest and  
discussion in Britain, especially among analytic chemists such as  
Huggins's friend and neighbour William Allen Miller (1817-1870).  
Miller, professor of chemistry at King's College, London, was an  
experienced spectroscopist and photographer whom Huggins later  
credited as both the source of his introduction to spectrum analysis  
and the catalyst for his later efforts to discover the chemical  
composition of the heavenly bodies. The intrusion of chemical  
instruments and research goals into the observatory required major  
alterations to the traditional organization of astronomical work and  
workspace. With Miller, Huggins perfected a spectroscope which,  
attached to his telescope, brought the prominent spectral lines of the  
brighter stars into view. Huggins's star spectroscope enabled  
astronomers to ask new questions and undertake new mensuration, and  
ultimately altered the boundaries of acceptable astronomical research.  
He was recognized by contemporaries as a principal founder of this new  
science of celestial spectroscopy.

Direct visual comparison of stellar spectra against those produced by  
known terrestrial elements was hindered by the lack of standard and  
precise spectrum maps. To rectify that, in 1863 Huggins embarked on an  
extensive examination of metallic spectra, making important  
improvements in instrument design and research methodology. As an  
independent observer he tested the spectroscope's analytic power on  
his choice of a variety of celestial objects. Thus in 1864 his  
research shifted from stars to nebulae in the hope that the  
spectroscope would resolve the many unanswered questions about their  
nature. It was a bold initiative which ultimately propelled Huggins to  
a position of prestige and authority among his fellow astronomers. He  
selected a bright planetary nebula (37 H. IV. Draconis) as his first  
object, fully expecting to find that it differed from a star not so  
much in terms of composition but in its temperature and density. He  
was astonished to find a bright line spectrum unlike that of any known  
terrestrial element. The spectra of other planetary nebulae showed  
similar characteristics, leading him to conclude that they were not  
only gaseous in nature but represented a class of truly unique  
celestial bodies. Huggins's announcement captured his colleagues'  
imagination and heightened their awareness of the potential of  
spectrum analysis to generate new knowledge about the heavens. In June  
1865 he was elected to fellowship in the Royal Society, and in  
February 1867 he and Miller were jointly awarded the RAS gold medal  
for their collaborative research on nebular spectra.

Celestial spectroscopy developed rapidly in a wide range of  
directions. No one knew which would prove most fruitful. Huggins  
therefore explored a variety of subjects in innovative and technically  
challenging ways. In May 1866 he became the first to analyse the  
spectrum of a nova (T Coronae). Months later he examined solar  
prominences, devising methods to observe them without an eclipse. He  
investigated the chemical composition of meteors, looked for reported  
changes in lunar surface features, and pioneered the use of a  
thermopile to measure the heat reaching earth from the moon and  
brighter stars. Although each of these projects met with mixed  
success, the attempts reveal much about his willingness to pursue  
risky projects to establish himself in the forefront of the new  
astronomy.

Huggins is renowned for his development of a spectroscopic method to  
determine a star's motion in the line of sight, begun in 1867.  
Although astronomers routinely measured the motion of stars across the  
field of view, they lacked visual cues for determining stellar motion  
towards or away from earth. Huggins believed that this information  
could be gained by observing an individual line in a star's spectrum  
alongside its counterpart in the spectrum of a known terrestrial  
element. As with the change in pitch that Christian Doppler  
(1803-1853) predicted would be heard emanating from a moving source of  
sound, Huggins reasoned that any lack of coincidence in the two lines'  
positions would be due to their sources' relative motion. He received  
encouragement from the physicist James Clerk Maxwell (1831-1879),  
along with a warning to expect the observed differences to be  
extremely small. Armed with new and more precise instruments, Huggins  
relied solely on direct visual observations of the bright star Sirius  
in February 1868; he compared the prominent Fraunhofer F line in the  
star's spectrum to that of a laboratory hydrogen spark, but obtained  
occasionally conflicting results. To reduce alignment error he  
designed an improved arrangement for throwing the light of the  
comparison spark into the telescopic view. He concluded that, despite  
some inconsistencies, Sirius appeared to be receding from the earth at  
a speed of 29.4 miles per second (the modern assignation is 5 miles  
per second towards the earth). In announcing his result Huggins  
expressed satisfaction that he had resolved the instrumental problems  
and stressed the care he had taken. He invoked Maxwell's name to  
underscore the theoretical soundness of his conclusions. His tone was  
one of confidence and spirited adventure. Indeed, arguably his  
greatest contribution to the successful introduction of this new  
method into astronomical research lay in his persuasion of his  
contemporaries that he had, in fact, accomplished what he claimed  
despite the overwhelming mensurational and interpretive difficulties  
the method entailed. Although few understood the physical theory, and  
although implementing his method was largely beyond the resources and  
ability of many of his fellow amateurs, celestial mechanicians such as  
those at the Royal Observatory, Greenwich, recognized, and later took  
up, its potential as an aid to charting the heavens. By giving  
astronomy an elegant and reliable research tool of broad utility,  
Huggins became recognized as the one upon whom even the astronomer  
royal, George Biddell Airy (1801-1892), could rely for advice on  
spectroscopic matters.

Funding: obligations and status

However, the highly refractive train of prisms that facilitated  
Huggins's line-of-sight investigations impaired his nebular work.  
Because of the limited light-gathering capability of his 8 inch  
telescope, the feeble light of a nebula faded to invisibility when  
subjected to his spectroscope's dispersive power. The influential  
director of the Armagh observatory, Thomas Romney Robinson  
(1792-1882), desiring to advance the cause of celestial spectroscopy,  
persuaded the Royal Society to finance for £2000 the construction of  
instruments for Huggins's use. Huggins enlarged his observatory in  
November 1870 to accommodate a pair of fine telescopes by Howard Grubb  
of Dublin-one a 15 inch refractor and the other an 18 inch reflector- 
which could be mounted interchangeably on the equatorial base.  
Although the accompanying spectroscopes were not yet complete, the  
telescopes were ready for visual observations in February 1871. (In  
1882 the instrument was modified to incorporate two independent  
declination axes so that both telescopes could be mounted and used  
simultaneously.)

The arrival of Huggins's Great Grubb Equatorial marked a turning point  
in his career. No longer independent of institutional expectations or  
constraints, he was now custodian of state-of-the-art telescopes paid  
for with funds appropriated by the Royal Society, and so directly  
answerable to criticism of his choice of observational problems, his  
methods, even his diligence in the use of these coveted instruments.  
During the protracted debate regarding state funds for research which  
split the RAS in 1872, there was criticism of awarding limited  
resources to private individuals, such as Huggins, who could further  
their own personal research goals instead of those in the national  
interest. To critics, Huggins exemplified the inadequacy and  
inefficiency of relying on individuals to carry out the essential work  
of the new astronomy.

For Huggins the trust which custody of the Royal Society's instruments  
represented imposed an overwhelming obligation to use them. He found  
the new work exhausting. No doubt he had planned to rely on Miller's  
skilled assistance, but Miller died unexpectedly in September 1870,  
just months before Grubb installed the new instruments. Huggins also  
needed to incorporate photography to maintain his pioneering role. His  
need for an assistant, preferably one familiar with the techniques of  
photography, combined with his sense of frugality may have encouraged  
him to commit to a greater change in his personal life. On 8 September  
1875 he married Margaret Lindsay Murray (1848-1915) [see Huggins,   
Margaret Lindsay] of Monkstown, on Dublin Bay, Ireland, a woman with  
skills and sufficient astronomical interest in whom he found a  
lifelong and devoted companion as well as a capable collaborator. They  
had no children. Margaret's presence changed both the kind of work  
done at the Tulse Hill observatory and its organization. Her entries  
in the observatory notebooks clearly reveal her initiative in problem  
selection, instrument design, methodological approach, and data  
interpretation. More importantly, they point to her as the impetus  
behind the establishment of Huggins's successful programme of  
photographic research. Her long hours of skilled guiding produced a  
sharpness in the definition of the photographs which was difficult to  
surpass for spectra only half an inch in length.

Solar research

Because he is remembered principally as a pioneer in the field of  
stellar and nebular spectroscopy, Huggins's forays into solar research  
are less well known; indeed, they are conspicuously missing from his  
retrospective account. He played a significant role in resolving the  
so-called willow-leaves controversy in 1864, and in 1866 was the first  
to develop both spectroscopic and non-spectroscopic methods for  
rendering solar prominences visible without an eclipse. In 1870 he led  
an eclipse expedition to observe the solar corona's spectrum, for  
which task he designed a sophisticated automatic recorder, but  
inclement weather left him empty-handed. His interest revived in 1882  
when he viewed a recent eclipse photograph showing the light of the  
coronal spectrum to be strongest in the violet. Eager to provide solar  
observers with a reliable means of routinely recording coronal  
phenomena, Huggins and his wife developed a unique method for  
photographing the corona whenever the sun was visible, first using  
violet glass as a filter, and later relying on selective sensitivity  
in photographic emulsions. They pursued this project enthusiastically  
for over a decade, during which time Huggins successfully petitioned  
the Royal Society to have the method tested in locations free of  
atmospheric obscuration. Some of the photographs thus obtained  
appeared to show the general form of the solar corona.

In 1885 Huggins gave two major addresses on the corona, including the  
Royal Society's Bakerian lecture, in which he described the method he  
and his wife had devised for observing the corona without an eclipse,  
giving particular attention to the many precautions taken to prevent  
the appearance of false effects. He emphasized the persuasive weight  
of the numbers of successful plates obtained, their corroboration by  
experts, and the tests in progress. He speculated on the nature of the  
corona, drawing attention to the analogous appearance of its  
structural features to the glowing streamers seen in comets' tails,  
suggesting that high electrical potential at the level of the  
photosphere could account for both the movement and the glow of  
oppositely charged material far above the sun's surface. In 1886  
Etienne Leopold Trouvelot (1827-1895), of the Meudon observatory in  
France, reported that he, too, had seen the corona without an eclipse.  
Despite this news, critics of Huggins's method abounded and further  
tests of the method proved inconclusive. By the time Bernard Lyot  
(1897-1952) took the first successful photograph of the solar corona  
without an eclipse in 1930, few remembered Huggins's earlier work.  
Nevertheless, his pioneering efforts contributed to the emerging  
discipline of solar research, the useful questions being asked about  
the solar atmosphere, the type and form of evidence considered as  
conclusive, and the direction in which solar observation was taken by  
the growing international network of solar observers.

Nebular theory

In 1887 the Hugginses began their search for the cause of the  
principal emission lines in nebular spectra, an exciting subject,  
though contentious because of the rich variety of nebular theories  
then vying for observational confirmation. Their conclusion that the  
lines derived from the glowing gas of some heretofore unknown element  
contradicted that of Norman Lockyer (1836-1920), who claimed they were  
produced by the magnesium in incandescent swarms of colliding  
meteorites. The rancorous controversy which ensued taxed Huggins's  
rhetorical skills. By advocating his method of gathering evidence and,  
hence, his interpretation of it, he contributed much towards refining  
and defining standards of proof within the maturing science of  
celestial spectroscopy.

In 1892 Huggins had the opportunity to subject the light of another  
nova (T Aurigae) to spectrum analysis. With his wife he conducted an  
exhaustive and exhausting study of the nova's spectrum. Understanding  
of the physical mechanisms at work in such events had not improved  
since T Coronae in 1866, nevertheless celestial spectroscopy and  
photography had greatly enriched the astronomer's methodological and  
interpretive potential. Alert now for any tell-tale signs of stellar  
motion in the line of sight, or spectral signatures betraying the  
presence of some new and as yet undiscovered element, the Hugginses,  
like all other astronomers for whom these methods had now become  
routine, looked at T Aurigae with new eyes.

In the final decade of his life, as direct telescopic observations  
became increasingly difficult for him, Huggins found other ways to  
advertise the investigative power of the spectroscope and to promote  
its use in astronomy as well as in other sciences. In 1899 he and his  
wife published An Atlas of Representative Stellar Spectra, a volume  
aimed at establishing Huggins as the pre-eminent authority in the  
field of stellar spectroscopy, and disseminating the spectrographic  
evidence gathered at Tulse Hill in support of his views on the  
chemical and physical nature of stars and their probable evolution. In  
1903 they embarked on a long-term spectroscopic study of the newly  
discovered element radium. In 1908, no longer able to make routine use  
of the instruments entrusted to his care for nearly four decades,  
Huggins recommended their transfer to enhance H. F. Newall's work at  
the Cambridge University observatory, where they remained until 1954.  
In 1909 the Hugginses published The Scientific Papers of Sir William  
Huggins, an edited collection of previously published documents  
organized topically and accompanied by new interpretive commentary.

Huggins was an active member, and served as president, of the Royal  
Astronomical Society (1876-8), the British Association for the  
Advancement of Science (1891), and the Royal Society (1900-05). He  
received honorary degrees from the universities of Cambridge (1870),  
Oxford (1871), Edinburgh (1871), Dublin (1886), St Andrews (1893), and  
various foreign countries, and he received the Royal Society's royal  
(1866), Rumford (1880), and Copley (1898) medals. In 1885 he joined  
the ranks of those elect few in the history of the RAS to be honoured  
with a second gold medal. The emperor of Brazil, Pedro II, bestowed on  
him the order of the Rose (1871). The Academie des Sciences in Paris  
awarded him the Lalande prize (1882), the Valz prize (1883), and the  
Janssen gold medal (1888), and he received the Draper medal (1901)  
from the National Academy of Sciences in Washington, DC. In addition  
he held honorary or foreign membership in numerous national learned  
societies, including the Academie des Sciences de l'Institut National  
de France, Paris; the Reale Accademia dei Lincei; the royal academies  
of Berlin and Gottingen; the Royal Irish Academy; the royal societies  
of Edinburgh, Sweden, Denmark, and the Netherlands; the National  
Academy of Sciences, Washington, DC; the American Philosophical  
Society, Philadelphia; and the American Academy of Arts and Sciences,  
Boston.

Huggins was created a KCB by Queen Victoria in 1897 and was among the  
first twelve individuals awarded the prestigious Order of Merit by  
Edward VII in 1902. He died on 12 May 1910 of heart failure following  
surgery. He was cremated and his ashes placed in Golders Green  
crematorium, Middlesex. He was survived by his wife and collaborator  
of thirty-four years, who bequeathed a number of his scientific  
instruments as well as six bound observatory notebooks to Wellesley  
College, Wellesley, Massachusetts. She also established a scholarship  
in her husband's name at the City of London School.

Barbara J. Becker

Sources  B. J. Becker, 'Eclecticism, opportunism, and the evolution of  
a new research agenda: William and Margaret Huggins and the origins of  
astrophysics', PhD diss., Johns Hopkins University, 1993 + B. J.  
Becker, 'Dispelling the myth of the able assistant: Margaret and  
William Huggins at work in the Tulse Hill observatory', Creative  
couples in the sciences, ed. H. Pycior and others (1996), 98-111 + C.  
E. Mills and C. F. Brooke, A sketch of the life of Sir William Huggins  
(1936) + W. Huggins and M. L. Huggins, observatory notebooks,  
Wellesley College, Wellesley, Massachusetts, USA, Margaret Clapp  
Library + W. Huggins, 'The new astronomy', Nineteenth Century, 41  
(1897), 907-29 + W. Huggins and Lady Huggins, An atlas of  
representative stellar spectra from l4870 to l3300: together with ...  
a short history of the observatory and its work (1899) + The  
scientific papers of Sir William Huggins, ed. W. Huggins and M. L.  
Huggins (1909) + TNA: PRO, RG4/4226 + m. cert. + d. cert. + census  
returns, 1841, 1851, 1861, 1871
Archives RAS, corresp. and papers + RS, corresp. + South African  
Astronomical Observatory, Cape Town, archives + Wellesley College,  
Massachusetts, Clapp Library, letters, observatory notebooks,  
scientific instruments, objets d'art | Air Force Research  
Laboratories, Cambridge, Massachusetts, letters to Lord Rayleigh +  
Bodl. Oxf., letters to Sir Henry Wentworth Acland + California  
Institute of Technology, Pasadena, archives, corresp. with George Hale  
+ CUL, corresp. with Sir George Stokes and T. R. Robinson + Dartmouth  
College, Hanover, New Hampshire, C. A. Young MSS + Hunt. L., G. E.  
Hale MSS + ICL, letters to S. P. Thompson + NYPL, J. Draper MSS + RS,  
corresp. with Sir J. F. W. Herschel + RS, J. Larmor MSS + U. Cal.,  
Santa Cruz, Lick Observatory, Mary Lea Shane archives, E. Holden MSS +  
University of Exeter, J. N. Lockyer MSS + W. Sussex RO, letters to Sir  
Alfred Kempe + Yale U., D. Todd MSS
Likenesses  photograph, c.1900, Hult. Arch. · J. Collier, oils, 1905,  
RS · J. Collier, oils, second version, 1905, NPG [see illus.] · Spy  
[L. Ward], caricature chromolithograph, NPG; repro. in VF (9 April  
1903) · H. J. Whitlock, carte-de-visite, NPG · oils, RAS
Wealth at death  £6920 3s. 5d.: probate, 15 July 1910, CGPLA Eng. &  
Wales